Merge branch 'master' into issues/compiledbindingsetsource

Avalonia.sln

@@ -230,6 +230,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MicroComGenerator", "src\to
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Avalonia.MicroCom", "src\Avalonia.MicroCom\Avalonia.MicroCom.csproj", "{FE2F3E5E-1E34-4972-8DC1-5C2C588E5ECE}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MiniMvvm", "samples\MiniMvvm\MiniMvvm.csproj", "{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}"
+EndProject
 Global
 	GlobalSection(SharedMSBuildProjectFiles) = preSolution
 		src\Shared\RenderHelpers\RenderHelpers.projitems*{3c4c0cb4-0c0f-4450-a37b-148c84ff905f}*SharedItemsImports = 13
@@ -2116,6 +2118,30 @@ Global
 		{FE2F3E5E-1E34-4972-8DC1-5C2C588E5ECE}.Release|iPhone.Build.0 = Release|Any CPU
 		{FE2F3E5E-1E34-4972-8DC1-5C2C588E5ECE}.Release|iPhoneSimulator.ActiveCfg = Release|Any CPU
 		{FE2F3E5E-1E34-4972-8DC1-5C2C588E5ECE}.Release|iPhoneSimulator.Build.0 = Release|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Ad-Hoc|Any CPU.ActiveCfg = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Ad-Hoc|Any CPU.Build.0 = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Ad-Hoc|iPhone.ActiveCfg = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Ad-Hoc|iPhone.Build.0 = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Ad-Hoc|iPhoneSimulator.ActiveCfg = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Ad-Hoc|iPhoneSimulator.Build.0 = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.AppStore|Any CPU.ActiveCfg = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.AppStore|Any CPU.Build.0 = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.AppStore|iPhone.ActiveCfg = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.AppStore|iPhone.Build.0 = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.AppStore|iPhoneSimulator.ActiveCfg = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.AppStore|iPhoneSimulator.Build.0 = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Debug|iPhone.ActiveCfg = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Debug|iPhone.Build.0 = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Debug|iPhoneSimulator.ActiveCfg = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Debug|iPhoneSimulator.Build.0 = Debug|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Release|Any CPU.Build.0 = Release|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Release|iPhone.ActiveCfg = Release|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Release|iPhone.Build.0 = Release|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Release|iPhoneSimulator.ActiveCfg = Release|Any CPU
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5}.Release|iPhoneSimulator.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -2176,6 +2202,7 @@ Global
 		{909A8CBD-7D0E-42FD-B841-022AD8925820} = {8B6A8209-894F-4BA1-B880-965FD453982C}
 		{11BE52AF-E2DD-4CF0-B19A-05285ACAF571} = {9B9E3891-2366-4253-A952-D08BCEB71098}
 		{AEC9031E-06EA-4A9E-9E7F-7D7C719404DD} = {4ED8B739-6F4E-4CD4-B993-545E6B5CE637}
+		{BC594FD5-4AF2-409E-A1E6-04123F54D7C5} = {9B9E3891-2366-4253-A952-D08BCEB71098}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {87366D66-1391-4D90-8999-95A620AD786A}

Documentation/build.md

@@ -60,15 +60,10 @@ git submodule update --init --recursive
 
 ### Build native libraries (macOS only)
 
-On macOS it is necessary to build and manually install the respective native libraries using [Xcode](https://developer.apple.com/xcode/).  The steps to get this working correctly are:
+On macOS it is necessary to build and manually install the respective native libraries using [Xcode](https://developer.apple.com/xcode/). Execute the build script in the root project with the `CompileNative` task. It will build the headers, build the libraries, and place them in the appropriate place to allow .NET to find them at compilation and run time.
-- (for revisions after 2 Nov 2020) Run `./build.sh GenerateCppHeaders` to generate `avalonia-native.h` from `avn.idl`
-- Navigate to the Avalonia/native/Avalonia.Native/src/OSX folder and open the `Avalonia.Native.OSX.xcodeproj` project
-- Build the library via the Product->Build menu.  This will generate binaries in your local path under ~/Library/Developer/Xcode/DerivedData/Avalonia.Native.OSX-*guid* where "guid" is uniquely generated every time you build.
-- Manually install the native library by copying it from the build artifacts folder into the shared dynamic library path:
 
-```
+```bash
-cd ~/Library/Developer/Xcode/DerivedData/Avalonia.Native.OSX-[guid]/Build/Products/Debug
+./build.sh CompileNative
-cp libAvalonia.Native.OSX.dylib /usr/local/lib/libAvaloniaNative.dylib
 ```
 
 ###  Build and Run Avalonia

build/ApiDiff.props

@@ -1,6 +1,6 @@
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
-    <ApiContractPackageVersion>0.10.0-preview3</ApiContractPackageVersion>
+    <ApiContractPackageVersion>0.10.0-preview6</ApiContractPackageVersion>
     <NugetPackageName Condition="'$(PackageId)' != ''">$(PackageId)</NugetPackageName>
     <NugetPackageName Condition="'$(PackageId)' == ''">Avalonia</NugetPackageName>
   </PropertyGroup>

build/EmbedXaml.props

@@ -4,8 +4,9 @@
      <Compile Update="**\*.xaml.cs">
       <DependentUpon>%(Filename)</DependentUpon>
     </Compile>
+    <None Remove="**\*.xaml"/>
     <AvaloniaResource Include="**\*.xaml">
       <SubType>Designer</SubType>
     </AvaloniaResource>
   </ItemGroup>
-</Project>
+</Project>

build/Rx.props

@@ -1,5 +1,5 @@
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup>
-    <PackageReference Include="System.Reactive" Version="4.4.1" />
+    <PackageReference Include="System.Reactive" Version="5.0" />
   </ItemGroup>
 </Project>

build/SharedVersion.props

@@ -16,7 +16,7 @@
     <PackageReleaseNotes>https://github.com/AvaloniaUI/Avalonia/releases</PackageReleaseNotes>
     <RepositoryType>git</RepositoryType>
     <AssemblyOriginatorKeyFile>$(MSBuildThisFileDirectory)\avalonia.snk</AssemblyOriginatorKeyFile>
-    <SignAssembly>false</SignAssembly>
+    <SignAssembly>true</SignAssembly>
     <DefineConstants Condition="$(SignAssembly) == true">$(DefineConstants);SIGNED_BUILD</DefineConstants>
   </PropertyGroup>
 

native/Avalonia.Native/src/OSX/Avalonia.Native.OSX.xcodeproj/project.pbxproj

@@ -8,19 +8,20 @@
 
 /* Begin PBXBuildFile section */
 		1A002B9E232135EE00021753 /* app.mm in Sources */ = {isa = PBXBuildFile; fileRef = 1A002B9D232135EE00021753 /* app.mm */; };
+		1A1852DC23E05814008F0DED /* deadlock.mm in Sources */ = {isa = PBXBuildFile; fileRef = 1A1852DB23E05814008F0DED /* deadlock.mm */; };
 		1A3E5EA823E9E83B00EDE661 /* rendertarget.mm in Sources */ = {isa = PBXBuildFile; fileRef = 1A3E5EA723E9E83B00EDE661 /* rendertarget.mm */; };
 		1A3E5EAA23E9F26C00EDE661 /* IOSurface.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 1A3E5EA923E9F26C00EDE661 /* IOSurface.framework */; };
-		1A1852DC23E05814008F0DED /* deadlock.mm in Sources */ = {isa = PBXBuildFile; fileRef = 1A1852DB23E05814008F0DED /* deadlock.mm */; };
-		1AFD334123E03C4F0042899B /* controlhost.mm in Sources */ = {isa = PBXBuildFile; fileRef = 1AFD334023E03C4F0042899B /* controlhost.mm */; };
 		1A3E5EAE23E9FB1300EDE661 /* cgl.mm in Sources */ = {isa = PBXBuildFile; fileRef = 1A3E5EAD23E9FB1300EDE661 /* cgl.mm */; };
 		1A3E5EB023E9FE8300EDE661 /* QuartzCore.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 1A3E5EAF23E9FE8300EDE661 /* QuartzCore.framework */; };
 		1A465D10246AB61600C5858B /* dnd.mm in Sources */ = {isa = PBXBuildFile; fileRef = 1A465D0F246AB61600C5858B /* dnd.mm */; };
+		1AFD334123E03C4F0042899B /* controlhost.mm in Sources */ = {isa = PBXBuildFile; fileRef = 1AFD334023E03C4F0042899B /* controlhost.mm */; };
 		37155CE4233C00EB0034DCE9 /* menu.h in Headers */ = {isa = PBXBuildFile; fileRef = 37155CE3233C00EB0034DCE9 /* menu.h */; };
 		37A517B32159597E00FBA241 /* Screens.mm in Sources */ = {isa = PBXBuildFile; fileRef = 37A517B22159597E00FBA241 /* Screens.mm */; };
 		37C09D8821580FE4006A6758 /* SystemDialogs.mm in Sources */ = {isa = PBXBuildFile; fileRef = 37C09D8721580FE4006A6758 /* SystemDialogs.mm */; };
 		37DDA9B0219330F8002E132B /* AvnString.mm in Sources */ = {isa = PBXBuildFile; fileRef = 37DDA9AF219330F8002E132B /* AvnString.mm */; };
 		37E2330F21583241000CB7E2 /* KeyTransform.mm in Sources */ = {isa = PBXBuildFile; fileRef = 37E2330E21583241000CB7E2 /* KeyTransform.mm */; };
 		520624B322973F4100C4DCEF /* menu.mm in Sources */ = {isa = PBXBuildFile; fileRef = 520624B222973F4100C4DCEF /* menu.mm */; };
+		522D5959258159C1006F7F7A /* Carbon.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 522D5958258159C1006F7F7A /* Carbon.framework */; };
 		5B21A982216530F500CEE36E /* cursor.mm in Sources */ = {isa = PBXBuildFile; fileRef = 5B21A981216530F500CEE36E /* cursor.mm */; };
 		5B8BD94F215BFEA6005ED2A7 /* clipboard.mm in Sources */ = {isa = PBXBuildFile; fileRef = 5B8BD94E215BFEA6005ED2A7 /* clipboard.mm */; };
 		AB00E4F72147CA920032A60A /* main.mm in Sources */ = {isa = PBXBuildFile; fileRef = AB00E4F62147CA920032A60A /* main.mm */; };
@@ -32,13 +33,13 @@
 
 /* Begin PBXFileReference section */
 		1A002B9D232135EE00021753 /* app.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = app.mm; sourceTree = "<group>"; };
+		1A1852DB23E05814008F0DED /* deadlock.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = deadlock.mm; sourceTree = "<group>"; };
 		1A3E5EA723E9E83B00EDE661 /* rendertarget.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = rendertarget.mm; sourceTree = "<group>"; };
 		1A3E5EA923E9F26C00EDE661 /* IOSurface.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = IOSurface.framework; path = System/Library/Frameworks/IOSurface.framework; sourceTree = SDKROOT; };
-		1A1852DB23E05814008F0DED /* deadlock.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = deadlock.mm; sourceTree = "<group>"; };
-		1AFD334023E03C4F0042899B /* controlhost.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = controlhost.mm; sourceTree = "<group>"; };
 		1A3E5EAD23E9FB1300EDE661 /* cgl.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = cgl.mm; sourceTree = "<group>"; };
 		1A3E5EAF23E9FE8300EDE661 /* QuartzCore.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = QuartzCore.framework; path = System/Library/Frameworks/QuartzCore.framework; sourceTree = SDKROOT; };
 		1A465D0F246AB61600C5858B /* dnd.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = dnd.mm; sourceTree = "<group>"; };
+		1AFD334023E03C4F0042899B /* controlhost.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = controlhost.mm; sourceTree = "<group>"; };
 		37155CE3233C00EB0034DCE9 /* menu.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = menu.h; sourceTree = "<group>"; };
 		379860FE214DA0C000CD0246 /* KeyTransform.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = KeyTransform.h; sourceTree = "<group>"; };
 		37A4E71A2178846A00EACBCD /* headers */ = {isa = PBXFileReference; lastKnownFileType = folder; name = headers; path = ../../inc; sourceTree = "<group>"; };
@@ -49,6 +50,7 @@
 		37DDA9B121933371002E132B /* AvnString.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = AvnString.h; sourceTree = "<group>"; };
 		37E2330E21583241000CB7E2 /* KeyTransform.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = KeyTransform.mm; sourceTree = "<group>"; };
 		520624B222973F4100C4DCEF /* menu.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = menu.mm; sourceTree = "<group>"; };
+		522D5958258159C1006F7F7A /* Carbon.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Carbon.framework; path = System/Library/Frameworks/Carbon.framework; sourceTree = SDKROOT; };
 		5B21A981216530F500CEE36E /* cursor.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = cursor.mm; sourceTree = "<group>"; };
 		5B8BD94E215BFEA6005ED2A7 /* clipboard.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = clipboard.mm; sourceTree = "<group>"; };
 		5BF943652167AD1D009CAE35 /* cursor.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = cursor.h; sourceTree = "<group>"; };
@@ -69,6 +71,7 @@
 				1A3E5EB023E9FE8300EDE661 /* QuartzCore.framework in Frameworks */,
 				1A3E5EAA23E9F26C00EDE661 /* IOSurface.framework in Frameworks */,
 				AB1E522C217613570091CD71 /* OpenGL.framework in Frameworks */,
+				522D5959258159C1006F7F7A /* Carbon.framework in Frameworks */,
 				AB661C1E2148230F00291242 /* AppKit.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -79,6 +82,7 @@
 		AB661C1C2148230E00291242 /* Frameworks */ = {
 			isa = PBXGroup;
 			children = (
+				522D5958258159C1006F7F7A /* Carbon.framework */,
 				1A3E5EAF23E9FE8300EDE661 /* QuartzCore.framework */,
 				1A3E5EA923E9F26C00EDE661 /* IOSurface.framework */,
 				AB1E522B217613570091CD71 /* OpenGL.framework */,

native/Avalonia.Native/src/OSX/KeyTransform.h

@@ -1,9 +1,14 @@
 #ifndef keytransform_h
 #define keytransform_h
 #include "common.h"
-#include "key.h"
 #include <map>
 
 extern std::map<int, AvnKey> s_KeyMap;
 
+extern std::map<AvnKey, int> s_AvnKeyMap;
+
+extern std::map<int, const char*> s_QwertyKeyMap;
+
+extern std::map<AvnKey, int> s_UnicodeKeyMap;
+
 #endif

native/Avalonia.Native/src/OSX/KeyTransform.mm

@@ -120,6 +120,138 @@ const int kVK_UpArrow = 0x7E;
 //const int kVK_JIS_Eisu = 0x66;
 const int kVK_JIS_Kana = 0x68;
 
+// converts from AvaloniaKeys to UnicodeSpecial keys.
+std::map<AvnKey, int> s_UnicodeKeyMap =
+{
+    { Up, NSUpArrowFunctionKey },
+    { Down, NSDownArrowFunctionKey },
+    { Left, NSLeftArrowFunctionKey },
+    { Right, NSRightArrowFunctionKey },
+    { F1, NSF1FunctionKey },
+    { F2, NSF2FunctionKey },
+    { F3, NSF3FunctionKey },
+    { F4, NSF4FunctionKey },
+    { F5, NSF5FunctionKey },
+    { F6, NSF6FunctionKey },
+    { F7, NSF7FunctionKey },
+    { F8, NSF8FunctionKey },
+    { F9, NSF9FunctionKey },
+    { F10, NSF10FunctionKey },
+    { F11, NSF11FunctionKey },
+    { F12, NSF12FunctionKey },
+    { F13, NSF13FunctionKey },
+    { F14, NSF14FunctionKey },
+    { F15, NSF15FunctionKey },
+    { F16, NSF16FunctionKey },
+    { F17, NSF17FunctionKey },
+    { F18, NSF18FunctionKey },
+    { F19, NSF19FunctionKey },
+    { F20, NSF20FunctionKey },
+    { F21, NSF21FunctionKey },
+    { F22, NSF22FunctionKey },
+    { F23, NSF23FunctionKey },
+    { F24, NSF24FunctionKey },
+    { Insert, NSInsertFunctionKey },
+    { Delete, NSDeleteFunctionKey },
+    { Home, NSHomeFunctionKey },
+    //{ Begin, NSBeginFunctionKey },
+    { End, NSEndFunctionKey },
+    { PageUp, NSPageUpFunctionKey },
+    { PageDown, NSPageDownFunctionKey },
+    { PrintScreen, NSPrintScreenFunctionKey },
+    { Scroll, NSScrollLockFunctionKey },
+    //{ SysReq, NSSysReqFunctionKey },
+    //{ Break, NSBreakFunctionKey },
+    //{ Reset, NSResetFunctionKey },
+    //{ Stop, NSStopFunctionKey },
+    //{ Menu, NSMenuFunctionKey },
+    //{ UserFunction, NSUserFunctionKey },
+    //{ SystemFunction, NSSystemFunctionKey },
+    { Print, NSPrintFunctionKey },
+    //{ ClearLine, NSClearLineFunctionKey },
+    //{ ClearDisplay, NSClearDisplayFunctionKey },
+};
+
+// Converts from Ansi virtual keys to Qwerty Keyboard map.
+std::map<int, const char*> s_QwertyKeyMap =
+{
+    { 0, "a" },
+    { 1, "s" },
+    { 2, "d" },
+    { 3, "f" },
+    { 4, "h" },
+    { 5, "g" },
+    { 6, "z" },
+    { 7, "x" },
+    { 8, "c" },
+    { 9, "v" },
+    { 10, "§" },
+    { 11, "b" },
+    { 12, "q" },
+    { 13, "w" },
+    { 14, "e" },
+    { 15, "r" },
+    { 16, "y" },
+    { 17, "t" },
+    { 18, "1" },
+    { 19, "2" },
+    { 20, "3" },
+    { 21, "4" },
+    { 22, "6" },
+    { 23, "5" },
+    { 24, "=" },
+    { 25, "9" },
+    { 26, "7" },
+    { 27, "-" },
+    { 28, "8" },
+    { 29, "0" },
+    { 30, "]" },
+    { 31, "o" },
+    { 32, "u" },
+    { 33, "[" },
+    { 34, "i" },
+    { 35, "p" },
+    { 37, "l" },
+    { 38, "j" },
+    { 39, "'" },
+    { 40, "k" },
+    { 41, ";" },
+    { 42, "\\" },
+    { 43, "," },
+    { 44, "/" },
+    { 45, "n" },
+    { 46, "m" },
+    { 47, "." },
+    { 49, " " },
+    { 50, "`" },
+    { 51, "" },
+    { 52, "" },
+    { 53, "" },
+    { 65, "." },
+    { 66, "" },
+    { 67, "*" },
+    { 69, "+" },
+    { 70, "" },
+    { 71, "" },
+    { 72, "" },
+    { 75, "/" },
+    { 76, "" },
+    { 77, "" },
+    { 78, "-" },
+    { 81, "=" },
+    { 82, "0" },
+    { 83, "1" },
+    { 84, "2" },
+    { 85, "3" },
+    { 86, "4" },
+    { 87, "5" },
+    { 88, "6" },
+    { 89, "7" },
+    { 91, "8" },
+    { 92, "9" }
+};
+
+// converts from ansi virtualkeys to AvnKeys.
  std::map<int, AvnKey> s_KeyMap =
  {
     {kVK_ANSI_A, A},
@@ -237,3 +369,22 @@ const int kVK_JIS_Kana = 0x68;
     {kVK_UpArrow, Up},
     {kVK_JIS_Kana, AvnKeyKanaMode},
 };
+
+static std::map<AvnKey, int> BuildAvnKeyMap ()
+{
+    std::map<AvnKey, int> result;
+    
+    for( auto it = s_KeyMap.begin(); it != s_KeyMap.end(); ++it )
+    {
+        int key = it->first;
+        AvnKey value = it->second;
+        
+        result[value] = key;
+    }
+    
+    return result;
+}
+
+// Converts AvnKeys to Ansi VirtualKeys
+std::map<AvnKey, int> s_AvnKeyMap = BuildAvnKeyMap();
+

native/Avalonia.Native/src/OSX/menu.h

@@ -45,7 +45,7 @@ public:
     
     virtual HRESULT SetTitle (char* utf8String) override;
     
-    virtual HRESULT SetGesture (char* key, AvnInputModifiers modifiers) override;
+    virtual HRESULT SetGesture (AvnKey key, AvnInputModifiers modifiers) override;
     
     virtual HRESULT SetAction (IAvnPredicateCallback* predicate, IAvnActionCallback* callback) override;
     

native/Avalonia.Native/src/OSX/menu.mm

@@ -2,6 +2,9 @@
 #include "common.h"
 #include "menu.h"
 #include "window.h"
+#include "KeyTransform.h"
+#include <CoreFoundation/CoreFoundation.h>
+#include <Carbon/Carbon.h> /* For kVK_ constants, and TIS functions. */
 
 @implementation AvnMenu
 {
@@ -122,23 +125,57 @@ HRESULT AvnAppMenuItem::SetTitle (char* utf8String)
     }
 }
 
-HRESULT AvnAppMenuItem::SetGesture (char* key, AvnInputModifiers modifiers)
+
+HRESULT AvnAppMenuItem::SetGesture (AvnKey key, AvnInputModifiers modifiers)
 {
     @autoreleasepool
     {
-        NSEventModifierFlags flags = 0;
+        if(key != AvnKeyNone)
-        
+        {
-        if (modifiers & Control)
+            NSEventModifierFlags flags = 0;
-            flags |= NSEventModifierFlagControl;
+            
-        if (modifiers & Shift)
+            if (modifiers & Control)
-            flags |= NSEventModifierFlagShift;
+                flags |= NSEventModifierFlagControl;
-        if (modifiers & Alt)
+            if (modifiers & Shift)
-            flags |= NSEventModifierFlagOption;
+                flags |= NSEventModifierFlagShift;
-        if (modifiers & Windows)
+            if (modifiers & Alt)
-            flags |= NSEventModifierFlagCommand;
+                flags |= NSEventModifierFlagOption;
-        
+            if (modifiers & Windows)
-        [_native setKeyEquivalent:[NSString stringWithUTF8String:(const char*)key]];
+                flags |= NSEventModifierFlagCommand;
-        [_native setKeyEquivalentModifierMask:flags];
+            
+            auto it = s_UnicodeKeyMap.find(key);
+            
+            if(it != s_UnicodeKeyMap.end())
+            {
+                auto keyString= [NSString stringWithFormat:@"%C", (unsigned short)it->second];
+                
+                [_native setKeyEquivalent: keyString];
+                [_native setKeyEquivalentModifierMask:flags];
+                
+                return S_OK;
+            }
+            else
+            {
+                auto it = s_AvnKeyMap.find(key); // check if a virtual key is mapped.
+                
+                if(it != s_AvnKeyMap.end())
+                {
+                    auto it1 = s_QwertyKeyMap.find(it->second); // convert virtual key to qwerty string.
+                    
+                    if(it1 != s_QwertyKeyMap.end())
+                    {
+                        [_native setKeyEquivalent: [NSString  stringWithUTF8String: it1->second]];
+                        [_native setKeyEquivalentModifierMask:flags];
+                        
+                        return S_OK;
+                    }
+                }
+            }
+        }
+        
+        // Nothing matched... clear.
+        [_native setKeyEquivalent: @""];
+        [_native setKeyEquivalentModifierMask: 0];
         
         return S_OK;
     }

native/Avalonia.Native/src/OSX/platformthreading.mm

@@ -101,7 +101,7 @@ public:
     
     virtual bool GetCurrentThreadIsLoopThread() override
     {
-        return [[NSThread currentThread] isMainThread];
+        return [NSThread isMainThread];
     }
     virtual void SetSignaledCallback(IAvnSignaledCallback* cb) override
     {

native/Avalonia.Native/src/OSX/rendertarget.mm

@@ -2,6 +2,7 @@
 #include "rendertarget.h"
 #import <IOSurface/IOSurface.h>
 #import <IOSurface/IOSurfaceObjC.h>
+#import <QuartzCore/QuartzCore.h>
 
 #include <OpenGL/CGLIOSurface.h>
 #include <OpenGL/OpenGL.h>
@@ -143,13 +144,17 @@ static IAvnGlSurfaceRenderTarget* CreateGlRenderTarget(IOSurfaceRenderTarget* ta
     return _layer;
 }
 
-- (void)resize:(AvnPixelSize)size withScale: (float) scale;{
+- (void)resize:(AvnPixelSize)size withScale: (float) scale{
     @synchronized (lock) {
         if(surface == nil
            || surface->size.Width != size.Width
            || surface->size.Height != size.Height
            || surface->scale != scale)
+        {
             surface = [[IOSurfaceHolder alloc] initWithSize:size withScale:scale withOpenGlContext:_glContext.getRaw()];
+            
+            [self updateLayer];
+        }
     }
 }
 
@@ -159,12 +164,15 @@ static IAvnGlSurfaceRenderTarget* CreateGlRenderTarget(IOSurfaceRenderTarget* ta
         @synchronized (lock) {
             if(_layer == nil)
                 return;
+            [CATransaction begin];
             [_layer setContents: nil];
             if(surface != nil)
             {
                 [_layer setContentsScale: surface->scale];
                 [_layer setContents: (__bridge IOSurface*) surface->surface];
             }
+            [CATransaction commit];
+            [CATransaction flush];
         }
     }
     else

native/Avalonia.Native/src/OSX/window.mm

@@ -106,13 +106,13 @@ public:
         return Window;
     }
     
-    virtual HRESULT Show() override
+    virtual HRESULT Show(bool activate) override
     {
         @autoreleasepool
         {
             SetPosition(lastPositionSet);
             UpdateStyle();
-            if(ShouldTakeFocusOnShow())
+            if(ShouldTakeFocusOnShow() && activate)
             {
                 [Window makeKeyAndOrderFront:Window];
                 [NSApp activateIgnoringOtherApps:YES];
@@ -561,11 +561,11 @@ private:
         }
     }
     
-    virtual HRESULT Show () override
+    virtual HRESULT Show (bool activate) override
     {
         @autoreleasepool
         {            
-            WindowBaseImpl::Show();
+            WindowBaseImpl::Show(activate);
             
             HideOrShowTrafficLights();
             

nukebuild/Build.cs

@@ -107,7 +107,7 @@ partial class Build : NukeBuild
                 .AddProperty("JavaSdkDirectory", GetVariable<string>("JAVA_HOME_8_X64")))
             .AddProperty("PackageVersion", Parameters.Version)
             .AddProperty("iOSRoslynPathHackRequired", true)
-            .SetToolPath(MsBuildExe.Value)
+            .SetProcessToolPath(MsBuildExe.Value)
             .SetConfiguration(Parameters.Configuration)
             .SetVerbosity(MSBuildVerbosity.Minimal)
             .Apply(configurator));
@@ -132,10 +132,10 @@ partial class Build : NukeBuild
             var webappDir = RootDirectory / "src" / "Avalonia.DesignerSupport" / "Remote" / "HtmlTransport" / "webapp";
 
             NpmTasks.NpmInstall(c => c
-                .SetWorkingDirectory(webappDir)
+                .SetProcessWorkingDirectory(webappDir)
-                .SetArgumentConfigurator(a => a.Add("--silent")));
+                .SetProcessArgumentConfigurator(a => a.Add("--silent")));
             NpmTasks.NpmRun(c => c
-                .SetWorkingDirectory(webappDir)
+                .SetProcessWorkingDirectory(webappDir)
                 .SetCommand("dist"));
         });
 
@@ -157,7 +157,7 @@ partial class Build : NukeBuild
         {
             if (Parameters.IsRunningOnWindows)
                 MsBuildCommon(Parameters.MSBuildSolution, c => c
-                    .SetArgumentConfigurator(a => a.Add("/r"))
+                    .SetProcessArgumentConfigurator(a => a.Add("/r"))
                     .AddTargets("Build")
                 );
 
@@ -194,7 +194,7 @@ partial class Build : NukeBuild
         var eventsProject = Path.Combine(eventsDirectory, "Avalonia.ReactiveUI.Events.csproj");
         if (Parameters.IsRunningOnWindows)
             MsBuildCommon(eventsProject, c => c
-                .SetArgumentConfigurator(a => a.Add("/r"))
+                .SetProcessArgumentConfigurator(a => a.Add("/r"))
                 .AddTargets("Build")
             );
         else
@@ -242,10 +242,10 @@ partial class Build : NukeBuild
             var webappTestDir = RootDirectory / "tests" / "Avalonia.DesignerSupport.Tests" / "Remote" / "HtmlTransport" / "webapp";
 
             NpmTasks.NpmInstall(c => c
-                .SetWorkingDirectory(webappTestDir)
+                .SetProcessWorkingDirectory(webappTestDir)
-                .SetArgumentConfigurator(a => a.Add("--silent")));
+                .SetProcessArgumentConfigurator(a => a.Add("--silent")));
             NpmTasks.NpmRun(c => c
-                .SetWorkingDirectory(webappTestDir)
+                .SetProcessWorkingDirectory(webappTestDir)
                 .SetCommand("test"));
         });
 

nukebuild/_build.csproj

@@ -10,7 +10,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Nuke.Common" Version="0.24.0" />
+    <PackageReference Include="Nuke.Common" Version="5.0.0" />
     <PackageReference Include="xunit.runner.console" Version="2.3.1" />
     <PackageReference Include="JetBrains.dotMemoryUnit" Version="3.0.20171219.105559" />
     <PackageReference Include="vswhere" Version="2.6.7" Condition=" '$(OS)' == 'Windows_NT' " />

samples/BindingDemo/App.xaml.cs

@@ -1,7 +1,6 @@
 using Avalonia;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
-using Avalonia.ReactiveUI;
 
 namespace BindingDemo
 {
@@ -25,7 +24,6 @@ namespace BindingDemo
         public static AppBuilder BuildAvaloniaApp()
           => AppBuilder.Configure<App>()
                 .UsePlatformDetect()
-                .UseReactiveUI()
                 .LogToTrace();
     }
 }

samples/BindingDemo/BindingDemo.csproj

@@ -6,12 +6,11 @@
   <ItemGroup>
     <ProjectReference Include="..\..\src\Avalonia.Diagnostics\Avalonia.Diagnostics.csproj" />
     <ProjectReference Include="..\..\src\Linux\Avalonia.LinuxFramebuffer\Avalonia.LinuxFramebuffer.csproj" />
-    <ProjectReference Include="..\..\src\Avalonia.ReactiveUI\Avalonia.ReactiveUI.csproj" />
+    <ProjectReference Include="..\MiniMvvm\MiniMvvm.csproj" />
   </ItemGroup>
   <Import Project="..\..\build\SampleApp.props" />
   <Import Project="..\..\build\EmbedXaml.props" />
   <Import Project="..\..\build\Rx.props" />
-  <Import Project="..\..\build\ReactiveUI.props" />
   <Import Condition="'$(TargetFramework)'=='net461'" Project="..\..\build\NetFX.props" />
   <Import Project="..\..\build\ReferenceCoreLibraries.props" />
   <Import Project="..\..\build\BuildTargets.targets" />

samples/BindingDemo/ViewModels/ExceptionErrorViewModel.cs

@@ -1,9 +1,9 @@
-using ReactiveUI;
+using MiniMvvm;
 using System;
 
 namespace BindingDemo.ViewModels
 {
-    public class ExceptionErrorViewModel : ReactiveObject
+    public class ExceptionErrorViewModel : ViewModelBase
     {
         private int _lessThan10;
 

samples/BindingDemo/ViewModels/IndeiErrorViewModel.cs

@@ -1,11 +1,11 @@
-using ReactiveUI;
+using MiniMvvm;
 using System;
 using System.ComponentModel;
 using System.Collections;
 
 namespace BindingDemo.ViewModels
 {
-    public class IndeiErrorViewModel : ReactiveObject, INotifyDataErrorInfo
+    public class IndeiErrorViewModel : ViewModelBase, INotifyDataErrorInfo
     {
         private int _maximum = 10;
         private int _value;

samples/BindingDemo/ViewModels/MainWindowViewModel.cs

@@ -5,14 +5,14 @@ using System.Reactive;
 using System.Reactive.Linq;
 using System.Threading.Tasks;
 using System.Threading;
-using ReactiveUI;
+using MiniMvvm;
 using Avalonia.Controls;
 using Avalonia.Metadata;
 using Avalonia.Controls.Selection;
 
 namespace BindingDemo.ViewModels
 {
-    public class MainWindowViewModel : ReactiveObject
+    public class MainWindowViewModel : ViewModelBase
     {
         private string _booleanString = "True";
         private double _doubleValue = 5.0;
@@ -32,13 +32,13 @@ namespace BindingDemo.ViewModels
 
             Selection = new SelectionModel<TestItem> { SingleSelect = false };
 
-            ShuffleItems = ReactiveCommand.Create(() =>
+            ShuffleItems = MiniCommand.Create(() =>
             {
                 var r = new Random();
                 Items.Move(r.Next(Items.Count), 1);
             });
 
-            StringValueCommand = ReactiveCommand.Create<object>(param =>
+            StringValueCommand = MiniCommand.Create<object>(param =>
             {
                 BooleanFlag = !BooleanFlag;
                 StringValue = param.ToString();
@@ -60,7 +60,7 @@ namespace BindingDemo.ViewModels
 
         public ObservableCollection<TestItem> Items { get; }
         public SelectionModel<TestItem> Selection { get; }
-        public ReactiveCommand<Unit, Unit> ShuffleItems { get; }
+        public MiniCommand ShuffleItems { get; }
 
         public string BooleanString
         {
@@ -93,7 +93,7 @@ namespace BindingDemo.ViewModels
         }
 
         public IObservable<DateTimeOffset> CurrentTimeObservable { get; }
-        public ReactiveCommand<object, Unit> StringValueCommand { get; }
+        public MiniCommand StringValueCommand { get; }
 
         public DataAnnotationsErrorViewModel DataAnnotationsValidation { get; } = new DataAnnotationsErrorViewModel();
         public ExceptionErrorViewModel ExceptionDataValidation { get; } = new ExceptionErrorViewModel();

samples/BindingDemo/ViewModels/NestedCommandViewModel.cs

@@ -1,18 +1,18 @@
-using ReactiveUI;
+using System;
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using System.Windows.Input;
+using MiniMvvm;
 
 namespace BindingDemo.ViewModels
 {
-    public class NestedCommandViewModel : ReactiveObject
+    public class NestedCommandViewModel : ViewModelBase
     {
         public NestedCommandViewModel()
         {
-            Command = ReactiveCommand.Create(() => { });
+            Command = MiniCommand.Create(() => { });
         }
 
         public ICommand Command { get; }

samples/BindingDemo/ViewModels/TestItem.cs

@@ -1,8 +1,8 @@
-using ReactiveUI;
+using MiniMvvm;
 
 namespace BindingDemo.ViewModels
 {
-    public class TestItem : ReactiveObject
+    public class TestItem : ViewModelBase
     {
         private string _stringValue = "String Value";
         private string _detail;

samples/ControlCatalog.Desktop/Program.cs

@@ -3,7 +3,6 @@ using System.Linq;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Platform;
-using Avalonia.ReactiveUI;
 
 namespace ControlCatalog
 {
@@ -19,8 +18,7 @@ namespace ControlCatalog
         public static AppBuilder BuildAvaloniaApp()
             => AppBuilder.Configure<App>()
                 .LogToTrace()
-                .UsePlatformDetect()
+                .UsePlatformDetect();
-                .UseReactiveUI();
 
         private static void ConfigureAssetAssembly(AppBuilder builder)
         {

samples/ControlCatalog.NetCore/Program.cs

@@ -10,7 +10,6 @@ using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Dialogs;
 using Avalonia.Headless;
 using Avalonia.LogicalTree;
-using Avalonia.ReactiveUI;
 using Avalonia.Threading;
 
 namespace ControlCatalog.NetCore
@@ -118,7 +117,6 @@ namespace ControlCatalog.NetCore
                     AllowEglInitialization = true
                 })
                 .UseSkia()
-                .UseReactiveUI()
                 .UseManagedSystemDialogs()
                 .LogToTrace();
 

samples/ControlCatalog/App.xaml.cs

@@ -23,7 +23,7 @@ namespace ControlCatalog
         {
             new StyleInclude(new Uri("avares://ControlCatalog/Styles"))
             {
-                Source = new Uri("avares://Avalonia.Themes.Fluent/Accents/FluentDark.xaml")
+                Source = new Uri("avares://Avalonia.Themes.Fluent/FluentDark.xaml")
             },
             DataGridFluent
         };
@@ -32,7 +32,7 @@ namespace ControlCatalog
         {
             new StyleInclude(new Uri("avares://ControlCatalog/Styles"))
             {
-                Source = new Uri("avares://Avalonia.Themes.Fluent/Accents/FluentLight.xaml")
+                Source = new Uri("avares://Avalonia.Themes.Fluent/FluentLight.xaml")
             },
             DataGridFluent
         };

samples/ControlCatalog/ControlCatalog.csproj

@@ -24,8 +24,8 @@
   <ItemGroup>
     <ProjectReference Include="..\..\packages\Avalonia\Avalonia.csproj" />
     <ProjectReference Include="..\..\src\Avalonia.Diagnostics\Avalonia.Diagnostics.csproj" />
-    <ProjectReference Include="..\..\src\Avalonia.ReactiveUI\Avalonia.ReactiveUI.csproj" />
     <ProjectReference Include="..\..\src\Avalonia.Controls.DataGrid\Avalonia.Controls.DataGrid.csproj" />
+    <ProjectReference Include="..\MiniMvvm\MiniMvvm.csproj" />
   </ItemGroup>
   
   <Import Project="..\..\build\BuildTargets.targets" />

samples/ControlCatalog/DecoratedWindow.xaml

@@ -6,25 +6,21 @@
         <NativeMenu.Menu>
     <NativeMenu>
       <NativeMenuItem Header="Decorated">
-        <NativeMenuItem.Menu>
+        <NativeMenu>
-          <NativeMenu>
+          <NativeMenuItem Header="Open"/>
-            <NativeMenuItem Header="Open"/>
+          <NativeMenuItem Header="Recent">
-            <NativeMenuItem Header="Recent">
+            <NativeMenuItem.Menu>
-              <NativeMenuItem.Menu>
+              <NativeMenu/>
-                <NativeMenu/>
+            </NativeMenuItem.Menu>
-              </NativeMenuItem.Menu>
+          </NativeMenuItem>
-            </NativeMenuItem>
+          <NativeMenuItem Header="Quit Avalonia" Gesture="CMD+Q"/>
-            <NativeMenuItem Header="Quit Avalonia" Gesture="CMD+Q"/>
+        </NativeMenu>
-          </NativeMenu>
-        </NativeMenuItem.Menu>
       </NativeMenuItem>
       <NativeMenuItem Header="Edit">
-        <NativeMenuItem.Menu>
+        <NativeMenu>
-          <NativeMenu>
+          <NativeMenuItem Header="Copy"/>
-            <NativeMenuItem Header="Copy"/>
+          <NativeMenuItem Header="Paste"/>
-            <NativeMenuItem Header="Paste"/>
+        </NativeMenu>
-          </NativeMenu>
-        </NativeMenuItem.Menu>
       </NativeMenuItem>
     </NativeMenu>
   </NativeMenu.Menu>

samples/ControlCatalog/MainWindow.xaml

@@ -16,47 +16,39 @@
   <NativeMenu.Menu>
     <NativeMenu>
       <NativeMenuItem Header="File">
-        <NativeMenuItem.Menu>
+        <NativeMenu>
-          <NativeMenu>
+          <NativeMenuItem Icon="/Assets/test_icon.ico" Header="Open" Clicked="OnOpenClicked" Gesture="Ctrl+O"/>
-            <NativeMenuItem Icon="/Assets/test_icon.ico" Header="Open" Clicked="OnOpenClicked" Gesture="Ctrl+O"/>
+          <NativeMenuItemSeperator/>
-            <NativeMenuItemSeperator/>
+          <NativeMenuItem Icon="/Assets/github_icon.png" Header="Recent">
-            <NativeMenuItem Icon="/Assets/github_icon.png" Header="Recent">
+            <NativeMenu/>
-              <NativeMenuItem.Menu>
+          </NativeMenuItem>
-                <NativeMenu/>
+          <NativeMenuItemSeperator/>
-              </NativeMenuItem.Menu>
+          <NativeMenuItem Header="{x:Static local:MainWindow.MenuQuitHeader}"
-            </NativeMenuItem>
+                          Gesture="{x:Static local:MainWindow.MenuQuitGesture}"
-            <NativeMenuItemSeperator/>
+                          Clicked="OnCloseClicked" />
-            <NativeMenuItem Header="{x:Static local:MainWindow.MenuQuitHeader}"
+        </NativeMenu>
-                            Gesture="{x:Static local:MainWindow.MenuQuitGesture}"
-                            Clicked="OnCloseClicked" />
-          </NativeMenu>
-        </NativeMenuItem.Menu>
       </NativeMenuItem>
       <NativeMenuItem Header="Edit">
-        <NativeMenuItem.Menu>
+        <NativeMenu>
-          <NativeMenu>
+          <NativeMenuItem Header="Copy"/>
-            <NativeMenuItem Header="Copy"/>
+          <NativeMenuItem Header="Paste"/>
-            <NativeMenuItem Header="Paste"/>
+        </NativeMenu>
-          </NativeMenu>
-        </NativeMenuItem.Menu>
       </NativeMenuItem>
       <NativeMenuItem Header="Options">
-        <NativeMenuItem.Menu>
+        <NativeMenu>
-          <NativeMenu>
+          <NativeMenuItem Header="Check Me (None)" 
-           <NativeMenuItem Header="Check Me (None)" 
+                          Command="{Binding ToggleMenuItemCheckedCommand}"
-                            Command="{Binding ToggleMenuItemCheckedCommand}"
+                          ToggleType="None"
-                            ToggleType="None"
+                          IsChecked="{Binding IsMenuItemChecked}"  />
-                            IsChecked="{Binding IsMenuItemChecked}"  />
+          <NativeMenuItem Header="Check Me (CheckBox)" 
-            <NativeMenuItem Header="Check Me (CheckBox)" 
+                          Command="{Binding ToggleMenuItemCheckedCommand}"
-                            Command="{Binding ToggleMenuItemCheckedCommand}"
+                          ToggleType="CheckBox"
-                            ToggleType="CheckBox"
+                          IsChecked="{Binding IsMenuItemChecked}"  />
-                            IsChecked="{Binding IsMenuItemChecked}"  />
+          <NativeMenuItem Header="Check Me (Radio)" 
-            <NativeMenuItem Header="Check Me (Radio)" 
+                          Command="{Binding ToggleMenuItemCheckedCommand}"
-                            Command="{Binding ToggleMenuItemCheckedCommand}"
+                          ToggleType="Radio"
-                            ToggleType="Radio"
+                          IsChecked="{Binding IsMenuItemChecked}"  />
-                            IsChecked="{Binding IsMenuItemChecked}"  />
+        </NativeMenu>
-          </NativeMenu>
-        </NativeMenuItem.Menu>
       </NativeMenuItem>
     </NativeMenu>
   </NativeMenu.Menu>

samples/ControlCatalog/MainWindow.xaml.cs

@@ -67,7 +67,7 @@ namespace ControlCatalog
             if (Application.Current.Styles.Contains(App.FluentDark)
                 || Application.Current.Styles.Contains(App.FluentLight))
             {
-                var theme = new Avalonia.Themes.Fluent.FluentTheme();
+                var theme = new Avalonia.Themes.Fluent.Controls.FluentControls();
                 theme.TryGetResource("Button", out _);
             }
             else

samples/ControlCatalog/Pages/DialogsPage.xaml.cs

@@ -4,6 +4,7 @@ using System.Linq;
 using System.Reflection;
 using Avalonia.Controls;
 using Avalonia.Dialogs;
+using Avalonia.Layout;
 using Avalonia.Markup.Xaml;
 #pragma warning disable 4014
 
@@ -112,11 +113,29 @@ namespace ControlCatalog.Pages
 
         private Window CreateSampleWindow()
         {
-            var window = new Window();
+            Button button;
-            window.Height = 200;
+            
-            window.Width = 200;
+            var window = new Window
-            window.Content = new TextBlock { Text = "Hello world!" };
+            {
-            window.WindowStartupLocation = WindowStartupLocation.CenterOwner;
+                Height = 200,
+                Width = 200,
+                Content = new StackPanel
+                {
+                    Spacing = 4,
+                    Children =
+                    {
+                        new TextBlock { Text = "Hello world!" },
+                        (button = new Button
+                        {
+                            HorizontalAlignment = HorizontalAlignment.Center,
+                            Content = "Click to close"
+                        })
+                    }
+                },
+                WindowStartupLocation = WindowStartupLocation.CenterOwner
+            };
+
+            button.Click += (_, __) => window.Close();
 
             return window;
         }

samples/ControlCatalog/Pages/LabelsPage.axaml.cs

@@ -2,7 +2,6 @@
 using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
 using ControlCatalog.Models;
-using ReactiveUI;
 
 namespace ControlCatalog.Pages
 {

samples/ControlCatalog/Pages/ListBoxPage.xaml

@@ -20,6 +20,6 @@
     <ListBox Items="{Binding Items}"
              Selection="{Binding Selection}"
              AutoScrollToSelectedItem="{Binding AutoScrollToSelectedItem}"
-             SelectionMode="{Binding SelectionMode}"/>
+             SelectionMode="{Binding SelectionMode^}"/>
   </DockPanel>
 </UserControl>

samples/ControlCatalog/Pages/MenuPage.xaml.cs

@@ -6,7 +6,6 @@ using System.Windows.Input;
 using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
 using ControlCatalog.ViewModels;
-using ReactiveUI;
 
 namespace ControlCatalog.Pages
 {

samples/ControlCatalog/Pages/NumericUpDownPage.xaml.cs

@@ -6,7 +6,7 @@ using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
 using Avalonia.Markup.Xaml;
-using ReactiveUI;
+using MiniMvvm;
 
 namespace ControlCatalog.Pages
 {
@@ -26,7 +26,7 @@ namespace ControlCatalog.Pages
 
     }
 
-    public class NumbersPageViewModel : ReactiveObject
+    public class NumbersPageViewModel : ViewModelBase
     {
         private IList<FormatObject> _formats;
         private FormatObject _selectedFormat;

samples/ControlCatalog/Pages/ScrollViewerPage.xaml.cs

@@ -2,11 +2,11 @@ using System.Collections.Generic;
 using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
 using Avalonia.Markup.Xaml;
-using ReactiveUI;
+using MiniMvvm;
 
 namespace ControlCatalog.Pages
 {
-    public class ScrollViewerPageViewModel : ReactiveObject
+    public class ScrollViewerPageViewModel : ViewModelBase
     {
         private bool _allowAutoHide;
         private ScrollBarVisibility _horizontalScrollVisibility;

samples/ControlCatalog/Pages/TabControlPage.xaml.cs

@@ -6,7 +6,7 @@ using Avalonia.Markup.Xaml;
 using Avalonia.Media.Imaging;
 using Avalonia.Platform;
 
-using ReactiveUI;
+using MiniMvvm;
 
 namespace ControlCatalog.Pages
 {
@@ -56,7 +56,7 @@ namespace ControlCatalog.Pages
             return new Bitmap(assets.Open(new Uri(uri)));
         }
 
-        private class PageViewModel : ReactiveObject
+        private class PageViewModel : ViewModelBase
         {
             private Dock _tabPlacement;
 

samples/ControlCatalog/ViewModels/ContextMenuPageViewModel.cs

@@ -3,7 +3,7 @@ using System.Reactive;
 using System.Threading.Tasks;
 using Avalonia.Controls;
 using Avalonia.VisualTree;
-using ReactiveUI;
+using MiniMvvm;
 
 namespace ControlCatalog.ViewModels
 {
@@ -12,9 +12,9 @@ namespace ControlCatalog.ViewModels
         public Control View { get; set; }
         public ContextMenuPageViewModel()
         {
-            OpenCommand = ReactiveCommand.CreateFromTask(Open);
+            OpenCommand = MiniCommand.CreateFromTask(Open);
-            SaveCommand = ReactiveCommand.Create(Save);
+            SaveCommand = MiniCommand.Create(Save);
-            OpenRecentCommand = ReactiveCommand.Create<string>(OpenRecent);
+            OpenRecentCommand = MiniCommand.Create<string>(OpenRecent);
 
             MenuItems = new[]
             {
@@ -44,9 +44,9 @@ namespace ControlCatalog.ViewModels
         }
 
         public IReadOnlyList<MenuItemViewModel> MenuItems { get; set; }
-        public ReactiveCommand<Unit, Unit> OpenCommand { get; }
+        public MiniCommand OpenCommand { get; }
-        public ReactiveCommand<Unit, Unit> SaveCommand { get; }
+        public MiniCommand SaveCommand { get; }
-        public ReactiveCommand<string, Unit> OpenRecentCommand { get; }
+        public MiniCommand OpenRecentCommand { get; }
 
         public async Task Open()
         {

samples/ControlCatalog/ViewModels/ItemsRepeaterPageViewModel.cs

@@ -2,11 +2,11 @@
 using System.Collections.ObjectModel;
 using System.Linq;
 using Avalonia.Media;
-using ReactiveUI;
+using MiniMvvm;
 
 namespace ControlCatalog.ViewModels
 {
-    public class ItemsRepeaterPageViewModel : ReactiveObject
+    public class ItemsRepeaterPageViewModel : ViewModelBase
     {
         private int _newItemIndex = 1;
         private int _newGenerationIndex = 0;
@@ -59,7 +59,7 @@ namespace ControlCatalog.ViewModels
                 }));
         }
 
-        public class Item : ReactiveObject
+        public class Item : ViewModelBase
         {
             private double _height = double.NaN;
 

samples/ControlCatalog/ViewModels/ListBoxPageViewModel.cs

@@ -4,18 +4,18 @@ using System.Linq;
 using System.Reactive;
 using Avalonia.Controls;
 using Avalonia.Controls.Selection;
-using ReactiveUI;
+using MiniMvvm;
 
 namespace ControlCatalog.ViewModels
 {
-    public class ListBoxPageViewModel : ReactiveObject
+    public class ListBoxPageViewModel : ViewModelBase
     {
         private bool _multiple;
         private bool _toggle;
         private bool _alwaysSelected;
         private bool _autoScrollToSelectedItem = true;
         private int _counter;
-        private ObservableAsPropertyHelper<SelectionMode> _selectionMode;
+        private IObservable<SelectionMode> _selectionMode;
 
         public ListBoxPageViewModel()
         {
@@ -29,14 +29,13 @@ namespace ControlCatalog.ViewModels
                 x => x.Toggle,
                 x => x.AlwaysSelected,
                 (m, t, a) =>
-                    (m ? SelectionMode.Multiple : 0) |
+                    (m ? Avalonia.Controls.SelectionMode.Multiple : 0) |
-                    (t ? SelectionMode.Toggle : 0) |
+                    (t ? Avalonia.Controls.SelectionMode.Toggle : 0) |
-                    (a ? SelectionMode.AlwaysSelected : 0))
+                    (a ? Avalonia.Controls.SelectionMode.AlwaysSelected : 0));
-                .ToProperty(this, x => x.SelectionMode);
 
-            AddItemCommand = ReactiveCommand.Create(() => Items.Add(GenerateItem()));
+            AddItemCommand = MiniCommand.Create(() => Items.Add(GenerateItem()));
 
-            RemoveItemCommand = ReactiveCommand.Create(() =>
+            RemoveItemCommand = MiniCommand.Create(() =>
             {
                 var items = Selection.SelectedItems.ToList();
 
@@ -46,7 +45,7 @@ namespace ControlCatalog.ViewModels
                 }
             });
 
-            SelectRandomItemCommand = ReactiveCommand.Create(() =>
+            SelectRandomItemCommand = MiniCommand.Create(() =>
             {
                 var random = new Random();
 
@@ -60,7 +59,7 @@ namespace ControlCatalog.ViewModels
 
         public ObservableCollection<string> Items { get; }
         public SelectionModel<string> Selection { get; }
-        public SelectionMode SelectionMode => _selectionMode.Value;
+        public IObservable<SelectionMode> SelectionMode => _selectionMode;
 
         public bool Multiple
         {
@@ -86,9 +85,9 @@ namespace ControlCatalog.ViewModels
             set => this.RaiseAndSetIfChanged(ref _autoScrollToSelectedItem, value);
         }
 
-        public ReactiveCommand<Unit, Unit> AddItemCommand { get; }
+        public MiniCommand AddItemCommand { get; }
-        public ReactiveCommand<Unit, Unit> RemoveItemCommand { get; }
+        public MiniCommand RemoveItemCommand { get; }
-        public ReactiveCommand<Unit, Unit> SelectRandomItemCommand { get; }
+        public MiniCommand SelectRandomItemCommand { get; }
 
         private string GenerateItem() => $"Item {_counter++.ToString()}";
     }

samples/ControlCatalog/ViewModels/MainWindowViewModel.cs

@@ -5,11 +5,11 @@ using Avalonia.Controls.Notifications;
 using Avalonia.Dialogs;
 using Avalonia.Platform;
 using System;
-using ReactiveUI;
+using MiniMvvm;
 
 namespace ControlCatalog.ViewModels
 {
-    class MainWindowViewModel : ReactiveObject
+    class MainWindowViewModel : ViewModelBase
     {
         private IManagedNotificationManager _notificationManager;
 
@@ -27,22 +27,22 @@ namespace ControlCatalog.ViewModels
         {
             _notificationManager = notificationManager;
 
-            ShowCustomManagedNotificationCommand = ReactiveCommand.Create(() =>
+            ShowCustomManagedNotificationCommand = MiniCommand.Create(() =>
             {
                 NotificationManager.Show(new NotificationViewModel(NotificationManager) { Title = "Hey There!", Message = "Did you know that Avalonia now supports Custom In-Window Notifications?" });
             });
 
-            ShowManagedNotificationCommand = ReactiveCommand.Create(() =>
+            ShowManagedNotificationCommand = MiniCommand.Create(() =>
             {
                 NotificationManager.Show(new Avalonia.Controls.Notifications.Notification("Welcome", "Avalonia now supports Notifications.", NotificationType.Information));
             });
 
-            ShowNativeNotificationCommand = ReactiveCommand.Create(() =>
+            ShowNativeNotificationCommand = MiniCommand.Create(() =>
             {
                 NotificationManager.Show(new Avalonia.Controls.Notifications.Notification("Error", "Native Notifications are not quite ready. Coming soon.", NotificationType.Error));
             });
 
-            AboutCommand = ReactiveCommand.CreateFromTask(async () =>
+            AboutCommand = MiniCommand.CreateFromTask(async () =>
             {
                 var dialog = new AboutAvaloniaDialog();
 
@@ -51,12 +51,12 @@ namespace ControlCatalog.ViewModels
                 await dialog.ShowDialog(mainWindow);
             });
 
-            ExitCommand = ReactiveCommand.Create(() =>
+            ExitCommand = MiniCommand.Create(() =>
             {
                 (App.Current.ApplicationLifetime as IClassicDesktopStyleApplicationLifetime).Shutdown();
             });
 
-            ToggleMenuItemCheckedCommand = ReactiveCommand.Create(() =>
+            ToggleMenuItemCheckedCommand = MiniCommand.Create(() =>
             {
                 IsMenuItemChecked = !IsMenuItemChecked;
             });
@@ -153,16 +153,16 @@ namespace ControlCatalog.ViewModels
             set { this.RaiseAndSetIfChanged(ref _isMenuItemChecked, value); }
         }
 
-        public ReactiveCommand<Unit, Unit> ShowCustomManagedNotificationCommand { get; }
+        public MiniCommand ShowCustomManagedNotificationCommand { get; }
 
-        public ReactiveCommand<Unit, Unit> ShowManagedNotificationCommand { get; }
+        public MiniCommand ShowManagedNotificationCommand { get; }
 
-        public ReactiveCommand<Unit, Unit> ShowNativeNotificationCommand { get; }
+        public MiniCommand ShowNativeNotificationCommand { get; }
 
-        public ReactiveCommand<Unit, Unit> AboutCommand { get; }
+        public MiniCommand AboutCommand { get; }
 
-        public ReactiveCommand<Unit, Unit> ExitCommand { get; }
+        public MiniCommand ExitCommand { get; }
 
-        public ReactiveCommand<Unit, Unit> ToggleMenuItemCheckedCommand { get; }
+        public MiniCommand ToggleMenuItemCheckedCommand { get; }
     }
 }

samples/ControlCatalog/ViewModels/MenuPageViewModel.cs

@@ -4,7 +4,7 @@ using System.Reactive.Linq;
 using System.Threading.Tasks;
 using Avalonia.Controls;
 using Avalonia.VisualTree;
-using ReactiveUI;
+using MiniMvvm;
 
 namespace ControlCatalog.ViewModels
 {
@@ -13,9 +13,9 @@ namespace ControlCatalog.ViewModels
         public Control View { get; set; }
         public MenuPageViewModel()
         {
-            OpenCommand = ReactiveCommand.CreateFromTask(Open);
+            OpenCommand = MiniCommand.CreateFromTask(Open);
-            SaveCommand = ReactiveCommand.Create(Save, Observable.Return(false));
+            SaveCommand = MiniCommand.Create(Save);
-            OpenRecentCommand = ReactiveCommand.Create<string>(OpenRecent);
+            OpenRecentCommand = MiniCommand.Create<string>(OpenRecent);
 
             var recentItems = new[]
             {
@@ -65,9 +65,9 @@ namespace ControlCatalog.ViewModels
 
         public IReadOnlyList<MenuItemViewModel> MenuItems { get; set; }
         public IReadOnlyList<MenuItemViewModel> RecentItems { get; set; }
-        public ReactiveCommand<Unit, Unit> OpenCommand { get; }
+        public MiniCommand OpenCommand { get; }
-        public ReactiveCommand<Unit, Unit> SaveCommand { get; }
+        public MiniCommand SaveCommand { get; }
-        public ReactiveCommand<string, Unit> OpenRecentCommand { get; }
+        public MiniCommand OpenRecentCommand { get; }
 
         public async Task Open()
         {

samples/ControlCatalog/ViewModels/NotificationViewModel.cs

@@ -1,6 +1,6 @@
 using System.Reactive;
 using Avalonia.Controls.Notifications;
-using ReactiveUI;
+using MiniMvvm;
 
 namespace ControlCatalog.ViewModels
 {
@@ -8,12 +8,12 @@ namespace ControlCatalog.ViewModels
     {
         public NotificationViewModel(INotificationManager manager)
         {
-            YesCommand = ReactiveCommand.Create(() =>
+            YesCommand = MiniCommand.Create(() =>
             {
                 manager.Show(new Avalonia.Controls.Notifications.Notification("Avalonia Notifications", "Start adding notifications to your app today."));
             });
 
-            NoCommand = ReactiveCommand.Create(() =>
+            NoCommand = MiniCommand.Create(() =>
             {
                 manager.Show(new Avalonia.Controls.Notifications.Notification("Avalonia Notifications", "Start adding notifications to your app today. To find out more visit..."));
             });
@@ -22,9 +22,9 @@ namespace ControlCatalog.ViewModels
         public string Title { get; set; }
         public string Message { get; set; }
 
-        public ReactiveCommand<Unit, Unit> YesCommand { get; }
+        public MiniCommand YesCommand { get; }
 
-        public ReactiveCommand<Unit, Unit> NoCommand { get; }
+        public MiniCommand NoCommand { get; }
 
     }
 }

samples/ControlCatalog/ViewModels/SplitViewPageViewModel.cs

@@ -1,10 +1,10 @@
 using System;
 using Avalonia.Controls;
-using ReactiveUI;
+using MiniMvvm;
 
 namespace ControlCatalog.ViewModels
 {
-    public class SplitViewPageViewModel : ReactiveObject
+    public class SplitViewPageViewModel : ViewModelBase
     {
         private bool _isLeft = true;
         private int _displayMode = 3; //CompactOverlay

samples/ControlCatalog/ViewModels/TreeViewPageViewModel.cs

@@ -3,11 +3,11 @@ using System.Collections.ObjectModel;
 using System.Linq;
 using System.Reactive;
 using Avalonia.Controls;
-using ReactiveUI;
+using MiniMvvm;
 
 namespace ControlCatalog.ViewModels
 {
-    public class TreeViewPageViewModel : ReactiveObject
+    public class TreeViewPageViewModel : ViewModelBase
     {
         private readonly Node _root;
         private SelectionMode _selectionMode;
@@ -19,16 +19,16 @@ namespace ControlCatalog.ViewModels
             Items = _root.Children;
             SelectedItems = new ObservableCollection<Node>();
 
-            AddItemCommand = ReactiveCommand.Create(AddItem);
+            AddItemCommand = MiniCommand.Create(AddItem);
-            RemoveItemCommand = ReactiveCommand.Create(RemoveItem);
+            RemoveItemCommand = MiniCommand.Create(RemoveItem);
-            SelectRandomItemCommand = ReactiveCommand.Create(SelectRandomItem);
+            SelectRandomItemCommand = MiniCommand.Create(SelectRandomItem);
         }
 
         public ObservableCollection<Node> Items { get; }
         public ObservableCollection<Node> SelectedItems { get; }
-        public ReactiveCommand<Unit, Unit> AddItemCommand { get; }
+        public MiniCommand AddItemCommand { get; }
-        public ReactiveCommand<Unit, Unit> RemoveItemCommand { get; }
+        public MiniCommand RemoveItemCommand { get; }
-        public ReactiveCommand<Unit, Unit> SelectRandomItemCommand { get; }
+        public MiniCommand SelectRandomItemCommand { get; }
 
         public SelectionMode SelectionMode
         {

samples/MiniMvvm/MiniCommand.cs

@@ -0,0 +1,66 @@
+using System;
+using System.Threading.Tasks;
+using System.Windows.Input;
+
+namespace MiniMvvm
+{
+    public sealed class MiniCommand<T> : MiniCommand, ICommand
+    {
+        private readonly Action<T> _cb;
+        private bool _busy;
+        private Func<T, Task> _acb;
+        
+        public MiniCommand(Action<T> cb)
+        {
+            _cb = cb;
+        }
+
+        public MiniCommand(Func<T, Task> cb)
+        {
+            _acb = cb;
+        }
+
+        private bool Busy
+        {
+            get => _busy;
+            set
+            {
+                _busy = value;
+                CanExecuteChanged?.Invoke(this, EventArgs.Empty);
+            }
+        }
+
+        
+        public override event EventHandler CanExecuteChanged;
+        public override bool CanExecute(object parameter) => !_busy;
+
+        public override async void Execute(object parameter)
+        {
+            if(Busy)
+                return;
+            try
+            {
+                Busy = true;
+                if (_cb != null)
+                    _cb((T)parameter);
+                else
+                    await _acb((T)parameter);
+            }
+            finally
+            {
+                Busy = false;
+            }
+        }
+    }
+    
+    public abstract class MiniCommand : ICommand
+    {
+        public static MiniCommand Create(Action cb) => new MiniCommand<object>(_ => cb());
+        public static MiniCommand Create<TArg>(Action<TArg> cb) => new MiniCommand<TArg>(cb);
+        public static MiniCommand CreateFromTask(Func<Task> cb) => new MiniCommand<object>(_ => cb());
+        
+        public abstract bool CanExecute(object parameter);
+        public abstract void Execute(object parameter);
+        public abstract event EventHandler CanExecuteChanged;
+    }
+}

samples/MiniMvvm/MiniMvvm.csproj

@@ -0,0 +1,6 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+  </PropertyGroup>
+  <Import Project="..\..\build\Rx.props" />
+</Project>

samples/MiniMvvm/PropertyChangedExtensions.cs

@@ -0,0 +1,108 @@
+using System;
+using System.ComponentModel;
+using System.Linq.Expressions;
+using System.Reactive.Linq;
+using System.Reflection;
+
+namespace MiniMvvm
+{
+    public static class PropertyChangedExtensions
+    {
+        class PropertyObservable<T> : IObservable<T>
+        {
+            private readonly INotifyPropertyChanged _target;
+            private readonly PropertyInfo _info;
+
+            public PropertyObservable(INotifyPropertyChanged target, PropertyInfo info)
+            {
+                _target = target;
+                _info = info;
+            }
+
+            class Subscription : IDisposable
+            {
+                private readonly INotifyPropertyChanged _target;
+                private readonly PropertyInfo _info;
+                private readonly IObserver<T> _observer;
+
+                public Subscription(INotifyPropertyChanged target, PropertyInfo info, IObserver<T> observer)
+                {
+                    _target = target;
+                    _info = info;
+                    _observer = observer;
+                    _target.PropertyChanged += OnPropertyChanged;
+                    _observer.OnNext((T)_info.GetValue(_target));
+                }
+
+                private void OnPropertyChanged(object sender, PropertyChangedEventArgs e)
+                {
+                    if (e.PropertyName == _info.Name)
+                        _observer.OnNext((T)_info.GetValue(_target));
+                }
+
+                public void Dispose()
+                {
+                    _target.PropertyChanged -= OnPropertyChanged;
+                    _observer.OnCompleted();
+                }
+            }
+
+            public IDisposable Subscribe(IObserver<T> observer)
+            {
+                return new Subscription(_target, _info, observer);
+            }
+        }
+
+        public static IObservable<TRes> WhenAnyValue<TModel, TRes>(this TModel model,
+            Expression<Func<TModel, TRes>> expr) where TModel : INotifyPropertyChanged
+        {
+            var l = (LambdaExpression)expr;
+            var ma = (MemberExpression)l.Body;
+            var prop = (PropertyInfo)ma.Member;
+            return new PropertyObservable<TRes>(model, prop);
+        }
+        
+        public static IObservable<TRes> WhenAnyValue<TModel, T1, TRes>(this TModel model,
+            Expression<Func<TModel, T1>> v1,
+            Func<T1,  TRes> cb
+        ) where TModel : INotifyPropertyChanged
+        {
+            return model.WhenAnyValue(v1).Select(cb);
+        }
+        
+        public static IObservable<TRes> WhenAnyValue<TModel, T1, T2, TRes>(this TModel model,
+            Expression<Func<TModel, T1>> v1,
+            Expression<Func<TModel, T2>> v2,
+            Func<T1, T2, TRes> cb
+        ) where TModel : INotifyPropertyChanged =>
+            Observable.CombineLatest(
+                model.WhenAnyValue(v1),
+                model.WhenAnyValue(v2),
+                cb);
+
+        public static IObservable<ValueTuple<T1, T2>> WhenAnyValue<TModel, T1, T2>(this TModel model,
+            Expression<Func<TModel, T1>> v1,
+            Expression<Func<TModel, T2>> v2
+        ) where TModel : INotifyPropertyChanged =>
+            model.WhenAnyValue(v1, v2, (a1, a2) => (a1, a2));
+
+        public static IObservable<TRes> WhenAnyValue<TModel, T1, T2, T3, TRes>(this TModel model,
+            Expression<Func<TModel, T1>> v1,
+            Expression<Func<TModel, T2>> v2,
+            Expression<Func<TModel, T3>> v3,
+            Func<T1, T2, T3, TRes> cb
+        ) where TModel : INotifyPropertyChanged =>
+            Observable.CombineLatest(
+                model.WhenAnyValue(v1),
+                model.WhenAnyValue(v2),
+                model.WhenAnyValue(v3),
+                cb);
+
+        public static IObservable<ValueTuple<T1, T2, T3>> WhenAnyValue<TModel, T1, T2, T3>(this TModel model,
+            Expression<Func<TModel, T1>> v1,
+            Expression<Func<TModel, T2>> v2,
+            Expression<Func<TModel, T3>> v3
+        ) where TModel : INotifyPropertyChanged =>
+            model.WhenAnyValue(v1, v2, v3, (a1, a2, a3) => (a1, a2, a3));
+    }
+}

samples/MiniMvvm/ViewModelBase.cs

@@ -0,0 +1,26 @@
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Reactive.Joins;
+using System.Runtime.CompilerServices;
+
+namespace MiniMvvm
+{
+    public class ViewModelBase : INotifyPropertyChanged
+    {
+        public event PropertyChangedEventHandler PropertyChanged;
+        protected bool RaiseAndSetIfChanged<T>(ref T field, T value, [CallerMemberName] string propertyName = null)
+        {
+            if (!EqualityComparer<T>.Default.Equals(field, value))
+            {
+                field = value;
+                RaisePropertyChanged(propertyName);
+                return true;
+            }
+            return false;
+        }
+        
+        
+        protected void RaisePropertyChanged([CallerMemberName] string propertyName = null)
+            => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+    }
+}

samples/Previewer/Previewer.csproj

@@ -8,7 +8,6 @@
       <DependentUpon>%(Filename)</DependentUpon>
     </Compile>
     <EmbeddedResource Include="**\*.xaml" />
-    <ProjectReference Include="..\..\src\Avalonia.ReactiveUI\Avalonia.ReactiveUI.csproj" />
   </ItemGroup>
   
   <Import Project="..\..\build\SampleApp.props" />

samples/RenderDemo/App.xaml

@@ -3,7 +3,7 @@
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     x:Class="RenderDemo.App">
     <Application.Styles>
-        <StyleInclude Source="avares://Avalonia.Themes.Fluent/Accents/FluentLight.xaml"/>
+        <FluentTheme/>
         <StyleInclude Source="avares://RenderDemo/SideBar.xaml"/>
     </Application.Styles>
 </Application>

samples/RenderDemo/App.xaml.cs

@@ -1,7 +1,6 @@
 using Avalonia;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
-using Avalonia.ReactiveUI;
 
 namespace RenderDemo
 {
@@ -32,7 +31,6 @@ namespace RenderDemo
                    OverlayPopups = true,
                })
                 .UsePlatformDetect()
-                .UseReactiveUI()
                 .LogToTrace();
     }
 }

samples/RenderDemo/MainWindow.xaml.cs

@@ -3,7 +3,7 @@ using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
 using RenderDemo.ViewModels;
-using ReactiveUI;
+using MiniMvvm;
 
 namespace RenderDemo
 {

samples/RenderDemo/RenderDemo.csproj

@@ -9,12 +9,11 @@
   <ItemGroup>
     <ProjectReference Include="..\..\src\Avalonia.Diagnostics\Avalonia.Diagnostics.csproj" />
     <ProjectReference Include="..\..\src\Linux\Avalonia.LinuxFramebuffer\Avalonia.LinuxFramebuffer.csproj" />
-    <ProjectReference Include="..\..\src\Avalonia.ReactiveUI\Avalonia.ReactiveUI.csproj" />
+    <ProjectReference Include="..\MiniMvvm\MiniMvvm.csproj" />
   </ItemGroup>
   <Import Project="..\..\build\SampleApp.props" />
   <Import Project="..\..\build\EmbedXaml.props" />
   <Import Project="..\..\build\Rx.props" />
-  <Import Project="..\..\build\ReactiveUI.props" />
   <Import Condition="'$(TargetFramework)'=='net461'" Project="..\..\build\NetFX.props" />
   <Import Project="..\..\build\ReferenceCoreLibraries.props" />
   <Import Project="..\..\build\BuildTargets.targets" />

samples/RenderDemo/ViewModels/AnimationsPageViewModel.cs

@@ -1,10 +1,10 @@
 using System;
-using ReactiveUI;
+using MiniMvvm;
 using Avalonia.Animation;
 
 namespace RenderDemo.ViewModels
 {
-    public class AnimationsPageViewModel : ReactiveObject
+    public class AnimationsPageViewModel : ViewModelBase
     {
         private bool _isPlaying = true;
 

samples/RenderDemo/ViewModels/MainWindowViewModel.cs

@@ -1,11 +1,10 @@
 using System.Reactive;
 using System.Threading.Tasks;
-
+using MiniMvvm;
-using ReactiveUI;
 
 namespace RenderDemo.ViewModels
 {
-    public class MainWindowViewModel : ReactiveObject
+    public class MainWindowViewModel : ViewModelBase
     {
         private bool drawDirtyRects = false;
         private bool drawFps = true;
@@ -14,9 +13,9 @@ namespace RenderDemo.ViewModels
 
         public MainWindowViewModel()
         {
-            ToggleDrawDirtyRects = ReactiveCommand.Create(() => DrawDirtyRects = !DrawDirtyRects);
+            ToggleDrawDirtyRects = MiniCommand.Create(() => DrawDirtyRects = !DrawDirtyRects);
-            ToggleDrawFps = ReactiveCommand.Create(() => DrawFps = !DrawFps);
+            ToggleDrawFps = MiniCommand.Create(() => DrawFps = !DrawFps);
-            ResizeWindow = ReactiveCommand.CreateFromTask(ResizeWindowAsync);
+            ResizeWindow = MiniCommand.CreateFromTask(ResizeWindowAsync);
         }
 
         public bool DrawDirtyRects
@@ -43,9 +42,9 @@ namespace RenderDemo.ViewModels
             set => this.RaiseAndSetIfChanged(ref height, value);
         }
 
-        public ReactiveCommand<Unit, bool> ToggleDrawDirtyRects { get; }
+        public MiniCommand ToggleDrawDirtyRects { get; }
-        public ReactiveCommand<Unit, bool> ToggleDrawFps { get; }
+        public MiniCommand ToggleDrawFps { get; }
-        public ReactiveCommand<Unit, Unit> ResizeWindow { get; }
+        public MiniCommand ResizeWindow { get; }
 
         private async Task ResizeWindowAsync()
         {

samples/Sandbox/App.axaml

@@ -3,6 +3,6 @@
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     x:Class="Sandbox.App">
     <Application.Styles>
-        <StyleInclude Source="avares://Avalonia.Themes.Fluent/Accents/FluentDark.xaml"/>
+        <FluentTheme Mode="Dark"/>
     </Application.Styles>
 </Application>

samples/Sandbox/Program.cs

@@ -1,5 +1,4 @@
 using Avalonia;
-using Avalonia.ReactiveUI;
 
 namespace Sandbox
 {
@@ -9,7 +8,6 @@ namespace Sandbox
         {
             AppBuilder.Configure<App>()
                 .UsePlatformDetect()
-                .UseReactiveUI()
                 .LogToTrace()
                 .StartWithClassicDesktopLifetime(args);
         }

samples/Sandbox/Sandbox.csproj

@@ -8,7 +8,6 @@
 
   <ItemGroup>
     <ProjectReference Include="..\..\src\Avalonia.Diagnostics\Avalonia.Diagnostics.csproj" />
-    <ProjectReference Include="..\..\src\Avalonia.ReactiveUI\Avalonia.ReactiveUI.csproj" />
     <ProjectReference Include="..\..\src\Avalonia.Controls.DataGrid\Avalonia.Controls.DataGrid.csproj" />
   </ItemGroup>
   

samples/VirtualizationDemo/Program.cs

@@ -1,5 +1,4 @@
 using Avalonia;
-using Avalonia.ReactiveUI;
 
 namespace VirtualizationDemo
 {
@@ -8,7 +7,6 @@ namespace VirtualizationDemo
         public static AppBuilder BuildAvaloniaApp()
             => AppBuilder.Configure<App>()
                 .UsePlatformDetect()
-                .UseReactiveUI()
                 .LogToTrace();
 
         public static int Main(string[] args)

samples/VirtualizationDemo/ViewModels/ItemViewModel.cs

@@ -1,9 +1,9 @@
 using System;
-using ReactiveUI;
+using MiniMvvm;
 
 namespace VirtualizationDemo.ViewModels
 {
-    internal class ItemViewModel : ReactiveObject
+    internal class ItemViewModel : ViewModelBase
     {
         private string _prefix;
         private int _index;

samples/VirtualizationDemo/ViewModels/MainWindowViewModel.cs

@@ -5,13 +5,13 @@ using System.Reactive;
 using Avalonia.Collections;
 using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
-using ReactiveUI;
 using Avalonia.Layout;
 using Avalonia.Controls.Selection;
+using MiniMvvm;
 
 namespace VirtualizationDemo.ViewModels
 {
-    internal class MainWindowViewModel : ReactiveObject
+    internal class MainWindowViewModel : ViewModelBase
     {
         private int _itemCount = 200;
         private string _newItemString = "New Item";
@@ -26,15 +26,15 @@ namespace VirtualizationDemo.ViewModels
         public MainWindowViewModel()
         {
             this.WhenAnyValue(x => x.ItemCount).Subscribe(ResizeItems);
-            RecreateCommand = ReactiveCommand.Create(() => Recreate());
+            RecreateCommand = MiniCommand.Create(() => Recreate());
 
-            AddItemCommand = ReactiveCommand.Create(() => AddItem());
+            AddItemCommand = MiniCommand.Create(() => AddItem());
 
-            RemoveItemCommand = ReactiveCommand.Create(() => Remove());
+            RemoveItemCommand = MiniCommand.Create(() => Remove());
 
-            SelectFirstCommand = ReactiveCommand.Create(() => SelectItem(0));
+            SelectFirstCommand = MiniCommand.Create(() => SelectItem(0));
 
-            SelectLastCommand = ReactiveCommand.Create(() => SelectItem(Items.Count - 1));
+            SelectLastCommand = MiniCommand.Create(() => SelectItem(Items.Count - 1));
         }
 
         public string NewItemString
@@ -90,11 +90,11 @@ namespace VirtualizationDemo.ViewModels
         public IEnumerable<ItemVirtualizationMode> VirtualizationModes => 
             Enum.GetValues(typeof(ItemVirtualizationMode)).Cast<ItemVirtualizationMode>();
 
-        public ReactiveCommand<Unit, Unit> AddItemCommand { get; private set; }
+        public MiniCommand AddItemCommand { get; private set; }
-        public ReactiveCommand<Unit, Unit> RecreateCommand { get; private set; }
+        public MiniCommand RecreateCommand { get; private set; }
-        public ReactiveCommand<Unit, Unit> RemoveItemCommand { get; private set; }
+        public MiniCommand RemoveItemCommand { get; private set; }
-        public ReactiveCommand<Unit, Unit> SelectFirstCommand { get; private set; }
+        public MiniCommand SelectFirstCommand { get; private set; }
-        public ReactiveCommand<Unit, Unit> SelectLastCommand { get; private set; }
+        public MiniCommand SelectLastCommand { get; private set; }
 
         public void RandomizeSize()
         {

samples/VirtualizationDemo/VirtualizationDemo.csproj

@@ -6,12 +6,11 @@
   <ItemGroup>
     <ProjectReference Include="..\..\src\Avalonia.Diagnostics\Avalonia.Diagnostics.csproj" />
     <ProjectReference Include="..\..\src\Linux\Avalonia.LinuxFramebuffer\Avalonia.LinuxFramebuffer.csproj" />
-    <ProjectReference Include="..\..\src\Avalonia.ReactiveUI\Avalonia.ReactiveUI.csproj" />
+    <ProjectReference Include="..\MiniMvvm\MiniMvvm.csproj" />
   </ItemGroup>
   <Import Project="..\..\build\SampleApp.props" />
   <Import Project="..\..\build\EmbedXaml.props" />
   <Import Project="..\..\build\Rx.props" />
-  <Import Project="..\..\build\ReactiveUI.props" />
   <Import Condition="'$(TargetFramework)'=='net461'" Project="..\..\build\NetFX.props" />
   <Import Project="..\..\build\ReferenceCoreLibraries.props" />
   <Import Project="..\..\build\BuildTargets.targets" />

samples/interop/Direct3DInteropSample/Direct3DInteropSample.csproj

@@ -22,9 +22,9 @@
       </EmbeddedResource>
     </ItemGroup>
     <ItemGroup>
-        <ProjectReference Include="..\..\..\src\Avalonia.ReactiveUI\Avalonia.ReactiveUI.csproj" />
         <ProjectReference Include="..\..\..\src\Windows\Avalonia.Direct2D1\Avalonia.Direct2D1.csproj" />
         <ProjectReference Include="..\..\..\src\Windows\Avalonia.Win32\Avalonia.Win32.csproj" />
+        <ProjectReference Include="..\..\MiniMvvm\MiniMvvm.csproj" />
     </ItemGroup>
     <Import Project="..\..\..\build\Rx.props" />
     <Import Project="..\..\..\build\ReferenceCoreLibraries.props" />

samples/interop/Direct3DInteropSample/MainWindowViewModel.cs

@@ -3,11 +3,11 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
-using ReactiveUI;
+using MiniMvvm;
 
 namespace Direct3DInteropSample
 {
-    public class MainWindowViewModel : ReactiveObject
+    public class MainWindowViewModel : ViewModelBase
     {
         private double _rotationX;
 

samples/interop/WindowsInteropTest/WindowsInteropTest.csproj

@@ -136,10 +136,6 @@
       <Project>{42472427-4774-4c81-8aff-9f27b8e31721}</Project>
       <Name>Avalonia.Layout</Name>
     </ProjectReference>
-    <ProjectReference Include="..\..\..\src\Avalonia.ReactiveUI\Avalonia.ReactiveUI.csproj">
-      <Project>{6417b24e-49c2-4985-8db2-3ab9d898ec91}</Project>
-      <Name>Avalonia.ReactiveUI</Name>
-    </ProjectReference>
     <ProjectReference Include="..\..\..\src\Avalonia.Visuals\Avalonia.Visuals.csproj">
       <Project>{eb582467-6abb-43a1-b052-e981ba910e3a}</Project>
       <Name>Avalonia.Visuals</Name>
@@ -190,4 +186,4 @@
   <Import Project="..\..\..\build\Rx.props" />
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <Import Project="..\..\..\build\LegacyProject.targets" />
-</Project>
+</Project>

src/Android/Avalonia.AndroidTestApplication/Avalonia.AndroidTestApplication.csproj

@@ -127,10 +127,6 @@
       <Project>{42472427-4774-4c81-8aff-9f27b8e31721}</Project>
       <Name>Avalonia.Layout</Name>
     </ProjectReference>
-    <ProjectReference Include="..\..\..\src\Avalonia.ReactiveUI\Avalonia.ReactiveUI.csproj">
-      <Project>{6417b24e-49c2-4985-8db2-3ab9d898ec91}</Project>
-      <Name>Avalonia.ReactiveUI</Name>
-    </ProjectReference>
     <ProjectReference Include="..\..\Avalonia.Visuals\Avalonia.Visuals.csproj">
       <Project>{eb582467-6abb-43a1-b052-e981ba910e3a}</Project>
       <Name>Avalonia.Visuals</Name>

src/Avalonia.Base/ApiCompatBaseline.txt

@@ -1,4 +1,4 @@
 Compat issues with assembly Avalonia.Base:
-CannotAddAbstractMembers : Member 'protected System.IObservable<Avalonia.AvaloniaPropertyChangedEventArgs> Avalonia.AvaloniaProperty.GetChanged()' is abstract in the implementation but is missing in the contract.
+MembersMustExist : Member 'public void Avalonia.Threading.AvaloniaSynchronizationContext..ctor(Avalonia.Threading.AvaloniaSynchronizationContext.INonPumpingPlatformWaitProvider)' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'Avalonia.Logging.DebugLogSink' does not exist in the implementation but it does exist in the contract.
+TypesMustExist : Type 'Avalonia.Threading.AvaloniaSynchronizationContext.INonPumpingPlatformWaitProvider' does not exist in the implementation but it does exist in the contract.
 Total Issues: 2

src/Avalonia.Base/Collections/AvaloniaList.cs

@@ -63,6 +63,15 @@ namespace Avalonia.Collections
             _inner = new List<T>();
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AvaloniaList{T}"/>.
+        /// </summary>
+        /// <param name="capacity">Initial list capacity.</param>
+        public AvaloniaList(int capacity)
+        {
+            _inner = new List<T>(capacity);
+        }
+
         /// <summary>
         /// Initializes a new instance of the <see cref="AvaloniaList{T}"/> class.
         /// </summary>
@@ -175,6 +184,15 @@ namespace Avalonia.Collections
             set { this[index] = (T)value; }
         }
 
+        /// <summary>
+        /// Gets or sets the total number of elements the internal data structure can hold without resizing.
+        /// </summary>
+        public int Capacity
+        {
+            get => _inner.Capacity;
+            set => _inner.Capacity = value;
+        }
+
         /// <summary>
         /// Adds an item to the collection.
         /// </summary>

src/Avalonia.Base/Properties/AssemblyInfo.cs

@@ -11,10 +11,12 @@ using Avalonia.Metadata;
 [assembly: InternalsVisibleTo("DynamicProxyGenAssembly2, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c547cac37abd99c8db225ef2f6c8a3602f3b3606cc9891605d02baa56104f4cfc0734aa39b93bf7852f7d9266654753cc297e7d2edfe0bac1cdcf9f717241550e0a7b191195b7667bb4f64bcb8e2121380fd1d9d46ad2d92d2d15605093924cceaf74c4861eff62abf69b9291ed0a340e113be11e6a7d3113e92484cf7045cc7")] 
 [assembly: InternalsVisibleTo("Avalonia.Controls.DataGrid, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c1bba1142285fe0419326fb25866ba62c47e6c2b5c1ab0c95b46413fad375471232cb81706932e1cef38781b9ebd39d5100401bacb651c6c5bbf59e571e81b3bc08d2a622004e08b1a6ece82a7e0b9857525c86d2b95fab4bc3dce148558d7f3ae61aa3a234086902aeface87d9dfdd32b9d2fe3c6dd4055b5ab4b104998bd87")]
 [assembly: InternalsVisibleTo("Avalonia.Markup.Xaml.UnitTests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c1bba1142285fe0419326fb25866ba62c47e6c2b5c1ab0c95b46413fad375471232cb81706932e1cef38781b9ebd39d5100401bacb651c6c5bbf59e571e81b3bc08d2a622004e08b1a6ece82a7e0b9857525c86d2b95fab4bc3dce148558d7f3ae61aa3a234086902aeface87d9dfdd32b9d2fe3c6dd4055b5ab4b104998bd87")]
+[assembly: InternalsVisibleTo("Avalonia.Visuals, PublicKey=0024000004800000940000000602000000240000525341310004000001000100c1bba1142285fe0419326fb25866ba62c47e6c2b5c1ab0c95b46413fad375471232cb81706932e1cef38781b9ebd39d5100401bacb651c6c5bbf59e571e81b3bc08d2a622004e08b1a6ece82a7e0b9857525c86d2b95fab4bc3dce148558d7f3ae61aa3a234086902aeface87d9dfdd32b9d2fe3c6dd4055b5ab4b104998bd87")]
 #else
 [assembly: InternalsVisibleTo("Avalonia.Base.UnitTests")]
 [assembly: InternalsVisibleTo("Avalonia.UnitTests")]
 [assembly: InternalsVisibleTo("DynamicProxyGenAssembly2")]
 [assembly: InternalsVisibleTo("Avalonia.Controls.DataGrid")]
 [assembly: InternalsVisibleTo("Avalonia.Markup.Xaml.UnitTests")]
+[assembly: InternalsVisibleTo("Avalonia.Visuals")]
 #endif

src/Avalonia.Base/Threading/AvaloniaSynchronizationContext.cs

@@ -9,20 +9,6 @@ namespace Avalonia.Threading
     /// </summary>
     public class AvaloniaSynchronizationContext : SynchronizationContext
     {
-        public interface INonPumpingPlatformWaitProvider
-        {
-            int Wait(IntPtr[] waitHandles, bool waitAll, int millisecondsTimeout);
-        }
-
-        private readonly INonPumpingPlatformWaitProvider _waitProvider;
-
-        public AvaloniaSynchronizationContext(INonPumpingPlatformWaitProvider waitProvider)
-        {
-            _waitProvider = waitProvider;
-            if (_waitProvider != null)
-                SetWaitNotificationRequired();
-        }
-
         /// <summary>
         /// Controls if SynchronizationContext should be installed in InstallIfNeeded. Used by Designer.
         /// </summary>
@@ -38,8 +24,7 @@ namespace Avalonia.Threading
                 return;
             }
 
-            SetSynchronizationContext(new AvaloniaSynchronizationContext(AvaloniaLocator.Current
+            SetSynchronizationContext(new AvaloniaSynchronizationContext());
-                .GetService<INonPumpingPlatformWaitProvider>()));
         }
 
         /// <inheritdoc/>
@@ -57,12 +42,6 @@ namespace Avalonia.Threading
                 Dispatcher.UIThread.InvokeAsync(() => d(state), DispatcherPriority.Send).Wait();
         }
 
-        [PrePrepareMethod]
+
-        public override int Wait(IntPtr[] waitHandles, bool waitAll, int millisecondsTimeout)
-        {
-            if (_waitProvider != null)
-                return _waitProvider.Wait(waitHandles, waitAll, millisecondsTimeout);
-            return base.Wait(waitHandles, waitAll, millisecondsTimeout);
-        }
     }
 }

src/Avalonia.Base/Utilities/AvaloniaPropertyValueStore.cs

@@ -1,5 +1,8 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+
+#nullable enable
 
 namespace Avalonia.Utilities
 {
@@ -9,12 +12,14 @@ namespace Avalonia.Utilities
     /// <typeparam name="TValue">Stored value type.</typeparam>
     internal sealed class AvaloniaPropertyValueStore<TValue>
     {
+        // The last item in the list is always int.MaxValue.
+        private static readonly Entry[] s_emptyEntries = { new Entry { PropertyId = int.MaxValue, Value = default! } };
+        
         private Entry[] _entries;
 
         public AvaloniaPropertyValueStore()
         {
-            // The last item in the list is always int.MaxValue
+            _entries = s_emptyEntries;
-            _entries = new[] { new Entry { PropertyId = int.MaxValue, Value = default } };
         }
 
         private (int, bool) TryFindEntry(int propertyId)
@@ -86,7 +91,7 @@ namespace Avalonia.Utilities
             return (0, false);
         }
 
-        public bool TryGetValue(AvaloniaProperty property, out TValue value)
+        public bool TryGetValue(AvaloniaProperty property, [MaybeNull] out TValue value)
         {
             (int index, bool found) = TryFindEntry(property.Id);
             if (!found)
@@ -132,7 +137,18 @@ namespace Avalonia.Utilities
 
             if (found)
             {
-                Entry[] entries = new Entry[_entries.Length - 1];
+                var newLength = _entries.Length - 1;
+                
+                // Special case - one element left means that value store is empty so we can just reuse our "empty" array.
+                if (newLength == 1)
+                {
+                    _entries = s_emptyEntries;
+                    
+                    return;
+                }
+                
+                var entries = new Entry[newLength];
+
                 int ix = 0;
 
                 for (int i = 0; i < _entries.Length; ++i)

src/Avalonia.Base/Utilities/MathUtilities.cs

@@ -5,7 +5,10 @@ namespace Avalonia.Utilities
     /// <summary>
     /// Provides math utilities not provided in System.Math.
     /// </summary>
-    public static class MathUtilities
+#if !BUILDTASK
+    public
+#endif
+    static class MathUtilities
     {
         // smallest such that 1.0+DoubleEpsilon != 1.0
         internal static readonly double DoubleEpsilon = 2.2204460492503131e-016;

src/Avalonia.Base/Utilities/NonPumpingLockHelper.cs

@@ -0,0 +1,14 @@
+using System;
+
+namespace Avalonia.Utilities
+{
+    public class NonPumpingLockHelper
+    {
+        public interface IHelperImpl
+        {
+            IDisposable Use();
+        }
+
+        public static IDisposable Use() => AvaloniaLocator.Current.GetService<IHelperImpl>()?.Use();
+    }
+}

src/Avalonia.Base/Utilities/StringTokenizer.cs

@@ -4,7 +4,10 @@ using static System.Char;
 
 namespace Avalonia.Utilities
 {
-    public struct StringTokenizer : IDisposable
+#if !BUILDTASK
+    public
+#endif
+    struct StringTokenizer : IDisposable
     {
         private const char DefaultSeparatorChar = ',';
 

src/Avalonia.Build.Tasks/Avalonia.Build.Tasks.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
     <PropertyGroup>
         <TargetFrameworks>netstandard2.0</TargetFrameworks>
-        <TargetFrameworks Condition="$(Configuration) == 'Debug'">netstandard2.0;netcoreapp2.0</TargetFrameworks>
+        <TargetFrameworks Condition="$(Configuration) == 'Debug'">netstandard2.0;netcoreapp3.1</TargetFrameworks>
         <OutputType>exe</OutputType>
         <GenerateDocumentationFile>false</GenerateDocumentationFile>
         <BuildOutputTargetFolder>tools</BuildOutputTargetFolder>
@@ -45,6 +45,12 @@
       <Compile Include="../Avalonia.Base/Utilities/IdentifierParser.cs">
         <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
       </Compile>
+      <Compile Include="../Avalonia.Base/Utilities/StringTokenizer.cs">
+        <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
+      </Compile>
+      <Compile Include="../Avalonia.Base/Utilities/MathUtilities.cs">
+        <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
+      </Compile>
       <Compile Include="..\Markup\Avalonia.Markup\Markup\Parsers\ArgumentListParser.cs">
         <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
       </Compile>
@@ -57,6 +63,33 @@
       <Compile Include="../Avalonia.Base/Utilities/StyleClassParser.cs">
         <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
       </Compile>
+      <Compile Include="../Avalonia.Visuals/Thickness.cs">
+        <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
+      </Compile>
+      <Compile Include="../Avalonia.Visuals/Size.cs">
+        <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
+      </Compile>
+      <Compile Include="../Avalonia.Visuals/Vector.cs">
+        <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
+      </Compile>
+      <Compile Include="../Avalonia.Visuals/Point.cs">
+        <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
+      </Compile>
+      <Compile Include="../Avalonia.Visuals/Matrix.cs">
+        <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
+      </Compile>
+      <Compile Include="../Avalonia.Visuals/CornerRadius.cs">
+        <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
+      </Compile>
+      <Compile Include="../Avalonia.Visuals/Media/Color.cs">
+        <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
+      </Compile>
+      <Compile Include="../Avalonia.Visuals/Media/KnownColors.cs">
+        <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
+      </Compile>
+      <Compile Include="../Avalonia.Controls/GridLength.cs">
+        <Link>Markup/%(RecursiveDir)%(FileName)%(Extension)</Link>
+      </Compile>
       <Compile Remove="../Markup/Avalonia.Markup.Xaml.Loader\xamlil.github\**\obj\**\*.cs" />
       <Compile Remove="../Markup/Avalonia.Markup.Xaml.Loader\xamlil.github\src\XamlX\IL\SreTypeSystem.cs" />
       <PackageReference Include="Mono.Cecil" Version="0.11.2" />

src/Avalonia.Build.Tasks/SpanCompat.cs

@@ -1,3 +1,4 @@
+#if !NETCOREAPP3_1
 namespace System
 {
     // This is a hack to enable our span code to work inside MSBuild task without referencing System.Memory
@@ -63,6 +64,8 @@ namespace System
         }
 
         public override string ToString() => _length == 0 ? string.Empty : _s.Substring(_start, _length);
+
+        public static implicit operator ReadOnlySpan<T>(char[] arr) => new ReadOnlySpan<T>(new string(arr));
     }
 
     static class SpanCompatExtensions
@@ -71,3 +74,4 @@ namespace System
     }
 
 }
+#endif

src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs

@@ -46,7 +46,9 @@ namespace Avalonia.Build.Tasks
             string output, bool verifyIl, MessageImportance logImportance, string strongNameKey, bool patchCom,
             bool skipXamlCompilation)
         {
-            var typeSystem = new CecilTypeSystem(references.Concat(new[] { input }), input);
+            var typeSystem = new CecilTypeSystem(references
+                .Where(r => !r.ToLowerInvariant().EndsWith("avalonia.build.tasks.dll"))
+                .Concat(new[] { input }), input);
             
             var asm = typeSystem.TargetAssemblyDefinition;
 

src/Avalonia.Controls.DataGrid/ApiCompatBaseline.txt

@@ -1,5 +1 @@
-Compat issues with assembly Avalonia.Controls.DataGrid:
+Total Issues: 0
-MembersMustExist : Member 'public Avalonia.StyledProperty<System.String> Avalonia.StyledProperty<System.String> Avalonia.Controls.DataGridTextColumn.FontFamilyProperty' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'public System.String Avalonia.Controls.DataGridTextColumn.FontFamily.get()' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'public void Avalonia.Controls.DataGridTextColumn.FontFamily.set(System.String)' does not exist in the implementation but it does exist in the contract.
-Total Issues: 3

src/Avalonia.Controls.DataGrid/Themes/Default.xaml

@@ -137,12 +137,37 @@
   </Style>
 
   <Style Selector="DataGridRowHeader">
+    <Setter Property="Focusable" Value="False" />
     <Setter Property="Template">
       <ControlTemplate>
         <Grid x:Name="PART_Root"
-        RowDefinitions="*,*,Auto"
+              RowDefinitions="*,*,Auto"
-        ColumnDefinitions="Auto,*">
+              ColumnDefinitions="Auto,*">
+          <Border Grid.RowSpan="3"
+                  Grid.ColumnSpan="2"
+                  BorderBrush="{TemplateBinding SeparatorBrush}"
+                  BorderThickness="0,0,1,0">
+            <Grid Background="{TemplateBinding Background}">
+              <Rectangle x:Name="RowInvalidVisualElement"
+                         Stretch="Fill" />
+              <Rectangle x:Name="BackgroundRectangle"
+                         Stretch="Fill" />
+            </Grid>
+          </Border>
+          <Rectangle x:Name="HorizontalSeparator"
+                     Grid.Row="2"
+                     Grid.ColumnSpan="2"
+                     Height="1"
+                     Margin="1,0,1,0"
+                     HorizontalAlignment="Stretch"
+                     Fill="{TemplateBinding SeparatorBrush}"
+                     IsVisible="{TemplateBinding AreSeparatorsVisible}" />
 
+          <ContentPresenter Grid.RowSpan="2"
+                            Grid.Column="1"
+                            HorizontalAlignment="Center"
+                            VerticalAlignment="Center"
+                            Content="{TemplateBinding Content}" />
         </Grid>
       </ControlTemplate>
     </Setter>

src/Avalonia.Controls/ApiCompatBaseline.txt

@@ -1,26 +1,5 @@
 Compat issues with assembly Avalonia.Controls:
-TypesMustExist : Type 'Avalonia.Controls.IndexPath' does not exist in the implementation but it does exist in the contract.
+InterfacesShouldHaveSameMembers : Interface member 'public void Avalonia.Platform.IWindowBaseImpl.Show()' is present in the contract but not in the implementation.
-TypesMustExist : Type 'Avalonia.Controls.ISelectedItemInfo' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public void Avalonia.Platform.IWindowBaseImpl.Show()' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'Avalonia.Controls.ISelectionModel' does not exist in the implementation but it does exist in the contract.
+InterfacesShouldHaveSameMembers : Interface member 'public void Avalonia.Platform.IWindowBaseImpl.Show(System.Boolean)' is present in the implementation but not in the contract.
-MembersMustExist : Member 'public Avalonia.DirectProperty<Avalonia.Controls.Primitives.SelectingItemsControl, Avalonia.Controls.ISelectionModel> Avalonia.DirectProperty<Avalonia.Controls.Primitives.SelectingItemsControl, Avalonia.Controls.ISelectionModel> Avalonia.Controls.ListBox.SelectionProperty' does not exist in the implementation but it does exist in the contract.
+Total Issues: 3
-MembersMustExist : Member 'public Avalonia.Controls.ISelectionModel Avalonia.Controls.ListBox.Selection.get()' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'public void Avalonia.Controls.ListBox.Selection.set(Avalonia.Controls.ISelectionModel)' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'Avalonia.Controls.SelectionModel' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'Avalonia.Controls.SelectionModelChildrenRequestedEventArgs' does not exist in the implementation but it does exist in the contract.
-TypesMustExist : Type 'Avalonia.Controls.SelectionModelSelectionChangedEventArgs' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'public Avalonia.StyledProperty<Avalonia.Controls.IControl> Avalonia.StyledProperty<Avalonia.Controls.IControl> Avalonia.Controls.SplitView.ContentProperty' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'public Avalonia.StyledProperty<Avalonia.Controls.IControl> Avalonia.StyledProperty<Avalonia.Controls.IControl> Avalonia.Controls.SplitView.PaneProperty' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'public Avalonia.Controls.IControl Avalonia.Controls.SplitView.Content.get()' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'public void Avalonia.Controls.SplitView.Content.set(Avalonia.Controls.IControl)' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'public Avalonia.Controls.IControl Avalonia.Controls.SplitView.Pane.get()' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'public void Avalonia.Controls.SplitView.Pane.set(Avalonia.Controls.IControl)' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'public Avalonia.DirectProperty<Avalonia.Controls.TreeView, Avalonia.Controls.ISelectionModel> Avalonia.DirectProperty<Avalonia.Controls.TreeView, Avalonia.Controls.ISelectionModel> Avalonia.Controls.TreeView.SelectionProperty' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'public Avalonia.Interactivity.RoutedEvent<Avalonia.Controls.SelectionChangedEventArgs> Avalonia.Interactivity.RoutedEvent<Avalonia.Controls.SelectionChangedEventArgs> Avalonia.Controls.TreeView.SelectionChangedEvent' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'public Avalonia.Controls.ISelectionModel Avalonia.Controls.TreeView.Selection.get()' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'public void Avalonia.Controls.TreeView.Selection.set(Avalonia.Controls.ISelectionModel)' does not exist in the implementation but it does exist in the contract.
-InterfacesShouldHaveSameMembers : Interface member 'public System.String[] Avalonia.Controls.ApplicationLifetimes.IClassicDesktopStyleApplicationLifetime.Args' is present in the implementation but not in the contract.
-InterfacesShouldHaveSameMembers : Interface member 'public System.String[] Avalonia.Controls.ApplicationLifetimes.IClassicDesktopStyleApplicationLifetime.Args.get()' is present in the implementation but not in the contract.
-MembersMustExist : Member 'public Avalonia.DirectProperty<Avalonia.Controls.Primitives.SelectingItemsControl, Avalonia.Controls.ISelectionModel> Avalonia.DirectProperty<Avalonia.Controls.Primitives.SelectingItemsControl, Avalonia.Controls.ISelectionModel> Avalonia.Controls.Primitives.SelectingItemsControl.SelectionProperty' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'protected Avalonia.Controls.ISelectionModel Avalonia.Controls.Primitives.SelectingItemsControl.Selection.get()' does not exist in the implementation but it does exist in the contract.
-MembersMustExist : Member 'protected void Avalonia.Controls.Primitives.SelectingItemsControl.Selection.set(Avalonia.Controls.ISelectionModel)' does not exist in the implementation but it does exist in the contract.
-Total Issues: 24

src/Avalonia.Controls/AutoCompleteBox.cs

@@ -1405,8 +1405,11 @@ namespace Avalonia.Controls
                     break;
 
                 case Key.Enter:
-                    OnAdapterSelectionComplete(this, new RoutedEventArgs());
+                    if (IsDropDownOpen)
-                    e.Handled = true;
+                    {
+                        OnAdapterSelectionComplete(this, new RoutedEventArgs());
+                        e.Handled = true;
+                    }
                     break;
 
                 default:

src/Avalonia.Controls/ComboBox.cs

@@ -173,11 +173,10 @@ namespace Avalonia.Controls
                 ComboBoxItem.ContentTemplateProperty);
         }
 
-        /// <inheritdoc/>
+        protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
-        protected override void OnAttachedToLogicalTree(LogicalTreeAttachmentEventArgs e)
         {
-            base.OnAttachedToLogicalTree(e);
+            base.OnAttachedToVisualTree(e);
-            this.UpdateSelectionBoxItem(this.SelectedItem);
+            this.UpdateSelectionBoxItem(SelectedItem);
         }
 
         /// <inheritdoc/>
@@ -373,19 +372,22 @@ namespace Avalonia.Controls
 
             if (control != null)
             {
-                control.Measure(Size.Infinity);
+                if (VisualRoot is object)
-
-                SelectionBoxItem = new Rectangle
                 {
-                    Width = control.DesiredSize.Width,
+                    control.Measure(Size.Infinity);
-                    Height = control.DesiredSize.Height,
+
-                    Fill = new VisualBrush
+                    SelectionBoxItem = new Rectangle
                     {
-                        Visual = control,
+                        Width = control.DesiredSize.Width,
-                        Stretch = Stretch.None,
+                        Height = control.DesiredSize.Height,
-                        AlignmentX = AlignmentX.Left,
+                        Fill = new VisualBrush
-                    }
+                        {
-                };
+                            Visual = control,
+                            Stretch = Stretch.None,
+                            AlignmentX = AlignmentX.Left,
+                        }
+                    };
+                }
             }
             else
             {

src/Avalonia.Controls/ContextMenu.cs

@@ -233,6 +233,16 @@ namespace Avalonia.Controls
             }
         }
 
+        protected override void OnPropertyChanged<T>(AvaloniaPropertyChangedEventArgs<T> change)
+        {
+            base.OnPropertyChanged(change);
+
+            if (change.Property == WindowManagerAddShadowHintProperty && _popup != null)
+            {
+                _popup.WindowManagerAddShadowHint = change.NewValue.GetValueOrDefault<bool>();
+            }
+        }
+
         /// <summary>
         /// Opens the menu.
         /// </summary>

src/Avalonia.Controls/DefinitionList.cs

@@ -1,8 +1,9 @@
-using System;
+using System.Collections;
 using System.Collections.Specialized;
-using System.Linq;
 using Avalonia.Collections;
 
+#nullable enable
+
 namespace Avalonia.Controls
 {
     public abstract class DefinitionList<T> : AvaloniaList<T> where T : DefinitionBase
@@ -14,44 +15,65 @@ namespace Avalonia.Controls
         }
 
         internal bool IsDirty = true;
-        private Grid _parent;
+        private Grid? _parent;
 
-        internal Grid Parent
+        internal Grid? Parent
         {
             get => _parent;
             set => SetParent(value);
         }
 
-        private void SetParent(Grid value)
+        private void SetParent(Grid? value)
         {
             _parent = value;
 
-            foreach (var pair in this.Select((definitions, index) => (definitions, index)))
+            var idx = 0;
+
+            foreach (T definition in this)
             {
-                pair.definitions.Parent = value;
+                definition.Parent = value;
-                pair.definitions.Index = pair.index;
+                definition.Index = idx++;
             }
         }
 
         internal void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
         {
-            foreach (var nI in this.Select((d, i) => (d, i)))
+            var idx = 0;
-                nI.d._parentIndex = nI.i;
 
-            foreach (var nD in e.NewItems?.Cast<DefinitionBase>()
+            foreach (T definition in this)
-                            ?? Enumerable.Empty<DefinitionBase>())
             {
-                nD.Parent = this.Parent;
+                definition.Index = idx++;
-                nD.OnEnterParentTree();
             }
+            
+            UpdateDefinitionParent(e.NewItems, false);
+            UpdateDefinitionParent(e.OldItems, true);
+            
+            IsDirty = true;
+        }
 
-            foreach (var oD in e.OldItems?.Cast<DefinitionBase>()
+        private void UpdateDefinitionParent(IList? items, bool wasRemoved)
-                            ?? Enumerable.Empty<DefinitionBase>())
+        {
+            if (items is null)
             {
-                oD.OnExitParentTree();
+                return;
             }
+            
+            var count = items.Count;
 
-            IsDirty = true;
+            for (var i = 0; i < count; i++)
+            {
+                var definition = (DefinitionBase) items[i];
+
+                if (wasRemoved)
+                {
+                    definition.OnExitParentTree();
+                }
+                else
+                {
+                    definition.Parent = Parent;
+                    definition.OnEnterParentTree();                    
+                }
+            }
         }
     }
-}
+}

src/Avalonia.Controls/Generators/ItemContainerInfo.cs

@@ -37,6 +37,6 @@ namespace Avalonia.Controls.Generators
         /// <summary>
         /// Gets the index of the item in the <see cref="ItemsControl.Items"/> collection.
         /// </summary>
-        public int Index { get; internal set; }
+        public int Index { get; set; }
     }
-}
+}

src/Avalonia.Controls/GridLength.cs

@@ -8,7 +8,10 @@ namespace Avalonia.Controls
     /// <summary>
     /// Defines the valid units for a <see cref="GridLength"/>.
     /// </summary>
-    public enum GridUnitType
+#if !BUILDTASK
+    public
+#endif
+    enum GridUnitType
     {
         /// <summary>
         /// The row or column is auto-sized to fit its content.
@@ -29,7 +32,10 @@ namespace Avalonia.Controls
     /// <summary>
     /// Holds the width or height of a <see cref="Grid"/>'s column and row definitions.
     /// </summary>
-    public struct GridLength : IEquatable<GridLength>
+#if !BUILDTASK
+    public
+#endif
+    struct GridLength : IEquatable<GridLength>
     {
         private readonly GridUnitType _type;
 

src/Avalonia.Controls/NativeMenuBar.cs

@@ -1,7 +1,6 @@
 using System;
 using Avalonia.Controls.Primitives;
 using Avalonia.Interactivity;
-using Avalonia.Styling;
 
 namespace Avalonia.Controls
 {
@@ -16,7 +15,7 @@ namespace Avalonia.Controls
             EnableMenuItemClickForwardingProperty.Changed.Subscribe(args =>
             {
                 var item = (MenuItem)args.Sender;
-                if (args.NewValue.Equals(true))
+                if (args.NewValue.GetValueOrDefault<bool>())
                     item.Click += OnMenuItemClick;
                 else
                     item.Click -= OnMenuItemClick;

src/Avalonia.Controls/NativeMenuItem.cs

@@ -2,6 +2,7 @@ using System;
 using System.Windows.Input;
 using Avalonia.Input;
 using Avalonia.Media.Imaging;
+using Avalonia.Metadata;
 using Avalonia.Utilities;
 
 namespace Avalonia.Controls
@@ -62,6 +63,7 @@ namespace Avalonia.Controls
         public static readonly DirectProperty<NativeMenuItem, NativeMenu> MenuProperty =
             AvaloniaProperty.RegisterDirect<NativeMenuItem, NativeMenu>(nameof(Menu), o => o.Menu, (o, v) => o.Menu = v);
 
+        [Content]
         public NativeMenu Menu
         {
             get => _menu;
@@ -151,7 +153,7 @@ namespace Avalonia.Controls
             IsEnabled = _command?.CanExecute(null) ?? true;
         }
 
-        public bool HasClickHandlers => Clicked != null;
+        public bool HasClickHandlers => Click != null;
 
         public ICommand Command
         {
@@ -182,11 +184,21 @@ namespace Avalonia.Controls
             set { SetValue(CommandParameterProperty, value); }
         }
 
-        public event EventHandler Clicked;
+        /// <summary>
+        /// Occurs when a <see cref="NativeMenuItem"/> is clicked.
+        /// </summary>
+        public event EventHandler Click;
+
+        [Obsolete("Use Click event.")]
+        public event EventHandler Clicked
+        {
+            add => Click += value;
+            remove => Click -= value;
+        }
 
         void INativeMenuItemExporterEventsImplBridge.RaiseClicked()
         {
-            Clicked?.Invoke(this, new EventArgs());
+            Click?.Invoke(this, new EventArgs());
 
             if (Command?.CanExecute(CommandParameter) == true)
             {

src/Avalonia.Controls/Platform/DefaultMenuInteractionHandler.cs

@@ -231,7 +231,7 @@ namespace Avalonia.Controls.Platform
                 {
                     var direction = e.Key.ToNavigationDirection();
 
-                    if (direction.HasValue)
+                    if (direction?.IsDirectional() == true)
                     {
                         if (item == null && _isContextMenu)
                         {

src/Avalonia.Controls/Platform/IWindowBaseImpl.cs

@@ -5,9 +5,9 @@ namespace Avalonia.Platform
     public interface IWindowBaseImpl : ITopLevelImpl
     {
         /// <summary>
-        /// Shows the top level.
+        /// Shows the window.
         /// </summary>
-        void Show();
+        void Show(bool activate);
 
         /// <summary>
         /// Hides the window.

src/Avalonia.Controls/Primitives/ScrollBar.cs

@@ -35,7 +35,7 @@ namespace Avalonia.Controls.Primitives
         /// Defines the <see cref="Visibility"/> property.
         /// </summary>
         public static readonly StyledProperty<ScrollBarVisibility> VisibilityProperty =
-            AvaloniaProperty.Register<ScrollBar, ScrollBarVisibility>(nameof(Visibility));
+            AvaloniaProperty.Register<ScrollBar, ScrollBarVisibility>(nameof(Visibility), ScrollBarVisibility.Visible);
 
         /// <summary>
         /// Defines the <see cref="Orientation"/> property.

src/Avalonia.Controls/Primitives/TemplatedControl.cs

@@ -354,11 +354,14 @@ namespace Avalonia.Controls.Primitives
         {
             control.SetValue(TemplatedParentProperty, this);
 
-            foreach (var child in control.LogicalChildren)
+            var children = control.LogicalChildren;
+            var count = children.Count;
+
+            for (var i = 0; i < count; i++)
             {
-                if (child is IControl c)
+                if (children[i] is IControl child)
                 {
-                    ApplyTemplatedParent(c);
+                    ApplyTemplatedParent(child);
                 }
             }
         }

src/Avalonia.Controls/Slider.cs

@@ -3,6 +3,7 @@ using Avalonia.Collections;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Mixins;
 using Avalonia.Controls.Primitives;
+using Avalonia.Data;
 using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Layout;
@@ -94,6 +95,8 @@ namespace Avalonia.Controls
             Thumb.DragStartedEvent.AddClassHandler<Slider>((x, e) => x.OnThumbDragStarted(e), RoutingStrategies.Bubble);
             Thumb.DragCompletedEvent.AddClassHandler<Slider>((x, e) => x.OnThumbDragCompleted(e),
                 RoutingStrategies.Bubble);
+            
+            ValueProperty.OverrideMetadata<Slider>(new DirectPropertyMetadata<double>(enableDataValidation: true));
         }
 
         /// <summary>
@@ -225,6 +228,14 @@ namespace Avalonia.Controls
             Value = IsSnapToTickEnabled ? SnapToTick(finalValue) : finalValue;
         }
 
+        protected override void UpdateDataValidation<T>(AvaloniaProperty<T> property, BindingValue<T> value)
+        {
+            if (property == ValueProperty)
+            {
+                DataValidationErrors.SetError(this, value.Error);
+            }
+        }
+
         protected override void OnPropertyChanged<T>(AvaloniaPropertyChangedEventArgs<T> change)
         {
             base.OnPropertyChanged(change);

src/Avalonia.Controls/TextBox.cs

@@ -867,7 +867,10 @@ namespace Avalonia.Controls
             {
                 var point = e.GetPosition(_presenter);
 
-                point = new Point(MathUtilities.Clamp(point.X, 0, _presenter.Bounds.Width - 1), MathUtilities.Clamp(point.Y, 0, _presenter.Bounds.Height - 1));
+                point = new Point(
+                    MathUtilities.Clamp(point.X, 0, Math.Max(_presenter.Bounds.Width - 1, 0)),
+                    MathUtilities.Clamp(point.Y, 0, Math.Max(_presenter.Bounds.Height - 1, 0)));
+
                 CaretIndex = SelectionEnd = _presenter.GetCaretIndex(point);
             }
         }

src/Avalonia.Controls/Window.cs

@@ -129,6 +129,12 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<SystemDecorations> SystemDecorationsProperty =
             AvaloniaProperty.Register<Window, SystemDecorations>(nameof(SystemDecorations), SystemDecorations.Full);
 
+        /// <summary>
+        /// Defines the <see cref="ShowActivated"/> property.
+        /// </summary>
+        public static readonly StyledProperty<bool> ShowActivatedProperty =
+            AvaloniaProperty.Register<Window, bool>(nameof(ShowActivated), true);
+
         /// <summary>
         /// Enables or disables the taskbar icon
         /// </summary>
@@ -352,13 +358,21 @@ namespace Avalonia.Controls
         /// <summary>
         /// Sets the system decorations (title bar, border, etc)
         /// </summary>
-        /// 
         public SystemDecorations SystemDecorations
         {
             get { return GetValue(SystemDecorationsProperty); }
             set { SetValue(SystemDecorationsProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets a value that indicates whether a window is activated when first shown. 
+        /// </summary>
+        public bool ShowActivated
+        {
+            get { return GetValue(ShowActivatedProperty); }
+            set { SetValue(ShowActivatedProperty, value); }
+        }
+
         /// <summary>
         /// Enables or disables the taskbar icon
         /// </summary>
@@ -650,7 +664,7 @@ namespace Avalonia.Controls
                 Owner = parent;
                 parent?.AddChild(this, false);
 
-                PlatformImpl?.Show();
+                PlatformImpl?.Show(ShowActivated);
                 Renderer?.Start();
                 SetWindowStartupLocation(Owner?.PlatformImpl);
             }
@@ -720,7 +734,7 @@ namespace Avalonia.Controls
                 PlatformImpl?.SetParent(owner.PlatformImpl);
                 Owner = owner;
                 owner.AddChild(this, true);
-                PlatformImpl?.Show();
+                PlatformImpl?.Show(ShowActivated);
 
                 Renderer?.Start();
 

src/Avalonia.Controls/WindowBase.cs

@@ -162,7 +162,7 @@ namespace Avalonia.Controls
                     LayoutManager.ExecuteInitialLayoutPass();
                     _hasExecutedInitialLayoutPass = true;
                 }
-                PlatformImpl?.Show();
+                PlatformImpl?.Show(true);
                 Renderer?.Start();
                 OnOpened(EventArgs.Empty);
             }

src/Avalonia.DesignerSupport/Remote/PreviewerWindowImpl.cs

@@ -20,7 +20,7 @@ namespace Avalonia.DesignerSupport.Remote
             ClientSize = new Size(1, 1);
         }
 
-        public void Show()
+        public void Show(bool activate)
         {
         }
 

src/Avalonia.DesignerSupport/Remote/Stubs.cs

@@ -77,7 +77,7 @@ namespace Avalonia.DesignerSupport.Remote
         {
         }
 
-        public void Show()
+        public void Show(bool activate)
         {
         }