Various fixes

src/Gtk/Avalonia.Gtk3/Gtk3Platform.cs

@@ -36,7 +36,7 @@ namespace Avalonia.Gtk3
                 .Bind<IMouseDevice>().ToConstant(Mouse)
                 .Bind<IPlatformSettings>().ToConstant(Instance)
                 .Bind<IPlatformThreadingInterface>().ToConstant(Instance)
-                .Bind<ISystemDialogImpl>().ToSingleton<SystemDialogStub>()
+                .Bind<ISystemDialogImpl>().ToSingleton<SystemDialog>()
                 .Bind<IRenderLoop>().ToConstant(new DefaultRenderLoop(60))
                 .Bind<IPlatformIconLoader>().ToConstant(new PlatformIconLoader());
 

src/Gtk/Avalonia.Gtk3/Interop/Native.cs

@@ -168,6 +168,9 @@ namespace Avalonia.Gtk3.Interop
             [UnmanagedFunctionPointer(CallingConvention.Cdecl), GtkImport(GtkDll.Gdk)]
             public delegate void gdk_window_begin_resize_drag(IntPtr window, WindowEdge edge, gint button, gint root_x, gint root_y, guint32 timestamp);
 
+            [UnmanagedFunctionPointer(CallingConvention.Cdecl), GtkImport(GtkDll.Gdk)]
+            public delegate void gdk_event_request_motions(IntPtr ev);
+
             [UnmanagedFunctionPointer(CallingConvention.Cdecl), GtkImport(GtkDll.Gtk)]
             public delegate IntPtr gtk_clipboard_get_for_display(IntPtr display, IntPtr atom);
 
@@ -299,6 +302,7 @@ namespace Avalonia.Gtk3.Interop
         public static D.gdk_window_get_pointer GdkWindowGetPointer;
         public static D.gdk_window_begin_move_drag GdkWindowBeginMoveDrag;
         public static D.gdk_window_begin_resize_drag GdkWindowBeginResizeDrag;
+        public static D.gdk_event_request_motions GdkEventRequestMotions;
 
         public static D.gdk_pixbuf_new_from_file GdkPixbufNewFromFile;
         public static D.gtk_icon_theme_get_default GtkIconThemeGetDefault;

src/Gtk/Avalonia.Gtk3/PopupImpl.cs

@@ -37,7 +37,9 @@ namespace Avalonia.Gtk3
                     return;
                 Native.GtkWindowSetDefaultSize(GtkWidget, (int)value.Width, (int)value.Height);
                 base.ClientSize = value;
-                var size = ClientSize;
+                if (Native.GtkWidgetGetWindow(GtkWidget) == IntPtr.Zero)
+                    Native.GtkWidgetRealize(GtkWidget);
+                Native.GdkWindowResize(Native.GtkWidgetGetWindow(GtkWidget), (int)value.Width, (int)value.Height);
             }
         }
     }

src/Gtk/Avalonia.Gtk3/SystemDialogs.cs

@@ -9,11 +9,9 @@ using Avalonia.Gtk3.Interop;
 using Avalonia.Input.Platform;
 using Avalonia.Platform;
 
-//TODO: This file should be empty once everything is implemented
-
 namespace Avalonia.Gtk3
 {
-    class SystemDialogStub : ISystemDialogImpl
+    class SystemDialog : ISystemDialogImpl
     {
 
         unsafe static Task<string[]> ShowDialog(string title, GtkWindow parent, GtkFileChooserAction action,

src/Gtk/Avalonia.Gtk3/TopLevelImpl.cs

@@ -31,7 +31,7 @@ namespace Avalonia.Gtk3
             _framebuffer = new FramebufferManager(this);
             _imContext = Native.GtkImMulticontextNew();
             Disposables.Add(_imContext);
-            Native.GtkWidgetSetEvents(gtkWidget, uint.MaxValue);
+            Native.GtkWidgetSetEvents(gtkWidget, 0xFFFFFE);
             Disposables.Add(Signal.Connect<Native.D.signal_commit>(_imContext, "commit", OnCommit));
             Connect<Native.D.signal_widget_draw>("draw", OnDraw);
             Connect<Native.D.signal_generic>("realize", OnRealized);
@@ -111,7 +111,7 @@ namespace Avalonia.Gtk3
                         : evnt->button == 3 ? RawMouseEventType.RightButtonDown : RawMouseEventType.MiddleButtonDown,
                 new Point(evnt->x, evnt->y), GetModifierKeys(evnt->state));
             Input?.Invoke(e);
-            return false;
+            return true;
         }
 
         private unsafe bool OnStateChanged(IntPtr w, IntPtr pev, IntPtr userData)
@@ -131,8 +131,7 @@ namespace Avalonia.Gtk3
         {
             var evnt = (GdkEventMotion*)ev;
             var position = new Point(evnt->x, evnt->y);
-            
-
+            Native.GdkEventRequestMotions(ev);
             var e = new RawMouseEventArgs(
                 Gtk3Platform.Mouse,
                 evnt->time,
@@ -140,7 +139,8 @@ namespace Avalonia.Gtk3
                 RawMouseEventType.Move,
                 position, GetModifierKeys(evnt->state));
             Input(e);
-            return false;
+            
+            return true;
         }
         private unsafe bool OnScroll(IntPtr w, IntPtr ev, IntPtr userdata)
         {
@@ -156,12 +156,13 @@ namespace Avalonia.Gtk3
             else if (evnt->direction == GdkScrollDirection.Left)
                 delta = new Vector(step, 0);
             else if (evnt->direction == GdkScrollDirection.Smooth)
-                delta = new Vector(evnt->delta_x, evnt->delta_y);
-
+            {
+                delta = new Vector(-evnt->delta_x, -evnt->delta_y);
+            }
             var e = new RawMouseWheelEventArgs(Gtk3Platform.Mouse, evnt->time, _inputRoot,
                 new Point(evnt->x, evnt->y), delta, GetModifierKeys(evnt->state));
             Input(e);
-            return false;
+            return true;
         }
 
         private unsafe bool OnKeyEvent(IntPtr w, IntPtr pev, IntPtr userData)
@@ -303,9 +304,6 @@ namespace Avalonia.Gtk3
                 if (GtkWidget.IsClosed)
                     return;
                 Native.GtkWindowResize(GtkWidget, (int)value.Width, (int)value.Height);
-                if (Native.GtkWidgetGetWindow(GtkWidget) == IntPtr.Zero)
-                    Native.GtkWidgetRealize(GtkWidget);
-                Native.GdkWindowResize(Native.GtkWidgetGetWindow(GtkWidget), (int)value.Width, (int)value.Height);
             }
         }