Added background color for designer

Fixed #183

src/Windows/Perspex.Designer/AppHost/HostedAppModel.cs

@@ -5,6 +5,7 @@ using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Text;
 using System.Threading.Tasks;
+using System.Windows.Media;
 using JetBrains.Annotations;
 
 namespace Perspex.Designer.AppHost
@@ -19,6 +20,7 @@ namespace Perspex.Designer.AppHost
         internal HostedAppModel(PerspexAppHost host)
         {
             _host = host;
+            Background = Settings.Background;
         }
 
         public IntPtr NativeWindowHandle
@@ -54,6 +56,17 @@ namespace Perspex.Designer.AppHost
             }
         }
 
+        public string Background
+        {
+            get { return _background; }
+            set
+            {
+                if (value == _background) return;
+                _background = value;
+                OnPropertyChanged();
+            }
+        }
+
         public IReadOnlyList<double> AvailableScalingFactors => new List<double>() {1, 2, 4, 8};
 
         public double CurrentScalingFactor
@@ -73,6 +86,8 @@ namespace Perspex.Designer.AppHost
         }
 
         double _currentScalingFactor = 1;
+        private string _color;
+        private string _background;
 
         public event PropertyChangedEventHandler PropertyChanged;
 

src/Windows/Perspex.Designer/AppHost/WindowHost.cs

@@ -20,7 +20,19 @@ namespace Perspex.Designer.AppHost
             Text = "ScrollableArea";
             Controls.Add(_windowHost);
             _windowHost.Anchor = AnchorStyles.None;
-            _timer.Tick += delegate { FixWindow(); };
+            _timer.Tick += delegate
+            {
+                ReloadSettings();
+                FixWindow();
+            };
+        }
+
+        private void ReloadSettings()
+        {
+            var bkg = Settings.Background;
+            var color = System.Drawing.ColorTranslator.FromHtml(bkg);
+            if (BackColor != color)
+                BackColor = color;
         }
 
         private Control _windowHost = new Control() {Text = "WindowWrapper"};
@@ -43,6 +55,12 @@ namespace Perspex.Designer.AppHost
             base.WndProc(ref m);
         }
 
+        protected override void OnPaint(PaintEventArgs e)
+        {
+            using (var b = new SolidBrush(BackColor))
+                e.Graphics.FillRectangle(b, e.ClipRectangle);
+        }
+
         void FixPosition()
         {
             var newScrollSize =  new Size(_desiredWidth, _desiredHeight);

src/Windows/Perspex.Designer/InProcDesigner/InProcDesignerView.xaml

@@ -16,6 +16,10 @@
                     </DataTemplate>
                 </ComboBox.ItemTemplate>
             </ComboBox>
+
+            <Rectangle Cursor="Hand" Stroke="Black" Width="{Binding RelativeSource={RelativeSource Self}, Path=ActualHeight}" Fill="{Binding Background}" 
+                       Margin="3" MouseDown="ColorPicker_OnClick"/>
+
             <Border x:Name="ErrorPanel" BorderBrush="Red" BorderThickness="3" Padding="3">
                 <StackPanel   Orientation="Horizontal">
                     <TextBlock Text="{Binding Error}" FontSize="16"/>

src/Windows/Perspex.Designer/InProcDesigner/InProcDesignerView.xaml.cs

@@ -1,18 +1,21 @@
 using System;
 using System.Collections.Generic;
+using System.Drawing;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using System.Windows;
-using System.Windows.Controls;
 using System.Windows.Data;
 using System.Windows.Documents;
+using System.Windows.Forms;
 using System.Windows.Input;
 using System.Windows.Media;
 using System.Windows.Media.Imaging;
 using System.Windows.Navigation;
 using System.Windows.Shapes;
 using Perspex.Designer.AppHost;
+using TextBox = System.Windows.Controls.TextBox;
+using UserControl = System.Windows.Controls.UserControl;
 
 namespace Perspex.Designer.InProcDesigner
 {
@@ -80,5 +83,16 @@ namespace Perspex.Designer.InProcDesigner
             };
             wnd.ShowDialog();
         }
+
+        private void ColorPicker_OnClick(object sender, MouseButtonEventArgs e)
+        {
+            var dlg = new ColorDialog() {Color = ColorTranslator.FromHtml(Settings.Background)};
+            if (dlg.ShowDialog(_host) == DialogResult.OK)
+            {
+                var color = ColorTranslator.ToHtml(dlg.Color);
+                _appModel.Background = color;
+                Settings.Background = color;
+            }
+        }
     }
 }

src/Windows/Perspex.Designer/Perspex.Designer.csproj

@@ -97,6 +97,7 @@
     </Compile>
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="Settings.cs" />
     <Compile Include="WinApi.cs" />
   </ItemGroup>
   <ItemGroup>

src/Windows/Perspex.Designer/Settings.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.Win32;
+
+namespace Perspex.Designer
+{
+    static class Settings
+    {
+        static readonly string Root = @"HKEY_CURRENT_USER\Software\PerspexUI\Designer";
+        public static string Background
+        {
+            get { return Registry.GetValue(Root, "Background", "#f3f3f3")?.ToString() ?? "#f3f3f3"; }
+            set { Registry.SetValue(Root, "Background", value); }
+        }
+    }
+}