Fixing PushOpacity for Cairo and landing TabStyle changes for Gallery

samples/TestApplication/App.cs

@@ -12,8 +12,9 @@ namespace TestApplication
         public App()
         {
             RegisterServices();
-            InitializeSubsystems((int)Environment.OSVersion.Platform);
+            InitializeSubsystems((int)Environment.OSVersion.Platform);            
             Styles = new DefaultTheme();
+            Styles.Add(new SampleTabStyle());
         }
     }
 }

samples/TestApplication/GalleryStyle.cs

@@ -0,0 +1,120 @@
+using Perspex;
+using Perspex.Controls;
+using Perspex.Controls.Presenters;
+using Perspex.Controls.Primitives;
+using Perspex.Controls.Templates;
+using Perspex.Media;
+using Perspex.Styling;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace TestApplication
+{
+    internal class SampleTabStyle : Styles
+    {
+        public SampleTabStyle()
+        {
+            this.AddRange(new[]
+            {
+                new Style (s => s.Class(":container").OfType<TabControl> ())
+                {
+                    Setters = new[]
+                    {
+                        new Setter (TemplatedControl.TemplateProperty, new ControlTemplate<TabControl> (TabControlTemplate))
+                    }
+                },
+
+                new Style(s => s.Class(":container").OfType<TabControl>().Child().Child().Child().Child().OfType<TabItem>())
+                {
+                    Setters = new[]
+                    {
+                        new Setter (TemplatedControl.TemplateProperty, new ControlTemplate<TabItem> (TabItemTemplate)),
+                    }
+                },
+
+                new Style(s => s.Class(":container").Child().Child().Child().Child().OfType<TabItem>())
+                {
+                    Setters = new[]
+                    {
+                        new Setter(TemplatedControl.FontSizeProperty, 14.0),
+                        new Setter(TemplatedControl.ForegroundProperty, Brushes.White)
+                    }
+                },
+
+                new Style(s => s.Class(":container").Child().Child().Child().Child().OfType<TabItem>().Class("selected"))
+                {
+                    Setters = new[]
+                    {
+                        new Setter(TemplatedControl.ForegroundProperty, Brushes.White),
+                        new Setter(TemplatedControl.BackgroundProperty, new SolidColorBrush(Colors.White) { Opacity = 0.1 }),
+                    },
+                },
+            });
+        }
+
+        public static Control TabItemTemplate(TabItem control)
+        {
+            return new ContentPresenter
+            {
+                DataTemplates = new DataTemplates
+                {
+                    new DataTemplate<string>(x => new Border
+                    {
+                        [~Border.BackgroundProperty] = control[~TemplatedControl.BackgroundProperty],
+                        Padding = new Thickness(10),
+                        Child = new TextBlock
+                        {
+                            VerticalAlignment = Perspex.Layout.VerticalAlignment.Center,
+                            Text = x
+                        }
+                    })
+                },
+                Name = "headerPresenter",
+                [~ContentPresenter.ContentProperty] = control[~HeaderedContentControl.HeaderProperty],
+            };
+        }
+
+        public static Control TabControlTemplate(TabControl control)
+        {
+            return new Grid
+            {
+                ColumnDefinitions = new ColumnDefinitions
+                {
+                    new ColumnDefinition(GridLength.Auto),
+                    new ColumnDefinition(new GridLength(1, GridUnitType.Star)),
+                },
+                Children = new Controls
+                {
+                    new Border
+                    {
+                        Width = 170,
+                        Background = SolidColorBrush.Parse("#373749"),
+                        Child = new TabStrip
+                        {
+                            ItemsPanel = new FuncTemplate<IPanel>(() => new StackPanel { Orientation = Orientation.Vertical, Gap = 4 }),
+                            Margin = new Thickness(0, 10, 0, 0),
+                            Name = "containerTabStrip",
+                            [!ItemsControl.ItemsProperty] = control[!ItemsControl.ItemsProperty],
+                            [!!SelectingItemsControl.SelectedItemProperty] = control[!!SelectingItemsControl.SelectedItemProperty],
+                        }
+                    },
+                    new Deck
+                    {
+                        Name = "deck",
+                        DataTemplates = new DataTemplates
+                        {
+                            new DataTemplate<TabItem>(x => (Control)control.MaterializeDataTemplate(x.Content)),
+                        },
+                        [~Deck.TransitionProperty] = control[~TabControl.TransitionProperty],
+                        [!ItemsControl.ItemsProperty] = control[!ItemsControl.ItemsProperty],
+                        [!SelectingItemsControl.SelectedItemProperty] = control[!SelectingItemsControl.SelectedItemProperty],
+                        [Grid.ColumnProperty] = 1,
+                    }
+                }
+            };
+        }
+    }
+}

samples/TestApplication/TestApplication.csproj

@@ -72,6 +72,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="App.cs" />
+    <Compile Include="GalleryStyle.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
@@ -80,6 +81,10 @@
     <None Include="packages.config" />
   </ItemGroup>
   <ItemGroup>
+    <ProjectReference Include="..\..\src\Gtk\Perspex.Cairo\Perspex.Cairo.csproj">
+      <Project>{fb05ac90-89ba-4f2f-a924-f37875fb547c}</Project>
+      <Name>Perspex.Cairo</Name>
+    </ProjectReference>
     <ProjectReference Include="..\..\src\Perspex.Animation\Perspex.Animation.csproj">
       <Project>{D211E587-D8BC-45B9-95A4-F297C8FA5200}</Project>
       <Name>Perspex.Animation</Name>

src/Gtk/Perspex.Cairo/Media/DrawingContext.cs

@@ -203,11 +203,14 @@ namespace Perspex.Cairo.Media
         /// <returns>A disposable used to undo the opacity.</returns>
         public IDisposable PushOpacity(double opacity)
         {
-            opacityOverride = opacity;
+            var tmp = opacityOverride;
+
+            if (opacity < 1.0f)
+                opacityOverride = opacity;
 
             return Disposable.Create(() =>
             {
-                opacityOverride = 1.0f;
+                opacityOverride = tmp;
             });
         }
 
@@ -254,7 +257,7 @@ namespace Perspex.Cairo.Media
 			} 
 			else 
 			{
-				impl = new SolidColorBrushImpl(null, 1.0f);
+				impl = new SolidColorBrushImpl(null, opacityOverride);
 			}
 
 			_context.SetSource(impl.PlatformBrush);

src/Gtk/Perspex.Cairo/Media/SolidColorBrushImpl.cs

@@ -9,11 +9,13 @@ namespace Perspex.Cairo
 		{
 			var color = brush?.Color.ToCairo() ?? new Color();
 
-			if (brush != null && brush.Opacity > 1)
+            if (brush != null)
 				color.A = Math.Min(brush.Opacity, color.A);
 			
-			color.A = Math.Min(opacityOverride, color.A);
-			this.PlatformBrush = new SolidPattern(brush?.Color.ToCairo() ?? new Color());
+            if (opacityOverride < 1.0f)
+			    color.A = Math.Min(opacityOverride, color.A);
+
+			this.PlatformBrush = new SolidPattern(color);
 		}
 	}
 }