[Win] Eyedropperermau-windows-eyedropper

Still needs icon/cursor.

6 files changed, 212 insertions, 2 deletions

diff --git a/Xamarin.PropertyEditing.Windows/Eyedropper.cs b/Xamarin.PropertyEditing.Windows/Eyedropper.cs
new file mode 100644
index 0000000..9e1a83e
--- /dev/null
+++ b/Xamarin.PropertyEditing.Windows/Eyedropper.cs
@@ -0,0 +1,151 @@
+using System;
+using System.ComponentModel;
+using System.Runtime.InteropServices;
+using System.Threading;
+
+using Xamarin.PropertyEditing.Drawing;
+
+namespace Xamarin.PropertyEditing.Windows
+{
+	internal class ColorEventArgs
+		: EventArgs
+	{
+		public ColorEventArgs (CommonColor color)
+		{
+			Color = color;
+		}
+
+		public CommonColor Color
+		{
+			get;
+		}
+	}
+
+	internal class ColorComittedEventArgs
+		: ColorEventArgs
+	{
+		public ColorComittedEventArgs (CommonColor color)
+			: base (color)
+		{
+		}
+
+		public ColorComittedEventArgs (Exception exception)
+			: base (default(CommonColor))
+		{
+			Exception = exception;
+		}
+
+		public Exception Exception
+		{
+			get;
+		}
+	}
+
+	internal class Eyedropper
+		: IDisposable
+	{
+		public Eyedropper ()
+		{
+			this.dc = GetDC (IntPtr.Zero);
+			this.updaterThread = new Thread (Updater);
+			this.updaterThread.Start ();
+		}
+
+		public event EventHandler<ColorEventArgs> ColorChanged;
+		public event EventHandler<ColorComittedEventArgs> ColorComitted;
+
+		public void Dispose ()
+		{
+			Dispose (true);
+			GC.SuppressFinalize (this);
+		}
+
+		~Eyedropper ()
+		{
+			Dispose (false);
+		}
+
+		protected virtual void Dispose (bool disposing)
+		{
+			if (!this.running)
+				return;
+
+			this.running = false;
+			this.updaterThread.Join ();
+			ReleaseDC (IntPtr.Zero, this.dc);
+		}
+
+		private readonly IntPtr dc;
+		private volatile bool running = true;
+		private readonly Thread updaterThread;
+		private readonly SynchronizationContext context = SynchronizationContext.Current;
+
+		private void Updater ()
+		{
+			// AFAICT it's this or global hooks. Global hooks are bad.
+			int pixel = 0;
+			while (this.running) {
+				if (!this.running)
+					return;
+
+				if (!GetCursorPos (out POINT point)) {
+					Finish (new ColorComittedEventArgs (new Win32Exception ()));
+					return;
+				}
+
+				short keyState = GetKeyState (VK_LBUTTON);
+				int newPixel = GetPixel (this.dc, point.x, point.y);
+				if (keyState > 0) {
+					Finish (new ColorComittedEventArgs (GetColor (newPixel)));
+					return;
+				}
+
+				if (pixel != newPixel)
+					Update (new ColorEventArgs (GetColor (newPixel)));
+
+				pixel = newPixel;
+				Thread.Sleep (0);
+			}
+		}
+
+		private CommonColor GetColor (int pixel)
+		{
+			return new CommonColor ((byte)(pixel & 0x000000ff), (byte)((pixel & 0x0000ff00) >> 0x8), (byte)((pixel & 0x00ff0000) >> 0x10));
+		}
+
+		private void Update (ColorEventArgs args)
+		{
+			this.context.Post (s => { ColorChanged?.Invoke (this, (ColorEventArgs) s); }, args);
+		}
+
+		private void Finish (ColorComittedEventArgs args)
+		{
+			this.context.Post (s => {
+				ColorComitted?.Invoke (this, (ColorComittedEventArgs)s);
+			}, args);
+		}
+
+		private struct POINT
+		{
+			public int x;
+			public int y;
+		}
+
+		private const short VK_LBUTTON = 0x01;
+
+		[DllImport ("Gdi32.dll")]
+		private static extern int GetPixel (IntPtr hdc, int x, int y);
+
+		[DllImport ("User32.dll")]
+		private static extern short GetKeyState (short vkey);
+
+		[DllImport ("User32.dll")]
+		private static extern bool GetCursorPos (out POINT point);
+
+		[DllImport ("User32.dll")]
+		private static extern IntPtr GetDC (IntPtr hwnd);
+
+		[DllImport ("User32.dll")]
+		private static extern int ReleaseDC (IntPtr hwnd, IntPtr dc);
+	}
+}
diff --git a/Xamarin.PropertyEditing.Windows/SolidBrushEditorControl.cs b/Xamarin.PropertyEditing.Windows/SolidBrushEditorControl.cs
index 3cee572..1954e27 100644
--- a/Xamarin.PropertyEditing.Windows/SolidBrushEditorControl.cs
+++ b/Xamarin.PropertyEditing.Windows/SolidBrushEditorControl.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Windows;
 using System.Windows.Controls;
+using System.Windows.Controls.Primitives;
 using Xamarin.PropertyEditing.Drawing;
 using Xamarin.PropertyEditing.ViewModels;
 
@@ -22,6 +23,10 @@ namespace Xamarin.PropertyEditing.Windows
 			if (this.colorSpacePicker == null)
 				throw new InvalidOperationException ($"{nameof (SolidBrushEditorControl)} is missing a child ComboBox named \"colorSpacePicker\"");
 
+			this.eyedropperButton = GetTemplateChild ("eyedropper") as ToggleButton;
+			if (this.eyedropperButton != null)
+				this.eyedropperButton.Checked += OnEyedropper;
+
 			// Handle color space changes
 			this.colorSpacePicker.SelectionChanged += (s, e) => {
 				if (ViewModel?.Value != null && ViewModel.Property.CanWrite) {
@@ -35,9 +40,28 @@ namespace Xamarin.PropertyEditing.Windows
 			AddHandler (CurrentColorCommitterControlBase.CommitHueEvent,
 				new RoutedEventHandler ((s, e) => ViewModel?.Solid.CommitHue ()));
 		}
-		
+
+		private ToggleButton eyedropperButton;
+		private Eyedropper eyedropper;
 		private ComboBox colorSpacePicker;
 
 		private BrushPropertyViewModel ViewModel => DataContext as BrushPropertyViewModel;
+
+		private void OnEyedropper (object sender, RoutedEventArgs e)
+		{
+			var eye = new Eyedropper ();
+			eye.ColorChanged += (o, args) => ViewModel.Solid.Color = args.Color;
+			eye.ColorComitted += (o, args) => {
+				if (args.Exception == null) {
+					ViewModel.Solid.Color = args.Color;
+					ViewModel.Solid.CommitLastColor ();
+				}
+
+				((Eyedropper)o).Dispose ();
+				this.eyedropperButton.IsChecked = false;
+			};
+
+			this.eyedropper = eye;
+		}
 	}
 }
diff --git a/Xamarin.PropertyEditing.Windows/Themes/Resources.xaml b/Xamarin.PropertyEditing.Windows/Themes/Resources.xaml
index e3bdad0..1ee71d1 100644
--- a/Xamarin.PropertyEditing.Windows/Themes/Resources.xaml
+++ b/Xamarin.PropertyEditing.Windows/Themes/Resources.xaml
@@ -740,6 +740,7 @@
 			</Setter.Value>
 		</Setter>
 	</Style>
+
 	<Style TargetType="local:SolidBrushEditorControl">
 		<Setter Property="Template">
 			<Setter.Value>
@@ -777,13 +778,15 @@
 									Margin="0,6,0,1" Panel.ZIndex="1"/>
 								<local:HueEditorControl
 									x:Name="hueChooser" HueColor="{Binding Path=Solid.HueColor, Mode=TwoWay}"
-									Grid.Column="1" Grid.ColumnSpan="1" Grid.Row="0" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Margin="1,6,3,1" Panel.ZIndex="0" Focusable="False"/>
+									Grid.Column="1" Grid.Row="0" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Margin="1,6,3,1" Panel.ZIndex="0" Focusable="False"/>
 								<local:CurrentColorEditorControl
 									Color="{Binding Path=Solid.Color, Mode=TwoWay}"
 									InitialColor="{Binding Solid.InitialColor}"
 									LastColor="{Binding Solid.LastColor}"
 									Grid.Column="0" Grid.Row="1" HorizontalAlignment="Stretch" Height="20"
 									Margin="0,0,0,0" Panel.ZIndex="0" Focusable="False"/>
+
+								<ToggleButton Grid.Column="1" Grid.Row="1" Name="eyedropper" Style="{DynamicResource ImageToggleButton}" Width="20" Height="20" />
 							</Grid>
 							<local:ColorComponentsEditorControl x:Name="componentEditor"
 								Color="{Binding Path=Solid.Color, Mode=TwoWay}"
@@ -1880,6 +1883,33 @@
 		</Setter>
 	</Style>
 
+	<Style x:Key="ImageToggleButton" TargetType="ToggleButton">
+		<Setter Property="Height" Value="16" />
+		<Setter Property="Width" Value="16"/>
+		<Setter Property="Background" Value="{DynamicResource IconButtonSimpleBackgroundBrush}" />
+		<Setter Property="Foreground" Value="{DynamicResource IconButtonForegroundBrush}" />
+		<Setter Property="BorderBrush" Value="Transparent" />
+		<Setter Property="Template">
+			<Setter.Value>
+				<ControlTemplate TargetType="ToggleButton">
+					<Border Name="border" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}">
+						<ContentPresenter />
+					</Border>
+					<ControlTemplate.Triggers>
+						<Trigger Property="IsMouseOver" Value="True">
+							<Setter TargetName="border" Property="Background" Value="{DynamicResource IconButtonMouseOverBackgroundBrush}" />
+							<Setter TargetName="border" Property="BorderBrush" Value="{DynamicResource IconButtonMouseOverBorderBrush}" />
+						</Trigger>
+						<Trigger Property="IsChecked" Value="True">
+							<Setter TargetName="border" Property="Background" Value="{DynamicResource IconButtonMouseOverBackgroundBrush}" />
+							<Setter TargetName="border" Property="BorderBrush" Value="{DynamicResource IconButtonMouseOverBorderBrush}" />
+						</Trigger>
+					</ControlTemplate.Triggers>
+				</ControlTemplate>
+			</Setter.Value>
+		</Setter>
+	</Style>
+
 	<Style x:Key="SearchButtonBase" TargetType="Button" BasedOn="{StaticResource IconButton}">
 		<Setter Property="Margin" Value="-1" />
 		<Setter Property="Template">
diff --git a/Xamarin.PropertyEditing.Windows/Themes/VS.Dark.xaml b/Xamarin.PropertyEditing.Windows/Themes/VS.Dark.xaml
index 880df43..1f8e5c7 100644
--- a/Xamarin.PropertyEditing.Windows/Themes/VS.Dark.xaml
+++ b/Xamarin.PropertyEditing.Windows/Themes/VS.Dark.xaml
@@ -94,6 +94,8 @@
 	<SolidColorBrush x:Key="IconButtonSimpleBorderBrush" Color="Transparent" />
 	<SolidColorBrush x:Key="IconButtonForegroundBrush">#FFF1F1F1</SolidColorBrush>
 	<SolidColorBrush x:Key="IconButtonMouseOverForegroundBrush">#FF007ACC</SolidColorBrush>
+	<SolidColorBrush x:Key="IconButtonMouseOverBackgroundBrush">#FF3E3E40</SolidColorBrush>
+	<SolidColorBrush x:Key="IconButtonMouseOverBorderBrush">#FF3E3E40</SolidColorBrush>
 	<SolidColorBrush x:Key="IconButtonPressedForegroundBrush">#FFFFFFFF</SolidColorBrush>
 
 	<SolidColorBrush x:Key="CategoryExpanderBorderBrush" Color="#333333" />
diff --git a/Xamarin.PropertyEditing.Windows/Themes/VS.Light.xaml b/Xamarin.PropertyEditing.Windows/Themes/VS.Light.xaml
index 3e8279a..f9163f9 100644
--- a/Xamarin.PropertyEditing.Windows/Themes/VS.Light.xaml
+++ b/Xamarin.PropertyEditing.Windows/Themes/VS.Light.xaml
@@ -94,6 +94,8 @@
 	<SolidColorBrush x:Key="IconButtonSimpleBorderBrush" Color="Transparent" />
 	<SolidColorBrush x:Key="IconButtonForegroundBrush">#FF1E1E1E</SolidColorBrush>
 	<SolidColorBrush x:Key="IconButtonMouseOverForegroundBrush">#FF1E1E1E</SolidColorBrush>
+	<SolidColorBrush x:Key="IconButtonMouseOverBackgroundBrush">#FFC9DEF5</SolidColorBrush>
+	<SolidColorBrush x:Key="IconButtonMouseOverBorderBrush">#FFC9DEF5</SolidColorBrush>
 	<SolidColorBrush x:Key="IconButtonPressedForegroundBrush">#FFFFFFFF</SolidColorBrush>
 
 	<SolidColorBrush x:Key="ComboBoxBackgroundBrush">#FFFFFFFF</SolidColorBrush>
diff --git a/Xamarin.PropertyEditing.Windows/Xamarin.PropertyEditing.Windows.csproj b/Xamarin.PropertyEditing.Windows/Xamarin.PropertyEditing.Windows.csproj
index 6fdaea3..bf9ec15 100644
--- a/Xamarin.PropertyEditing.Windows/Xamarin.PropertyEditing.Windows.csproj
+++ b/Xamarin.PropertyEditing.Windows/Xamarin.PropertyEditing.Windows.csproj
@@ -95,6 +95,7 @@
     <Compile Include="CurrentColorEditorControl.cs" />
     <Compile Include="DoubleToPercentageConverter.cs" />
     <Compile Include="DoubleToQuantityConverter.cs" />
+    <Compile Include="Eyedropper.cs" />
     <Compile Include="HasItemsToVisibilityConverter.cs" />
     <Compile Include="InvertedVisibilityConverter.cs" />
     <Compile Include="IPropertiesHost.cs" />