PintaProject · cameronwhite · Jul 22, 2025 · Jul 10, 2025 · Jul 10, 2025 · Jul 10, 2025
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -23,6 +23,7 @@ Thanks to the following contributors who worked on this release:
 - Added a right click menu for layers, containing actions that can be applied to the selected layer (#1588) 
 - The Dithering effect can now use Pinta's current palette in addition to the effect's preset color palettes (#1594)
 - Random seed values for effects can now be directly controlled, in addition to use the Reseed button (#1592, #1591)
+- Support for color picking in `SimpleEffectDialog`. Useful for add-in developers (#1611)
 
 ### Changed
 - Updated dependencies to require GTK 4.18+ and libadwaita 1.7+

diff --git a/Pinta.Gui.Widgets/Dialogs/SimpleEffectDialog.cs b/Pinta.Gui.Widgets/Dialogs/SimpleEffectDialog.cs
@@ -34,6 +34,7 @@
 using System.Linq;
 using System.Reflection;
 using System.Threading.Tasks;
+using Cairo;
 using Mono.Addins.Localization;
 using Pinta.Core;
 
@@ -242,6 +243,8 @@ static IEnumerable<char> GenerateCharacters (string name)
 			return CreatePointPicker;
 		else if (memberType == typeof (CenterOffset<double>))
 			return CreateOffsetPicker;
+		else if (memberType == typeof (Color))
+			return CreateCairoColorPicker;
 		else if (memberType.IsEnum)
 			return CreateEnumComboBox;
 		else
@@ -254,6 +257,64 @@ private delegate Gtk.Widget WidgetFactory (
 		MemberSettings settings,
 		IWorkspaceService workspace);
 
+	private Gtk.Widget CreateCairoColorPicker (
+		string caption,
+		EffectData effectData,
+		MemberSettings settings,
+		IWorkspaceService workspace)
+	{
+		Color currentColorCairo =
+			(settings.reflector.GetValue (effectData) is Color c)
+			? c
+			: Color.Black;
+
+		PintaColorButton colorButton = new () {
+			DisplayColor = currentColorCairo,
+			Hexpand = false,
+			Halign = Gtk.Align.Start,
+			WidthRequest = 80,
+		};
+
+		colorButton.OnClicked += async (_, _) => {
+
+			using ColorPickerDialog dialog = new (
+				this,
+				PintaCore.Palette,
+				new SingleColor (currentColorCairo),
+				primarySelected: true,
+				false,
+				Translations.GetString ("Choose Color"));
+
+			try {
+				Gtk.ResponseType response = await dialog.RunAsync ();
+
+				if (response != Gtk.ResponseType.Ok)
+					return;
+
+				var pick = (SingleColor) dialog.Colors;
+
+				Color newColorCairo = pick.Color;
+
+				colorButton.DisplayColor = newColorCairo;
+				currentColorCairo = newColorCairo;
+
+				SetAndNotify (settings.reflector, effectData, newColorCairo);
+			} finally {
+				dialog.Destroy ();
+			}
+		};
+
+		Gtk.Label label = Gtk.Label.New (caption);
+		label.Halign = Gtk.Align.Start;
+		label.AddCssClass (AdwaitaStyles.Title4);
+
+		Gtk.Box combinedWidget = Gtk.Box.New (Gtk.Orientation.Vertical, 6);
+		combinedWidget.Append (label);
+		combinedWidget.Append (colorButton);
+
+		return combinedWidget;
+	}
+
 	private ComboBoxWidget CreateEnumComboBox (
 		string caption,
 		EffectData effectData,

diff --git a/Pinta.Gui.Widgets/Widgets/PintaColorButton.cs b/Pinta.Gui.Widgets/Widgets/PintaColorButton.cs
@@ -0,0 +1,48 @@
+using Cairo;
+using Pinta.Core;
+
+namespace Pinta.Gui.Widgets;
+
+internal sealed class PintaColorButton : Gtk.Button
+{
+	private Color display_color = Color.Black;
+	public Color DisplayColor {
+		get => display_color;
+		set {
+			if (display_color == value) return;
+			display_color = value;
+			color_drawing_area.QueueDraw ();
+		}
+	}
+
+	private readonly Gtk.DrawingArea color_drawing_area;
+	internal PintaColorButton ()
+	{
+		Gtk.DrawingArea colorDrawingArea = new () {
+			Hexpand = true,
+			Vexpand = true,
+		};
+		colorDrawingArea.SetDrawFunc (OnDraw);
+		SetChild (colorDrawingArea);
+		color_drawing_area = colorDrawingArea;
+	}
+
+	private void OnDraw (
+		Gtk.DrawingArea drawingArea,
+		Context cr,
+		int width,
+		int height)
+	{
+		const int TILE_SIZE = 16;
+
+		using Pattern checkeredPattern =
+			CairoExtensions.CreateTransparentBackgroundPattern (TILE_SIZE);
+
+		cr.SetSource (checkeredPattern);
+		cr.Paint ();
+
+		cr.SetSourceColor (display_color);
+		cr.Rectangle (0, 0, width, height);
+		cr.Fill ();
+	}
+}