PintaProject · cameronwhite · Sep 10, 2025 · Sep 5, 2025 · Sep 5, 2025 · Sep 5, 2025
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -27,14 +27,15 @@ Thanks to the following contributors who worked on this release:
 - Support for color picking in `SimpleEffectDialog`. Useful for add-in developers (#1611)
 - The text tool now supports using Ctrl+Backspace to delete words (#1680)
 - Added a Windows ARM64 installer (#1699, #1378)
+- The selection of an area on the canvas is now being projected and highlighted on the rulers (#1723)
 
 ### Changed
 - Packaging changes
   - Updated dependencies to require GTK 4.18+ and libadwaita 1.7+
   - Pinta now consistently uses an application ID of `com.github.PintaProject.Pinta`, which previously had been applied in patches for downstream packages (#1706, #1419)
 - Breaking API changes for add-ins will require add-ins to be rebuilt against Pinta 3.1
-  - Attributes used for effect configuration properties (`CaptionAttribute`, `MaximumValueAttribute`, ...) are now in the `Pinta.Core` assembly and the `Pinta.Core` namespace
-  - Methods `RegisterEffect`, `UnregisterInstanceOfEffect`, `RegisterAdjustment`, and `UnregisterInstanceOfAdjustment` in `EffectsManager` are now generic
+  - Attributes used for effect configuration properties (`CaptionAttribute`, `MaximumValueAttribute`, ...) are now in the `Pinta.Core` assembly and the `Pinta.Core` namespace (#1665)
+  - Methods `RegisterEffect`, `UnregisterInstanceOfEffect`, `RegisterAdjustment`, and `UnregisterInstanceOfAdjustment` in `EffectsManager` are now generic (#1678)
 - Removed use of deprecated Gtk.FontButton (#1421)
 - View menu moved from hamburger menu to dedicated button (#1428, #1471)
 - Updated the application icon on macOS to better match the platform's icon style guidelines (#1572)

diff --git a/Pinta.Gui.Widgets/Widgets/Canvas/CanvasWindow.cs b/Pinta.Gui.Widgets/Widgets/Canvas/CanvasWindow.cs
@@ -146,6 +146,20 @@ public CanvasWindow (
 		// Also update if the view size changed without affecting the size of
 		// the canvas widget (e.g. when zoomed out and no scrollbars are required)
 		document.Workspace.ViewSizeChanged += UpdateRulerRange;
+		document.SelectionChanged += UpdateRulerSelection;
+	}
+
+	private void UpdateRulerSelection (object? sender, EventArgs e)
+	{
+		if (document.Selection.Visible) {
+			RectangleD bounds = document.Selection.GetBounds ();
+			horizontal_ruler.SetSelectionRange (bounds.Left, bounds.Left + bounds.Width);
+			vertical_ruler.SetSelectionRange (bounds.Top, bounds.Top + bounds.Height);
+		} else {
+			// If there's no selection, clear the highlight
+			horizontal_ruler.SetSelectionRange (null, null);
+			vertical_ruler.SetSelectionRange (null, null);
+		}
 	}
 
 	private void HandleMotion (

diff --git a/Pinta.Gui.Widgets/Widgets/Ruler.cs b/Pinta.Gui.Widgets/Widgets/Ruler.cs
@@ -27,6 +27,7 @@
 using System;
 using System.Collections.Immutable;
 using System.Diagnostics;
+using System.Runtime.CompilerServices;
 using Cairo;
 using Pinta.Core;
 
@@ -51,6 +52,20 @@ public sealed class Ruler : Gtk.DrawingArea
 	private Surface? cached_surface = null;
 	private Size? last_known_size = null;
 
+	private double? selection_start = null;
+	private double? selection_end = null;
+
+	public void SetSelectionRange (double? start, double? end)
+	{
+		if (selection_start == start && selection_end == end)
+			return;
+
+		selection_start = start;
+		selection_end = end;
+
+		QueueDraw ();
+	}
+
 	/// <summary>
 	/// Whether the ruler is horizontal or vertical.
 	/// </summary>
@@ -162,15 +177,15 @@ private readonly record struct RulerDrawSettings (
 		int Start,
 		int End,
 		double MarkerPosition,
-		RectangleD RulerBottomLine,
+		RectangleD RulerOuterLine,
 		Size EffectiveSize,
 		Color Color,
 		Gtk.Orientation Orientation);
 	private RulerDrawSettings CreateSettings (Size preliminarySize)
 	{
 		GetStyleContext ().GetColor (out Color color);
 
-		RectangleD rulerBottomLine = Orientation switch {
+		RectangleD rulerOuterLine = Orientation switch {
 
 			Gtk.Orientation.Vertical => new (
 				X: preliminarySize.Width - 1,
@@ -256,8 +271,8 @@ private RulerDrawSettings CreateSettings (Size preliminarySize)
 			UnitsPerTick: unitsPerTick,
 			Start: (int) Math.Floor (scaledLower * ticksPerUnit),
 			End: (int) Math.Ceiling (scaledUpper * ticksPerUnit),
-			MarkerPosition: (Position - Lower) * (effectiveSize.Width / (Upper - Lower)),
-			RulerBottomLine: rulerBottomLine,
+			MarkerPosition: GetPositionOnRuler (Position, effectiveSize.Width),
+			RulerOuterLine: rulerOuterLine,
 			EffectiveSize: effectiveSize,
 			Color: color,
 			Orientation: Orientation);
@@ -274,6 +289,31 @@ private void Draw (Context cr, Size preliminarySize)
 
 		cached_surface ??= CreateBaseRuler (settings, preliminarySize);
 
+		// Draw the selection projection if a selection exists
+		if (selection_start.HasValue && selection_end.HasValue) {
+
+			// Convert selection coordinates to ruler widget coordinates
+			double p1 = GetPositionOnRuler (selection_start.Value, settings.EffectiveSize.Width);
+			double p2 = GetPositionOnRuler (selection_end.Value, settings.EffectiveSize.Width);
+
+			cr.SetSourceRgba ( // Semi-transparent blue
+				red: 0.21,
+				green: 0.52,
+				blue: 0.89,
+				alpha: 0.25);
+
+			switch (Orientation) {
+				case Gtk.Orientation.Horizontal:
+					cr.Rectangle (p1, 0, p2 - p1, settings.EffectiveSize.Height);
+					break;
+				default:
+					cr.Rectangle (0, p1, settings.EffectiveSize.Height, p2 - p1);
+					break;
+			}
+
+			cr.Fill ();
+		}
+
 		cr.SetSourceSurface (cached_surface, 0, 0);
 		cr.Paint ();
 
@@ -306,7 +346,7 @@ private ImageSurface CreateBaseRuler (in RulerDrawSettings settings, Size prelim
 
 		drawingContext.SetSourceColor (settings.Color);
 		drawingContext.LineWidth = 1.0;
-		drawingContext.Rectangle (settings.RulerBottomLine);
+		drawingContext.Rectangle (settings.RulerOuterLine);
 		drawingContext.Fill ();
 
 		for (int i = settings.Start; i <= settings.End; ++i) {
@@ -355,6 +395,15 @@ private ImageSurface CreateBaseRuler (in RulerDrawSettings settings, Size prelim
 		return result;
 	}
 
+	[MethodImpl (MethodImplOptions.AggressiveInlining)]
+	private double GetPositionOnRuler (double position, double width)
+	{
+		double range = Upper - Lower;
+		double scaledWidth = width / range;
+		double positionFromLower = position - Lower;
+		return positionFromLower * scaledWidth;
+	}
+
 	private static int GetFontSize (Pango.FontDescription font, int scaleFactor)
 	{
 		int fontSize = PangoExtensions.UnitsToPixels (font.GetSize ());