- further refactoring of how zoom and cursors work together

- fix bug in slash brush where the angle could be perceived as slightly off due to zero-area correction
- fix bug in cursor creation where at high zoom levels the slash brush cursor was no longer correctly drawn

Author: spaghetti22

Pinta.Core/Classes/BaseTool.cs

@@ -37,7 +37,7 @@ namespace Pinta.Core;
 public abstract class BaseTool
 {
 	private readonly IToolService tools;
-	private readonly IWorkspaceService workspace;
+	protected readonly IWorkspaceService workspace;
 
 	protected IResourceService Resources { get; }
 	protected ISettingsService Settings { get; }
@@ -55,11 +55,9 @@ protected BaseTool (IServiceProvider services)
 		CurrentCursor = DefaultCursor;
 
 		// Update cursor when active document changes
-		workspace.ActiveDocumentChanged += (_, _) => {
-			if (tools.CurrentTool == this)
-				SetCursor (CurrentCursor);
-		};
-
+		workspace.ActiveDocumentChanged += (_, _) => RefreshCursorIfActive ();
+		// Update cursor on zoom
+		workspace.ViewSizeChanged += (_, _) => RefreshCursorIfActive ();
 		// Give tools a chance to save their settings on application quit
 		Settings.SaveSettingsBeforeQuit += (_, _)
 			=> OnSaveSettings (Settings);
@@ -92,12 +90,6 @@ public virtual Cursor? DefaultCursor
 	/// </summary>
 	public Cursor? CurrentCursor { get; private set; }
 
-	/// <summary>
-	/// Specifies whether this application needs to update this tool's
-	/// cursor after a zoom operation.
-	/// </summary>
-	public virtual bool CursorChangesOnZoom
-		=> false;
 
 	/// <summary>
 	/// Specifies whether the tool manipulates selections.
@@ -170,14 +162,6 @@ public virtual bool UseAlphaBlending {
 		}
 	}
 
-	public virtual void OnCanvasZoom ()
-	{
-		if (CursorChangesOnZoom) {
-			//The current tool's cursor changes when the zoom changes.
-			SetCursor (DefaultCursor);
-		}
-	}
-
 	/// <summary>
 	/// Called when the tool is selected from the toolbox.
 	/// </summary>
@@ -335,6 +319,18 @@ public void SetCursor (Cursor? cursor)
 			workspace.ActiveWorkspace.Canvas.Cursor = cursor;
 	}
 
+	private void RefreshCursorIfActive ()
+	{
+		if (tools.CurrentTool == this) {
+			RefreshCursor ();
+		}
+	}
+
+	protected virtual void RefreshCursor ()
+	{
+		SetCursor (DefaultCursor);
+	}
+
 	#region Toolbar
 	private ToolBoxButton? tool_item;
 	private ToolBarDropDownButton? antialiasing_button;

Pinta.Core/Classes/Document.cs

@@ -80,7 +80,7 @@ public Document (
 		Selection = new DocumentSelection ();
 
 		Layers = new DocumentLayers (tools, this);
-		Workspace = new DocumentWorkspace (actions, tools, this);
+		Workspace = new DocumentWorkspace (actions, this);
 		IsDirty = false;
 		HasBeenSavedInSession = false;
 		ImageSize = size;

Pinta.Core/Classes/DocumentWorkspace.cs

@@ -33,7 +33,6 @@ public sealed class DocumentWorkspace
 	private readonly Document document;
 
 	private readonly ActionManager actions;
-	private readonly ToolManager tools;
 
 	private enum ZoomType
 	{
@@ -44,11 +43,9 @@ private enum ZoomType
 
 	internal DocumentWorkspace (
 		ActionManager actions,
-		ToolManager tools,
 		Document document)
 	{
 		this.actions = actions;
-		this.tools = tools;
 
 		this.document = document;
 
@@ -116,7 +113,6 @@ public double Scale {
 			ViewSize = GetNewViewSize (document.ImageSize, value);
 
 			Invalidate ();
-			tools.CurrentTool?.OnCanvasZoom ();
 		}
 	}
 

Pinta.Core/Extensions/GdkExtensions.cs

@@ -130,8 +130,8 @@ public static Gdk.Texture CreateIconWithShape (
 		RectangleI initialShapeBBox = new (
 			imgToShapeX - Math.Max (halfOfShapeWidth, halfOfShapeHeight),
 			imgToShapeY - Math.Max (halfOfShapeWidth, halfOfShapeHeight),
-			clampedWidth,
-			clampedHeight);
+			Math.Max (clampedWidth, clampedHeight),
+			Math.Max (clampedWidth, clampedHeight));
 
 		// Inflate shape bounding box to allow for anti-aliasing
 		RectangleI inflatedBBox = initialShapeBBox.Inflated (2, 2);
@@ -186,7 +186,7 @@ public static Gdk.Texture CreateIconWithShape (
 						shapeRect = shapeRect.Inflated (-1, -1);
 						PointD[] pointsOfInflatedRotatedRectangle = RotateRectangle (shapeRect, shapeAngle);
 						g.DrawPolygonal (new ReadOnlySpan<PointD> (pointsOfRotatedRectangle), outerColor, LineCap.Butt);
-						g.DrawPolygonal (new ReadOnlySpan<PointD> (pointsOfInflatedRotatedRectangle), innerColor, LineCap.Butt);
+						g.DrawPolygonal (new ReadOnlySpan<PointD> ([.. pointsOfInflatedRotatedRectangle, pointsOfInflatedRotatedRectangle[0]]), innerColor, LineCap.Butt);
 					}
 					break;
 			}

Pinta.Core/Managers/WorkspaceManager.cs

@@ -50,6 +50,7 @@ public interface IWorkspaceService
 	public event EventHandler? LayerAdded;
 	public event EventHandler? LayerRemoved;
 	public event EventHandler? SelectedLayerChanged;
+	public event EventHandler? ViewSizeChanged;
 	public event PropertyChangedEventHandler? LayerPropertyChanged;
 }
 
@@ -207,6 +208,7 @@ public void ActivateDocument (Document document)
 		document.Layers.LayerRemoved += Document_LayerRemoved;
 		document.Layers.SelectedLayerChanged += Document_SelectedLayerChanged;
 		document.Layers.LayerPropertyChanged += Document_LayerPropertyChanged;
+		document.Workspace.ViewSizeChanged += Document_ViewSizeChanged;
 
 		open_documents.Add (document);
 
@@ -236,6 +238,11 @@ private void Document_LayerAdded (object? sender, IndexEventArgs e)
 		LayerAdded?.Invoke (sender, e);
 	}
 
+	private void Document_ViewSizeChanged (object? sender, EventArgs ev)
+	{
+		ViewSizeChanged?.Invoke (sender, ev);
+	}
+
 	public void CloseDocument (Document document)
 	{
 		int index = open_documents.IndexOf (document);
@@ -263,6 +270,7 @@ public void CloseDocument (Document document)
 		document.Layers.LayerRemoved -= Document_LayerRemoved;
 		document.Layers.SelectedLayerChanged -= Document_SelectedLayerChanged;
 		document.Layers.LayerPropertyChanged -= Document_LayerPropertyChanged;
+		document.Workspace.ViewSizeChanged -= Document_ViewSizeChanged;
 		document.Close ();
 
 		OnDocumentClosed (new DocumentEventArgs (document));
@@ -453,6 +461,7 @@ private Task ShowFilePermissionErrorDialog (
 	public event EventHandler? LayerRemoved;
 	public event EventHandler? SelectedLayerChanged;
 	public event PropertyChangedEventHandler? LayerPropertyChanged;
+	public event EventHandler? ViewSizeChanged;
 
 	public event EventHandler<DocumentEventArgs>? DocumentActivated;
 	public event EventHandler<DocumentEventArgs>? DocumentClosed;

Pinta.Tools/Brushes/SlashBrush.cs

@@ -86,7 +86,7 @@ present logic...
 			new_bottom.X * old_bottom.Y - new_bottom.Y * old_bottom.X +
 			old_bottom.X * old_top.Y - old_bottom.Y * old_top.X));
 
-		if (area < 2) {
+		if (area < 2 && (last_pos.X != current_pos.X || last_pos.Y != current_pos.Y)) {
 			old_top = OffsetPoint (old_top, -1, 1, angle + 90);
 			new_top = OffsetPoint (new_top, -1, 1, angle + 90);
 			old_bottom = OffsetPoint (old_bottom, 1, 1, angle + 90);

Pinta.Tools/Tools/CloneStampTool.cs

@@ -47,7 +47,6 @@ public CloneStampTool (IServiceProvider services) : base (services)
 	public override string Icon => Pinta.Resources.Icons.ToolCloneStamp;
 	// Translators: {0} is 'Ctrl', or a platform-specific key such as 'Command' on macOS.
 	public override string StatusBarText => Translations.GetString ("{0} + left click to set origin, left click to paint.", system_manager.CtrlLabel ());
-	public override bool CursorChangesOnZoom => true;
 	public override Gdk.Key ShortcutKey => new (Gdk.Constants.KEY_L);
 	public override int Priority => 47;
 	protected override bool ShowAntialiasingButton => true;

Pinta.Tools/Tools/ColorPickerTool.cs

@@ -48,7 +48,6 @@ public ColorPickerTool (IServiceProvider services) : base (services)
 	public override string Name => Translations.GetString ("Color Picker");
 	public override string Icon => Pinta.Resources.Icons.ToolColorPicker;
 	public override string StatusBarText => Translations.GetString ("Left click to set primary color.\nRight click to set secondary color.");
-	public override bool CursorChangesOnZoom => true;
 	public override Gdk.Key ShortcutKey => new (Gdk.Constants.KEY_K);
 	public override int Priority => 33;
 	private int SampleSize => SampleSizeDropDown.SelectedItem.GetTagOrDefault (1);

Pinta.Tools/Tools/EraserTool.cs

@@ -56,9 +56,6 @@ public override string Icon
 	public override string StatusBarText
 		=> Translations.GetString ("Left click to erase to transparent, right click to erase to secondary color. ");
 
-	public override bool CursorChangesOnZoom
-		=> true;
-
 	public override Gdk.Key ShortcutKey
 		=> new (Gdk.Constants.KEY_E);
 

Pinta.Tools/Tools/LassoSelectTool.cs

@@ -33,10 +33,8 @@
 
 namespace Pinta.Tools;
 
-public sealed class LassoSelectTool : BaseTool
+public sealed class LassoSelectTool (IServiceProvider services) : BaseTool (services)
 {
-	private readonly IWorkspaceService workspace;
-
 	private bool is_dragging = false;
 	private CombineMode combine_mode;
 	private SelectionHistoryItem? hist;
@@ -47,11 +45,6 @@ public sealed class LassoSelectTool : BaseTool
 	private Label? lasso_mode_label;
 	private ToolBarDropDownButton? lasso_mode_buttom;
 
-	public LassoSelectTool (IServiceProvider services) : base (services)
-	{
-		workspace = services.GetService<IWorkspaceService> ();
-	}
-
 	public override string Name => Translations.GetString ("Lasso Select");
 	public override string Icon => Pinta.Resources.Icons.ToolSelectLasso;
 	public override string StatusBarText => Translations.GetString ("In Freeform mode, click and drag to draw the outline for a selection area." +