Handle dirty state correctly when closing document

Pinta.Core/Managers/WorkspaceManager.cs

@@ -383,12 +383,13 @@ public void SetActiveDocument (
 	}
 
 	internal void SetActiveDocumentInternal (
-		ToolManager tools,
-		Document document)
+	    ToolManager tools,
+	    Document document,
+	    bool suppressCommit = false)
 	{
 		// Work around a case where we closed a document but haven't updated
 		// the active_document_index yet and it points to the closed document
-		if (HasOpenDocuments && active_document_index != -1 && open_documents.Count > active_document_index)
+		if (!suppressCommit && HasOpenDocuments && active_document_index != -1 && open_documents.Count > active_document_index)
 			tools.Commit ();
 
 		int index = open_documents.IndexOf (document);
@@ -397,6 +398,13 @@ internal void SetActiveDocumentInternal (
 		OnActiveDocumentChanged (EventArgs.Empty);
 	}
 
+	public void SetActiveDocumentForClose (Document document)
+	{
+		// Sets the active document in preparation for closing it. This avoids committing
+		// tool state when switching, so canceling the close will not finalize editable shapes, for example.
+		SetActiveDocumentInternal (PintaCore.Tools, document, suppressCommit: true);
+	}
+
 	private void OnActiveDocumentChanged (EventArgs _)
 	{
 		ActiveDocumentChanged?.Invoke (this, EventArgs.Empty);

Pinta.Docking/DockNotebook.cs

@@ -45,6 +45,7 @@ public sealed class DockNotebook : Gtk.Box
 	private readonly Adw.TabView tab_view;
 	private readonly Adw.TabBar tab_bar;
 	private readonly HashSet<IDockNotebookItem> items = [];
+	public bool IsClosingTab { get; private set; }
 
 	public DockNotebook ()
 	{
@@ -95,12 +96,17 @@ private bool TabView_OnClosePage (Adw.TabView _, Adw.TabView.ClosePageSignalArgs
 
 		TabClosedEventArgs close_args = new (item);
 
-		TabClosed?.Invoke (this, close_args);
+		IsClosingTab = true;
+		try {
+			TabClosed?.Invoke (this, close_args);
 
-		tab_view.ClosePageFinish (page, !close_args.Cancel);
+			tab_view.ClosePageFinish (page, !close_args.Cancel);
 
-		if (!close_args.Cancel)
-			items.Remove (item);
+			if (!close_args.Cancel)
+				items.Remove (item);
+		} finally {
+			IsClosingTab = false;
+		}
 
 		// Prevent the default close handler from running.
 		return Gdk.Constants.EVENT_STOP;

Pinta.Gui.Widgets/Widgets/Canvas/PintaCanvas.cs

@@ -256,6 +256,11 @@ private void DrawHandles (Gtk.Snapshot snapshot, Graphene.Rect canvasViewBounds)
 		if (tool is null)
 			return;
 
+		// Only draw tool handles on the canvas for the active document.
+		// This prevents handles from one document appearing on another tab's canvas.
+		if (!ReferenceEquals (document, PintaCore.Workspace.ActiveDocumentOrDefault))
+			return;
+
 		snapshot.PushClip (canvasViewBounds);
 
 		foreach (IToolHandle control in tool.Handles.Where (c => c.Active)) {

Pinta.Tools/Editable/EditEngines/BaseEditEngine.cs

@@ -177,9 +177,40 @@ public ShapeEngine? ActiveShapeEngine {
 	//Helps to keep track of the first modification on a shape after the mouse is clicked, to prevent unnecessary history items.
 	protected bool clicked_without_modifying = false;
 
-	//Stores the editable shape data.
+	// Stores editable shape data per document; the static SEngines reference is
+	// rebound on active-document changes to point at the current document's list.
+	private static readonly Dictionary<Document, Collection<ShapeEngine>> shapes_by_document = new ();
+
+	// Stores the editable shape data for the currently active document.
 	public static Collection<ShapeEngine> SEngines = [];
 
+	static BaseEditEngine ()
+	{
+		// Initialize mapping for the current active document if available.
+		if (PintaCore.Workspace.ActiveDocumentOrDefault is Document doc)
+			SEngines = GetShapesForDocument (doc);
+
+		PintaCore.Workspace.ActiveDocumentChanged += (_, __) => {
+			if (PintaCore.Workspace.ActiveDocumentOrDefault is Document active)
+				SEngines = GetShapesForDocument (active);
+		};
+
+		PintaCore.Workspace.DocumentClosed += (_, e) => {
+			// Clean up mapping for closed documents.
+			if (e.Document is Document closed)
+				shapes_by_document.Remove (closed);
+		};
+	}
+
+	private static Collection<ShapeEngine> GetShapesForDocument (Document doc)
+	{
+		if (!shapes_by_document.TryGetValue (doc, out var shapes)) {
+			shapes = [];
+			shapes_by_document[doc] = shapes;
+		}
+		return shapes;
+	}
+
 	#region ToolbarEventHandlers
 
 	protected virtual void BrushMinusButtonClickedEvent (object? o, EventArgs args)
@@ -1455,7 +1486,8 @@ protected void CalculateModifiedCurrentPoint ()
 	/// </summary>
 	protected void ResetShapes ()
 	{
-		SEngines = [];
+		// Clear the current document's editable shape data.
+		SEngines.Clear ();
 
 		//The fields are modified instead of the properties here because a redraw call is undesired (for speed/efficiency).
 		SelectedPointIndex = -1;

Pinta/Actions/File/CloseDocumentAction.cs

@@ -59,9 +59,6 @@ void IActionHandler.Uninitialize ()
 
 	private void Activated (object sender, EventArgs e)
 	{
-		// Commit any pending changes
-		tools.Commit ();
-
 		// If it's not dirty, just close it
 		if (!workspace.ActiveDocument.IsDirty) {
 			workspace.CloseActiveDocument (actions);

Pinta/MainWindow.cs

@@ -150,7 +150,7 @@ private void DockNotebook_TabClosed (object? sender, TabClosedEventArgs e)
 		if (PintaCore.Workspace.OpenDocuments.IndexOf (view.Document) < 0)
 			return;
 
-		PintaCore.Actions.Window.SetActiveDocument (view.Document);
+		PintaCore.Workspace.SetActiveDocumentForClose (view.Document);
 		PintaCore.Actions.File.Close.Activate ();
 
 		if (PintaCore.Workspace.OpenDocuments.IndexOf (view.Document) < 0)
@@ -162,6 +162,9 @@ private void DockNotebook_TabClosed (object? sender, TabClosedEventArgs e)
 
 	private void DockNotebook_ActiveTabChanged (object? sender, EventArgs e)
 	{
+		if (canvas_pad.Notebook.IsClosingTab)
+			return;
+
 		var item = canvas_pad.Notebook.ActiveItem;
 
 		if (item == null)