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Merged
cameronwhite merged 2 commits into from
Jan 9, 2026
Merged

Attach canvas event handlers to the parent widget #1929

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01b692d
Attach canvas event handlers to the outer grid.
cameronwhite Jan 8, 2026
eceee8f
Update the canvas position in the statusbar while dragging
cameronwhite Jan 8, 2026
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146 changes: 136 additions & 10 deletions Pinta.Gui.Widgets/Widgets/Canvas/CanvasWindow.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -33,14 +33,16 @@ namespace Pinta;
public sealed class CanvasWindow : Gtk.Grid
{
private readonly Document document;
private readonly ChromeManager chrome;
private readonly ToolManager tools;

private readonly Ruler horizontal_ruler;
private readonly Ruler vertical_ruler;
private readonly Gtk.ScrolledWindow scrolled_window;
private readonly Gtk.EventControllerMotion motion_controller;
private readonly Gtk.GestureDrag drag_controller;
private readonly Gtk.GestureZoom gesture_zoom;

private PointD current_window_pos = PointD.Zero;
private PointD current_canvas_pos = PointD.Zero;
private double cumulative_zoom_amount;
private double last_scale_delta;
Expand All @@ -67,9 +69,7 @@ public CanvasWindow (
scrollController.OnDecelerate += (_, _) => gestureZoom.IsActive (); // Cancel scroll deceleration when zooming

PintaCanvas canvas = new (
chrome,
tools,
this,
document,
canvasGrid
) {
Expand All @@ -82,6 +82,15 @@ public CanvasWindow (
viewPort.AddController (scrollController);
viewPort.Child = canvas;

// Use the drag gesture to forward a sequence of mouse press -> move -> release events to the current tool.
// This is more reliable than using just a click gesture in combination with the move controller (see bug #1456)
// Note that we attach this to the root canvas widget, not the canvas, so that it can receive drags that start outside the canvas.
Gtk.GestureDrag dragController = Gtk.GestureDrag.New ();
dragController.SetButton (0); // Listen for all mouse buttons.
dragController.OnDragBegin += OnDragBegin;
dragController.OnDragUpdate += OnDragUpdate;
dragController.OnDragEnd += OnDragEnd;

Gtk.ScrolledWindow scrolledWindow = new () {
Hexpand = true,
Vexpand = true,
Expand All @@ -108,6 +117,7 @@ public CanvasWindow (
Focusable = true;

AddController (gestureZoom);
AddController (dragController);
AddController (motionController);

// --- Initialization (Gtk.Grid)
Expand All @@ -123,13 +133,16 @@ public CanvasWindow (

Canvas = canvas;

this.chrome = chrome;
this.tools = tools;
this.document = document;

scrolled_window = scrolledWindow;
gesture_zoom = gestureZoom;
horizontal_ruler = horizontalRuler;
vertical_ruler = verticalRuler;
motion_controller = motionController;
drag_controller = dragController;

// --- Further initialization

Expand Down Expand Up @@ -165,19 +178,35 @@ private void UpdateRulerSelection (object? sender, EventArgs e)
}

private void HandleMotion (
Gtk.EventControllerMotion _,
Gtk.EventControllerMotion controller,
Gtk.EventControllerMotion.MotionSignalArgs args)
{
PointD newPosition = new (args.X, args.Y);
PointD rootPoint = new (args.X, args.Y);

// These coordinates are relative to our grid widget, so transform into the child image
// view's coordinates, and then to the canvas coordinates.
this.TranslateCoordinates (Canvas, newPosition, out PointD viewPos);
this.TranslateCoordinates (Canvas, rootPoint, out PointD viewPos);

current_window_pos = newPosition;
current_canvas_pos = document.Workspace.ViewPointToCanvas (viewPos);
horizontal_ruler.Position = current_canvas_pos.X;
vertical_ruler.Position = current_canvas_pos.Y;

// Forward mouse move events to the current tool when not dragging.
if (drag_controller.GetStartPoint (out _, out _))
return;

if (document.Workspace.PointInCanvas (current_canvas_pos))
chrome.LastCanvasCursorPoint = current_canvas_pos.ToInt ();

ToolMouseEventArgs tool_args = new () {
State = controller.GetCurrentEventState (),
MouseButton = MouseButton.None,
PointDouble = current_canvas_pos,
WindowPoint = viewPos,
RootPoint = rootPoint,
};

tools.DoMouseMove (document, tool_args);
}

private void HandleGestureZoomScaleChanged (object? sender, EventArgs e)
Expand Down Expand Up @@ -206,9 +235,6 @@ private void HandleGestureZoomScaleChanged (object? sender, EventArgs e)
last_scale_delta = gesture_zoom.GetScaleDelta () - 1;
}

public PointD WindowMousePosition
=> current_window_pos;

public bool IsMouseOnCanvas
=> motion_controller.ContainsPointer;

Expand Down Expand Up @@ -314,4 +340,104 @@ private bool HandleScrollEvent (

return true;
}

private void OnDragBegin (Gtk.GestureDrag gesture, Gtk.GestureDrag.DragBeginSignalArgs args)
{
// A mouse click on the canvas should grab focus away from any toolbar widgets, etc
// Using the root canvas widget works best - if the drawing area is given focus, the scroll
// widget jumps back to the origin.
GrabFocus ();

// Note: if we ever regain support for docking multiple canvas
// widgets side by side (like Pinta 1.7 could), a mouse click should switch
// the active document to this document.

// Send the mouse press event to the current tool.
// Translate coordinates to the canvas widget.
PointD rootPoint = new (args.StartX, args.StartY);
this.TranslateCoordinates (Canvas, rootPoint, out PointD viewPoint);
PointD canvasPoint = document.Workspace.ViewPointToCanvas (viewPoint);

ToolMouseEventArgs tool_args = new () {
State = gesture.GetCurrentEventState (),
MouseButton = gesture.GetCurrentMouseButton (),
PointDouble = canvasPoint,
WindowPoint = viewPoint,
RootPoint = rootPoint,
};

tools.DoMouseDown (document, tool_args);
}

private void OnDragUpdate (Gtk.GestureDrag gesture, Gtk.GestureDrag.DragUpdateSignalArgs args)
{
gesture.GetStartPoint (out double startX, out double startY);
PointD rootPoint = new (startX + args.OffsetX, startY + args.OffsetY);

// Translate coordinates to the canvas widget.
this.TranslateCoordinates (Canvas, rootPoint, out PointD viewPoint);

current_canvas_pos = document.Workspace.ViewPointToCanvas (viewPoint);
if (document.Workspace.PointInCanvas (current_canvas_pos))
chrome.LastCanvasCursorPoint = current_canvas_pos.ToInt ();

// Send the mouse move event to the current tool.
ToolMouseEventArgs tool_args = new () {
State = gesture.GetCurrentEventState (),
MouseButton = gesture.GetCurrentMouseButton (),
PointDouble = current_canvas_pos,
WindowPoint = viewPoint,
RootPoint = rootPoint,
};

tools.DoMouseMove (document, tool_args);
}

private void OnDragEnd (Gtk.GestureDrag gesture, Gtk.GestureDrag.DragEndSignalArgs args)
{
gesture.GetStartPoint (out double startX, out double startY);
PointD rootPoint = new (startX + args.OffsetX, startY + args.OffsetY);

// Translate coordinates to the canvas widget.
this.TranslateCoordinates (Canvas, rootPoint, out PointD viewPoint);
PointD canvasPoint = document.Workspace.ViewPointToCanvas (viewPoint);

// Send the mouse release event to the current tool.
ToolMouseEventArgs tool_args = new () {
State = gesture.GetCurrentEventState (),
MouseButton = gesture.GetCurrentMouseButton (),
PointDouble = canvasPoint,
WindowPoint = viewPoint,
RootPoint = rootPoint,
};

tools.DoMouseUp (document, tool_args);
}

public bool DoKeyPressEvent (
Gtk.EventControllerKey controller,
Gtk.EventControllerKey.KeyPressedSignalArgs args)
{
// Give the current tool a chance to handle the key press
ToolKeyEventArgs tool_args = new () {
Event = controller.GetCurrentEvent (),
Key = args.GetKey (),
State = args.State,
};

return tools.DoKeyDown (document, tool_args);
}

public bool DoKeyReleaseEvent (
Gtk.EventControllerKey controller,
Gtk.EventControllerKey.KeyReleasedSignalArgs args)
{
ToolKeyEventArgs tool_args = new () {
Event = controller.GetCurrentEvent (),
Key = args.GetKey (),
State = args.State,
};

return tools.DoKeyUp (document, tool_args);
}
}
137 changes: 0 additions & 137 deletions Pinta.Gui.Widgets/Widgets/Canvas/PintaCanvas.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -35,9 +35,7 @@ public sealed class PintaCanvas : Gtk.Picture
{
private readonly CanvasRenderer cr;
private readonly Document document;
private readonly CanvasWindow canvas_window;
private readonly ICanvasGridService canvas_grid;
private readonly Gtk.GestureDrag drag_controller;

private uint queued_update_id = 0;

Expand All @@ -51,19 +49,14 @@ public sealed class PintaCanvas : Gtk.Picture
private readonly uint selection_animation_timer_id;
private float selection_animation_dash_offset;

private readonly ChromeManager chrome;
private readonly ToolManager tools;

public PintaCanvas (
ChromeManager chrome,
ToolManager tools,
CanvasWindow window,
Document document,
ICanvasGridService canvasGrid)
{
this.chrome = chrome;
this.tools = tools;
canvas_window = window;
canvas_grid = canvasGrid;
this.document = document;

Expand All @@ -80,20 +73,6 @@ public PintaCanvas (
// Timer for selection outline animation
selection_animation_timer_id = GLib.Functions.TimeoutAdd (GLib.Constants.PRIORITY_DEFAULT, 80, SelectionAnimationTick);

// Use the drag gesture to forward a sequence of mouse press -> move -> release events to the current tool.
// This is more reliable than using just a click gesture in combination with the move controller (see bug #1456)
drag_controller = Gtk.GestureDrag.New ();
drag_controller.SetButton (0); // Listen for all mouse buttons.
drag_controller.OnDragBegin += OnDragBegin;
drag_controller.OnDragUpdate += OnDragUpdate;
drag_controller.OnDragEnd += OnDragEnd;
AddController (drag_controller);

// Forward mouse move events to the current tool when not dragging.
Gtk.EventControllerMotion motion_controller = Gtk.EventControllerMotion.New ();
motion_controller.OnMotion += OnMouseMove;
AddController (motion_controller);

// If there is additional space available, keep the image centered and prevent stretching.
Hexpand = false;
Halign = Gtk.Align.Center;
Expand Down Expand Up @@ -468,122 +447,6 @@ private void OnViewSizeChanged (object? o, System.EventArgs args)
SetSizeRequest (viewSize.Width, viewSize.Height);
}

private void OnDragBegin (Gtk.GestureDrag gesture, Gtk.GestureDrag.DragBeginSignalArgs args)
{
// Note we don't call gesture.SetState (Gtk.EventSequenceState.Claimed) here, so
// that the CanvasWindow can also receive motion events to update the root window mouse position.

// A mouse click on the canvas should grab focus away from any toolbar widgets, etc
// Using the root canvas widget works best - if the drawing area is given focus, the scroll
// widget jumps back to the origin.
canvas_window.GrabFocus ();

// Note: if we ever regain support for docking multiple canvas
// widgets side by side (like Pinta 1.7 could), a mouse click should switch
// the active document to this document.

// Send the mouse press event to the current tool.
PointD window_point = new (args.StartX, args.StartY);
PointD canvas_point = document.Workspace.ViewPointToCanvas (window_point);

ToolMouseEventArgs tool_args = new () {
State = gesture.GetCurrentEventState (),
MouseButton = gesture.GetCurrentMouseButton (),
PointDouble = canvas_point,
WindowPoint = window_point,
RootPoint = canvas_window.WindowMousePosition,
};

tools.DoMouseDown (document, tool_args);
}

private void OnDragUpdate (Gtk.GestureDrag gesture, Gtk.GestureDrag.DragUpdateSignalArgs args)
{
// Send the mouse move event to the current tool.
gesture.GetStartPoint (out double startX, out double startY);
PointD window_point = new (startX + args.OffsetX, startY + args.OffsetY);
PointD canvas_point = document.Workspace.ViewPointToCanvas (window_point);

ToolMouseEventArgs tool_args = new () {
State = gesture.GetCurrentEventState (),
MouseButton = gesture.GetCurrentMouseButton (),
PointDouble = canvas_point,
WindowPoint = window_point,
RootPoint = canvas_window.WindowMousePosition,
};

tools.DoMouseMove (document, tool_args);
}

private void OnDragEnd (Gtk.GestureDrag gesture, Gtk.GestureDrag.DragEndSignalArgs args)
{
// Send the mouse release event to the current tool.
gesture.GetStartPoint (out double startX, out double startY);
PointD window_point = new (startX + args.OffsetX, startY + args.OffsetY);
PointD canvas_point = document.Workspace.ViewPointToCanvas (window_point);

ToolMouseEventArgs tool_args = new () {
State = gesture.GetCurrentEventState (),
MouseButton = gesture.GetCurrentMouseButton (),
PointDouble = canvas_point,
WindowPoint = window_point,
RootPoint = canvas_window.WindowMousePosition,
};

tools.DoMouseUp (document, tool_args);
}

private void OnMouseMove (Gtk.EventControllerMotion controller, Gtk.EventControllerMotion.MotionSignalArgs args)
{
// Don't send duplicate mouse move events while a drag is active.
if (drag_controller.GetStartPoint (out _, out _))
return;

PointD window_point = new (args.X, args.Y);
PointD canvas_point = document.Workspace.ViewPointToCanvas (window_point);

if (document.Workspace.PointInCanvas (canvas_point))
chrome.LastCanvasCursorPoint = canvas_point.ToInt ();

ToolMouseEventArgs tool_args = new () {
State = controller.GetCurrentEventState (),
MouseButton = MouseButton.None,
PointDouble = canvas_point,
WindowPoint = window_point,
RootPoint = canvas_window.WindowMousePosition,
};

tools.DoMouseMove (document, tool_args);
}

public bool DoKeyPressEvent (
Gtk.EventControllerKey controller,
Gtk.EventControllerKey.KeyPressedSignalArgs args)
{
// Give the current tool a chance to handle the key press
ToolKeyEventArgs tool_args = new () {
Event = controller.GetCurrentEvent (),
Key = args.GetKey (),
State = args.State,
};

return tools.DoKeyDown (document, tool_args);
}

public bool DoKeyReleaseEvent (
Gtk.EventControllerKey controller,
Gtk.EventControllerKey.KeyReleasedSignalArgs args)
{
ToolKeyEventArgs tool_args = new () {
Event = controller.GetCurrentEvent (),
Key = args.GetKey (),
State = args.State,
};

return tools.DoKeyUp (document, tool_args);
}


#region Selection outline animation
private bool SelectionAnimationTick ()
{
Expand Down
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