[GTK] Can draw outside window on Wayland

[tmssngr]

Describe the bug
It is possible easily by setting clipping to draw outside a window (shell) on Wayland.

To Reproduce
Run following snippet on a Wayland system:

import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class DrawOutsideShell {

    public static void main(String[] args) {
        Display display = new Display();
        Shell shell = new Shell(display);
        Composite composite = new Composite(shell, SWT.DOUBLE_BUFFERED);
        composite.setBounds(-50, 0, 500, 250);
        composite.addListener(SWT.Paint, event -> {
            event.gc.setClipping(0, 0, 500, 250);
            event.gc.fillRectangle(0, 0, 500, 250);
        });
        shell.setSize(300, 200);
        shell.open();

        while (!shell.isDisposed()) {
            if (!display.readAndDispatch()) {
                display.sleep();
            }
        }

        display.dispose();
    }
}

Expected behavior
The drawing area is clipped to the controls/shells bounds, no matter what clipping area is set by the user.

Screenshots

Environment:

1. Select the platform(s) on which the behavior is seen:

• • All OS
• • Windows
• • Linux
• • macOS

2. Additional OS info (e.g. OS version, Linux Desktop, etc)
   Tried on latest Fedora and on Linux Mint with experimental Wayland support.

[Phillipus]

I tested your Snippet on Ubuntu 24.04 Wayland and Linux Mint Wayland and it's working OK. Are you using latest SWT build?