Bug 4793 Canvas.scroll not working when source y around 65536 (1GIXDPD)
Run the code below and press a key. You will see one pixel line of cheese at the top or bottom depending on which sourceY is used. To make this more obvious divide height by 2. This works fine on NT. import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.*; import org.eclipse.swt.widgets.*; public class PR_1GIXDPD { static boolean scrolled = false; public static void main(String[] args) { final Shell shell = new Shell(); shell.addListener(SWT.KeyDown, new Listener() { public void handleEvent(Event e) { Rectangle clientArea = shell.getClientArea(); int height = clientArea.height; int sourceY = 65536 - (height - 3); // int sourceY = 65536 + (height - 1); // does not work if 65536 - (height - 2) < sourceY < 65536 + height shell.scroll(0, 0, 0, sourceY, clientArea.width, clientArea.height, true); scrolled = true; System.out.println(clientArea); } }); shell.addListener(SWT.Paint, new Listener() { public void handleEvent(Event event) { int lineHeight = 15; if (scrolled == false) { for (int i = 0; i < event.y + event.height; i += lineHeight) { event.gc.drawText("Line " + i, 0, i); } } } }); shell.open(); Display display = shell.getDisplay (); while (!shell.isDisposed ()) { if (!display.readAndDispatch ()) display.sleep (); } } } NOTES:
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/actions/SelectionConverter.java
if (part instanceof JavaEditor)
			return new StructuredSelection(codeResolve((JavaEditor)part));
		ISelectionProvider provider= part.getSite().getSelectionProvider();
		if (provider != null) {
			ISelection selection= provider.getSelection();
			if (selection instanceof IStructuredSelection)
				return (IStructuredSelection)selection;
		}
		return StructuredSelection.EMPTY;
	}
	
	/**
	 * Converts the given structured selection into an array of Java elements.
	 * An empty array is returned if one of the elements stored in the structured
	 * selection is not of tupe <code>IJavaElement</code>
	 */
	public static IJavaElement[] getElements(IStructuredSelection selection) {
		if (!selection.isEmpty()) {
			IJavaElement[] result= new IJavaElement[selection.size()];
			int i= 0;
			for (Iterator iter= selection.iterator(); iter.hasNext(); i++) {
				Object element= (Object) iter.next();
				if (!(element instanceof IJavaElement))
					return EMPTY_RESULT;
				result[i]= (IJavaElement)element;
			}
			return result;
		}
		return EMPTY_RESULT;
	}