Bug 81254 ControlExample spews warnings
observed on Solaris and hpux - run the ControlExample with warnings turned on (do this in Device I think) - a scrollbar warning is spewed on each page that's shown - this is ugly when using the swt-only download since warning messages are not supressed in this context
examples/org.eclipse.swt.examples/src/org/eclipse/swt/examples/controlexample/CanvasTab.java
void scrollHorizontal (ScrollBar scrollBar) {
		Rectangle bounds = canvas.getClientArea();
		int x = -scrollBar.getSelection();
		if (x + maxX < bounds.width) {
			x = bounds.width - maxX;
		}
		canvas.scroll(x, cy, cx, cy, maxX, maxY, false);
		cx = x;
	}
	/**
	 * Scrolls the canvas vertically.
	 * 
	 * @param scrollBar
	 */
	void scrollVertical (ScrollBar scrollBar) {
		Rectangle bounds = canvas.getClientArea();
		int y = -scrollBar.getSelection();
		if (y + maxY < bounds.height) {
			y = bounds.height - maxY;
		}
		canvas.scroll(cx, y, cx, cy, maxX, maxY, false);
		cy = y;
	}
	/**
	 * Sets or clears the caret in the "Example" widget.
	 */
	void setCaret () {
		Caret oldCaret = canvas.getCaret ();
		if (caretButton.getSelection ()) {
			Caret newCaret = new Caret(canvas, SWT.NONE);