Bug 144590 [Accessibility] BIRT custom controls should support active accessibility
Description: BIRT custom controls should support active accessibility. There are some custom controls in BIRT GUI. In Eclipse, when implementing a custom control you should also implement some or all of (as they apply to your control) org.eclipse.swt.accessibility.AccessibleListener, org.eclipse.swt.accessibility.AccessibleControlListener and org.eclipse.swt.accessibility.AccessibleTextListener. Also, the custom control can notify Active Accessibility of changes within the control using org.eclipse.swt.accessibility.Accessible methods such as setFocus(), selectionChanged(), textCaretMoved(), textChanged() and textSelectionChanged().
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/util/graphics/ImageCanvas.java
syncScrollBars( );
	}
	/**
	 * Clear the canvas
	 */
	public void clear( )
	{
		if ( sourceImage != null )
		{
			sourceImage.dispose( );
			sourceImage = null;
			GC clearGC = new GC( this );
			paint( clearGC );
			clearGC.dispose( );
		}
	}
	/**
	 * Perform a zooming operation.
	 * 
	 * @param dx
	 * @param dy
	 * @param scale
	 * @param af
	 */
	public void centerZoom( double dx, double dy, double scale,
			AffineTransform af )
	{
		af.preConcatenate( AffineTransform.getTranslateInstance( -dx, -dy ) );
		af.preConcatenate( AffineTransform.getScaleInstance( scale, scale ) );
		af.preConcatenate( AffineTransform.getTranslateInstance( dx, dy ) );