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
if ( sourceImage == null )
		{
			redraw( );
			return;
		}
		AffineTransform af = transform;
		double sx = af.getScaleX( ), sy = af.getScaleY( );
		double tx = af.getTranslateX( ), ty = af.getTranslateY( );
		if ( tx > 0 )
			tx = 0;
		if ( ty > 0 )
			ty = 0;
		Rectangle imageBound = sourceImage.getBounds( );
		int cw = getClientArea( ).width, ch = getClientArea( ).height;
		ScrollBar horizontal = getHorizontalBar( );
		if ( horizontal != null )
		{
			horizontal.setIncrement( (int) ( getClientArea( ).width / 100 ) );
			horizontal.setPageIncrement( getClientArea( ).width );
			if ( imageBound.width * sx > cw )
			{
				horizontal.setMaximum( (int) ( imageBound.width * sx ) );
				horizontal.setEnabled( true );
				if ( ( (int) -tx ) > horizontal.getMaximum( ) - cw )
					tx = -horizontal.getMaximum( ) + cw;
			}
			else
			{
				horizontal.setEnabled( false );
				tx = ( cw - imageBound.width * sx ) / 2;