org.spearce.egit.ui/src/org/spearce/egit/ui/internal/components/CenteredImageLabelProvider.java

   1 /*******************************************************************************
   2  * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
   3  *
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * See LICENSE for the full license text, also available.
   7  *******************************************************************************/
   8 package org.spearce.egit.ui.internal.components;
   9
  10 import org.eclipse.jface.viewers.OwnerDrawLabelProvider;
  11 import org.eclipse.swt.graphics.Image;
  12 import org.eclipse.swt.graphics.Rectangle;
  13 import org.eclipse.swt.widgets.Event;
  14 import org.eclipse.swt.widgets.TableItem;
  15
  16 /**
  17  * Label provider displaying image centered.
  18  * <p>
  19  * This implementation is actually workaround for lacking SWT/JFace features.
  20  * Code is based on official snippet found on Internet.
  21  */
  22 // FIXME: doesn't work on Mac OS X 10.5 / Eclipse 3.3
  23 public abstract class CenteredImageLabelProvider extends OwnerDrawLabelProvider {
  24         /**
  25          * @param element
  26          *            element to provide label for.
  27          * @return image for provided element.
  28          */
  29         protected abstract Image getImage(final Object element);
  30
  31         @Override
  32         protected void measure(Event event, Object element) {
  33                 // empty
  34         }
  35
  36         @Override
  37         protected void paint(final Event event, final Object element) {
  38                 final Image image = getImage(element);
  39                 final Rectangle bounds = ((TableItem) event.item)
  40                                 .getBounds(event.index);
  41                 final Rectangle imgBounds = image.getBounds();
  42                 bounds.width /= 2;
  43                 bounds.width -= imgBounds.width / 2;
  44                 bounds.height /= 2;
  45                 bounds.height -= imgBounds.height / 2;
  46
  47                 final int x = bounds.width > 0 ? bounds.x + bounds.width : bounds.x;
  48                 final int y = bounds.height > 0 ? bounds.y + bounds.height : bounds.y;
  49
  50                 event.gc.drawImage(image, x, y);
  51         }
  52 }