Java Tutorial/SWT/TreeItem

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Add Icon to TreeItem

   <source lang="java">

/*******************************************************************************

* Copyright (c) 2000, 2006 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
*     IBM Corporation - initial API and implementation
*******************************************************************************/

//package org.eclipse.swt.snippets; /*

* Tree example snippet: Images on the right side of the TreeItem
*
* For a list of all SWT example snippets see
* http://www.eclipse.org/swt/snippets/
* 
* @since 3.2
*/

import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.layout.FillLayout; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Tree; import org.eclipse.swt.widgets.TreeColumn; import org.eclipse.swt.widgets.TreeItem; public class TreeIconAddItem {

 public static void main(String[] args) {
   Display display = new Display();
   final Image image = display.getSystemImage(SWT.ICON_INFORMATION);
   Shell shell = new Shell(display);
   shell.setText("Images on the right side of the TreeItem");
   shell.setLayout(new FillLayout());
   Tree tree = new Tree(shell, SWT.MULTI | SWT.FULL_SELECTION);
   tree.setHeaderVisible(true);
   tree.setLinesVisible(true);
   int columnCount = 4;
   for (int i = 0; i < columnCount; i++) {
     TreeColumn column = new TreeColumn(tree, SWT.NONE);
     column.setText("Column " + i);
   }
   int itemCount = 3;
   for (int i = 0; i < itemCount; i++) {
     TreeItem item1 = new TreeItem(tree, SWT.NONE);
     item1.setText("item " + i);
     for (int c = 1; c < columnCount; c++) {
       item1.setText(c, "item [" + i + "-" + c + "]");
     }
     for (int j = 0; j < itemCount; j++) {
       TreeItem item2 = new TreeItem(item1, SWT.NONE);
       item2.setText("item [" + i + " " + j + "]");
       for (int c = 1; c < columnCount; c++) {
         item2.setText(c, "item [" + i + " " + j + "-" + c + "]");
       }
       for (int k = 0; k < itemCount; k++) {
         TreeItem item3 = new TreeItem(item2, SWT.NONE);
         item3.setText("item [" + i + " " + j + " " + k + "]");
         for (int c = 1; c < columnCount; c++) {
           item3.setText(c, "item [" + i + " " + j + " " + k + "-" + c + "]");
         }
       }
     }
   }
   /*
    * NOTE: MeasureItem, PaintItem and EraseItem are called repeatedly.
    * Therefore, it is critical for performance that these methods be as
    * efficient as possible.
    */
   Listener paintListener = new Listener() {
     public void handleEvent(Event event) {
       switch (event.type) {
       case SWT.MeasureItem: {
         Rectangle rect = image.getBounds();
         event.width += rect.width;
         event.height = Math.max(event.height, rect.height + 2);
         break;
       }
       case SWT.PaintItem: {
         int x = event.x + event.width;
         Rectangle rect = image.getBounds();
         int offset = Math.max(0, (event.height - rect.height) / 2);
         event.gc.drawImage(image, x, event.y + offset);
         break;
       }
       }
     }
   };
   tree.addListener(SWT.MeasureItem, paintListener);
   tree.addListener(SWT.PaintItem, paintListener);
   for (int i = 0; i < columnCount; i++) {
     tree.getColumn(i).pack();
   }
   shell.setSize(500, 200);
   shell.open();
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch())
       display.sleep();
   }
   if (image != null)
     image.dispose();
   display.dispose();
 }

}</source>