/*******************************************************************************
* Copyright (c) 2000, 2016 IBM Corporation and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* 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 detailed explanation of this snippet see
* http://www.eclipse.org/articles/Article-CustomDrawingTableAndTreeItems/customDraw.htm#_example5
*
* For a list of all SWT example snippets see
* http://www.eclipse.org/swt/snippets/
*
* @since 3.2
*/
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;
public class Snippet220 {
public static void main(String [] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setText("Snippet 220");
shell.setBounds(10, 10, 350, 200);
Image xImage = new Image (display, 16, 16);
GC gc = new GC(xImage);
gc.setForeground(display.getSystemColor(SWT.COLOR_RED));
gc.drawLine(1, 1, 14, 14);
gc.drawLine(1, 14, 14, 1);
gc.drawOval(2, 2, 11, 11);
gc.dispose();
final int IMAGE_MARGIN = 2;
final Tree tree = new Tree(shell, SWT.CHECK);
tree.setBounds(10, 10, 300, 150);
TreeItem item = new TreeItem(tree, SWT.NONE);
item.setText("root item");
for (int i = 0; i < 4; i++) {
TreeItem newItem = new TreeItem(item, SWT.NONE);
newItem.setText("descendent " + i);
if (i % 2 == 0) newItem.setData(xImage);
item.setExpanded(true);
item = newItem;
}
/*
* NOTE: MeasureItem and PaintItem are called repeatedly. Therefore it is
* critical for performance that these methods be as efficient as possible.
*/
tree.addListener(SWT.MeasureItem, event -> {
TreeItem item1 = (TreeItem)event.item;
Image trailingImage = (Image)item1.getData();
if (trailingImage != null) {
event.width += trailingImage.getBounds().width + IMAGE_MARGIN;
}
});
tree.addListener(SWT.PaintItem, event -> {
TreeItem item1 = (TreeItem)event.item;
Image trailingImage = (Image)item1.getData();
if (trailingImage != null) {
int x = event.x + event.width + IMAGE_MARGIN;
int itemHeight = tree.getItemHeight();
int imageHeight = trailingImage.getBounds().height;
int y = event.y + (itemHeight - imageHeight) / 2;
event.gc.drawImage(trailingImage, x, y);
}
});
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) display.sleep();
}
xImage.dispose();
display.dispose();
}
}
