Mega Code Archive
Tree event
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/*******************************************************************************
* 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 TreeEventMeasurePaintErase {
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();
}
}
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