snippet231.java

Eclipse JAVA开发软件中SWT各控件范例源码

/*******************************************************************************
 * Copyright (c) 2000, 2007 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;

/* 
 * example snippet: draw multiple lines in a table item
 *
 * For a detailed explanation of this snippet see
 * http://www.eclipse.org/articles/Article-CustomDrawingTableAndTreeItems/customDraw.htm#_example6
 *
 * 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 Snippet231 {
	
public static void main(String [] args) {
	final int COLUMN_COUNT = 4;
	final int ITEM_COUNT = 8;
	final int TEXT_MARGIN = 3;
	Display display = new Display();
	Shell shell = new Shell(display);
	final Table table = new Table(shell, SWT.FULL_SELECTION);
	table.setHeaderVisible(true);
	table.setLinesVisible(true);
	for (int i = 0; i < COLUMN_COUNT; i++) {
		new TableColumn(table, SWT.NONE);
	}
	for (int i = 0; i < ITEM_COUNT; i++) {
		TableItem item = new TableItem(table, SWT.NONE);
		for (int j = 0; j < COLUMN_COUNT; j++) {
			String string = "item " + i + " col " + j;
			if ((i + j) % 3 == 1) {
				string +="\nnew line1";
			}
			if ((i + j) % 3 == 2) {
				string +="\nnew line1\nnew line2";
			}
			item.setText(j, string);
		}
	}

	/*
	 * NOTE: MeasureItem, PaintItem and EraseItem are called repeatedly.
	 * Therefore, it is critical for performance that these methods be
	 * as efficient as possible.
	 */
	table.addListener(SWT.MeasureItem, new Listener() {
		public void handleEvent(Event event) {
			TableItem item = (TableItem)event.item;
			String text = item.getText(event.index);
			Point size = event.gc.textExtent(text);
			event.width = size.x + 2 * TEXT_MARGIN;
			event.height = Math.max(event.height, size.y + TEXT_MARGIN);
		}
	});
	table.addListener(SWT.EraseItem, new Listener() {
		public void handleEvent(Event event) {
			event.detail &= ~SWT.FOREGROUND;
		}
	});
	table.addListener(SWT.PaintItem, new Listener() {
		public void handleEvent(Event event) {
			TableItem item = (TableItem)event.item;
			String text = item.getText(event.index);
			/* center column 1 vertically */
			int yOffset = 0;
			if (event.index == 1) {
				Point size = event.gc.textExtent(text);
				yOffset = Math.max(0, (event.height - size.y) / 2);
			}
			event.gc.drawText(text, event.x + TEXT_MARGIN, event.y + yOffset, true);
		}
	});

	for (int i = 0; i < COLUMN_COUNT; i++) {
		table.getColumn(i).pack();
	}
	table.pack();
	shell.pack();
	shell.open();
	while (!shell.isDisposed()) {
		if (!display.readAndDispatch()) display.sleep();
	}
	display.dispose();
}
}