Java tutorial
/* * JFreeChart : a free chart library for the Java(tm) platform * * * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jfreechart/index.html * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public * License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. * * [Java is a trademark or registered trademark of Sun Microsystems, Inc. * in the United States and other countries.] * * ------------- * SWTUtils.java * ------------- * (C) Copyright 2006, 2007, by Henry Proudhon and Contributors. * * Original Author: Henry Proudhon (henry.proudhon AT ensmp.fr); * Contributor(s): Rainer Blessing; * David Gilbert (david.gilbert@object-refinery.com); * Christoph Beck. * * Changes * ------- * 01-Aug-2006 : New class (HP); * 16-Jan-2007 : Use FontData.getHeight() instead of direct field access (RB); * 31-Jan-2007 : Moved the dummy JPanel from SWTGraphics2D.java, * added a new convert method for mouse events (HP); * 12-Jul-2007 : Improved the mouse event conversion with buttons * and modifiers handling, patch sent by Christoph Beck (HP); * 27-Aug-2007 : Modified toAwtMouseEvent signature (HP); * 27-Nov-2007 : Moved convertToSWT() method from SWTGraphics2D and added * convertAWTImageToSWT() (DG); * 01-Jul-2008 : Simplify AWT/SWT font style conversions (HP); * */ import java.awt.Graphics; import java.awt.Image; import java.awt.event.InputEvent; import java.awt.event.MouseEvent; import java.awt.geom.Point2D; import java.awt.geom.Rectangle2D; import java.awt.image.BufferedImage; import java.awt.image.DirectColorModel; import java.awt.image.IndexColorModel; import java.awt.image.WritableRaster; import javax.swing.JPanel; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.graphics.Device; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.FontData; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.ImageData; import org.eclipse.swt.graphics.PaletteData; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.RGB; import org.eclipse.swt.graphics.Rectangle; /** * Utility class gathering some useful and general method. * Mainly convert forth and back graphical stuff between * awt and swt. */ public class SWTUtils { private final static String Az = "ABCpqr"; /** A dummy JPanel used to provide font metrics. */ protected static final JPanel DUMMY_PANEL = new JPanel(); /** * Create a <code>FontData</code> object which encapsulate * the essential data to create a swt font. The data is taken * from the provided awt Font. * <p>Generally speaking, given a font size, the returned swt font * will display differently on the screen than the awt one. * Because the SWT toolkit use native graphical resources whenever * it is possible, this fact is platform dependent. To address * this issue, it is possible to enforce the method to return * a font with the same size (or at least as close as possible) * as the awt one. * <p>When the object is no more used, the user must explicitly * call the dispose method on the returned font to free the * operating system resources (the garbage collector won't do it). * * @param device The swt device to draw on (display or gc device). * @param font The awt font from which to get the data. * @param ensureSameSize A boolean used to enforce the same size * (in pixels) between the awt font and the newly created swt font. * @return a <code>FontData</code> object. */ public static FontData toSwtFontData(Device device, java.awt.Font font, boolean ensureSameSize) { FontData fontData = new FontData(); fontData.setName(font.getFamily()); // SWT and AWT share the same style constants. fontData.setStyle(font.getStyle()); // convert the font size (in pt for awt) to height in pixels for swt int height = (int) Math.round(font.getSize() * 72.0 / device.getDPI().y); fontData.setHeight(height); // hack to ensure the newly created swt fonts will be rendered with the // same height as the awt one if (ensureSameSize) { GC tmpGC = new GC(device); Font tmpFont = new Font(device, fontData); tmpGC.setFont(tmpFont); if (tmpGC.textExtent(Az).x > DUMMY_PANEL.getFontMetrics(font).stringWidth(Az)) { while (tmpGC.textExtent(Az).x > DUMMY_PANEL.getFontMetrics(font).stringWidth(Az)) { tmpFont.dispose(); height--; fontData.setHeight(height); tmpFont = new Font(device, fontData); tmpGC.setFont(tmpFont); } } else if (tmpGC.textExtent(Az).x < DUMMY_PANEL.getFontMetrics(font).stringWidth(Az)) { while (tmpGC.textExtent(Az).x < DUMMY_PANEL.getFontMetrics(font).stringWidth(Az)) { tmpFont.dispose(); height++; fontData.setHeight(height); tmpFont = new Font(device, fontData); tmpGC.setFont(tmpFont); } } tmpFont.dispose(); tmpGC.dispose(); } return fontData; } /** * Create an awt font by converting as much information * as possible from the provided swt <code>FontData</code>. * <p>Generally speaking, given a font size, an swt font will * display differently on the screen than the corresponding awt * one. Because the SWT toolkit use native graphical ressources whenever * it is possible, this fact is platform dependent. To address * this issue, it is possible to enforce the method to return * an awt font with the same height as the swt one. * * @param device The swt device being drawn on (display or gc device). * @param fontData The swt font to convert. * @param ensureSameSize A boolean used to enforce the same size * (in pixels) between the swt font and the newly created awt font. * @return An awt font converted from the provided swt font. */ public static java.awt.Font toAwtFont(Device device, FontData fontData, boolean ensureSameSize) { int height = (int) Math.round(fontData.getHeight() * device.getDPI().y / 72.0); // hack to ensure the newly created awt fonts will be rendered with the // same height as the swt one if (ensureSameSize) { GC tmpGC = new GC(device); Font tmpFont = new Font(device, fontData); tmpGC.setFont(tmpFont); JPanel DUMMY_PANEL = new JPanel(); java.awt.Font tmpAwtFont = new java.awt.Font(fontData.getName(), fontData.getStyle(), height); if (DUMMY_PANEL.getFontMetrics(tmpAwtFont).stringWidth(Az) > tmpGC.textExtent(Az).x) { while (DUMMY_PANEL.getFontMetrics(tmpAwtFont).stringWidth(Az) > tmpGC.textExtent(Az).x) { height--; tmpAwtFont = new java.awt.Font(fontData.getName(), fontData.getStyle(), height); } } else if (DUMMY_PANEL.getFontMetrics(tmpAwtFont).stringWidth(Az) < tmpGC.textExtent(Az).x) { while (DUMMY_PANEL.getFontMetrics(tmpAwtFont).stringWidth(Az) < tmpGC.textExtent(Az).x) { height++; tmpAwtFont = new java.awt.Font(fontData.getName(), fontData.getStyle(), height); } } tmpFont.dispose(); tmpGC.dispose(); } return new java.awt.Font(fontData.getName(), fontData.getStyle(), height); } }