Create a FontData object which encapsulate the essential data to create a swt font. : SWT AWT Swing « SWT « 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);
    }

}








17.118.SWT AWT Swing
17.118.1.Embeded Swing/AWT components to SWTEmbeded Swing/AWT components to SWT
17.118.2.Using AWT to paint inside SWTUsing AWT to paint inside SWT
17.118.3.Embed a JTable in SWT (no flicker)Embed a JTable in SWT (no flicker)
17.118.4.Create a FontData object which encapsulate the essential data to create a swt font.
17.118.5.Create an awt font by converting as much information as possible from the provided swt Font.
17.118.6.Create an awt font by converting as much information as possible from the provided swt FontData.
17.118.7.Creates a swt color instance to match the rgb values of the specified awt color. alpha channel is not supported.
17.118.8.Creates a swt color instance to match the rgb values of the specified awt paint.
17.118.9.Creates an AWT MouseEvent from a swt event.
17.118.10.Creates an awt color instance to match the rgb values of the specified swt color.
17.118.11.Draw Graphics2D stuff on a swt composite
17.118.12.Returns an AWT point with the same coordinates as the specified SWT point.
17.118.13.Returns an SWT point with the same coordinates as the specified AWT point (rounded to integer values).
17.118.14.Returns an SWT point with the same coordinates as the specified AWT point.
17.118.15.Transform a swt Rectangle instance into an AWT Rectangle.
17.118.16.Transform an awt Rectangle2d instance into a swt Rectangle2d.