libjava/classpath/gnu/java/awt/ClasspathToolkit.java

   1 /* ClasspathToolkit.java -- Abstract superclass for Classpath toolkits.
   2    Copyright (C) 2003, 2004, 2005  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package gnu.java.awt;
  40
  41 import gnu.java.awt.EmbeddedWindow;
  42 import gnu.java.awt.peer.ClasspathFontPeer;
  43 import gnu.java.awt.peer.EmbeddedWindowPeer;
  44 import gnu.java.awt.peer.ClasspathTextLayoutPeer;
  45 import gnu.java.security.action.SetAccessibleAction;
  46
  47 import java.awt.AWTException;
  48 import java.awt.Component;
  49 import java.awt.Dimension;
  50 import java.awt.DisplayMode;
  51 import java.awt.Font;
  52 import java.awt.FontMetrics;
  53 import java.awt.GraphicsDevice;
  54 import java.awt.GraphicsEnvironment;
  55 import java.awt.Image;
  56 import java.awt.Toolkit;
  57 import java.awt.font.FontRenderContext;
  58 import java.awt.image.ColorModel;
  59 import java.awt.image.ImageProducer;
  60 import java.awt.peer.RobotPeer;
  61 import java.io.File;
  62 import java.io.InputStream;
  63 import java.lang.reflect.Constructor;
  64 import java.lang.reflect.InvocationTargetException;
  65 import java.net.MalformedURLException;
  66 import java.net.URL;
  67 import java.text.AttributedString;
  68 import java.util.HashMap;
  69 import java.util.Map;
  70 import java.security.AccessController;
  71
  72 import javax.imageio.spi.IIORegistry;
  73
  74 /**
  75  * An abstract superclass for Classpath toolkits.
  76  *
  77  * <p>There exist some parts of AWT and Java2D that are specific to
  78  * the underlying platform, but for which the {@link Toolkit} class
  79  * does not provide suitable abstractions. Examples include some
  80  * methods of {@link Font} or {@link GraphicsEnvironment}. Those
  81  * methods use ClasspathToolkit as a central place for obtaining
  82  * platform-specific functionality.
  83  *
  84  * <p>In addition, ClasspathToolkit implements some abstract methods
  85  * of {@link java.awt.Toolkit} that are not really platform-specific,
  86  * such as the maintenance of a cache of loaded images.
  87  *
  88  * <p><b>Thread Safety:</b> The methods of this class may safely be
  89  * called without external synchronization. This also hold for any
  90  * inherited {@link Toolkit} methods. Subclasses are responsible for
  91  * the necessary synchronization.
  92  *
  93  * @author Sascha Brawer (brawer@dandelis.ch)
  94  */
  95 public abstract class ClasspathToolkit
  96   extends Toolkit
  97 {
  98   /**
  99    * Returns a shared instance of the local, platform-specific
 100    * graphics environment.
 101    *
 102    * <p>This method is specific to GNU Classpath. It gets called by
 103    * the Classpath implementation of {@link
 104    * GraphicsEnvironment.getLocalGraphcisEnvironment()}.
 105    */
 106   public abstract GraphicsEnvironment getLocalGraphicsEnvironment();
 107
 108   /**
 109    * Acquires an appropriate {@link ClasspathFontPeer}, for use in
 110    * classpath's implementation of {@link java.awt.Font}.
 111    *
 112    * @param name The logical name of the font. This may be either a face
 113    * name or a logical font name, or may even be null. A default
 114    * implementation of name decoding is provided in
 115    * {@link ClasspathFontPeer}, but may be overridden in other toolkits.
 116    *
 117    * @param attrs Any extra {@link java.awt.font.TextAttribute} attributes
 118    * this font peer should have, such as size, weight, family name, or
 119    * transformation.
 120    */
 121   public abstract ClasspathFontPeer getClasspathFontPeer (String name, Map attrs);
 122
 123   public abstract ClasspathTextLayoutPeer
 124   getClasspathTextLayoutPeer (AttributedString str, FontRenderContext frc);
 125
 126
 127   /**
 128    * Creates a {@link Font}, in a platform-specific manner.
 129    *
 130    * The default implementation simply constructs a {@link Font}, but some
 131    * toolkits may wish to override this, to return {@link Font} subclasses
 132    * which implement {@link java.awt.font.OpenType} or
 133    * {@link java.awt.font.MultipleMaster}.
 134    */
 135   public Font getFont (String name, Map attrs)
 136   {
 137     Font f = null;
 138
 139     // Circumvent the package-privateness of the
 140     // java.awt.Font.Font(String,Map) constructor.
 141     try
 142       {
 143         Constructor fontConstructor = Font.class.getDeclaredConstructor
 144           (new Class[] { String.class, Map.class });
 145         AccessController.doPrivileged
 146           (new SetAccessibleAction(fontConstructor));
 147         f = (Font) fontConstructor.newInstance(new Object[] { name, attrs });
 148       }
 149     catch (IllegalAccessException e)
 150       {
 151         throw new AssertionError(e);
 152       }
 153     catch (NoSuchMethodException e)
 154       {
 155         throw new AssertionError(e);
 156       }
 157     catch (InstantiationException e)
 158       {
 159         throw new AssertionError(e);
 160       }
 161     catch (InvocationTargetException e)
 162       {
 163         throw new AssertionError(e);
 164       }
 165     return f;
 166   }
 167
 168   /**
 169    * Creates a font, reading the glyph definitions from a stream.
 170    *
 171    * <p>This method provides the platform-specific implementation for
 172    * the static factory method {@link Font#createFont(int,
 173    * java.io.InputStream)}.
 174    *
 175    * @param format the format of the font data, such as {@link
 176    * Font#TRUETYPE_FONT}. An implementation may ignore this argument
 177    * if it is able to automatically recognize the font format from the
 178    * provided data.
 179    *
 180    * @param stream an input stream from where the font data is read
 181    * in. The stream will be advanced to the position after the font
 182    * data, but not closed.
 183    *
 184    * @throws IllegalArgumentException if <code>format</code> is
 185    * not supported.
 186    *
 187    * @throws FontFormatException if <code>stream</code> does not
 188    * contain data in the expected format, or if required tables are
 189    * missing from a font.
 190    *
 191    * @throws IOException if a problem occurs while reading in the
 192    * contents of <code>stream</code>.
 193    */
 194   public abstract Font createFont(int format, InputStream stream);
 195
 196   public abstract RobotPeer createRobot (GraphicsDevice screen)
 197     throws AWTException;
 198
 199   /**
 200    * Creates an embedded window peer, and associates it with an
 201    * EmbeddedWindow object.
 202    *
 203    * @param w The embedded window with which to associate a peer.
 204    */
 205   public abstract EmbeddedWindowPeer createEmbeddedWindow (EmbeddedWindow w);
 206
 207   /**
 208    * Used to register ImageIO SPIs provided by the toolkit.
 209    */
 210    public void registerImageIOSpis(IIORegistry reg)
 211    {
 212    }
 213 }