001    /* GraphicsDevice.java -- information about a graphics device
002       Copyright (C) 2002, 2005  Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package java.awt;
040    
041    import java.awt.image.VolatileImage;
042    
043    /**
044     * This describes a graphics device available to the given environment. This
045     * includes screen and printer devices, and the different configurations for
046     * each device. Also, this allows you to create virtual devices which operate
047     * over a multi-screen environment.
048     *
049     * @author Eric Blake (ebb9@email.byu.edu)
050     * @see GraphicsEnvironment
051     * @see GraphicsConfiguration
052     * @since 1.3
053     * @status updated to 1.4
054     */
055    public abstract class GraphicsDevice
056    {
057      /** Device is a raster screen. */
058      public static final int TYPE_RASTER_SCREEN = 0;
059    
060      /** Device is a printer. */
061      public static final int TYPE_PRINTER = 1;
062    
063      /** Device is an image buffer not visible to the user. */
064      public static final int TYPE_IMAGE_BUFFER = 2;
065    
066      /** The current full-screen window, or null if there is none. */
067      private Window full_screen;
068    
069      /**
070       * The bounds of the fullscreen window before it has been switched to full
071       * screen.
072       */
073      private Rectangle fullScreenOldBounds;
074    
075      /** The current display mode, or null if unknown. */
076      private DisplayMode mode;
077    
078      /**
079       * The default constructor.
080       *
081       * @see GraphicsEnvironment#getScreenDevices()
082       * @see GraphicsEnvironment#getDefaultScreenDevice()
083       * @see GraphicsConfiguration#getDevice()
084       */
085      protected GraphicsDevice()
086      {
087      }
088    
089      /**
090       * Returns the type of the device.
091       *
092       * @return the device type
093       * @see #TYPE_RASTER_SCREEN
094       * @see #TYPE_PRINTER
095       * @see #TYPE_IMAGE_BUFFER
096       */
097      public abstract int getType();
098    
099      /**
100       * Returns an identification string for the device. This can be
101       * vendor-specific, and may be useful for debugging.
102       *
103       * @return the identification
104       */
105      public abstract String getIDstring();
106    
107      /**
108       * Return all configurations valid for this device.
109       *
110       * @return an array of configurations
111       */
112      public abstract GraphicsConfiguration[] getConfigurations();
113    
114      /**
115       * Return the default configuration for this device.
116       *
117       * @return the default configuration
118       */
119      public abstract GraphicsConfiguration getDefaultConfiguration();
120    
121      /**
122       * Return the best configuration, according to the criteria in the given
123       * template.
124       *
125       * @param template the template to adjust by
126       * @return the best configuration
127       * @throws NullPointerException if template is null
128       */
129      public GraphicsConfiguration getBestConfiguration
130        (GraphicsConfigTemplate template)
131      {
132        return template.getBestConfiguration(getConfigurations());
133      }
134    
135      /**
136       * Returns true if the device supports full-screen exclusive mode. The
137       * default implementation returns true; subclass it if this is not the case.
138       *
139       * @return true if full screen support is available
140       * @since 1.4
141       */
142      public boolean isFullScreenSupported()
143      {
144        return true;
145      }
146    
147      /**
148       * Toggle the given window between full screen and normal mode. The previous
149       * full-screen window, if different, is restored; if the given window is
150       * null, no window will be full screen. If
151       * <code>isFullScreenSupported()</code> returns true, full screen mode is
152       * considered to be exclusive, which implies:<ul>
153       * <li>Windows cannot overlap the full-screen window. All other application
154       *     windows will always appear beneath the full-screen window in the
155       *     Z-order.</li>
156       * <li>Input method windows are disabled. It is advisable to call
157       *     <code>Component.enableInputMethods(false)</code> to make a component
158       *     a non-client of the input method framework.</li>
159       * </ul><br>
160       * If <code>isFullScreenSupported()</code> returns false, full-screen
161       * exclusive mode is simulated by resizing the window to the size of the
162       * screen and positioning it at (0,0). This is also what this method does.
163       * If a device supports real fullscreen mode then it should override this
164       * method as well as #isFullScreenSupported and #getFullScreenWindow.
165       *
166       * @param w the window to toggle
167       * @see #isFullScreenSupported()
168       * @see #getFullScreenWindow()
169       * @see #setDisplayMode(DisplayMode)
170       * @see Component#enableInputMethods(boolean)
171       * @since 1.4
172       */
173      public synchronized void setFullScreenWindow(Window w)
174      {
175        // Restore the previous window to normal mode and release the reference.
176        if (full_screen != null)
177          {
178            full_screen.setBounds(fullScreenOldBounds);
179          }
180    
181        full_screen = null;
182    
183        // If w != null, make it full-screen.
184        if (w != null)
185          {
186            fullScreenOldBounds = w.getBounds();
187            full_screen = w;
188            DisplayMode dMode = getDisplayMode();
189            full_screen.setBounds(0, 0, dMode.getWidth(), dMode.getHeight());
190            full_screen.requestFocus();
191            full_screen.setLocationRelativeTo(null);
192          }
193      }
194    
195      /**
196       * Returns the current full-screen window of the device, or null if no
197       * window is full-screen.
198       *
199       * @return the full-screen window
200       * @see #setFullScreenWindow(Window)
201       * @since 1.4
202       */
203      public Window getFullScreenWindow()
204      {
205        return full_screen;
206      }
207    
208      /**
209       * Returns whether this device supports low-level display changes. This may
210       * depend on whether full-screen exclusive mode is available.
211       *
212       * XXX The default implementation returns false for now.
213       *
214       * @return true if display changes are supported
215       * @see #setDisplayMode(DisplayMode)
216       * @since 1.4
217       */
218      public boolean isDisplayChangeSupported()
219      {
220        return false;
221      }
222    
223      /**
224       * Sets the display mode. This may be dependent on the availability of
225       * full-screen exclusive mode.
226       *
227       * @param mode the new mode
228       * @throws IllegalArgumentException if the new mode is not in getDisplayModes
229       * @throws UnsupportedOperationException if ! isDisplayChangeSupported()
230       * @see #getDisplayMode()
231       * @see #getDisplayModes()
232       * @see #isDisplayChangeSupported()
233       * @since 1.4
234       */
235      public void setDisplayMode(DisplayMode mode)
236      {
237        DisplayMode[] array = getDisplayModes();
238        if (! isDisplayChangeSupported())
239          throw new UnsupportedOperationException();
240        int i = array == null ? 0 : array.length;
241        while (--i >= 0)
242          if (array[i].equals(mode))
243            break;
244        if (i < 0)
245          throw new IllegalArgumentException();
246        this.mode = mode;
247      }
248    
249      /**
250       * Returns the current display mode of this device, or null if unknown.
251       *
252       * @return the current display mode
253       * @see #setDisplayMode(DisplayMode)
254       * @see #getDisplayModes()
255       * @since 1.4
256       */
257      public DisplayMode getDisplayMode()
258      {
259        return mode;
260      }
261    
262      /**
263       * Return an array of all available display modes. This implementation
264       * returns a 0-length array, so subclasses must override this.
265       *
266       * @return the array of available modes
267       * @since 1.4
268       */
269      public DisplayMode[] getDisplayModes()
270      {
271        return new DisplayMode[0];
272      }
273    
274      /**
275       * Return the number of bytes available in accelerated memory on this
276       * device. The device may support creation or caching on a first-come,
277       * first-served basis, depending on the operating system and driver.
278       * Memory may be a finite resource, and because of multi-threading, you
279       * are not guaranteed that the result of this method ensures your image
280       * will successfully be put in accelerated memory. A negative result means
281       * the memory is unlimited. The default implementation assumes no special
282       * memory is available, and returns 0.
283       *
284       * @return the size of accelerated memory available
285       * @see VolatileImage#flush()
286       * @see ImageCapabilities#isAccelerated()
287       */
288      public int getAvailableAcceleratedMemory()
289      {
290        return 0;
291      }
292    } // class GraphicsDevice