/*
 * @(#)GraphicsDevice.java	1.30 03/12/19
 *
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */


package java.awt;

import java.awt.image.ColorModel;

/**
 * The <code>GraphicsDevice</code> class describes the graphics devices
 * that might be available in a particular graphics environment.  These
 * include screen and printer devices. Note that there can be many screens
 * and many printers in an instance of {@link GraphicsEnvironment}. Each
 * graphics device has one or more {@link GraphicsConfiguration} objects
 * associated with it.  These objects specify the different configurations
 * in which the <code>GraphicsDevice</code> can be used.
 * <p>  
 * In a multi-screen environment, the <code>GraphicsConfiguration</code>
 * objects can be used to render components on multiple screens.  The 
 * following code sample demonstrates how to create a <code>JFrame</code>
 * object for each <code>GraphicsConfiguration</code> on each screen
 * device in the <code>GraphicsEnvironment</code>:
 * <pre>
 *   GraphicsEnvironment ge = GraphicsEnvironment.
 *   getLocalGraphicsEnvironment();
 *   GraphicsDevice[] gs = ge.getScreenDevices();
 *   for (int j = 0; j < gs.length; j++) { 
 *      GraphicsDevice gd = gs[j];
 *      GraphicsConfiguration[] gc =
 * 	gd.getConfigurations();
 *      for (int i=0; i < gc.length; i++) {
 *         JFrame f = new
 *         JFrame(gs[j].getDefaultConfiguration());
 *         Canvas c = new Canvas(gc[i]); 
 *         Rectangle gcBounds = gc[i].getBounds();
 *         int xoffs = gcBounds.x;
 *         int yoffs = gcBounds.y;
 *	   f.getContentPane().add(c);
 *	   f.setLocation((i*50)+xoffs, (i*60)+yoffs);
 *         f.show();
 *      }
 *   }
 * </pre>                           
 * @see GraphicsEnvironment
 * @see GraphicsConfiguration
 * @version 1.30, 12/19/03
 */
public abstract class GraphicsDevice {

    private Window fullScreenWindow;
    private Rectangle windowedModeBounds;
    
    /**
     * This is an abstract class that cannot be instantiated directly.
     * Instances must be obtained from a suitable factory or query method.
     * @see GraphicsEnvironment#getScreenDevices
     * @see GraphicsEnvironment#getDefaultScreenDevice
     * @see GraphicsConfiguration#getDevice
     */
    protected GraphicsDevice() {
    }

    /**
     * Device is a raster screen.
     */
    public final static int TYPE_RASTER_SCREEN		= 0;

    /**
     * Device is a printer.
     */
    public final static int TYPE_PRINTER		= 1;

    /**
     * Device is an image buffer.  This buffer can reside in device
     * or system memory but it is not physically viewable by the user.
     */
    public final static int TYPE_IMAGE_BUFFER           = 2;
    
    /**
     * Returns the type of this <code>GraphicsDevice</code>.
     * @return the type of this <code>GraphicsDevice</code>, which can
     * either be TYPE_RASTER_SCREEN, TYPE_PRINTER or TYPE_IMAGE_BUFFER.
     * @see #TYPE_RASTER_SCREEN
     * @see #TYPE_PRINTER
     * @see #TYPE_IMAGE_BUFFER
     */
    public abstract int getType();

    /**
     * Returns the identification string associated with this 
     * <code>GraphicsDevice</code>.
     * <p>
     * A particular program might use more than one 
     * <code>GraphicsDevice</code> in a <code>GraphicsEnvironment</code>.
     * This method returns a <code>String</code> identifying a
     * particular <code>GraphicsDevice</code> in the local
     * <code>GraphicsEnvironment</code>.  Although there is
     * no public method to set this <code>String</code>, a programmer can
     * use the <code>String</code> for debugging purposes.  Vendors of 
     * the Java<sup><font size=-2>TM</font></sup> Runtime Environment can
     * format the return value of the <code>String</code>.  To determine 
     * how to interpret the value of the <code>String</code>, contact the
     * vendor of your Java Runtime.  To find out who the vendor is, from
     * your program, call the 
     * {@link System#getProperty(String) getProperty} method of the
     * System class with "java.vendor".
     * @return a <code>String</code> that is the identification
     * of this <code>GraphicsDevice</code>.
     */
    public abstract String getIDstring();
    
    /**
     * Returns all of the <code>GraphicsConfiguration</code>
     * objects associated with this <code>GraphicsDevice</code>.
     * @return an array of <code>GraphicsConfiguration</code>
     * objects that are associated with this 
     * <code>GraphicsDevice</code>.
     */
    public abstract GraphicsConfiguration[] getConfigurations();

    /**
     * Returns the default <code>GraphicsConfiguration</code>
     * associated with this <code>GraphicsDevice</code>.
     * @return the default <code>GraphicsConfiguration</code>
     * of this <code>GraphicsDevice</code>.
     */
    public abstract GraphicsConfiguration getDefaultConfiguration();

    /**
     * Returns the "best" configuration possible that passes the
     * criteria defined in the {@link GraphicsConfigTemplate}.
     * @param gct the <code>GraphicsConfigTemplate</code> object
     * used to obtain a valid <code>GraphicsConfiguration</code>
     * @return a <code>GraphicsConfiguration</code> that passes
     * the criteria defined in the specified
     * <code>GraphicsConfigTemplate</code>.
     * @see GraphicsConfigTemplate
     */
    public GraphicsConfiguration
           getBestConfiguration(GraphicsConfigTemplate gct) {
        GraphicsConfiguration[] configs = getConfigurations();
        return gct.getBestConfiguration(configs);
    }
 
    /**
     * Returns <code>true</code> if this <code>GraphicsDevice</code>
     * supports full-screen exclusive mode.
     * @return whether full-screen exclusive mode is available for
     * this graphics device
     * @since 1.4
     */
    public boolean isFullScreenSupported() {
        return false;
    }
    
    /**
     * Enter full-screen mode, or return to windowed mode.
     * <p>
     * If <code>isFullScreenSupported</code> returns <code>true</code>, full
     * screen mode is considered to be <i>exclusive</i>, which implies:
     * <ul>
     * <li>Windows cannot overlap the full-screen window.  All other application
     * windows will always appear beneath the full-screen window in the Z-order.
     * <li>Input method windows are disabled.  It is advisable to call
     * <code>Component.enableInputMethods(false)</code> to make a component
     * a non-client of the input method framework.
     * </ul>
     * <p>
     * If <code>isFullScreenSupported</code> returns
     * <code>false</code>, full-screen exclusive mode is simulated by resizing
     * the window to the size of the screen and positioning it at (0,0).
     * <p>
     * When entering full-screen exclusive mode, if the window to be used as the 
     * full-screen window is not visible, this method will make it visible. 
     * It will remain visible when returning to windowed mode.  
     * <p>
     * When returning to windowed mode from an exclusive full-screen window, any
     * display changes made by calling <code>setDisplayMode</code> are
     * automatically restored to their original state.
     *
     * @param w a window to use as the full-screen window; <code>null</code>
     * if returning to windowed mode.  Some platforms expect the
     * fullscreen window to be a top-level component (i.e., a Frame);
     * therefore it is preferable to use a Frame here rather than a
     * Window. 
     * @see #isFullScreenSupported
     * @see #getFullScreenWindow
     * @see #setDisplayMode
     * @see Component#enableInputMethods
     * @see Component#setVisible
     * @since 1.4
     */
    public void setFullScreenWindow(Window w) {
        // Get display mode before changing the full screen window
        DisplayMode dm;
        if (w == null) {
            dm = null;
        } else {
            dm = getDisplayMode();
        }
        if (fullScreenWindow != null && windowedModeBounds != null) {
            fullScreenWindow.setBounds(windowedModeBounds);
	}
        // Set the full screen window
        fullScreenWindow = w;
        if (fullScreenWindow != null) {
            windowedModeBounds = fullScreenWindow.getBounds();
            fullScreenWindow.setBounds(0, 0, dm.getWidth(), dm.getHeight());
            fullScreenWindow.setVisible(true);
            fullScreenWindow.toFront();
        }
    }
    
    /**
     * Returns the <code>Window</code> object representing the 
     * full-screen window if the device is in full-screen mode.
     * 
     * @return the full-screen window, or <code>null</code> if the device is
     * not in full-screen mode.
     * @see #setFullScreenWindow(Window)
     * @since 1.4
     */
    public Window getFullScreenWindow() {
        return fullScreenWindow;
    }
    
    /**
     * Returns <code>true</code> if this <code>GraphicsDevice</code>
     * supports low-level display changes.
     * @return whether low-level display changes are supported for this
     * graphics device.  Note that this may or may not be dependent on
     * full-screen exclusive mode.
     * @see #setDisplayMode
     * @since 1.4
     */
    public boolean isDisplayChangeSupported() {
        return false;
    }
    
    /**
     * Sets the display mode of this graphics device.  This may only be allowed
     * in full-screen, exclusive mode.
     * @param dm the new display mode of this graphics device
     * @exception IllegalArgumentException if the <code>DisplayMode</code>
     * supplied is <code>null</code>, or is not available in the array returned
     * by <code>getDisplayModes</code>
     * @exception UnsupportedOperationException if
     * <code>isDisplayChangeSupported</code> returns <code>false</code>
     * @see #getDisplayMode
     * @see #getDisplayModes
     * @see #isDisplayChangeSupported
     * @since 1.4
     */
    public void setDisplayMode(DisplayMode dm) {
        throw new UnsupportedOperationException("Cannot change display mode");
    }
    
    /**
     * Returns the current display mode of this 
     * <code>GraphicsDevice</code>.
     * @return the current display mode of this graphics device.
     * @see #setDisplayMode(DisplayMode)
     * @since 1.4
     */
    public DisplayMode getDisplayMode() {
        GraphicsConfiguration gc = getDefaultConfiguration();
        Rectangle r = gc.getBounds();
        ColorModel cm = gc.getColorModel();
        return new DisplayMode(r.width, r.height, cm.getPixelSize(), 0);
    }
    
    /**
     * Returns all display modes available for this      
     * <code>GraphicsDevice</code>.
     * @return all of the display modes available for this graphics device.
     * @since 1.4
     */
    public DisplayMode[] getDisplayModes() {
        return new DisplayMode[] { getDisplayMode() };
    }

    /**
     * This method returns the number of bytes available in
     * accelerated memory on this device.
     * Some images are created or cached
     * in accelerated memory on a first-come,
     * first-served basis.  On some operating systems,
     * this memory is a finite resource.  Calling this method
     * and scheduling the creation and flushing of images carefully may
     * enable applications to make the most efficient use of
     * that finite resource.
     * <br>
     * Note that the number returned is a snapshot of how much
     * memory is available; some images may still have problems
     * being allocated into that memory.  For example, depending
     * on operating system, driver, memory configuration, and
     * thread situations, the full extent of the size reported
     * may not be available for a given image.  There are further
     * inquiry methods on the {@link ImageCapabilities} object
     * associated with a VolatileImage that can be used to determine
     * whether a particular VolatileImage has been created in accelerated
     * memory.
     * @return number of bytes available in accelerated memory.
     * A negative return value indicates that accelerated memory
     * is unlimited.
     * @see java.awt.image.VolatileImage#flush
     * @see ImageCapabilities#isAccelerated
     */
    public int getAvailableAcceleratedMemory() {
	return -1;
    }
}