1 /*

     2  * Copyright 2002-2007 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Sun designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Sun in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    22  * CA 95054 USA or visit www.sun.com if you need additional information or

    23  * have any questions.

    24  */

    25 package sun.awt.X11;

    26 

    27 import java.awt.*;

    28 import java.awt.peer.*;

    29 

    30 import sun.awt.ComponentAccessor;

    31 import sun.awt.SunToolkit;

    32 

    33 import sun.awt.X11GraphicsConfig;

    34 import sun.awt.X11GraphicsDevice;

    35 

    36 class XCanvasPeer extends XComponentPeer implements CanvasPeer {

    37 

    38     private boolean eraseBackgroundDisabled;

    39 

    40     XCanvasPeer() {}

    41 

    42     XCanvasPeer(XCreateWindowParams params) {

    43         super(params);

    44     }

    45 

    46     XCanvasPeer(Component target) {

    47         super(target);

    48     }

    49 

    50     void preInit(XCreateWindowParams params) {

    51         super.preInit(params);

    52         if (SunToolkit.getSunAwtNoerasebackground()) {

    53             disableBackgroundErase();

    54         }

    55     }

    56 

    57     void resetTargetGC(Component target) {

    58         ComponentAccessor.resetGC(target);

    59     }

    60 

    61     /*

    62      * Called when the Window this

    63      * Canvas is on is moved onto another Xinerama screen.

    64      *

    65      * Canvases can be created with a non-defulat GraphicsConfiguration.  The

    66      * GraphicsConfiguration needs to be changed to one on the new screen,

    67      * preferably with the same visual ID.

    68      *

    69      * Up-called for other windows peer instances (XPanelPeer, XWindowPeer).

    70      *

    71      * Should only be called from the event thread.

    72      */

    73     public void displayChanged(int screenNum) {

    74         resetLocalGC(screenNum);

    75         resetTargetGC(target);

    76     }

    77 

    78     /* Set graphicsConfig to a GraphicsConfig with the same visual on the new

    79      * screen, which should be easy in Xinerama mode.

    80      *

    81      * Should only be called from displayChanged(), and therefore only from

    82      * the event thread.

    83      */

    84     void resetLocalGC(int screenNum) {

    85         // Opt: Only need to do if we're not using the default GC

    86         if (graphicsConfig != null) {

    87             X11GraphicsConfig parentgc;

    88             // save vis id of current gc

    89             int visual = graphicsConfig.getVisual();

    90 

    91             X11GraphicsDevice newDev = (X11GraphicsDevice) GraphicsEnvironment.

    92                 getLocalGraphicsEnvironment().

    93                 getScreenDevices()[screenNum];

    94 

    95             for (int i = 0; i < newDev.getNumConfigs(screenNum); i++) {

    96                 if (visual == newDev.getConfigVisualId(i, screenNum)) {

    97                     // use that

    98                     graphicsConfig = (X11GraphicsConfig)newDev.getConfigurations()[i];

    99                     break;

   100                 }

   101             }

   102             // just in case...

   103             if (graphicsConfig == null) {

   104                 graphicsConfig = (X11GraphicsConfig) GraphicsEnvironment.

   105                     getLocalGraphicsEnvironment().

   106                     getScreenDevices()[screenNum].

   107                     getDefaultConfiguration();

   108             }

   109         }

   110     }

   111     protected boolean shouldFocusOnClick() {

   112         // Canvas should always be able to be focused by mouse clicks.

   113         return true;

   114     }

   115 

   116     public void disableBackgroundErase() {

   117         eraseBackgroundDisabled = true;

   118     }

   119     protected boolean doEraseBackground() {

   120         return !eraseBackgroundDisabled;

   121     }

   122     public void setBackground(Color c) {

   123         boolean doRepaint = false;

   124         if( getPeerBackground() == null ||

   125            !getPeerBackground().equals( c ) ) {

   126             doRepaint = true;

   127         }

   128         super.setBackground(c);

   129         if( doRepaint ) {

   130             target.repaint();

   131         }

   132     }

   133 }