1 /*
2  * Copyright (c) 2002, 2013, Oracle and/or its affiliates. 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.  Oracle designates this
8  * particular file as subject to the "Classpath" exception as provided
9  * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22  * or visit www.oracle.com if you need additional information or have any
23  * questions.
24  */
25 package sun.awt.X11;
26 
27 import java.awt.*;
28 import java.awt.peer.*;
29 
30 import sun.awt.SunToolkit;
31 
32 import sun.awt.X11GraphicsConfig;
33 import sun.awt.X11GraphicsDevice;
34 
35 class XCanvasPeer extends XComponentPeer implements CanvasPeer {
36 
37     private boolean eraseBackgroundDisabled;
38 
XCanvasPeer()39     XCanvasPeer() {}
40 
XCanvasPeer(XCreateWindowParams params)41     XCanvasPeer(XCreateWindowParams params) {
42         super(params);
43     }
44 
XCanvasPeer(Component target)45     XCanvasPeer(Component target) {
46         super(target);
47     }
48 
preInit(XCreateWindowParams params)49     void preInit(XCreateWindowParams params) {
50         super.preInit(params);
51         if (SunToolkit.getSunAwtNoerasebackground()) {
52             disableBackgroundErase();
53         }
54     }
55 
56     /* Get a GraphicsConfig with the same visual on the new
57      * screen, which should be easy in Xinerama mode.
58      */
getAppropriateGraphicsConfiguration( GraphicsConfiguration gc)59     public GraphicsConfiguration getAppropriateGraphicsConfiguration(
60                                     GraphicsConfiguration gc)
61     {
62         if (graphicsConfig == null || gc == null) {
63             return gc;
64         }
65         // Opt: Only need to do if we're not using the default GC
66 
67         int screenNum = ((X11GraphicsDevice)gc.getDevice()).getScreen();
68 
69         X11GraphicsConfig parentgc;
70         // save vis id of current gc
71         int visual = graphicsConfig.getVisual();
72 
73         X11GraphicsDevice newDev = (X11GraphicsDevice) GraphicsEnvironment.
74             getLocalGraphicsEnvironment().
75             getScreenDevices()[screenNum];
76 
77         for (int i = 0; i < newDev.getNumConfigs(screenNum); i++) {
78             if (visual == newDev.getConfigVisualId(i, screenNum)) {
79                 // use that
80                 graphicsConfig = (X11GraphicsConfig)newDev.getConfigurations()[i];
81                 break;
82             }
83         }
84         // just in case...
85         if (graphicsConfig == null) {
86             graphicsConfig = (X11GraphicsConfig) GraphicsEnvironment.
87                 getLocalGraphicsEnvironment().
88                 getScreenDevices()[screenNum].
89                 getDefaultConfiguration();
90         }
91 
92         return graphicsConfig;
93     }
94 
shouldFocusOnClick()95     protected boolean shouldFocusOnClick() {
96         // Canvas should always be able to be focused by mouse clicks.
97         return true;
98     }
99 
disableBackgroundErase()100     public void disableBackgroundErase() {
101         eraseBackgroundDisabled = true;
102     }
doEraseBackground()103     protected boolean doEraseBackground() {
104         return !eraseBackgroundDisabled;
105     }
106 }
107