1 /*
   2  * Copyright (c) 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 
  26 package sun.awt;
  27 
  28 import java.awt.Component;
  29 import java.awt.Container;
  30 import java.awt.Frame;
  31 import java.awt.Graphics;
  32 import java.awt.Image;
  33 import java.awt.MenuBar;
  34 import java.awt.MenuComponent;
  35 import java.awt.Rectangle;
  36 import java.awt.Toolkit;
  37 import java.awt.dnd.DragGestureEvent;
  38 import java.awt.dnd.DragGestureListener;
  39 import java.awt.dnd.DragGestureRecognizer;
  40 import java.awt.dnd.DragSource;
  41 import java.awt.dnd.DropTarget;
  42 import java.awt.dnd.InvalidDnDOperationException;
  43 import java.awt.dnd.peer.DragSourceContextPeer;
  44 import java.awt.peer.FramePeer;
  45 
  46 /**
  47  * The class provides basic functionality for a lightweight frame
  48  * implementation. A subclass is expected to provide painting to an
  49  * offscreen image and access to it. Thus it can be used for lightweight
  50  * embedding.
  51  *
  52  * @author Artem Ananiev
  53  * @author Anton Tarasov
  54  */
  55 @SuppressWarnings("serial")
  56 public abstract class LightweightFrame extends Frame {
  57 
  58     /**
  59      * Constructs a new, initially invisible {@code LightweightFrame}
  60      * instance.
  61      */
  62     public LightweightFrame() {
  63         setUndecorated(true);
  64         setResizable(true);
  65         setEnabled(true);
  66     }
  67 
  68     /**
  69      * Blocks introspection of a parent window by this child.
  70      *
  71      * @return null
  72      */
  73     @Override public final Container getParent() { return null; }
  74 
  75     @Override public Graphics getGraphics() { return null; }
  76 
  77     @Override public final boolean isResizable() { return true; }
  78 
  79     // Block modification of any frame attributes, since they aren't
  80     // applicable for a lightweight frame.
  81 
  82     @Override public final void setTitle(String title) {}
  83     @Override public final void setIconImage(Image image) {}
  84     @Override public final void setIconImages(java.util.List<? extends Image> icons) {}
  85     @Override public final void setMenuBar(MenuBar mb) {}
  86     @Override public final void setResizable(boolean resizable) {}
  87     @Override public final void remove(MenuComponent m) {}
  88     @Override public final void toFront() {}
  89     @Override public final void toBack() {}
  90 
  91     @Override public void addNotify() {
  92         synchronized (getTreeLock()) {
  93             if (getPeer() == null) {
  94                 SunToolkit stk = (SunToolkit)Toolkit.getDefaultToolkit();
  95                 try {
  96                     setPeer(stk.createLightweightFrame(this));
  97                 } catch (Exception e) {
  98                     throw new RuntimeException(e);
  99                 }
 100             }
 101             super.addNotify();
 102         }
 103     }
 104 
 105     private void setPeer(final FramePeer p) {
 106         AWTAccessor.getComponentAccessor().setPeer(this, p);
 107     }
 108 
 109     /**
 110      * Requests the peer to emulate activation or deactivation of the
 111      * frame. Peers should override this method if they are to implement
 112      * this functionality.
 113      *
 114      * @param activate if <code>true</code>, activates the frame;
 115      *                 otherwise, deactivates the frame
 116      */
 117     public void emulateActivation(boolean activate) {
 118         ((FramePeer)getPeer()).emulateActivation(activate);
 119     }
 120 
 121     /**
 122      * Delegates the focus grab action to the client (embedding) application.
 123      * The method is called by the AWT grab machinery.
 124      *
 125      * @see SunToolkit#grab(java.awt.Window)
 126      */
 127     public abstract void grabFocus();
 128 
 129     /**
 130      * Delegates the focus ungrab action to the client (embedding) application.
 131      * The method is called by the AWT grab machinery.
 132      *
 133      * @see SunToolkit#ungrab(java.awt.Window)
 134      */
 135     public abstract void ungrabFocus();
 136 
 137     /**
 138      * Returns the scale factor of this frame. The default value is 1.
 139      *
 140      * @return the scale factor
 141      * @see #notifyDisplayChanged(int)
 142      */
 143     public abstract int getScaleFactor();
 144 
 145     /**
 146      * Called when display of the hosted frame is changed.
 147      *
 148      * @param scaleFactor the scale factor
 149      */
 150     public abstract void notifyDisplayChanged(int scaleFactor);
 151 
 152     /**
 153      * Host window absolute bounds.
 154      */
 155     private int hostX, hostY, hostW, hostH;
 156 
 157     /**
 158      * Returns the absolute bounds of the host (embedding) window.
 159      *
 160      * @return the host window bounds
 161      */
 162     public Rectangle getHostBounds() {
 163         if (hostX == 0 && hostY == 0 && hostW == 0 && hostH == 0) {
 164             // The client app is probably unaware of the setHostBounds.
 165             // A safe fall-back:
 166             return getBounds();
 167         }
 168         return new Rectangle(hostX, hostY, hostW, hostH);
 169     }
 170 
 171     /**
 172      * Sets the absolute bounds of the host (embedding) window.
 173      */
 174     public void setHostBounds(int x, int y, int w, int h) {
 175         hostX = x;
 176         hostY = y;
 177         hostW = w;
 178         hostH = h;
 179     }
 180 
 181     /**
 182      * Create a drag gesture recognizer for the lightweight frame.
 183      */
 184     public abstract <T extends DragGestureRecognizer> T createDragGestureRecognizer(
 185             Class<T> abstractRecognizerClass,
 186             DragSource ds, Component c, int srcActions,
 187             DragGestureListener dgl);
 188 
 189     /**
 190      * Create a drag source context peer for the lightweight frame.
 191      */
 192     public abstract DragSourceContextPeer createDragSourceContextPeer(DragGestureEvent dge) throws InvalidDnDOperationException;
 193 
 194     /**
 195      * Adds a drop target to the lightweight frame.
 196      */
 197     public abstract void addDropTarget(DropTarget dt);
 198 
 199     /**
 200      * Removes a drop target from the lightweight frame.
 201      */
 202     public abstract void removeDropTarget(DropTarget dt);
 203 }