Initial revision

From-SVN: r102074

libjava/classpath/gnu/java/awt/peer/GLightweightPeer.java

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+/* GLightweightPeer.java --
+   Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package gnu.java.awt.peer;
+
+import java.awt.AWTEvent;
+import java.awt.AWTException;
+import java.awt.BufferCapabilities;
+import java.awt.Color;
+import java.awt.Component;
+import java.awt.Cursor;
+import java.awt.Dimension;
+import java.awt.Font;
+import java.awt.FontMetrics;
+import java.awt.Graphics;
+import java.awt.GraphicsConfiguration;
+import java.awt.Image;
+import java.awt.Insets;
+import java.awt.Point;
+import java.awt.Toolkit;
+import java.awt.event.PaintEvent;
+import java.awt.image.ColorModel;
+import java.awt.image.ImageObserver;
+import java.awt.image.ImageProducer;
+import java.awt.image.VolatileImage;
+import java.awt.peer.ContainerPeer;
+import java.awt.peer.LightweightPeer;
+
+/*
+ * Another possible implementation strategy for lightweight peers is
+ * to make GLightweightPeer a placeholder class that implements
+ * LightweightPeer.  Then the Component and Container classes could
+ * identify a peer as lightweight and handle it specially.  The
+ * current approach is probably more clear but less efficient.
+ */
+
+/**
+ * A stub class that implements the ComponentPeer and ContainerPeer
+ * interfaces using callbacks into the Component and Container
+ * classes.  GLightweightPeer allows the Component and Container
+ * classes to treat lightweight and heavyweight peers in the same way.
+ *
+ * Lightweight components are painted directly onto their parent
+ * containers through an Image object provided by the toolkit.
+ */
+public class GLightweightPeer
+  implements LightweightPeer, ContainerPeer
+{
+  private Component comp;
+
+  private Insets containerInsets;
+
+  public GLightweightPeer(Component comp)
+  {
+    this.comp = comp;
+  }
+
+  // -------- java.awt.peer.ContainerPeer implementation:
+  
+  public Insets insets()
+  {
+    return getInsets ();
+  }
+  
+  public Insets getInsets()
+  {
+    if (containerInsets == null)
+      containerInsets = new Insets (0,0,0,0);
+    return containerInsets;
+  }
+  
+  public void beginValidate()
+  {
+  }
+  
+  public void endValidate()
+  {
+  }
+  
+  public void beginLayout()
+  {
+  }
+  
+  public void endLayout()
+  {
+  }
+  
+  public boolean isPaintPending()
+  {
+    return false;
+  }
+
+  // -------- java.awt.peer.ComponentPeer implementation:
+
+  public int checkImage(Image img, int width, int height, ImageObserver o)
+  {
+    return comp.getToolkit().checkImage(img, width, height, o);
+  }
+
+  public Image createImage(ImageProducer prod)
+  {
+    return comp.getToolkit().createImage(prod);
+  }
+
+  /* This method is not called. */
+  public Image createImage(int width, int height)
+  {
+    return null;
+  }
+
+  public void disable() {}
+
+  public void dispose() {}
+
+  public void enable() {}
+
+  public GraphicsConfiguration getGraphicsConfiguration()
+  {
+    return null;
+  }
+
+  public FontMetrics getFontMetrics(Font f)
+  {
+    return comp.getToolkit().getFontMetrics(f);
+  }
+
+  /* Returning null here tells the Component object that called us to
+   * use its parent's Graphics. */
+  public Graphics getGraphics()
+  {
+    return null;
+  }
+
+  public Point getLocationOnScreen()
+  {
+    Point parentLocation = comp.getParent().getLocationOnScreen();
+    return new Point (parentLocation.x + comp.getX(),
+                      parentLocation.y + comp.getY());
+  }
+
+  public Dimension getMinimumSize()
+  {
+    return new Dimension(comp.getWidth(), comp.getHeight());
+  }
+
+  /* A lightweight component's preferred size is equivalent to its
+   * Component width and height values. */
+  public Dimension getPreferredSize()
+  {
+    return new Dimension(comp.getWidth(), comp.getHeight());
+  }
+
+  /* Returning null here tells the Component object that called us to
+   * use its parent's Toolkit. */
+  public Toolkit getToolkit()
+  {
+    return null;
+  }
+
+  public void handleEvent(AWTEvent e) {}
+
+  public void hide() {}
+
+  public boolean isFocusable() 
+  {
+    return false;
+  }
+
+  public boolean isFocusTraversable()
+  {
+    return false;
+  }
+
+  public Dimension minimumSize()
+  {
+    return getMinimumSize();
+  }
+
+  public Dimension preferredSize()
+  {
+    return getPreferredSize();
+  }
+
+  public void paint(Graphics graphics) {}
+
+  public boolean prepareImage(Image img, int width, int height,
+			      ImageObserver o)
+  {
+    return comp.getToolkit().prepareImage(img, width, height, o);
+  }
+
+  public void print(Graphics graphics) {}
+
+  public void repaint(long tm, int x, int y, int width, int height) {}
+
+  public void requestFocus() {}
+
+  public boolean requestFocus(Component source, boolean bool1, boolean bool2, long x)
+  {
+    return false;
+  }
+
+  public void reshape(int x, int y, int width, int height) {}
+
+  public void setBackground(Color color) {}
+
+  public void setBounds(int x, int y, int width, int height) {}
+
+  public void setCursor(Cursor cursor) {}
+
+  public void setEnabled(boolean enabled) {}
+
+  public void setEventMask(long eventMask) {}
+
+  public void setFont(Font font) {}
+
+  public void setForeground(Color color) {}
+
+  public void setVisible(boolean visible) {}
+
+  public void show() {}
+
+  public ColorModel getColorModel ()
+  {
+    return comp.getColorModel ();
+  }
+
+  public boolean isObscured()
+  {
+    return false;
+  }
+
+  public boolean canDetermineObscurity()
+  {
+    return false;
+  }
+
+  public void coalescePaintEvent(PaintEvent e) { }
+
+  public void updateCursorImmediately() { }
+
+  public VolatileImage createVolatileImage(int width, int height) 
+  { 
+    return null; 
+  }
+
+  public boolean handlesWheelScrolling()
+  {
+    return false;
+  }
+
+  public void createBuffers(int x, BufferCapabilities capabilities) 
+    throws AWTException { }
+
+  public Image getBackBuffer()
+  {
+    return null;
+  }
+
+  public void flip(BufferCapabilities.FlipContents contents) { }
+
+  public void destroyBuffers() { }
+}