-/* Copyright (C) 2000 Free Software Foundation
+/* Image.java -- superclass for images
+ Copyright (C) 1999, 2002, 2004 Free Software Foundation, Inc.
- This file is part of libgcj.
+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., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 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. */
-This software is copyrighted work licensed under the terms of the
-Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
-details. */
package java.awt;
-/**
- * @author Warren Levy <warrenl@cygnus.com>
- * @date March 15, 2000.
- */
+import java.awt.image.FilteredImageSource;
+import java.awt.image.ImageObserver;
+import java.awt.image.ImageProducer;
+import java.awt.image.ReplicateScaleFilter;
/**
- * Written using on-line Java Platform 1.2 API Specification, as well
- * as "The Java Class Libraries", 2nd edition (Addison-Wesley, 1998).
- * Status: Stubbed; A very incomplete placeholder.
+ * This is the abstract superclass of all image objects in Java.
+ *
+ * @author Aaron M. Renn <arenn@urbanophile.com>
+ * @since 1.0
+ * @status updated to 1.4
*/
-
-public abstract class Image extends Object
+public abstract class Image
{
+ /**
+ * This variable is returned whenever a property that is not defined
+ * is requested.
+ */
+ // For debug purposes, this might as well be a unique string.
+ public static final Object UndefinedProperty
+ = new String("undefined property");
+
+ /**
+ * Constant indicating that the default scaling algorithm should be used.
+ *
+ * @since 1.1
+ */
+ public static final int SCALE_DEFAULT = 1;
+
+ /**
+ * Constant indicating that a fast scaling algorithm should be used.
+ *
+ * @since 1.1
+ */
+ public static final int SCALE_FAST = 2;
+
+ /**
+ * Constant indicating that a smooth scaling algorithm should be used.
+ *
+ * @since 1.1
+ */
+ public static final int SCALE_SMOOTH = 4;
+
+ /**
+ * Constant indicating that the <code>ReplicateScaleFilter</code> class
+ * algorithm should be used for scaling.
+ *
+ * @see ReplicateScaleFilter
+ * @since 1.1
+ */
+ public static final int SCALE_REPLICATE = 8;
+
+ /**
+ * Constant indicating that the area averaging scaling algorithm should be
+ * used.
+ *
+ * @see AreaAveragingScaleFilter
+ * @since 1.1
+ */
+ public static final int SCALE_AREA_AVERAGING = 16;
+
+ /**
+ * A default constructor for subclasses.
+ */
public Image()
{
- super(); // ???
- throw new Error("java.awt.Image: not implemented");
}
-}
+
+ /**
+ * Returns the width of the image, or -1 if it is unknown. If the
+ * image width is unknown, the observer object will be notified when
+ * the value is known.
+ *
+ * @param observer the image observer for this object
+ * @return the width in pixels
+ * @see #getHeight(ImageObserver)
+ */
+ public abstract int getWidth(ImageObserver observer);
+
+ /**
+ * Returns the height of the image, or -1 if it is unknown. If the
+ * image height is unknown, the observer object will be notified when
+ * the value is known.
+ *
+ * @param observer the image observer for this object
+ * @return the height in pixels
+ * @see #getWidth(ImageObserver)
+ */
+ public abstract int getHeight(ImageObserver observer);
+
+ /**
+ * Returns the image producer object for this object. The producer is the
+ * object which generates pixels for this image.
+ *
+ * @return the image producer for this object
+ */
+ public abstract ImageProducer getSource();
+
+ /**
+ * Returns a graphics context object for drawing an off-screen object.
+ * This method is only valid for off-screen objects.
+ *
+ * @return a graphics context object for an off-screen object
+ * @see Graphics#createImage(int, int)
+ */
+ public abstract Graphics getGraphics();
+
+ /**
+ * This method requests a named property for an object. The value of the
+ * property is returned. The value <code>UndefinedProperty</code> is
+ * returned if there is no property with the specified name. The value
+ * <code>null</code> is returned if the properties for the object are
+ * not yet known. In this case, the specified image observer is notified
+ * when the properties are known.
+ *
+ * @param name the requested property name
+ * @param observer the image observer for this object
+ * @return the named property, if available
+ * @see #UndefinedProperty
+ */
+ public abstract Object getProperty(String name, ImageObserver observer);
+
+ /**
+ * Scales the image to the requested dimension. A new Image with asynchronous
+ * loading will be produced according to the hints of the algorithm
+ * requested. If either the width or height is non-positive, it is adjusted
+ * to preserve the original aspect ratio.
+ *
+ * @param width the width of the scaled image
+ * @param height the height of the scaled image
+ * @param flags a value indicating the algorithm to use
+ * @return the scaled <code>Image</code> object
+ * @see #SCALE_DEFAULT
+ * @see #SCALE_FAST
+ * @see #SCALE_SMOOTH
+ * @see #SCALE_REPLICATE
+ * @see #SCALE_AREA_AVERAGING
+ * @since 1.1
+ */
+ public Image getScaledInstance(int width, int height, int flags)
+ {
+ switch (flags)
+ {
+ case SCALE_DEFAULT:
+ case SCALE_FAST:
+ case SCALE_REPLICATE:
+ ImageProducer producer =
+ new FilteredImageSource(this.getSource(),
+ new ReplicateScaleFilter(width, height));
+ return Toolkit.getDefaultToolkit().createImage(producer);
+ case SCALE_SMOOTH:
+ case SCALE_AREA_AVERAGING:
+ default:
+ throw new Error("not implemented");
+ }
+ }
+
+ /**
+ * Flushes (that is, destroys) any resources used for this image. This
+ * includes the actual image data.
+ */
+ public abstract void flush();
+} // class Image
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