/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @author Igor V. Stolyarov
* @version $Revision$
*/
package java.awt;
import java.awt.image.AreaAveragingScaleFilter;
import java.awt.image.FilteredImageSource;
import java.awt.image.ImageFilter;
import java.awt.image.ImageObserver;
import java.awt.image.ImageProducer;
import java.awt.image.ReplicateScaleFilter;
import org.apache.harmony.awt.internal.nls.Messages;
/**
* The Image abstract class represents the graphic images.
*
* @since Android 1.0
*/
public abstract class Image {
/**
* The UndefinedProperty object should be returned if property is not
* defined for a particular image.
*/
public static final Object UndefinedProperty = new Object(); // $NON-LOCK-1$
/**
* The Constant SCALE_DEFAULT indicates the default image scaling algorithm.
*/
public static final int SCALE_DEFAULT = 1;
/**
* The Constant SCALE_FAST indicates an image scaling algorithm which places
* a higher priority on scaling speed than on the image's smoothness.
*/
public static final int SCALE_FAST = 2;
/**
* The Constant SCALE_SMOOTH indicates an image scaling algorithm which
* places a higher priority on image smoothness than on scaling speed.
*/
public static final int SCALE_SMOOTH = 4;
/**
* The Constant SCALE_REPLICATE indicates the image scaling algorithm in the
* ReplicateScaleFilter class.
*/
public static final int SCALE_REPLICATE = 8;
/**
* The Constant SCALE_AREA_AVERAGING indicates the area averaging image
* scaling algorithm.
*/
public static final int SCALE_AREA_AVERAGING = 16;
/**
* The acceleration priority indicates image acceleration.
*/
protected float accelerationPriority = 0.5f;
/**
* The Constant capabilities.
*/
private static final ImageCapabilities capabilities = new ImageCapabilities(false);
/**
* Gets the image property with the specified name. The UndefinedProperty
* object should be return if the property is not specified for this image.
* The return value should be null if the property is currently unknown yet
* and the specified ImageObserver is to be notified later.
*
* @param name
* the name of image's property.
* @param observer
* the ImageObserver.
* @return the Object which represents value of the specified property.
*/
public abstract Object getProperty(String name, ImageObserver observer);
/**
* Gets the ImageProducer object which represents data of this Image.
*
* @return the ImageProducer object which represents data of this Image.
*/
public abstract ImageProducer getSource();
/**
* Gets the width of this image. The specified ImageObserver object is
* notified when the width of this image is available.
*
* @param observer
* the ImageObserver object which is is notified when the width
* of this image is available.
* @return the width of image, or -1 if the width of this image is not
* available.
*/
public abstract int getWidth(ImageObserver observer);
/**
* Gets the height of this image. The specified ImageObserver object is
* notified when the height of this image is available.
*
* @param observer
* the ImageObserver object which is is notified when the height
* of this image is available.
* @return the height of image, or -1 if the height of this image is not
* available.
*/
public abstract int getHeight(ImageObserver observer);
/**
* Gets the scaled instance of this Image. This method returns an Image
* object constructed from the source of this image with the specified
* width, height, and applied scaling algorithm.
*
* @param width
* the width of scaled Image.
* @param height
* the height of scaled Image.
* @param hints
* the constant which indicates scaling algorithm.
* @return the scaled Image.
*/
public Image getScaledInstance(int width, int height, int hints) {
ImageFilter filter;
if ((hints & (SCALE_SMOOTH | SCALE_AREA_AVERAGING)) != 0) {
filter = new AreaAveragingScaleFilter(width, height);
} else {
filter = new ReplicateScaleFilter(width, height);
}
ImageProducer producer = new FilteredImageSource(getSource(), filter);
return Toolkit.getDefaultToolkit().createImage(producer);
}
/**
* Gets a Graphics object for rendering this image. This method can be used
* for off-screen images.
*
* @return a Graphics object for rendering to this image.
*/
public abstract Graphics getGraphics();
/**
* Flushes resources which are used by this Image object. This method resets
* the image to the reconstructed state from the image's source.
*/
public abstract void flush();
/**
* Gets the acceleration priority of this image.
*
* @return the acceleration priority of this image.
*/
public float getAccelerationPriority() {
return accelerationPriority;
}
/**
* Sets the acceleration priority for this image.
*
* @param priority
* the new acceleration priority (value in the range 0-1).
*/
public void setAccelerationPriority(float priority) {
if (priority < 0 || priority > 1) {
// awt.10A=Priority must be a value between 0 and 1, inclusive
throw new IllegalArgumentException(Messages.getString("awt.10A")); //$NON-NLS-1$
}
accelerationPriority = priority;
}
/**
* Gets an ImageCapabilities object of this Image object for the specified
* GraphicsConfiguration.
*
* @param gc
* the specified GraphicsConfiguration object (null value means
* default GraphicsConfiguration).
* @return an ImageCapabilities object of this Image object for the
* specified GraphicsConfiguration.
*/
public ImageCapabilities getCapabilities(GraphicsConfiguration gc) {
// Note: common image is not accelerated.
return capabilities;
}
}
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