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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package java.awt;
/**
* Capabilities and properties of buffers.
*
* @see java.awt.image.BufferStrategy#getCapabilities()
* @see GraphicsConfiguration#getBufferCapabilities
* @author Michael Martak
* @since 1.4
*/
public class BufferCapabilities implements Cloneable {
private ImageCapabilities frontCaps;
private ImageCapabilities backCaps;
private FlipContents flipContents;
/**
* Creates a new object for specifying buffering capabilities
* @param frontCaps the capabilities of the front buffer; cannot be
* <code>null</code>
* @param backCaps the capabilities of the back and intermediate buffers;
* cannot be <code>null</code>
* @param flipContents the contents of the back buffer after page-flipping,
* <code>null</code> if page flipping is not used (implies blitting)
* @exception IllegalArgumentException if frontCaps or backCaps are
* <code>null</code>
*/
public BufferCapabilities(ImageCapabilities frontCaps,
ImageCapabilities backCaps, FlipContents flipContents) {
if (frontCaps == null || backCaps == null) {
throw new IllegalArgumentException(
"Image capabilities specified cannot be null");
}
this.frontCaps = frontCaps;
this.backCaps = backCaps;
this.flipContents = flipContents;
}
/**
* @return the image capabilities of the front (displayed) buffer
*/
public ImageCapabilities getFrontBufferCapabilities() {
return frontCaps;
}
/**
* @return the image capabilities of all back buffers (intermediate buffers
* are considered back buffers)
*/
public ImageCapabilities getBackBufferCapabilities() {
return backCaps;
}
/**
* @return whether or not the buffer strategy uses page flipping; a set of
* buffers that uses page flipping
* can swap the contents internally between the front buffer and one or
* more back buffers by switching the video pointer (or by copying memory
* internally). A non-flipping set of
* buffers uses blitting to copy the contents from one buffer to
* another; when this is the case, <code>getFlipContents</code> returns
* <code>null</code>
*/
public boolean isPageFlipping() {
return (getFlipContents() != null);
}
/**
* @return the resulting contents of the back buffer after page-flipping.
* This value is <code>null</code> when the <code>isPageFlipping</code>
* returns <code>false</code>, implying blitting. It can be one of
* <code>FlipContents.UNDEFINED</code>
* (the assumed default), <code>FlipContents.BACKGROUND</code>,
* <code>FlipContents.PRIOR</code>, or
* <code>FlipContents.COPIED</code>.
* @see #isPageFlipping
* @see FlipContents#UNDEFINED
* @see FlipContents#BACKGROUND
* @see FlipContents#PRIOR
* @see FlipContents#COPIED
*/
public FlipContents getFlipContents() {
return flipContents;
}
/**
* @return whether page flipping is only available in full-screen mode. If this
* is <code>true</code>, full-screen exclusive mode is required for
* page-flipping.
* @see #isPageFlipping
* @see GraphicsDevice#setFullScreenWindow
*/
public boolean isFullScreenRequired() {
return false;
}
/**
* @return whether or not
* page flipping can be performed using more than two buffers (one or more
* intermediate buffers as well as the front and back buffer).
* @see #isPageFlipping
*/
public boolean isMultiBufferAvailable() {
return false;
}
/**
* @return a copy of this BufferCapabilities object.
*/
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException e) {
// Since we implement Cloneable, this should never happen
throw new InternalError();
}
}
// Inner class FlipContents
/**
* A type-safe enumeration of the possible back buffer contents after
* page-flipping
* @since 1.4
*/
public static final class FlipContents extends AttributeValue {
private static int I_UNDEFINED = 0;
private static int I_BACKGROUND = 1;
private static int I_PRIOR = 2;
private static int I_COPIED = 3;
private static final String NAMES[] =
{ "undefined", "background", "prior", "copied" };
/**
* When flip contents are <code>UNDEFINED</code>, the
* contents of the back buffer are undefined after flipping.
* @see #isPageFlipping
* @see #getFlipContents
* @see #BACKGROUND
* @see #PRIOR
* @see #COPIED
*/
public static final FlipContents UNDEFINED =
new FlipContents(I_UNDEFINED);
/**
* When flip contents are <code>BACKGROUND</code>, the
* contents of the back buffer are cleared with the background color after
* flipping.
* @see #isPageFlipping
* @see #getFlipContents
* @see #UNDEFINED
* @see #PRIOR
* @see #COPIED
*/
public static final FlipContents BACKGROUND =
new FlipContents(I_BACKGROUND);
/**
* When flip contents are <code>PRIOR</code>, the
* contents of the back buffer are the prior contents of the front buffer
* (a true page flip).
* @see #isPageFlipping
* @see #getFlipContents
* @see #UNDEFINED
* @see #BACKGROUND
* @see #COPIED
*/
public static final FlipContents PRIOR =
new FlipContents(I_PRIOR);
/**
* When flip contents are <code>COPIED</code>, the
* contents of the back buffer are copied to the front buffer when
* flipping.
* @see #isPageFlipping
* @see #getFlipContents
* @see #UNDEFINED
* @see #BACKGROUND
* @see #PRIOR
*/
public static final FlipContents COPIED =
new FlipContents(I_COPIED);
private FlipContents(int type) {
super(type, NAMES);
}
} // Inner class FlipContents
}