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src/java.desktop/share/classes/java/awt/Canvas.java
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*** 27,43 ****
import java.awt.image.BufferStrategy;
import java.awt.peer.CanvasPeer;
import javax.accessibility.*;
/**
! * A <code>Canvas</code> component represents a blank rectangular
* area of the screen onto which the application can draw or from
* which the application can trap input events from the user.
* <p>
! * An application must subclass the <code>Canvas</code> class in
* order to get useful functionality such as creating a custom
! * component. The <code>paint</code> method must be overridden
* in order to perform custom graphics on the canvas.
*
* @author Sami Shaio
* @since 1.0
*/
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import java.awt.image.BufferStrategy;
import java.awt.peer.CanvasPeer;
import javax.accessibility.*;
/**
! * A {@code Canvas} component represents a blank rectangular
* area of the screen onto which the application can draw or from
* which the application can trap input events from the user.
* <p>
! * An application must subclass the {@code Canvas} class in
* order to get useful functionality such as creating a custom
! * component. The {@code paint} method must be overridden
* in order to perform custom graphics on the canvas.
*
* @author Sami Shaio
* @since 1.0
*/
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}
/**
* Paints this canvas.
* <p>
! * Most applications that subclass <code>Canvas</code> should
* override this method in order to perform some useful operation
* (typically, custom painting of the canvas).
* The default operation is simply to clear the canvas.
* Applications that override this method need not call
* super.paint(g).
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}
/**
* Paints this canvas.
* <p>
! * Most applications that subclass {@code Canvas} should
* override this method in order to perform some useful operation
* (typically, custom painting of the canvas).
* The default operation is simply to clear the canvas.
* Applications that override this method need not call
* super.paint(g).
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}
/**
* Updates this canvas.
* <p>
! * This method is called in response to a call to <code>repaint</code>.
* The canvas is first cleared by filling it with the background
* color, and then completely redrawn by calling this canvas's
! * <code>paint</code> method.
* Note: applications that override this method should either call
* super.update(g) or incorporate the functionality described
* above into their own code.
*
* @param g the specified Graphics context
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}
/**
* Updates this canvas.
* <p>
! * This method is called in response to a call to {@code repaint}.
* The canvas is first cleared by filling it with the background
* color, and then completely redrawn by calling this canvas's
! * {@code paint} method.
* Note: applications that override this method should either call
* super.update(g) or incorporate the functionality described
* above into their own code.
*
* @param g the specified Graphics context
*** 149,159 ****
/**
* Creates a new strategy for multi-buffering on this component.
* Multi-buffering is useful for rendering performance. This method
* attempts to create the best strategy available with the number of
! * buffers supplied. It will always create a <code>BufferStrategy</code>
* with that number of buffers.
* A page-flipping strategy is attempted first, then a blitting strategy
* using accelerated buffers. Finally, an unaccelerated blitting
* strategy is used.
* <p>
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/**
* Creates a new strategy for multi-buffering on this component.
* Multi-buffering is useful for rendering performance. This method
* attempts to create the best strategy available with the number of
! * buffers supplied. It will always create a {@code BufferStrategy}
* with that number of buffers.
* A page-flipping strategy is attempted first, then a blitting strategy
* using accelerated buffers. Finally, an unaccelerated blitting
* strategy is used.
* <p>
*** 178,205 ****
* <p>
* Each time this method
* is called, the existing buffer strategy for this component is discarded.
* @param numBuffers number of buffers to create
* @param caps the required capabilities for creating the buffer strategy;
! * cannot be <code>null</code>
* @exception AWTException if the capabilities supplied could not be
* supported or met; this may happen, for example, if there is not enough
* accelerated memory currently available, or if page flipping is specified
* but not possible.
* @exception IllegalArgumentException if numBuffers is less than 1, or if
! * caps is <code>null</code>
* @see #getBufferStrategy
* @since 1.4
*/
public void createBufferStrategy(int numBuffers,
BufferCapabilities caps) throws AWTException {
super.createBufferStrategy(numBuffers, caps);
}
/**
! * Returns the <code>BufferStrategy</code> used by this component. This
! * method will return null if a <code>BufferStrategy</code> has not yet
* been created or has been disposed.
*
* @return the buffer strategy used by this component
* @see #createBufferStrategy
* @since 1.4
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* <p>
* Each time this method
* is called, the existing buffer strategy for this component is discarded.
* @param numBuffers number of buffers to create
* @param caps the required capabilities for creating the buffer strategy;
! * cannot be {@code null}
* @exception AWTException if the capabilities supplied could not be
* supported or met; this may happen, for example, if there is not enough
* accelerated memory currently available, or if page flipping is specified
* but not possible.
* @exception IllegalArgumentException if numBuffers is less than 1, or if
! * caps is {@code null}
* @see #getBufferStrategy
* @since 1.4
*/
public void createBufferStrategy(int numBuffers,
BufferCapabilities caps) throws AWTException {
super.createBufferStrategy(numBuffers, caps);
}
/**
! * Returns the {@code BufferStrategy} used by this component. This
! * method will return null if a {@code BufferStrategy} has not yet
* been created or has been disposed.
*
* @return the buffer strategy used by this component
* @see #createBufferStrategy
* @since 1.4
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return accessibleContext;
}
/**
* This class implements accessibility support for the
! * <code>Canvas</code> class. It provides an implementation of the
* Java Accessibility API appropriate to canvas user-interface elements.
* @since 1.3
*/
protected class AccessibleAWTCanvas extends AccessibleAWTComponent
{
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return accessibleContext;
}
/**
* This class implements accessibility support for the
! * {@code Canvas} class. It provides an implementation of the
* Java Accessibility API appropriate to canvas user-interface elements.
* @since 1.3
*/
protected class AccessibleAWTCanvas extends AccessibleAWTComponent
{
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