org.fife.ui.rtextarea.VolatileImageBackgroundPainterStrategy Maven / Gradle / Ivy
/*
* 01/22/2005
*
* VolatileImageBackgroundPainterStrategy.java - Renders an RTextAreaBase's
* background as an image using VolatileImages.
*
* This library is distributed under a modified BSD license. See the included
* LICENSE file for details.
*/
package org.fife.ui.rtextarea;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.VolatileImage;
/**
* A strategy for painting the background of an RTextAreaBase
* as an image. The image is always stretched to completely fill the
* RTextAreaBase.
*
* A java.awt.image.VolatileImage is used for rendering;
* theoretically, this should be the best image format for performance.
*
* You can set the scaling hint used when stretching/skewing the image
* to fit in the RTextAreaBase's background via the
* setScalingHint method, but keep in mind the more
* accurate the scaling hint, the less responsive your application will
* be when stretching the window (as that's the only time the image's
* size is recalculated).
*
* @author Robert Futrell
* @version 0.1
* @see org.fife.ui.rtextarea.ImageBackgroundPainterStrategy
* @see org.fife.ui.rtextarea.BufferedImageBackgroundPainterStrategy
*/
public class VolatileImageBackgroundPainterStrategy
extends ImageBackgroundPainterStrategy {
private VolatileImage bgImage;
/**
* Constructor.
*
* @param ta The text area whose background we'll be painting.
*/
public VolatileImageBackgroundPainterStrategy(RTextAreaBase ta) {
super(ta);
}
/**
* Paints the image at the specified location. This method assumes
* scaling has already been done, and simply paints the background
* image "as-is."
*
* @param g The graphics context.
* @param x The x-coordinate at which to paint.
* @param y The y-coordinate at which to paint.
*/
@Override
protected void paintImage(Graphics g, int x, int y) {
if (bgImage != null) {
do {
int rc = bgImage.validate(null);//getGraphicsConfiguration());
if (rc==VolatileImage.IMAGE_RESTORED) {
// FIXME: If the image needs to be restored are its width
// and height still valid?? If not, we'll need to cache
// these values...
renderImage(bgImage.getWidth(), bgImage.getHeight(),
getScalingHint());
}
g.drawImage(bgImage, x,y, null);
} while (bgImage.contentsLost());
}
}
/**
* Renders the image at the proper size into bgImage.
* This method assumes that bgImage is not
* null.
*
* @param width The width of the volatile image to render into.
* @param height The height of the volatile image to render into.
* @param hint The scaling hint to use.
*/
private void renderImage(int width, int height, int hint) {
Image master = getMasterImage();
if (master!=null) {
do {
Image i = master.getScaledInstance(width,height, hint);
tracker.addImage(i, 1);
try {
tracker.waitForID(1);
} catch (InterruptedException e) {
e.printStackTrace();
bgImage = null;
return;
} finally {
tracker.removeImage(i, 1);
}
bgImage.getGraphics().drawImage(i, 0,0, null);
tracker.addImage(bgImage, 0);
try {
tracker.waitForID(0);
} catch (InterruptedException e) {
e.printStackTrace();
bgImage = null;
return;
} finally {
tracker.removeImage(bgImage, 0);
}
} while (bgImage.contentsLost());
} // End of if (master!=null).
else {
bgImage = null;
}
}
/**
* Rescales the displayed image to be the specified size.
*
* @param width The new width of the image.
* @param height The new height of the image.
* @param hint The scaling hint to use.
*/
@Override
protected void rescaleImage(int width, int height, int hint) {
bgImage = getRTextAreaBase().createVolatileImage(width, height);
if (bgImage!=null) {
renderImage(width, height, hint);
}
}
}