org.fife.ui.rtextarea.ImageBackgroundPainterStrategy Maven / Gradle / Ivy
Show all versions of rsyntaxtextarea Show documentation
/*
* 01/22/2005
*
* ImageBackgroundPainterStrategy.java - Renders an RTextAreaBase's
* background as an image.
*
* This library is distributed under a modified BSD license. See the included
* RSyntaxTextArea.License.txt file for details.
*/
package org.fife.ui.rtextarea;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.net.URL;
import javax.imageio.ImageIO;
/**
* A strategy for painting the background of an RTextAreaBase
* as an image. The image is always stretched to completely fill the
* RTextAreaBase.
*
* 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.BufferedImageBackgroundPainterStrategy
* @see org.fife.ui.rtextarea.VolatileImageBackgroundPainterStrategy
*/
public abstract class ImageBackgroundPainterStrategy
implements BackgroundPainterStrategy {
protected MediaTracker tracker;
private RTextAreaBase textArea;
private Image master;
private int oldWidth, oldHeight;
private int scalingHint;
/**
* Constructor.
*
* @param textArea The text area using this image as its background.
*/
public ImageBackgroundPainterStrategy(RTextAreaBase textArea) {
this.textArea = textArea;
tracker = new MediaTracker(textArea);
scalingHint = Image.SCALE_FAST;
}
/**
* Returns the text area using this strategy.
*
* @return The text area.
*/
public RTextAreaBase getRTextAreaBase() {
return textArea;
}
/**
* Returns the "master" image; that is, the original, unscaled image.
* When the image needs to be rescaled, scaling should be done from
* this image, to prevent repeated scaling from distorting the image.
*
* @return The master image.
*/
public Image getMasterImage() {
return master;
}
/**
* Returns the scaling hint being used.
*
* @return The scaling hint to use when scaling an image.
* @see #setScalingHint
*/
public int getScalingHint() {
return scalingHint;
}
/**
* Paints the image at the specified location and at the specified size.
*
* @param g The graphics context.
* @param bounds The bounds in which to paint the image. The image
* will be scaled to fit exactly in these bounds if necessary.
*/
@Override
public final void paint(Graphics g, Rectangle bounds) {
if (bounds.width!=oldWidth || bounds.height!=oldHeight) {
rescaleImage(bounds.width, bounds.height, getScalingHint());
oldWidth = bounds.width;
oldHeight = bounds.height;
}
paintImage(g, bounds.x,bounds.y);
}
/**
* 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.
*/
protected abstract void paintImage(Graphics g, int x, int y);
/**
* 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.
*/
protected abstract void rescaleImage(int width, int height,
int hint);
/**
* Sets the image this background painter displays.
*
* @param imageURL URL of a file containing the image to display.
*/
public void setImage(URL imageURL) {
BufferedImage image = null;
try {
image = ImageIO.read(imageURL);
} catch (Exception e) {
e.printStackTrace();
}
setImage(image);
}
/**
* Sets the image this background painter displays.
*
* @param image The new image to use for the background.
*/
public void setImage(Image image) {
master = image;
oldWidth = -1; // To trick us into fixing bgImage.
}
/**
* Sets the scaling hint to use when scaling the image.
*
* @param hint The hint to apply; e.g. Image.SCALE_DEFAULT.
* @see #getScalingHint
*/
public void setScalingHint(int hint) {
this.scalingHint = hint;
}
}