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/*
* ImagePanel.java
*
* Copyright (C) 2007 Scott Carpenter (scottc at movingtofreedom dot org)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see http://www.gnu.org/licenses/.
*
* Created on November 9, 2007, 4:07 PM
*
*/
package PicHelper;
import java.io.*;
import java.awt.*;
import javax.swing.*;
import javax.imageio.*;
public class ImagePanel extends JPanel {
private Image image;
private Image scaledImage;
private int imageWidth = 0;
private int imageHeight = 0;
// private long paintCount = 0;
// constructor
public ImagePanel() {
super();
}
public void loadImage(String file) throws IOException {
loadImage(new File(file));
}
public void loadImage(File file) throws IOException {
image = ImageIO.read(file);
// might be a situation where image isn't fully loaded, and
// should check for that before setting...
imageWidth = image.getWidth(this);
imageHeight = image.getHeight(this);
setScaledImage();
}
// e.g., containing frame might call this from formComponentResized
public void scaleImage() {
setScaledImage();
}
// override paintComponent
public void paintComponent(Graphics g) {
super.paintComponent(g);
if (scaledImage != null) {
// System.out.println("ImagePanel paintComponent " + ++paintCount);
g.drawImage(scaledImage, 0, 0, this);
}
}
private void setScaledImage() {
if (image != null) {
// use floats so division below won't round
float iw = imageWidth;
float ih = imageHeight;
float pw = this.getWidth(); // panel width
float ph = this.getHeight(); // panel height
if (pw < iw || ph < ih) {
/*
* compare some ratios and then decide which side of image to
* anchor to panel and scale the other side (this is all based
* on empirical observations and not at all grounded in theory)
*/
// System.out.println("pw/ph=" + pw/ph + ", iw/ih=" + iw/ih);
if ((pw / ph) > (iw / ih)) {
iw = -1;
ih = ph;
} else {
iw = pw;
ih = -1;
}
// prevent errors if panel is 0 wide or high
if (iw == 0) {
iw = -1;
}
if (ih == 0) {
ih = -1;
}
scaledImage = image.getScaledInstance(new Float(iw).intValue(),
new Float(ih).intValue(), Image.SCALE_DEFAULT);
} else {
scaledImage = image;
}
// System.out.println("iw = " + iw + ", ih = " + ih + ", pw = " + pw
// + ", ph = " + ph);
}
}
}
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