84 lines
2.7 KiB
Java
Executable File
84 lines
2.7 KiB
Java
Executable File
import java.awt.image.*;
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import javax.imageio.*;
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import javax.swing.*;
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import java.io.*;
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/**
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* ImageFileManager is a small utility class with static methods to load
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* and save images.
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*
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* The files on disk can be in JPG or PNG image format. For files written
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* by this class, the format is determined by the constant IMAGE_FORMAT.
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*
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* @author Michael Kölling and David J. Barnes.
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* @version 1.0
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*/
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public class ImageFileManager
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{
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// A constant for the image format that this writer uses for writing.
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// Available formats are "jpg" and "png".
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private static final String IMAGE_FORMAT = "jpg";
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private static JFileChooser fileChooser = new JFileChooser(System.getProperty("user.dir"));
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/**
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* Open a file chooser and let the user select an image file in the file
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* system. Then read an image file from disk and return it as an image. This method
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* can read JPG and PNG file formats. In case of any problem (e.g the file does
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* not exist, is in an undecodable format, or any other read error) this method
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* returns null.
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*
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* @return The image object or null is it was not a valid image file.
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*/
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public static OFImage getImage()
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{
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int returnVal = fileChooser.showOpenDialog(null);
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if(returnVal != JFileChooser.APPROVE_OPTION) {
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return null; // cancelled
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}
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File selectedFile = fileChooser.getSelectedFile();
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return loadImage(selectedFile);
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}
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/**
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* Read an image file from disk and return it as a BufferedImage. This method
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* can read JPG and PNG file formats. In case of any problem (e.g the file does
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* not exist, is in an undecodable format, or any other read error) this method
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* returns null.
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*
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* @param imageFile The image file to be loaded.
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* @return The image object or null if it was not a valid image file.
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*/
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public static OFImage loadImage(File imageFile)
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{
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try {
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BufferedImage image = ImageIO.read(imageFile);
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if(image == null || (image.getWidth(null) < 0)) {
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// we could not load the image - probably invalid file format
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return null;
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}
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return new OFImage(image);
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}
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catch(IOException exc) {
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return null;
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}
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}
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/**
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* Write an image file to disk. The file format is JPG. In case of any problem
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* the method just silently returns.
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*
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* @param image The image to be saved.
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* @param file The file to save to.
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*/
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public static void saveImage(OFImage image, File file)
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{
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try {
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ImageIO.write(image, IMAGE_FORMAT, file);
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}
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catch(IOException exc) {
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return;
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}
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}
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}
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