package ij.plugin;
import ij.*;
import ij.process.*;
import ij.gui.*;
import java.awt.*;
import ij.io.*;
import java.net.URL;
import java.awt.image.*;

/** This plugin implements the Help/About ImageJ command by opening
    the about.jpg in ij.jar, scaling it 400% and adding some text. */
    public class AboutBox implements PlugIn {
        static final int SMALL_FONT=14, LARGE_FONT=30;

    public void run(String arg) {
        System.gc();
        int lines = 7;
        String[] text = new String[lines];
        text[0] = "ImageJ "+ImageJ.VERSION+ImageJ.BUILD;
        text[1] = "Wayne Rasband";
        text[2] = "National Institutes of Health, USA";
        text[3] = IJ.URL;
        text[4] = "Java "+System.getProperty("java.version")+(IJ.is64Bit()?" (64-bit)":" (32-bit)");
        text[5] = IJ.freeMemory();
        text[6] = "ImageJ is in the public domain";
        ImageProcessor ip = null;
        ImageJ ij = IJ.getInstance();
        URL url = ij .getClass() .getResource("/about.jpg");
        if (url!=null) {
            Image img = null;
            try {img = ij.createImage((ImageProducer)url.getContent());}
            catch(Exception e) {}
            if (img!=null) {
                ImagePlus imp = new ImagePlus("", img);
                ip = imp.getProcessor();
            }
        }
        if (ip==null) 
            ip =  new ColorProcessor(55,45);
        ip = ip.resize(ip.getWidth()*4, ip.getHeight()*4);
        ip.setFont(new Font("SansSerif", Font.PLAIN, LARGE_FONT));
        ip.setAntialiasedText(true);
        int[] widths = new int[lines];
        widths[0] = ip.getStringWidth(text[0]);
        ip.setFont(new Font("SansSerif", Font.PLAIN, SMALL_FONT));
        for (int i=1; i<lines-1; i++)
            widths[i] = ip.getStringWidth(text[i]);
        int max = 0;
        for (int i=0; i<lines-1; i++) 
            if (widths[i]>max)
                max = widths[i];
        ip.setColor(new Color(255,255, 140));
        ip.setFont(new Font("SansSerif", Font.PLAIN, LARGE_FONT));
        int y  = 45;
        ip.drawString(text[0], x(text[0],ip,max), y);
        ip.setFont(new Font("SansSerif", Font.PLAIN, SMALL_FONT));
        y += 30;
        ip.drawString(text[1], x(text[1],ip,max), y);
        y += 18;
        ip.drawString(text[2], x(text[2],ip,max), y);
        y += 18;
        ip.drawString(text[3], x(text[3],ip,max), y);
        y += 18;
        ip.drawString(text[4], x(text[4],ip,max), y);
        if (IJ.maxMemory()>0L) {
            y += 18;
            ip.drawString(text[5], x(text[5],ip,max), y);
        }
        ip.drawString(text[6], ip.getWidth()-ip.getStringWidth(text[6])-10, ip.getHeight()-3);
        ImageWindow.centerNextImage();
        ImagePlus imp = new ImagePlus("About ImageJ", ip);
        String info = text[0] +"\n" + text[4] +"\n" + text[5];
        imp.setProperty("Info", info);
        imp.show();
    }

    int x(String text, ImageProcessor ip, int max) {
        return ip.getWidth() - max + (max - ip.getStringWidth(text))/2 - 10;
    }

}