import java.awt.*;
import java.awt.event.*;
import java.io.*;
import ij.*;
import ij.io.*;
import ij.plugin.PlugIn;

public class Open_ITEX implements PlugIn {

    public void run(String argv) {
	OpenDialog OD = new OpenDialog("open ITEX ...", argv);
	String D = OD.getDirectory(); if (D == null) return;
	String FN = OD.getFileName(); if (FN == null) return;

	ImagePlus IP = open(D, FN);
	if (IP != null)
	    IP.show();
	else
	    IJ.showMessage("open ITEX ...", "failed.");
    }
    public static ImagePlus open(String D, String FN) {
	File F = new File(D, FN);
	try {
	    FileInputStream FIS = new FileInputStream(F);
	    byte[] H = new byte[64];
	    if (FIS.read(H) != 64) {
		IJ.showMessage("open ITEX ...", "header read error.");
		return null;
	    }
	    if ((H[12] != 0 && H[12] != 2 && H[12] != 3) || H[13] != 0) {
		IJ.showMessage("open ITEX ...", "unknown image type.");
		return null;
	    }
	    int L = ((int)H[2] & 255) + ((int)H[3] & 255) * 256;

	    FileInfo FI = new FileInfo();
	    if (L != 0) {
		byte[] C = new byte[L];
		if (FIS.read(C) != L) {
		    IJ.showMessage("open ITEX ...", "comment read error.");
		    return null;
		}
		int l = 0;
		while (l < L && C[l] != 0) ++l;
		if (l != 0) FI.info = new String(C, 0, l, "UTF-8");
	    }
	    FI.directory = D;
	    FI.fileName = FN;
	    FI.width = ((int)H[4] & 255) + ((int)H[5] & 255) * 256;
	    FI.height = ((int)H[6] & 255) + ((int)H[7] & 255) * 256;
	    FI.offset = 64 + L;

	    FI.fileFormat = FI.RAW;
	    FI.intelByteOrder = true;
	    FI.fileType = (H[12] == 3)?FileInfo.GRAY32_UNSIGNED:
			  (H[12] == 2)?FileInfo.GRAY16_UNSIGNED:FileInfo.GRAY8;
	    FI.nImages = 1;
	    FI.gapBetweenImages = 0;

	    FileOpener FO = new FileOpener(FI);
	    ImagePlus IP = FO.open(false);
	    IJ.showStatus("");
	    return IP;
	}
	catch(IOException e) {
	    IJ.error("an error occured reading the file.\n" + e);
	    IJ.showStatus("");
	    return null;
	}
    }
}

/*
    ImageJ/plugins/Input-Output/HandleExtraFileTypes.java :
	...
	public class HandleExtraFileTypes extends ImagePlus implements PlugIn {
	    ...
	    private Object tryOpen(String directory, String name, String path) {
		...
----------------
		if (name.endsWith(".img") && buf[0]==73 && buf[1]==77)
		    return tryPlugIn("Open_ITEX", path);
----------------
		...
		if (name.endsWith(".img") ...) {
		    ...
		}
	... ... ...
*/