ij.plugin.Coordinates (Java2HTML)

package ij.plugin;
import ij.*;
import ij.gui.*;
import ij.measure.Calibration;
import java.awt.AWTEvent;
import java.awt.geom.Rectangle2D;

/**
 * The plugin implements the Image/Adjust/Coordinates command. It allows
 * the user to set the corner coordinates of the selection bounds or the full image.
 * This modifies the image scale (pixelWidth, pixelHeight) and the xOrigin, yOrigin.
 * If a single point is selected, the coordinates of the point can be specified, which only
 * sets the xOrigin and yOrigin.
 * The units for x and y can be also selected.
 * 2016-08-30 Michael Schmid
 */
 
public class Coordinates implements PlugIn, DialogListener {

    private static final String help = "<html>"
    +"<h1>Image&gt;Adjust&gt;Coordinates</h1>"
    +"<font size=+1>"
    +"This command allows the user to set the corner coordinates of<br>the selection bounds "
    +"or the full image. This modifies the image<br>scale (<i>pixelWidth</i>, <i>pixelHeight</i>) and <i>xOrigin</i> and <i>yOrigin</i>. "
    +"If a<br>single point is selected, the coordinates of the point can be<br>specified, which only "
    +"sets <i>xOrigin</i> and <i>yOrigin</i>. The units for X<br>and Y can be also selected.<br> "
    +"</font>";

    private final static String SAME_AS_X = "<same as x unit>";
    private final static int IMAGE = 0, ROI_BOUNDS = 1, POINT = 2;  //mode: coordinates of what to specify
    private int mode = IMAGE;


    public void run(String arg) {
        ImagePlus imp = IJ.getImage();
        int imageHeight = imp.getHeight();
        Calibration cal = imp.getCalibration();
        Roi roi = imp.getRoi();
        Rectangle2D.Double bounds = null;
        if (roi != null) {
            bounds = roi.getFloatBounds();
            if (bounds.width==0 && bounds.height==0)
                mode = POINT;
            else
                mode = ROI_BOUNDS;
        } else {    //no Roi, use image bounds
            bounds = new Rectangle2D.Double(0, 0, imp.getWidth(), imp.getHeight());
        }
        String title = (mode==IMAGE ? "Image" : "Selection") +" Coordinates";
        if (mode == POINT)
            title = "Point Coordinates";
        GenericDialog gd = new GenericDialog(title);
        if (mode == POINT) {
            gd.addNumericField("X:", cal.getX(bounds.x), 2, 8, "");
            gd.addNumericField("Y:", cal.getY(bounds.y, imageHeight), 2, 8, "");
        } else {
            gd.addNumericField("Left:", cal.getX(bounds.x), 2, 8, "");
            gd.addNumericField("Right:", cal.getX(bounds.x+bounds.width), 2, 8, "");
            gd.addNumericField("Top:", cal.getY(bounds.y, imageHeight), 2, 8, "");
            gd.addNumericField("Bottom:", cal.getY(bounds.y+bounds.height, imageHeight), 2, 8, "");
        }
        String xUnit = cal.getUnit();
        String yUnit = cal.getYUnit();
        gd.addStringField("X_unit:", xUnit, 18);
        gd.addStringField("Y_unit:", yUnit.equals(xUnit) ? SAME_AS_X : yUnit, 18);
        gd.addHelp(help);
        gd.addDialogListener(this);
        gd.showDialog();
        if (gd.wasCanceled())
            return;
        if (mode == POINT) {
            double x = gd.getNextNumber();
            double y = gd.getNextNumber();
            if (gd.invalidNumber()) {
                IJ.error("Invalid number");
                return;
            }
            cal.xOrigin = coordinate2offset(x, bounds.x, cal.pixelWidth);
            cal.yOrigin = coordinate2offset(y, bounds.y, cal.getInvertY() ? -cal.pixelHeight : cal.pixelHeight);
        } else {
            double xl = gd.getNextNumber();
            double xr = gd.getNextNumber();
            double yt = gd.getNextNumber();
            double yb = gd.getNextNumber();
            if (gd.invalidNumber()) {
                IJ.error("Invalid number");
                return;
            }
            cal.pixelWidth = (xr-xl)/bounds.width;
            cal.pixelHeight = (yb-yt)/bounds.height;
            cal.xOrigin = coordinate2offset(xl, bounds.x, cal.pixelWidth);
            cal.yOrigin = coordinate2offset(yt, bounds.y, cal.pixelHeight);
            cal.setInvertY(cal.pixelHeight < 0);
            if (cal.pixelHeight < 0)
                cal.pixelHeight = -cal.pixelHeight;
        }
        cal.setXUnit(gd.getNextString());
        yUnit = gd.getNextString();
        cal.setYUnit((yUnit.equals("") || yUnit.equals(SAME_AS_X)) ? null : yUnit);
        ImageWindow win = imp.getWindow();
        imp.repaintWindow();
    }

    // In interactive mode, disable 'ok' in case of input errors (bad numbers, zero range or inverted x)
    public boolean dialogItemChanged(GenericDialog gd, AWTEvent e) {
        if (mode == POINT) {
            gd.getNextNumber();
            gd.getNextNumber();
            return (!gd.invalidNumber());
        } else {
            double xl = gd.getNextNumber();
            double xr = gd.getNextNumber();
            double yt = gd.getNextNumber();
            double yb = gd.getNextNumber();
            return (!gd.invalidNumber() && xr>xl && yt!=yb);
        }
    }

    // Calculates pixel offset from scaled coordinates of a point with given pixel position
    private double coordinate2offset(double coordinate, double pixelPos, double pixelSize) {
        return  pixelPos - coordinate/pixelSize;
    }

}