ImageJ Keypress example

SpaceToContinueExample.java

import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

import ij.IJ;
import ij.ImageJ;
import ij.ImagePlus;

public class SpaceToContinueExample implements KeyListener {

	final ImageJ ij;
	ImagePlus ip;
	
	public SpaceToContinueExample(  )
	{
		ij = IJ.getInstance();
		System.out.println( "ij: " + ij );
	}
	
	public SpaceToContinueExample( ImagePlus ip )
	{	
		this();
		this.ip = ip;
		ip.show();
		ip.getCanvas().addKeyListener(this);
	}
	
	public void processBefore()
	{
		ip = IJ.getImage();
		IJ.run("Gaussian Blur...", "sigma=2");
		IJ.getImage().show();
	}
	
	public void processAfter()
	{
		System.out.println("process after");	
		IJ.run("Measure");
		
		// remove this key listener to be safe
		ip.getCanvas().removeKeyListener(this);
	}
	
	public void run()
	{
		processBefore();
		// process After is called on keypress
	}

	@Override
	public void keyTyped(KeyEvent e) {}

	@Override
	public void keyPressed(KeyEvent e) { }

	@Override
	public void keyReleased(KeyEvent e) {
		if ( e.getKeyCode() == KeyEvent.VK_SPACE )
		{
			processAfter();
		}
	}
	
	public static void main(String[] args) {
		ImageJ ij = new ImageJ();
		IJ.run("Boats (356K)");
		SpaceToContinueExample obj = new SpaceToContinueExample( IJ.getImage() );
		obj.run();
	}
}

This java snippet:

1. starts ImageJ,
2. opens an image (boats)
3. blurs it and shows the results
4. waits for the user to do things, like draw an ROI, pressing space when finished
5. Then calls "Measure"