Prossel Software

Here is how to make the Processing window resizable AND get an event when the window is resized.

Tested with Processing 3.

// For resize event
import java.awt.Canvas;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentAdapter;


void setup() {
  surface.setResizable(true);

  ((Canvas)surface.getNative()).addComponentListener(new ComponentAdapter() {
    @Override public void componentResized(ComponentEvent e) {
      println("resized " + width + " " + height);
    }
  }
  );
}