How to find primary monitor

Question

Hi,
I need to find whether frame is on Primary monitor or not. How to find out?
Regards
Ketan

Answer 1

I am not really sure but I just did some tests and on my machine it looks as if the primary monitor is the one whose bounds start at 0,0.
Of course I only tested with an "extended desktop" setting, where my desktop is spanned across 2 monitors. But in the case where both monitors show the same stuff it shouldn't really matter, right?
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.GridLayout;
import java.awt.Rectangle;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class PrimaryMonitor
  public static void main(String[] args)
    GraphicsEnvironment graphicsEnvironment = GraphicsEnvironment.getLocalGraphicsEnvironment();
    GraphicsDevice[] screenDevices = graphicsEnvironment.getScreenDevices();
    for(GraphicsDevice screenDevice : screenDevices)
      System.out.println(screenDevice + ", ID=" + screenDevice.getIDstring());
      GraphicsConfiguration screenConfiguration = screenDevice.getDefaultConfiguration();
      Rectangle screenBounds = screenConfiguration.getBounds();
      System.out.println(screenBounds);
      JFrame frame = new JFrame(screenDevice.getIDstring());
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.setLayout(new GridLayout(0, 1));
      frame.add(new JLabel(screenDevice.getIDstring()));
      frame.add(new JLabel("" + screenBounds));
      if(screenBounds.x == 0)
        frame.add(new JLabel("Primary?"));
      frame.setBounds(screenBounds.x, screenBounds.y, 600, 200);
      frame.setVisible(true);
}