How do I determine which monitor a Swing mouse event occurs in?

Question

I have a Java MouseListener on a component to detect mouse presses. How can I tell which monitor the mouse press occurred in?

@Override
public void mousePressed(MouseEvent e) {
  // I want to make something happen on the monitor the user clicked in
}

The effect I'm trying to achieve is: when the user presses the mouse button in my app, a popup window shows some info, until the mouse is released. I want to ensure this window is positioned where the user clicks, but I need to adjust the window position on the current screen so that the entire window is visible.

Answer 1

You can get display information from java.awt.GraphicsEnvironment. You can use this to get a information about your local system. Including the bounds of each monitor.

Point point = event.getPoint();

GraphicsEnvironment e 
     = GraphicsEnvironment.getLocalGraphicsEnvironment();

GraphicsDevice[] devices = e.getScreenDevices();

Rectangle displayBounds = null;

//now get the configurations for each device
for (GraphicsDevice device: devices) { 

    GraphicsConfiguration[] configurations =
        device.getConfigurations();
    for (GraphicsConfiguration config: configurations) {
        Rectangle gcBounds = config.getBounds();

        if(gcBounds.contains(point)) {
            displayBounds = gcBounds;
        }
    }
}

if(displayBounds == null) {
    //not found, get the bounds for the default display
    GraphicsDevice device = e.getDefaultScreenDevice();

    displayBounds =device.getDefaultConfiguration().getBounds();
}
//do something with the bounds
...