java & fullscreen over multiple monitors

Question

A snippet from my Java application:

 JFrame f = new JFrame();
 GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
 GraphicsDevice gd = ge.getDefaultScreenDevice();
 gd.setFullScreenWindow(f);

So what it does is make it self fullscreen. Now the odd thing is that the program is fullscreen but only on one monitor! E.g. I have a windows vista system with two screens that are combined in one desktop. What to do automatically let it go fullscreen over all monitors?

---

Ok I tried that:

import java.awt.image.ColorModel;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Rectangle;

class grdevs
{
    public static void main(String [] args)
    {
        GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
        GraphicsDevice[] gs = ge.getScreenDevices();
        for(GraphicsDevice curGs : gs)
        {
            GraphicsConfiguration[] gc = curGs.getConfigurations();
            for(GraphicsConfiguration curGc : gc)
            {
                Rectangle bounds = curGc.getBounds();
                ColorModel cm = curGc.getColorModel();

                System.out.println("" + bounds.getX() + "," + bounds.getY() + " " + bounds.getWidth() + "x" + bounds.getHeight() + " " + cm);
            }
        } 
    }
}

but it gives:

0.0,0.0 1024.0x768.0 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0
0.0,0.0 1024.0x768.0 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0
0.0,0.0 1024.0x768.0 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0
0.0,0.0 1024.0x768.0 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0
0.0,0.0 1024.0x768.0 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0
0.0,0.0 1024.0x768.0 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0
1024.0,0.0 1024.0x768.0 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0
1024.0,0.0 1024.0x768.0 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0
1024.0,0.0 1024.0x768.0 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0
1024.0,0.0 1024.0x768.0 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0
1024.0,0.0 1024.0x768.0 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0
1024.0,0.0 1024.0x768.0 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0

E.g I would expect a device capable of 2048x768 as they are combined in one (I clicked on "extend desktop").

Answer 1

You could try:

int width = 0;
int height = 0;
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice[] gs = ge.getScreenDevices();
for (GraphicsDevice curGs : gs)
{
  DisplayMode mode = curGs.getDisplayMode();
  width += mode.getWidth();
  height = mode.getHeight();
}

This should calculate the total width of multiple screens. Obviously it only supports horizontally aligned screens in the form above - you'd have to analyse the bounds of the graphics configurations to handle other monitor alignments (depends how bulletproof you want to make it).

Edit: And then set the size of your frame: f.setSize(width, height);

Answer 2

A more general solution to Ash's code is to union the bounds of all the graphics configurations

Rectangle2D result = new Rectangle2D.Double();
GraphicsEnvironment localGE = GraphicsEnvironment.getLocalGraphicsEnvironment();
for (GraphicsDevice gd : localGE.getScreenDevices()) {
  for (GraphicsConfiguration graphicsConfiguration : gd.getConfigurations()) {
    result.union(result, graphicsConfiguration.getBounds(), result);
  }
}
f.setSize(result.getWidth(), result.getHeight());

This will work for vertically aligned monitors as well as horizontal.

Answer 3

This is not what "setFullScreenWindow" is for. It's really for applications that want more direct access to the framebuffer (better performance) - like a 3D game does in DirectX, for instance. This kind of implies ONE monitor.

See this other answer I did: JDialog Not Displaying When in Fullscreen Mode

Answer 4

That is the normal behavior when you maximize a window in Windows when you have two monitors. In order two get the full resolution size, you will need to look at GraphicsConfiguration to check each GraphicsDevice.

Answer 5

Using java.awt.Toolkit you can get the full screen size (all monitors):

    Toolkit tk = Toolkit.getDefaultToolkit();
    Dimension dim = tk.getScreenSize();