Centering Applications, spawning windows and other GUI stuff

Question

Hi, possibly a silly question, but leave me alone I'm new :o)
How do I get my application to center on the screen ? At the moment it opens upin the top left hand corner of the screen.
Also whilst I'm on the topic my app with goes from screen to screen, that is when you click a button it makes turns that window "off" and opens the new destination window with setVisible(true/false), however when ever I move to the new window it always opens in the default location, is there a way in whivh the opened window appears in the location of the old one, for example, invoke the app, move the window around the screen, clikc a refresh button which will close and then re-open the same window and for the new scren to be in the new location, at the moment it will re-open in the top left hand corner of the screen as per usual

Answer 1

Hi,
You could just create a class that does it for you. See the code below for an example class that centers itself on any screen.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MyFrame extends JFrame
  public MyFrame()
    this( null );
  public MyFrame( String title )
    super( title );
  public void setVisible( boolean flag )
    if( flag )
      // Show should center on screen
      this.show();
    else
      // Hide should just call parent to perform function.
      super.setVisible( flag );
  public void show()
    //  Center this window to the main window.
    Dimension screenDim = Toolkit.getDefaultToolkit().getScreenSize();
    Dimension thisDim = this.getSize();
    Point thisLoc = new Point();
    thisLoc.x = (screenDim.width / 2) - (thisDim.width / 2);
    thisLoc.y = (screenDim.height / 2) - (thisDim.height / 2);
    this.setLocation( thisLoc );
    //  Display window now.
    super.show();
}Enjoy,
Manfred.