package ij.gui;
import java.awt.*;
import ij.*;

/** This class consists of static GUI utility methods. */
public class GUI {

    /** Positions the specified window in the center of the screen. */
    public static void center(Window w) {
        Dimension screen = IJ.getScreenSize();
        Dimension window = w.getSize();
        if (window.width==0)
            return;
        int left = screen.width/2-window.width/2;
        int top = (screen.height-window.height)/4;
        if (top<0) top = 0;
        w.setLocation(left, top);
    }
    
    static private Frame frame;
    
    /** Creates a white AWT Image image of the specified size. */
    public static Image createBlankImage(int width, int height) {
        if (width==0 || height==0)
            throw new IllegalArgumentException("");
        if (frame==null) {
            frame = new Frame();
            frame.pack();
            frame.setBackground(Color.white);
        }
        Image img = frame.createImage(width, height);
        return img;
    }
    
}