grid.java

PIY(Program It Yourself)是一个基于Java的应用程序开发环境

package piy;

import javax.swing.JPanel;
import java.awt.*;

/**
* The grid that is on the UserEditWindow.  This appears _underneath_ the components
* on the window, it doesn't actually contain the components.
* @author David Vivash
* @version 1.0, 2/12/00
*/
public class Grid extends JPanel {

	private Image grid = null;
	private int gridWidth = 5, gridHeight = 5;

	public Grid(int width, int height) {
		setGrid(width, height);
	}

	/**
	* Sets the size (spacing) used for the grid.
	* @param width the horizontal spacing between dots on the grid
	* @param height the vertical spacing between dots on the grid
	*/
	public void setGrid(int width, int height) {
		gridWidth = (width > 1) ? width : 5;
		gridHeight = (height > 1) ? height : 5;
		repaint();
	}


	public void update(Graphics g) {
		paint(g);
	}

	public void paint(Graphics g) {

		Dimension d = getSize();

		if (grid == null || grid.getWidth(null) < d.width || grid.getHeight(null) < d.height) {
			grid = createImage(d.width, d.height);
			Graphics og = grid.getGraphics();
    
			for (int x=0; x <= d.width; x += gridWidth)    
                for (int y=0; y <= d.height; y += gridHeight)
					og.drawRect(x,y,0,0);

            og.dispose();
        }

        g.drawImage(grid, 0, 0, null); 
	}

}