package convexHull;

import java.awt.*;
import java.awt.event.*;

/**
 * This is a container for a canvas. This container will display rulers
 * around the canvas (on the top and left).
 */
public class MouseCanvas extends java.awt.Panel
{
    /** canvas for the top ruler */
    private TopCanvas topCanvas;
    /** canvas for the left ruler */
    private LeftCanvas leftCanvas;
    /** the main canvas */
    private Canvas mainCanvas;

    /**
     * Lays out its children (top & left rulers + the user
     * defined canvas). Associates callbacks with various mouse events,
     * so that the rulers can be properly updated.
     *
     * @param mainCanvas java.awt.Canvas
     * - the real user-graphics canvas
     */
    public MouseCanvas(Canvas mainCanvas)
    {
	super();
	setLayout(null);
	// get the dimensions of the panel
	// setup the top canvas
	topCanvas = new TopCanvas();
	add(topCanvas);
	
	// setup the left canvas
	leftCanvas = new LeftCanvas();
	add(leftCanvas);
	
	// setup the main canvas
	this.mainCanvas = mainCanvas;
	add(mainCanvas);
	
	// add a mouse motion listener to all canvases
	mainCanvas.addMouseMotionListener(new MouseMotionAdapter() {
	    public void mouseMoved(MouseEvent e) {
		mouseCB(e);
	    }
	});
	mainCanvas.addMouseListener(new MouseAdapter() {
	    public void mouseExited(MouseEvent e) {
		mouseCB(e);
	    }
	});
    }

    /**
     * Makes sure that the rulers and the main canvas are always properly
     * laid out.
     */
    public void doLayout()
    {
	// invoke the default layout procedure
	super.doLayout();
	// get the size of the panel
	Dimension d = getSize();
	// layout the canvases
	topCanvas.setBounds(10, 0, d.width - 10, 10);
	leftCanvas.setBounds(0, 10, 10, d.height - 10);
	mainCanvas.setBounds(10, 10, d.width - 10, d.height - 10);
    }

    /**
     * Callback for the mouse
     *
     * @param e java.awt.Event.MouseEvent
     * - mouse event that triggered this event
     */
    public void mouseCB(MouseEvent e)
    {
	if (e.getID() == MouseEvent.MOUSE_MOVED) {
	    topCanvas.setPointer(e.getX());
	    leftCanvas.setPointer(e.getY());
	}
	else if (e.getID() == MouseEvent.MOUSE_EXITED) {
	    topCanvas.setPointer(-1);
	    leftCanvas.setPointer(-1);
	}
    }

    /**
     * This method allows the user to set the background.
     *
     * @param col java.awt.Color
     * - the user defined color
     */
    public void setBackground(Color col)
    {
	super.setBackground(col);
	// topCanvas.setBackground(col);
	// leftCanvas.setBackground(col);
    }
}