/***************************************************************
 * SmileyPanel.java
 * Dean & Dean
 *
 * This class contains a smiley image and listeners
 * that enable image dragging and image swapping.
 ***************************************************************/

package class8_2_DragListener;

import javax.swing.ImageIcon;
import javax.swing.JPanel;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.*;

/**
 * @author Dean & Dean.  This example taken nearly straight from the classic Java
 *          text, p. 801.
 */
public class SmileyPanel extends JPanel {
    private final ImageIcon SMILEY;
    private final ImageIcon SCARED;

    // Question: why aren't these constants static?
    private final int PANEL_WIDTH;
    private final int PANEL_HEIGHT;

    private boolean isPressed = false;
    private boolean wasPressed = false;

    /**
     * image's top-left corner location
     */
    private Point imageCorner;

    /**
     * mouse location for previous event (?)
     */
    private Point mouseDownLocation;

    /**
     * Either SMILEY or SCARED, depending on what we want...
     */
    private ImageIcon image;

    /**
     * Create the SmileyPanel
     */
    public SmileyPanel() {
        SMILEY = new ImageIcon("smiley.png");
        SCARED = new ImageIcon("scared.png");
        PANEL_WIDTH = SMILEY.getIconWidth();
        PANEL_HEIGHT = SMILEY.getIconHeight();

        image = SMILEY;
        imageCorner = new Point(0, 0); // image starts at top left
        ClickListener clickListener = new ClickListener();
        DragListener dragListener = new DragListener();
        this.addMouseListener(clickListener);
        this.addMouseMotionListener(dragListener);
    } // end SmileyComponent constructor

    //************************************************************

    private class ClickListener extends MouseAdapter
    {
        // When mouse pressed, change to scared image.

        public void mousePressed(MouseEvent e)
        {
            e.getModifiersEx();
            isPressed = true;
            image = SCARED;
            mouseDownLocation = e.getPoint();  // save current position
            repaint();
        } // end mousePressed

        // When mouse released, return to smiley image.

        public void mouseReleased(MouseEvent e)
        {
            isPressed = false;
            wasPressed = false;
            image = SMILEY;
            repaint();
        } // end mouseReleased
    } // end class ClickListener

    //*******************************************************

    private class DragListener extends MouseMotionAdapter
    {
        // Enable image to be dragged by mouse.

        public void mouseDragged(MouseEvent e)
        {
            Point currentPt = e.getPoint(); // current position

            if (isPressed && wasPressed || isPressed && currentPt.getX() >= imageCorner.getX() &&
                    currentPt.getX() <= imageCorner.getX() + PANEL_WIDTH &&
                    currentPt.getY() >= imageCorner.getY() &&
                    currentPt.getY() <= imageCorner.getY() + PANEL_HEIGHT )
            {
                wasPressed = true;
                System.out.println("Got here.");
                imageCorner.translate(
                        (int) (currentPt.getX() - mouseDownLocation.getX()),
                        (int) (currentPt.getY() - mouseDownLocation.getY()));
                mouseDownLocation = currentPt; // save current position
                repaint();
            }

        } // end mouseDragged
    } // end class DragListener

    //*******************************************************

    /**
     * Draw the window, including the icon.
     * @param g the icon
     */
    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        image.paintIcon(this, g,
                (int) imageCorner.getX(), (int) imageCorner.getY());
    } // end paintComponent
}