package edu.princeton.swing;

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

/**
 * PImagePanel is like a JPanel, except that its background can be set to an image.
 *
 * @author btsang
 * @version 7.1
 */
public class PImagePanel extends JComponent
{
    private Icon background;

    /**
     * Constructs a new PImagePanel.
     */
    public PImagePanel(Icon background, LayoutManager layout)
    {
        this.background = background;

        setLayout(layout);
        setDoubleBuffered(true);
        setOpaque(true);
    }

    /**
     * Constructs a new PImagePanel.
     */
    public PImagePanel(Icon background)
    {
        this(background, new FlowLayout());
    }

    /**
     * Constructs a new PImagePanel.
     */
    public PImagePanel()
    {
        this(null, new FlowLayout());
    }

    /**
     * Override javax.swing.JComponent's getPreferredSize method so that the background image is
     * taken into consideration.
     */
    public Dimension getPreferredSize()
    {
        Dimension size = super.getPreferredSize();

        size.width  = Math.max(size.width, background.getIconWidth());
        size.height = Math.max(size.height, background.getIconHeight());

        return size;
    }

    /**
     * Gets the background icon.
     *
     * @return The Icon being displayed in the background of this panel.
     */
    public Icon getBackgroundIcon()
    {
        return background;
    }

    /**
     * Sets the background icon.
     *
     * @param background The Icon to be displayed in the background of this panel.
     */
    public void setBackgroundIcon(Icon background)
    {
        this.background = background;
    }

    /**
     * Override javax.swing.JComponent's paintComponent method to paint the background
     * appropriately.
     */
    protected void paintComponent(Graphics g)
    {
        Rectangle clip = g.getClipBounds();
        g.setColor(getBackground());
        g.fillRect(clip.x, clip.y, clip.width, clip.height);

        if (background != null)
            background.paintIcon(this, g, 0, 0);
    }
}