Button.java

/**
* Copyright (c) 2012-2013 Nokia Corporation. All rights reserved.
* Nokia and Nokia Connecting People are registered trademarks of Nokia Corporation. 
* Oracle and Java are trademarks or registered trademarks of Oracle and/or its
* affiliates. Other product and company names mentioned herein may be trademarks
* or trade names of their respective owners. 
* See LICENSE.TXT for license information.
*/

package com.nokia.example.paint.views.components;

import com.nokia.example.paint.helpers.ImageLoader;
import java.util.Vector;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.Sprite;

/*
 * Generic class for buttons.
 */
public abstract class Button {

    protected Image pressed;
    protected Image unpressed;
    protected Sprite sprite;
    protected int width;
    protected int height;
    protected int x = 0;
    protected int y = 0;
    protected boolean isPressed = false;
    private boolean isSprite = false;
    private Vector listeners;

    public Button(String pressed_image_url, String unpressed_image_url) {
        this();
        setImages(pressed_image_url, unpressed_image_url);

    }

    public Button() {
        //default constructor
        listeners = new Vector();
    }

    protected void setImages(String pressed_image_url, String unpressed_image_url) {
        ImageLoader loader = ImageLoader.getInstance();
        pressed = loader.loadImage(pressed_image_url);
        unpressed = loader.loadImage(unpressed_image_url);
        width = pressed.getWidth();
        height = pressed.getHeight();
        isSprite = false;
    }

    protected void setSprite(String sprite_url, int spriteWidth, int spriteHeight) {

        sprite = new Sprite(ImageLoader.getInstance().loadImage(sprite_url), spriteWidth, spriteHeight);

        width = sprite.getWidth();
        height = sprite.getHeight();
        isSprite = true;
    }

    public Button(String sprite_url) {
        setSprite(sprite_url, 46, 41);
        listeners = new Vector();
    }

    public void addListener(ButtonListener listener) {
        listeners.addElement(listener);
    }

    public abstract void onSelected();

    public void render(Graphics g) {
        if (isSprite) {
            sprite.setPosition(x, y);
            sprite.paint(g);
        }
        else {
            if (isPressed) {
                g.drawImage(pressed, x, y, Graphics.TOP | Graphics.LEFT);
            }
            else {
                g.drawImage(unpressed, x, y, Graphics.TOP | Graphics.LEFT);
            }
        }
    }

    public void setPosition(int x, int y) {
        this.x = x;
        this.y = y;
    }

    /**
     * Calls the onSelected method if x and y are inside the tool area.
     * @param x
     * @param y
     */
    public void pressed(int x, int y) {
        if (x >= this.x && x <= (this.x + width)) {
            if (y >= this.y && y <= this.y + height) {
                isPressed = true;
            }
        }
    }

    public void unpressed(int x, int y) {
        isPressed = false;
        if (x >= this.x && x <= (this.x + width)) {
            if (y >= this.y && y <= this.y + height) {

                onSelected();
                int l = listeners.size();
                for (int i = 0; i < l; i++) {
                    ButtonListener listener = (ButtonListener) listeners.elementAt(i);
                    listener.buttonPressed(this);
                }
            }
        }
    }

    public int getWidth() {
        return width;
    }

    public int getHeight() {
        return height;
    }
}