/*
 * 文件: ImageButton.java
 * 日期         作者        改變情況
 * 2004-9-1     Dorian      創(chuàng)建
*/

package com.javaworld.dorian;

import java.awt.AlphaComposite;
import java.awt.Composite;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.Image;
import java.awt.Transparency;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;

/**
 * <p>帶圖標按鈕類</p>
 * <P>---------------------------------------------------------
 * <p>可提供ImageIcon參數(shù)改變按鈕圖標。提供參數(shù)時可提供圖標透明化
 * 的程度(THIRD_TRANSPARENCY、TRANSLUCENCE、TOWPART_TRANSPARENCY、
 * OPACITY)
 * <p>For Example:
 * <p>  JFrame frame = new JFrame();
 * <p>  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 * <p>  frame.setSize(250, 300);
 * <p>  frame.setTitle("圖片按鈕測試");
 * <P>  JButton button = ImageButton.createButton(ImageIcon);
 * <p>  button.setFocusable(false);
 * <p>  frame.getContentPane().add(button);
 * <P>  panel.add(button);
 * <p>  frame.setVisible(true);
 * <P>---------------------------------------------------------
 * <P>Copyright (c) 2004 Dorian. All rights reserved</p>
 * <P>(#)ImageButton.java</p>
 * <P>創(chuàng)建日期 2004-9-1</p>
 * <P>更新日期 2004-9-1</p>
 * <p>@author <a href="mailto:Dorian@citiz.net">Dorian</a></p>
 * @version 1.0.0</p>
 */
public class ImageButton {
    /**
     * ImageButton的構造函數(shù)，聲明為Private
     * 使其不能被實例化。
     */
    private ImageButton() {}
    
    /**
     * 創(chuàng)建帶一個圖片的按鈕
     * @param iconName - 
     * @return JButton - 帶此圖片的按鈕
     */
    public static JButton createButton(String iconName) {
        ImageIcon icon = getImageIcon(iconName);
        return createButton(icon);
    }

    /**
     * 創(chuàng)建帶一個圖片的按鈕
     * @param rolloverIcon - 按鈕的ImageIcon
     * @return JButton - 帶此圖片的按鈕
     */
    public static JButton createButton(ImageIcon rolloverIcon) {
        return createButton(null,rolloverIcon,0);
    }
    
    /**
     * 創(chuàng)建帶一個圖片的按鈕并指定透明類型
     * @param rolloverIcon - 按鈕的ImageIcon
     * @param alpha - alpha值(按鈕的透明形式)，可取本類的常量值
     * @return JButton - 帶此圖片的按鈕
     */
    public static JButton createButton(ImageIcon rolloverIcon,float alpha) {
        return createButton(null,rolloverIcon,alpha);
    }

    /**
     * 創(chuàng)建帶兩個圖片的按鈕
     * @param defaultIcon - 按鈕的一般ImageIcon
     * @param rolloverIcon - 鼠標滑過按鈕時的ImageIcon
     * @param alpha - alpha值(按鈕的透明形式)，可取本類的常量值
     * @return - 帶此圖片的按鈕
     */
    public static JButton createButton(ImageIcon defaultIcon,ImageIcon rolloverIcon) {
        return createButton(defaultIcon,rolloverIcon,null,0);
    }
    
    /**
     * 創(chuàng)建帶兩個圖片的按鈕
     * @param defaultIcon - 按鈕的一般ImageIcon
     * @param rolloverIcon - 鼠標滑過按鈕時的ImageIcon
     * @param alpha - alpha值(按鈕的透明形式)，可取本類的常量值
     * @return - 帶此圖片的按鈕
     */
    public static JButton createButton(ImageIcon defaultIcon,ImageIcon rolloverIcon,
                                       float alpha) {
        return createButton(defaultIcon,rolloverIcon,null,alpha);
    }
    
    /**
     * 創(chuàng)建帶的三個圖片的按鈕
     * @param defaultIcon - 按鈕的一般ImageIcon
     * @param rolloverIcon - 鼠標滑過按鈕時的ImageIcon
     * @param pressedIcon - 鼠標按下按鈕時的ImageIcon
     * @return - 帶此圖片的按鈕
     */
    public static JButton createButton(ImageIcon defaultIcon,ImageIcon rolloverIcon,
                                       ImageIcon pressedIcon) {
        return initButton(defaultIcon,rolloverIcon,pressedIcon,0,null);
    }
    
    /**
     * 創(chuàng)建帶的三個圖片的按鈕
     * @param defaultIcon - 按鈕的一般ImageIcon
     * @param rolloverIcon - 鼠標滑過按鈕時的ImageIcon
     * @param pressedIcon - 鼠標按下按鈕時的ImageIcon
     * @param alpha - alpha值(按鈕的透明形式)，可取本類的常量值
     * @return - 帶此圖片的按鈕
     */
    public static JButton createButton(ImageIcon defaultIcon,ImageIcon rolloverIcon,
                                       ImageIcon pressedIcon,float alpha) {
        return initButton(defaultIcon,rolloverIcon,pressedIcon,alpha,null);
    }
    
    /**
     * 初始化圖片按鈕
     */
    private static JButton initButton(ImageIcon defaultIcon,ImageIcon rolloverIcon,
                                      ImageIcon pressedIcon,float alpha,String text) {
        //獲取鼠標滑過按鈕的寬和高(供轉換圖片時之用)
        int width = rolloverIcon.getIconWidth();
        int height = rolloverIcon.getIconHeight();
        
        //如果alpha值為0，則設置alpha值為半透明
        if(alpha == 0)
            alpha = ImageButton.TRANSLUCENCE;
        
        //如果一般按鈕或鼠標壓下按鈕的ImageIcon為Null
        //則轉換鼠標滑過按鈕的圖片，賦值給這兩個為Null的圖片
        if(defaultIcon == null)
            defaultIcon = getImageIcon(rolloverIcon,width,height,0,0,alpha);
        if(pressedIcon == null)
            pressedIcon = getImageIcon(rolloverIcon,width,height,2,2,ImageButton.OPACITY);
        
        //創(chuàng)建帶圖片的JButton
        JButton button;
        if(text == null)
            button = new JButton();
        else
            button = new JButton(text);
        button.setIgnoreRepaint(true);          //忽略重繪
        button.setBorder(null);                 //不繪制邊框
        button.setContentAreaFilled(false);     //不繪制背景
        button.setIcon(defaultIcon);            //設置按鈕默認時的圖片
        button.setRolloverIcon(rolloverIcon);   //設置鼠標滑過按鈕時的圖片
        button.setPressedIcon(pressedIcon);     //設置鼠標按下按鈕時的圖片
        
        return button;
    }

    /**
     * 轉換圖片并返回ImageIcon
     */
    private static ImageIcon getImageIcon(ImageIcon defaultIcon,int width,
                                          int height,int x,int y,float alpha) {           
        JFrame frame = new JFrame();
        //得到窗體的圖形配置，并創(chuàng)建兼容的圖片
        GraphicsConfiguration gc = frame.getGraphicsConfiguration();
        Image image = gc.createCompatibleImage(width,height,Transparency.TRANSLUCENT);
        
        //轉換圖片的透明值和位置
        Graphics2D g2D = (Graphics2D)image.getGraphics();
        if(alpha > 0) {
            Composite alphaTemp = AlphaComposite.getInstance(AlphaComposite.SRC_OVER,alpha);
            g2D.setComposite(alphaTemp);
        }
        g2D.drawImage(defaultIcon.getImage(),x,y,null);
        g2D.dispose();
        
        return new ImageIcon(image);
    }
    
    /**
     * 獲取自帶(各個常量值)的圖片并返回ImageIcon
     */
    private static ImageIcon getImageIcon(String fileName) {
        fileName = "images/" + fileName + ".png";
        return new ImageIcon(ImageButton.class.getResource(fileName));
    }
    
    
    //ImageButton 的各個常量
    public static final float THIRD_TRANSPARENCY = 0.3f;    //3/1透明
    public static final float TRANSLUCENCE = 0.5f;          //半透明
    public static final float TOWPART_TRANSPARENCY = 0.8f;  //3/2透明
    public static final float OPACITY = -1f;                //不透明
}