folderpaneui.java

SWING的界面UI包 SWING的界面UI包

/*
 * FolderPaneUI.java
 *
 * Created on June 9, 2007, 9:33 AM
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */
package dyno.swing.beans;

import java.awt.Color;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;

import javax.swing.BorderFactory;
import javax.swing.JComponent;
import javax.swing.Timer;
import javax.swing.plaf.ComponentUI;


/**
 * FolderPane的UI类
 *
 * @author William Chen
 */
public class FolderPaneUI extends ComponentUI {
    //缺省常量
    private static final Color BACK_COLOR = new Color(116, 149, 226);
    private static final int LEFT_PADDING = 12;
    private static final int TOP_PADDING = 12;
    private static final int RIGHT_PADDING = 12;
    private static final int BOTTOM_PADDING = 12;
    private static final double INCDEC = 0.085;
    private static final double DECRATIO = 0.925;
    private static final int ANIMATION_INTERVAL = 15;

    //FolderPane的实例
    private FolderPane pane;

    //安装ui
    public void installUI(JComponent c) {
        c.setOpaque(true);
        c.setBackground(BACK_COLOR);
        c.setBorder(BorderFactory.createEmptyBorder(TOP_PADDING, LEFT_PADDING,
                RIGHT_PADDING, BOTTOM_PADDING));
        pane = (FolderPane) c;
    }

    //为该面板添加折叠处理事件
    void addTab(Folder tab) {
        tab.getCaption().addItemListener(new FolderTabItemListener(tab));
    }

    //折叠事件处理器
    class FolderTabItemListener implements ItemListener {
        private Folder tab;
        private Timer timer;

        public FolderTabItemListener(Folder t) {
            tab = t;
        }

        public void itemStateChanged(ItemEvent e) {
            if (pane.isAnimated()) {
                //需要动画效果，先关闭可能的timer
                if (timer != null) {
                    if (timer.isRunning()) {
                        timer.stop();
                    }
                }
                
                //生成新的timer
                timer = new Timer(ANIMATION_INTERVAL, null);

                //根据展开或者是关闭选择不同的动画处理动作
                ActionListener action;

                if (e.getStateChange() == e.DESELECTED) {
                    action = new FolderingAction(tab, timer);
                } else {
                    action = new ExpandingAction(tab, timer);
                }

                tab.getDrawer().clearOffImage();
                timer.addActionListener(action);
                //启动timer
                timer.start();
            } else {
                //无动画效果，直接展开或者关闭
                tab.getDrawer()
                   .setRatio((e.getStateChange() == e.DESELECTED) ? 0 : 1.0);
                pane.doLayout();
            }

            //确保界面更新
            pane.repaint();
        }
    }

    //折叠事件基类
    abstract class FolderAction implements ActionListener {
        //当前折叠的面板
        private Folder tab;

        //相关的时钟
        private Timer timer;

        //下面两个参数计算抽屉抽出或者关闭的实时速度
        private double ratio;
        private double exponent;

        public FolderAction(Folder t, Timer timer) {
            tab = t;
            this.timer = timer;
            ratio = INCDEC;
            exponent = DECRATIO;
            //将抽屉置于动画效果状态
            tab.getDrawer().setAnimating(true);
        }

        //计算速度变化，可以允许非匀速运动效果的抽屉
        protected double getDelta() {
            double r = ratio;
            ratio = ratio * exponent;

            return r;
        }

        public void actionPerformed(ActionEvent e) {
            //计算新的值
            double r = delta(tab.getDrawer().getRatio(), getDelta());

            if (overflow(r)) {
                //溢出则置为界限值
                r = bound();
                //设置抽屉状态，停止动画效果，重新布局折叠面板，停止时钟，最好释放时钟
                tab.getDrawer().setAnimating(false);
                doLayout(r);
                timer.stop();
                timer = null;
            } else {
                //普通动画的一帧，设置抽屉状态，重新布局折叠面板
                doLayout(r);
            }
        }

        private void doLayout(final double r) {
            tab.getDrawer().setRatio(r);

            //相比以前添加了动画时，动态调整父容器布局，这对于父容器是JScrolPane
            //的FolderPane来说很重要，它需要实时调整ScrollBar
            Container parent = pane.getParent();

            if (parent != null) {
                parent.doLayout();
            }

            //调整自己的尺寸布局
            pane.doLayout();
        }

        //计算新的位置和透明度
        protected abstract double delta(double r, double d);

        //当前值是否溢出，比如超过1.0或者小于了0
        protected abstract boolean overflow(double r);

        //当前运动的界限值
        protected abstract double bound();
    }

    //展开用的动画处理事件
    class ExpandingAction extends FolderAction {
        public ExpandingAction(Folder t, Timer timer) {
            super(t, timer);
        }

        protected double delta(double r, double d) {
            return r + d;
        } //递增

        protected boolean overflow(double r) {
            return r > 1;
        } //上限为1

        protected double bound() {
            return 1;
        } //上限值位1
    }

    //折叠时用的动画处理事件
    class FolderingAction extends FolderAction {
        public FolderingAction(Folder t, Timer timer) {
            super(t, timer);
        }

        protected double delta(double r, double d) {
            return r - d;
        } //递减

        protected boolean overflow(double r) {
            return r < 0;
        } //下限为0

        protected double bound() {
            return 0;
        } //下限值为0
    }
}