/**
 * L2FProd.com Common Components 6.9.1 License.
 *
 * Copyright 2005-2006 L2FProd.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.l2fprod.common.swing;

import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Composite;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.LayoutManager;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import javax.swing.AbstractAction;
import javax.swing.JComponent;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;

/**
 * <code>JCollapsiblePane</code> provides a component which can collapse or
 * expand its content area with animation and fade in/fade out effects.
 * It also acts as a standard container for other Swing components.
 * 
 * <p>
 * In this example, the <code>JCollapsiblePane</code> is used to build
 * a Search pane which can be shown and hidden on demand.
 * 
 * <pre>
 * <code>
 * JCollapsiblePane cp = new JCollapsiblePane();
 *
 * // JCollapsiblePane can be used like any other container
 * cp.setLayout(new BorderLayout());
 * 
 * // the Controls panel with a textfield to filter the tree
 * JPanel controls = new JPanel(new FlowLayout(FlowLayout.LEFT, 4, 0));
 * controls.add(new JLabel("Search:"));
 * controls.add(new JTextField(10));    
 * controls.add(new JButton("Refresh"));
 * controls.setBorder(new TitledBorder("Filters"));
 * cp.add("Center", controls);
 *   
 * JFrame frame = new JFrame();
 * frame.setLayout(new BorderLayout());
 *  
 * // Put the "Controls" first
 * frame.add("North", cp);
 *    
 * // Then the tree - we assume the Controls would somehow filter the tree
 * JScrollPane scroll = new JScrollPane(new JTree());
 * frame.add("Center", scroll);
 *
 * // Show/hide the "Controls"
 * JButton toggle = new JButton(cp.getActionMap().get(JCollapsiblePane.TOGGLE_ACTION));
 * toggle.setText("Show/Hide Search Panel");
 * frame.add("South", toggle);
 *
 * frame.pack();
 * frame.setVisible(true);
 * </code>
 * </pre>
 * 
 * <p>
 * Note: <code>JCollapsiblePane</code> requires its parent container to have a
 * {@link java.awt.LayoutManager} using {@link #getPreferredSize()} when
 * calculating its layout (example {@link com.l2fprod.common.swing.PercentLayout},
 * {@link java.awt.BorderLayout}). 
 * 
 * @javabean.attribute
 *          name="isContainer"
 *          value="Boolean.TRUE"
 *          rtexpr="true"
 * 
 * @javabean.attribute
 *          name="containerDelegate"
 *          value="getContentPane"
 *          
 * @javabean.class
 *          name="JCollapsiblePane"
 *          shortDescription="A pane which hides its content with an animation."
 *          stopClass="java.awt.Component"
 *          
 * @author rbair (from the JDNC project)
 * @author <a href="mailto:fred@L2FProd.com">Frederic Lavigne</a>
 */
public class JCollapsiblePane extends JPanel {

  /**
   * Used when generating PropertyChangeEvents for the "animationState" property
   */
  public final static String ANIMATION_STATE_KEY = "animationState";
  
  /**
   * JCollapsible has a built-in toggle action which can be bound to buttons.
   * Accesses the action through
   * <code>collapsiblePane.getActionMap().get(JCollapsiblePane.TOGGLE_ACTION)</code>.
   */
  public final static String TOGGLE_ACTION = "toggle";
  
  /**
   * The icon used by the "toggle" action when the JCollapsiblePane is
   * expanded, i.e the icon which indicates the pane can be collapsed.
   */
  public final static String COLLAPSE_ICON = "collapseIcon";
  
  /**
   * The icon used by the "toggle" action when the JCollapsiblePane is
   * collapsed, i.e the icon which indicates the pane can be expanded.
   */
  public final static String EXPAND_ICON = "expandIcon";

  /**
   * Indicates whether the component is collapsed or expanded
   */
  private boolean collapsed = false;

  /**
   * Timer used for doing the transparency animation (fade-in)
   */
  private Timer animateTimer;
  private AnimationListener animator;
  private int currentHeight = -1;
  private WrapperContainer wrapper;
  private boolean useAnimation = true;
  private AnimationParams animationParams;

  /**
   * Constructs a new JCollapsiblePane with a {@link JPanel} as content pane and
   * a vertical {@link PercentLayout} with a gap of 2 pixels as layout manager.
   */
  public JCollapsiblePane() {
    super.setLayout(new BorderLayout(0, 0));

    JPanel panel = new JPanel();
    panel.setLayout(new PercentLayout(PercentLayout.VERTICAL, 2));
    setContentPane(panel);

    animator = new AnimationListener();
    setAnimationParams(new AnimationParams(30, 8, 0.01f, 1.0f));
    
    // add an action to automatically toggle the state of the pane
    getActionMap().put(TOGGLE_ACTION, new ToggleAction());
  }

  /**
   * Toggles the JCollapsiblePane state and updates its icon based on the
   * JCollapsiblePane "collapsed" status.
   */
  private class ToggleAction extends AbstractAction  implements
    PropertyChangeListener {
    public ToggleAction() {
      super(TOGGLE_ACTION);
      updateIcon();
      // the action must track the collapsed status of the pane to update its
      // icon
      JCollapsiblePane.this.addPropertyChangeListener("collapsed", this);
    }
    public void putValue(String key, Object newValue) {
      super.putValue(key, newValue);
      if (EXPAND_ICON.equals(key) || COLLAPSE_ICON.equals(key)) {
        updateIcon();
      }
    }
    public void actionPerformed(ActionEvent e) {      
      setCollapsed(!isCollapsed());
    }
    public void propertyChange(PropertyChangeEvent evt) {
      updateIcon();
    }
    void updateIcon() {      
      if (isCollapsed()) {
        putValue(SMALL_ICON, getValue(EXPAND_ICON));
      } else {
        putValue(SMALL_ICON, getValue(COLLAPSE_ICON));
      }
    }
  }

  /**
   * Sets the content pane of this JCollapsiblePane. Components must be added
   * to this content pane, not to the JCollapsiblePane.
   * 
   * @param contentPanel
   * @throws IllegalArgumentException
   *           if contentPanel is null
   */
  public void setContentPane(Container contentPanel) {
    if (contentPanel == null) {
      throw new IllegalArgumentException("Content pane can't be null");
    }
    
    if (wrapper != null) {
      super.remove(wrapper);
    }
    wrapper = new WrapperContainer(contentPanel);
    super.addImpl(wrapper, BorderLayout.CENTER, -1);
  }

  /**
   * @return the content pane
   */
  public Container getContentPane() {
    return wrapper.c;
  }

  /**
   * Overriden to redirect call to the content pane.
   */
  public void setLayout(LayoutManager mgr) {
    // wrapper can be null when setLayout is called by "super()" constructor
    if (wrapper != null) {
      getContentPane().setLayout(mgr);
    }
  }

  /**
   * Overriden to redirect call to the content pane.
   */
  protected void addImpl(Component comp, Object constraints, int index) {
    getContentPane().add(comp, constraints, index);
  }

  /**
   * Overriden to redirect call to the content pane
   */
  public void remove(Component comp) {
    getContentPane().remove(comp);
  }

  /**
   * Overriden to redirect call to the content pane.
   */
  public void remove(int index) {
    getContentPane().remove(index);
  }
  
  /**
   * Overriden to redirect call to the content pane.
   */
  public void removeAll() {
    getContentPane().removeAll();
  }
  
  /**
   * If true, enables the animation when pane is collapsed/expanded. If false,
   * animation is turned off.
   * 
   * <p>
   * When animated, the <code>JCollapsiblePane</code> will progressively
   * reduce (when collapsing) or enlarge (when expanding) the height of its
   * content area until it becomes 0 or until it reaches the preferred height of
   * the components it contains. The transparency of the content area will also
   * change during the animation.
   * 
   * <p>
   * If not animated, the <code>JCollapsiblePane</code> will simply hide
   * (collapsing) or show (expanding) its content area.
   * 
   * @param animated
   * @javabean.property bound="true" preferred="true"
   */
  public void setAnimated(boolean animated) {
    if (animated != useAnimation) {
      useAnimation = animated;
      firePropertyChange("animated", !useAnimation, useAnimation);
    }
  }

  /**
   * @return true if the pane is animated, false otherwise
   * @see #setAnimated(boolean)
   */
  public boolean isAnimated() {
    return useAnimation;
  }

  /**
   * @return true if the pane is collapsed, false if expanded
   */
  public boolean isCollapsed() {
    return collapsed;
  }

  /**
   * Expands or collapses this <code>JCollapsiblePane</code>.
   * 
   * <p>
   * If the component is collapsed and <code>val</code> is false, then this
   * call expands the JCollapsiblePane, such that the entire JCollapsiblePane
   * will be visible. If {@link #isAnimated()} returns true, the expansion will
   * be accompanied by an animation.
   * 
   * <p>
   * However, if the component is expanded and <code>val</code> is true, then
   * this call collapses the JCollapsiblePane, such that the entire
   * JCollapsiblePane will be invisible. If {@link #isAnimated()} returns true,
   * the collapse will be accompanied by an animation.
   * 
   * @see #isAnimated()
   * @see #setAnimated(boolean)
   * @javabean.property
   *          bound="true"
   *          preferred="true"
   */
  public void setCollapsed(boolean val) {
    if (collapsed != val) {
      collapsed = val;
      if (isAnimated()) {
        if (collapsed) {
          setAnimationParams(new AnimationParams(30, Math.max(8, wrapper
            .getHeight() / 10), 1.0f, 0.01f));
          animator.reinit(wrapper.getHeight(), 0);
          animateTimer.start();
        } else {