lwtree.java

Zaval Light-Weight Visual Components Library (LwVCL) is a pure Java alternative to humble AWT-based

/**
 *     Caption: Zaval Light-Weight Visual Components Library
 *     $Revision: 2.79 $
 *     $Date: 2003/08/22 11:24:16 $
 *
 *     @author:     Andrei Vishnevsky
 *     @version:    3.50
 *
 * Zaval Light-Weight Visual Components Library (LwVCL) is a pure Java
 * alternative to humble AWT-based and SWING-based GUI interfaces for
 * wide ranges of platforms, including J2SE, PersonalJava and J2ME.
 *
 * Designed as light-weight but, alternatively to Swing, built separately
 * from AWT (not on top of the java.awt library like Swing), the LwVCL is
 * the good alternative to highly performant, memory-efficient, flexible
 * GUI solution for embedded, stand-alone and applet applications.
 *
 * For more info on this product read Zaval Light-Weight Visual Components Library Tutorial
 * (It comes within this package).
 * The latest product version is always available from the product's homepage:
 * http://www.zaval.org/products/lwvcl/
 * and from the SourceForge:
 * http://sourceforge.net/projects/zaval0003/
 *
 * Contacts:
 *   Support : [e-mail]
 *   Change Requests : [e-mail]
 *   Feedback : [e-mail]
 *   Other : [e-mail]
 *
 * Copyright (C) 2001-2003  Zaval Creative Engineering Group (http://www.zaval.org)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * (version 2) as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */
package org.zaval.lw.tree;

import java.util.*;
import java.awt.*;
import java.awt.event.*;

import org.zaval.data.*;
import org.zaval.data.event.*;
import org.zaval.lw.event.*;
import org.zaval.lw.*;
import org.zaval.misc.*;
import org.zaval.util.*;

/**
 * This is tree view component. The component renders the specified  <code>TreeModel</code>
 * and organizes navigation through the tree. The sample below illustrates
 * the component usage:
 * <pre>
 *   ...
 *   Item root = new Item("root");
 *   TreeModel data = new Tree(root);
 *   data.add(data.getRoot(), new Item("First Child root"));
 *   data.add(data.getRoot(), new Item("Second Child root"));
 *   LwTree tree = new LwTree(data);
 *   ...
 * </pre>
 * <p>
 * The class provides ability to customize the tree node rendering by defining the
 * <code>LwViewProvider</code> provider. It allows to specify the view for the tree item.
 * The default tree item view is LwTextRender.
 * <p>
 * Use <code>addSelectionListener</code> and <code>removeSelectionListener</code> methods to
 * handle selection events. The events are performed by the component whenever the tree node
 * has been selected, deselected.
 * <p>
 * Use <code>addActionListener</code> and <code>removeActionListener</code> methods to
 * be notified whenever the node has been expanded or collapsed. The action event contains
 * the tree expanded or collapsed item that can be got by <code>getData</code> method of the
 * action event object.
 * <p>
 * It is possible to disable node selection by the <code>enableSelection</code> method.
 * <p>
 * It is possible to customize views for some elements of the tree by <code>setView</code>
 * The default views of the elements are read as static objects by following keys:
 * <ul>
 *   <li>The toggle off view is fetched by "toggle.off" key.</li>
 *   <li>The toggle on view is fetched by "toggle.on" key.</li>
 *   <li>The list node view is fetched by the "tree.least" key.</li>
 *   <li>The opened node view is fetched by the "tree.open" key.</li>
 *   <li>The closed node view is fetched by the "tree.close" key.</li>
 * </ul>
 * <p>
 * The tree nodes height and width can be extended by <code>setGaps</code> method that
 * defines horizontal and vertical gaps between the nodes.
 * <p>
 * It is possible disables tree view line rendering by <code>showLines</code> method.
 */
public class LwTree
extends LwCanvas
implements TreeListener, LwViewProvider, LwMouseListener,
           LwFocusListener, LwKeyListener , ScrollObj
{
  /**
   * Defines list view element type.
   */
   public static final int LEAST_VIEW  = 1;

  /**
   * Defines opened view element type.
   */
   public static final int OPENED_VIEW = 2;

  /**
   * Defines closed view element type.
   */
   public static final int CLOSED_VIEW = 3;

  /**
   * Defines toggle off view element type.
   */
   public static final int TOGGLE_OFF_VIEW = 4;

  /**
   * Defines toggle on view element type.
   */
   public static final int TOGGLE_ON_VIEW  = 5;

   /* To speed up */
   private static final Dimension ZERO = new Dimension();

   private TreeModel          data;
   private LwActionSupport    actions;
   private LwActionSupport    selection;
   private boolean isOpenVal;

   private LwViewProvider  provider;
   private LwView          openedImg, closedImg, leastImg, toggleOnView, toggleOffView;
   private Hashtable       nodes;
   private int             gapx = 5, gapy = 2, dx, dy;
   private Item            selected, firstVisible;
   private Rectangle       visibleArea;
   private Dimension       max,openedImgSize, closedImgSize, leastImgSize, toggleOnSize, toggleOffSize;
   private ScrollMan       man;
   private LwTextRender    defaultRender = new LwTextRender("");
   private Color           selectColor1 = LwToolkit.darkBlue, selectColor2 = Color.yellow, linesColor = Color.gray;

  /**
   * Constructs a tree view component with the specified tree model.
   * @param <code>d</code> the specified tree model.
   */
   public LwTree(TreeModel d) {
     this(d, true);
   }

  /**
   * Constructs a tree view component with the specified tree model and tree node state.
   * The state defines if all nodes that have children should be opened or closed.
   * @param <code>d</code> the specified tree model.
   * @param <code>b</code> the specified tree node state.
   */
   public LwTree(TreeModel d, boolean b)
   {
     isOpenVal = b;
     setModel(d);
     setViewProvider(this);
     setView(TOGGLE_ON_VIEW,  LwManager.getView("toggle.on"));
     setView(TOGGLE_OFF_VIEW, LwManager.getView("toggle.off"));
     setView(LEAST_VIEW,      LwManager.getView("tree.least"));
     setView(OPENED_VIEW,     LwManager.getView("tree.open"));
     setView(CLOSED_VIEW,     LwManager.getView("tree.close"));
     enableSelection(true);
     showLines(true);
   }

   public /*C#override*/ boolean canHaveFocus() {
     return true;
   }

  /**
   * Enables the tree node selecting.
   * @param <code>b</code> use <code>true</code> to enable the tree node selecting;
   * <code>false</code> otherwise.
   */
   public void enableSelection(boolean b)
   {
     if (isSelectionEnabled() != b)
     {
       if (!b && selected != null) select(null);
       bits = MathBox.getBits(bits, ENSEL_BIT, b);
       repaint();
     }
   }

  /**
   * Tests if the tree items selection is enabled.
   * @return <code>true</code> if the tree items selection is enabled;
   * <code>false</code> otherwise.
   */
   public boolean isSelectionEnabled() {
     return MathBox.checkBit(bits, ENSEL_BIT);
   }

  /**
   * Enables the tree lines rendering.
   * @param <code>b</code> use <code>true</code> to enable the tree line rendering;
   * <code>false</code> otherwise.
   */
   public void showLines(boolean b)
   {
     if (isLinesShown() != b)
     {
       bits = MathBox.getBits(bits, ENLINES_BIT, b);
       repaint();
     }
   }

  /**
   * Tests if the tree line rendering is enabled.
   * @return <code>true</code> if the line rendering is enabled;
   * <code>false</code> otherwise.
   */
   public boolean isLinesShown() {
     return MathBox.checkBit(bits, ENLINES_BIT);
   }

  /**
   * Gets the color that is used to paint tree lines.
   * @param a color.
   */
   public Color getLinesColor() {
     return linesColor;
   }

  /**
   * Sets the specified color to paint tree lines.
   * @param <code>c</code> the specified color.
   */
   public void setLinesColor(Color c)
   {
     if (!c.equals (linesColor))
     {
       linesColor = c;
       repaint();
     }
   }

  /**
   * Sets the specified vertical and horizontal gaps. The method doesn't touch
   * a gap in case if it is less zero, so it is possible to use the method to
   * set only vertical or only horizontal gap.
   * @param <code>gx</code> the specified horizontal gap.
   * @param <code>gy</code> the specified vertical gap.
   */
   public void setGaps (int gx, int gy)
   {
     if ((gx >= 0 && gx != gapx)||
         (gy >= 0 && gy != gapy)  )
     {
       gapx = gx<0?gapx:gx;
       gapy = gy<0?gapy:gy;
       invalidateMetrics();
       repaint();
     }
   }

  /**
   * Gets the tree model that is rendered with the tree view component.
   * @return a tree model.
   */
   public TreeModel getModel() {
     return data;
   }

  /**
   * Sets the specified view provider. The provider is used to define a view that
   * will be used to paint the node. It is possible to use <code>null</code> value
   * as the input argument, in this case the LwTextRender view is used (the method
   * sets itself as the view provider) to paint the node.
   * @param <code>p</code> the specified view provider.
   */
   public void setViewProvider (LwViewProvider p)
   {
     if (p == null) p = this;
     if (provider != p)
     {
       provider = p;
       invalidateData();
       repaint();
     }
   }

  /**
   * Gets the view provider.
   * @return a view provider.
   */
   public LwViewProvider getViewProvider () {
     return provider;
   }

  /**
   * Sets the specified view for the specified tree view element. Use one of the following
   * constants as the view element id:
   * <ul>
   *   <li>
   *      LEAST_VIEW - to define least node element.
   *   </li>
   *   <li>
   *      OPENED_VIEW - to define opened node element.
   *   </li>
   *   <li>
   *      CLOSED_VIEW - to define closed node element.
   *   </li>
   *   <li>
   *      TOGGLE_OFF_VIEW - to define toggle off node element.
   *   </li>
   *   <li>
   *      TOGGLE_ON_VIEW - to define toggle on node element.
   *   </li>
   * </ul>
   * @param <code>id</code> the specified element id.
   * @param <code>v</code> the specified view.
   */
   public void setView(int id, LwView v)
   {
     switch (id)
     {
       case LEAST_VIEW     : if (v != leastImg)  { leastImg  = v; leastImgSize  = viewPS(v); } break;
       case OPENED_VIEW    : if (v != openedImg) { openedImg = v; openedImgSize = viewPS(v); } break;
       case CLOSED_VIEW    : if (v != closedImg) { closedImg = v; closedImgSize = viewPS(v); } break;
       case TOGGLE_OFF_VIEW: if (v != toggleOffView) { toggleOffView = v; toggleOffSize = viewPS(v); } break;
       case TOGGLE_ON_VIEW : if (v != toggleOnView)  { toggleOnView = v; toggleOnSize = viewPS(v); } break;
       default: throw new IllegalArgumentException();
     }
     invalidateMetrics();
     repaint();
   }

  /**
   * Sets the specified tree model to be rendered with the component.
   * @param <code>d</code> the specified tree model.
   */
   public void setModel(TreeModel d)
   {
     if (data != d)
     {
       if (data != null) data.removeTreeListener(this);
       data = d;
       if (data != null) data.addTreeListener(this);
       invalidateData();
       repaint();
     }
   }

  /**
   * Paints this component.
   * @param <code>g</code> the graphics context to be used for painting.
   */
   public /*C#override*/ void paint (Graphics g)
   {
     if (data != null)
     {
       vVisibility();
       if (MathBox.checkBit(bits, VALVIS_BIT) && firstVisible != null)
         paintTree (g, firstVisible);
     }
   }