lwslider.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;

import java.awt.*;
import java.awt.event.*;
import org.zaval.lw.event.*;
import org.zaval.util.*;

/**
 * This is slider component that can be used to select a value from the
 * specified integer interval. The minimum, maximum, intervals sizes and other properties
 * are specified by <code>setValues</code> method. The table below explains the
 * properties meaning in more detail:
 * <table border="1">
 *    <tr>
 *      <td align="center">Property</td>
 *      <td align="center">Description</td>
 *    </tr>
 *    <tr>
 *      <td align="center" valign="center">
 *           max
 *      </td>
 *      <td>
 *           This is maximum possible value of the slider interval. Use <code>getMax</code>
 *           method to get the property value. It is impossible to set a slider value that is
 *           greater than the maximum.
 *      </td>
 *    </tr>
 *    <tr>
 *      <td align="center" valign="center">
 *           min
 *      </td>
 *      <td>
 *           This is minimum possible value of the slider interval. Use <code>getMin</code>
 *           method to get the property value. It is impossible to set a slider value that is
 *           less than the minimum.
 *      </td>
 *    </tr>
 *    <tr>
 *      <td align="center" valign="center">
 *          roughStep
 *      </td>
 *      <td>
 *           This property defines a rough step that is used to change current slider value for
 *           none-interval slider model. The step is used (to change the slider value) when the
 *           left mouse button has been pressed.
 *      </td>
 *    </tr>
 *    <tr>
 *      <td align="center" valign="center">
 *          exactStep
 *      </td>
 *      <td>
 *           This property defines an exact step that is used to change current slider value for
 *           none-interval slider model. The step is used (to change the slider value) when
 *           appropriate key has been pressed or mouse drag event has been performed.
 *      </td>
 *    </tr>
 *    <tr>
 *      <td align="center" valign="center">
 *          interval[]
 *      </td>
 *      <td>
 *          This property defines slider intervals sizes. The intervals are used to
 *          navigate through the slider component for interval model. The painting
 *          process uses the intervals to render scale and the scale titles.
 *      </td>
 *    </tr>
 *    <tr>
 *      <td align="center" valign="center">
 *          isIntervalModel
 *      </td>
 *      <td>
 *          This property defines navigation model. There are two possible models:
 *          <ul>
 *            <li>
 *              None-interval model (if the property is false). In this case the slider
 *              changes its value using the defined steps properties (roughStep and
 *              exactStep steps).
 *            </li>
 *            <li>
 *              Interval model (if the property is true). In this case the slider
 *              changes its value using the interval sizes as the step.
 *            </li>
 *          </ul>
 *      </td>
 *    </tr>
 * </table>
 * <br>
 * The basic components features are described below:
 * <ul>
 *  <li>
 *     It is possible to customize the slider bundle and gauge views by
 *     <code>setView</code> method. The component uses "sl.hbundle"
 *     (horizontal slider), "sl.vbundle" (vertical slider) and "sl.gauge" (gauge view)
 *     static views as the default.
 *  </li>
 *  <li>
 *     The scale and titles rendering can be disabled or enabled by the
 *     <code>showScale</code> and <code>showTitle</code> methods.
 *  </li>
 *  <li>
 *     To render titles the component uses views that are provided by LwViewProvider.
 *     Use <code>setViewProvider</code> method to customize the titles views.
 *  </li>
 *  <li>
 *     Use <code>setOrientation</code> method to define the slider orientation.
 *  </li>
 *  <li>
 *     To listen whenever the slider value has been changed use action events listener.
 *  </li>
 * </ul>
 */
public class LwSlider
extends LwCanvas
implements LwKeyListener, LwMouseListener, LwMouseMotionListener,
           LwViewProvider
{
 /**
  * The bundle view id.
  */
  public static final int BUNDLE_VIEW  = 0;

 /**
  * The gauge view id.
  */
  public static final int GAUGE_VIEW   = 1;

  private int             max, min, value, roughStep, exactStep;
  private int             netSize = 3, gap = 3, orient, scaleStep, psW, psH;
  private int[]           intervals, pl;
  private LwView[]        views = new LwView[2];
  private LwActionSupport support;
  private Color           scaleColor = LwToolkit.darkBlue;
  private LwViewProvider  provider;
  private LwTextRender    render = new LwTextRender("");

 /**
  * Constructs a slider. The slider will use horizontal orientation.
  */
  public LwSlider() {
    this (LwToolkit.HORIZONTAL);
  }

 /**
  * Constructs a slider with the specified orientation. Use LwToolkit.HORIZONTAL or
  * LwToolkit.VERTICAL constant as the orientation property value.
  * @param <code>o</code> the specified orientation.
  */
  public LwSlider(int o)
  {
    provider = this;
    setOrientation(o);
    setView (GAUGE_VIEW, LwManager.getView("sl.gauge"));
    setValues (0, 20, new int[] { 0, 5, 10 }, 2, 1);
    render = new LwTextRender("");
    render.setFont (LwToolkit.BFONT);
    render.setForeground (scaleColor);
    setScaleStep(1);
    showScale (true);
    showTitle (true);
  }


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


 /**
  * Gets the scale gap. The gap defines distance between the bundle element and the scale
  * element.
  * @return a gap.
  */
  public int getScaleGap (){
    return gap;
  }

 /**
  * Sets the specified scale gap. The gap defines distance between the bundle element
  * and the scale element.
  * @param <code>g</code> the specified scale gap.
  */
  public void setScaleGap (int g)
  {
    if (g != gap) {
      gap = g;
      vrp();
    }
  }

 /**
  * Gets the scale color.
  * @return a scale color.
  */
  public Color getScaleColor () {
    return scaleColor;
  }

 /**
  * Sets the scale color.
  * @param <code>c</code> the scale color.
  */
  public void setScaleColor (Color c)
  {
    if (!c.equals(scaleColor)) {
      scaleColor = c;
      repaint();
    }
  }

 /**
  * Sets the scale step.
  * @param <code>s</code> the scale step.
  */
  public void setScaleStep (int s)
  {
    if (s != scaleStep)
    {
      scaleStep = s;
      repaint();
    }
  }

 /**
  * Sets the scale element visibility.
  * @param <code>b</code> the scale element visibility.
  */
  public void showScale (boolean b)
  {
    if (MathBox.checkBit(bits, SHOW_SCALE) != b) {
      bits = MathBox.getBits(bits, SHOW_SCALE, b);
      vrp();
    }
  }

 /**
  * Tests if the slider value will be changed according to the mouse cursor location by
  * mouse presssed event.
  * @return <code>true</code> if the slider value is changed by mouse pressed event
  * according to the mouse cursor location.
  */
  public boolean isJumpOnPress () {
    return MathBox.checkBit(bits, JUMP_ONPRESS);
  }

 /**
  * Sets if the slider value should be changed according to the mouse cursor location by
  * mouse presssed event.
  * @param <code>b</code> use <code>true</code> as the argument value to allow the slider
  * value changing by mouse pressed event according to the mouse cursor location.
  */
  public void jumpOnPress (boolean b) {
    bits = MathBox.getBits(bits, JUMP_ONPRESS, b);
  }

 /**
  * Sets the slider title visibility.
  * @param <code>b</code> the slider title visibility.
  */
  public void showTitle (boolean b)
  {
    if (MathBox.checkBit(bits, SHOW_TITLE) != b) {
      bits = MathBox.getBits(bits, SHOW_TITLE, b);
      vrp();
    }
  }

 /**
  * Sets the specified titles views provider. The provider defines views for the slider
  * titles that are used to render the titles.
  * @param <code>p</code> the specified titles views provider.
  */
  public void setViewProvider(LwViewProvider p)
  {
    if (p != provider)
    {
      provider = p;
      vrp();
    }
  }

  public LwView getView(Drawable d, Object o) {
    render.getTextModel().setText(o!=null?o.toString():"");
    return render;
  }

 /**
  * Sets the specified slider orientation. It is possible to use LwToolkit.HORIZONTAL or
  * LwToolkit.VERTICAL as the orientation value. Draw attention that the method restores
  * appropriate bundle view.
  * @param <code>o</code> the specified slider orientation.
  */
  public void setOrientation(int o)
  {
    if (o != LwToolkit.HORIZONTAL && o != LwToolkit.VERTICAL)
      throw new IllegalArgumentException();

    if (o != orient)
    {
      orient = o;
      setView (BUNDLE_VIEW, o == LwToolkit.HORIZONTAL?LwManager.getView("sl.hbundle")
                                                     :LwManager.getView("sl.vbundle"));
    }
  }

 /**
  * Gets the slider orientation.
  * @return a slider orientation.
  */
  public int getOrientation() {
    return orient;
  }

 /**
  * Gets the view of the specified slider element.
  * @param <code>id</code> the specified slider element id.
  * @return a view that is used to render the slider element.
  */
  public LwView getView (int id) {
    return views[id];
  }

 /**
  * Sets the view for the specified slider element. There are two elements views can be
  * specified by the method: BUNDLE_VIEW and GAUGE_VIEW.
  * @param <code>id</code> the specified slider element id.
  * @param <code>v</code> the specified view.
  */
  public void setView (int id, LwView v)
  {
    if (v != views[id])
    {
      views[id] = v;
      vrp();
    }
  }

 /**
  * Tests if the interval model is used to navigate through the slider.
  * The interval model defines that navigation possible only between slider intervals.
  * @return <code>true</code> if the interval model is used; otherwise <code>false</code>.
  */
  public boolean isIntervalModel() {
    return MathBox.checkBit(bits, INTERVAL_MODEL_BIT);
  }

 /**
  * Sets the specified navigation model.
  * @param <code>b</code> specified navigation model. Use <code>true</code> to set interval
  * model; otherwise <code>false</code>.
  */
  public void useIntervalModel(boolean b) {
    if (b != isIntervalModel())
      bits = MathBox.getBits (bits, INTERVAL_MODEL_BIT, b);
  }

 /**
  * Gets the current slider value.
  * @return a current slider value.
  */
  public int getValue() {
    return value;
  }

 /**
  * Sets the specified slider value. The value should be less than maximal and greater than
  * minimal possible properties.
  * @param <code>v</code> the specified slider value.
  */
  public void setValue(int v)
  {
    if (v < min || v > max) throw new IllegalArgumentException();

    int prev = value;
    if (value != v)
    {
      value = v;
      if (support != null) support.perform(new LwActionEvent(this, new Integer(prev)));
      repaint();
    }
  }

 /**
  * Gets the maximal possible value.
  * @return a maximal possible value.
  */
  public int getMax () {
    return max;
  }