/*
 * UI-package
 * Copyright (c) 1998 Mats Bovin. All rights reserved.
 *
 * File: ModePanel.java
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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 embe.ui;

import java.awt.*;
import java.util.Hashtable;


/**
 * This class, together with ModeButton, works like
 * a "tabbed notebook". This class uses a CardLayout to
 * display different Panels. Every Panel is represented by
 * a ModeButton. All the ModeButtons form a toolbar which
 * can be placed along any border. When a button is
 * clicked the corresponding Panel will be shown and the
 * button will be activated.
 *
 * @see embe.ui.ModeButton
 * @see java.awt.CardLayout
 *
 * @version 1.1 july-98
 * @author Mats Bovin
 */
public class ModePanel extends java.awt.Panel {

  /** Constant for placing the buttons along the top border */
  public static final int TOP    = 0;
  /** Constant for placing the buttons along the bottom border */
  public static final int BOTTOM = 1;
  /** Constant for placing the buttons along the left border */
  public static final int LEFT   = 2;
  /** Constant for placing the buttons along the right border */
  public static final int RIGHT  = 3;

  /** Color of button */
  protected Color btnCol_ = Color.lightGray;
  /** Color of buttontext */
  protected Color btnTxtCol_ = Color.black;
  /** Color of selected button */
  protected Color selectedCol_ = Color.red;
  /** Width of rectangle around selected btn */
  protected int rectWidth_;

  /** The 'toolbar' with buttons */
  protected Panel btnBar_ = new Panel();
  /** The selected button */
  protected ModeButton selectedBtn_ = null;
  /** The panel containing the other panels */
  protected Panel mainPanel_ = new Panel();
  /** A hashtable containing all the panels (or modes) */
  protected Hashtable modes_ = new Hashtable(4);


  /**
   * Constructs a new ModePanel.
   * The buttons will be placed along the top.
   */
  public ModePanel() { this(TOP, 3); }

  /**
   * Constructs a new ModePanel. The <TT>pos</TT> argument must be
   * either of <TT>ModePanel.TOP</TT>, <TT>ModePanel.BOTTOM</TT>,
   * <TT>ModePanel.LEFT</TT> or <TT>ModePanel.RIGHT</TT>.
   * @param pos the position of the buttons.
   */
  public ModePanel(int pos) {
    this(pos, 3);
  }

  /**
   * Constructs a new ModePanel. The <TT>pos</TT> argument must be
   * either of <TT>ModePanel.TOP</TT>, <TT>ModePanel.BOTTOM</TT>,
   * <TT>ModePanel.LEFT</TT> or <TT>ModePanel.RIGHT</TT>.
   * @param pos the position of the buttons.
   * @param rectWidth width of rectangle around selected button.
   */
  public ModePanel(int pos, int rectWidth) {
    int rows=0, cols=0, hgap=0, vgap=0;
    String posStr;
    switch(pos) {
      case TOP :
        posStr = "North";
        rows = 1; hgap = 3;
        break;
      case BOTTOM :
        posStr = "South";
        rows = 1; hgap = 3;
        break;
      case RIGHT :
        posStr = "East";
        cols = 1; vgap = 3;
        break;
      case LEFT :
        posStr = "West";
        cols = 1; vgap = 3;
        break;
      default :
        posStr = "North";
        rows = 1; hgap = 3;
        break;
    }

    btnBar_.setLayout(new GridLayout(rows, cols, hgap, vgap));
    mainPanel_.setLayout(new CardLayout());

    setLayout(new BorderLayout());
    add(posStr, btnBar_);
    add("Center",  mainPanel_);

    rectWidth_ = rectWidth;
  }


  /**
   * Adds a new mode to this panel.
   * @param panel the panel representing the new mode.
   * @param btnLabel the label of the button that is
   * to represent the new mode.
   */
  public void addMode(Panel panel, String btnLabel) {
   // add mode to Hashtable
    modes_.put(btnLabel, panel);
   // create a button for this new mode
    ModeButton btn = new ModeButton(btnLabel, selectedCol_, rectWidth_);
    btn.setButtonColor(btnCol_);
    btn.setButtonTextColor(btnTxtCol_);
    if(selectedBtn_ == null) {
      btn.select();
      selectedBtn_ = btn;
    }
   // add button and panel
    btnBar_.add(btn);
    mainPanel_.add(btnLabel, panel);
  }


  /**
   * Shows a given mode.
   * @param modeStr a string representing this mode. Should
   * be the same as the button label for the mode.
   */
  public void selectMode(String modeStr) {
   // find which ModeButton was clicked
    Component comps[] = btnBar_.getComponents();
    ModeButton newBtn = null;
    for(int a = 0; a < comps.length; a++) {
      newBtn = (ModeButton)comps[a];
      if(modeStr.equals(newBtn.getLabel()))
        break;
    }

   // repaint & exit if it's the button that already is selected
    if(newBtn == selectedBtn_) {
      getSelectedPanel().repaint();
      return;
    }

   // unselect old mode
    selectedBtn_.unSelect();
   // show new mode
    ((CardLayout)mainPanel_.getLayout()).show(mainPanel_, modeStr);

   // select the new button
    selectedBtn_ = newBtn;
    selectedBtn_.select();
  }


  /** Returns the string for the selected mode. */
  public String getSelectedMode() {
    return selectedBtn_.getLabel();
  }

  /** Returns the panel for the selected mode. */
  public Panel getSelectedPanel() {
    return getPanel(getSelectedMode());
  }


  /**
   * Returns the panel corresponding to modeStr.
   * Returns null if no panel exists that matches the string.
   */
  public Panel getPanel(String modeStr) {
    return (Panel)modes_.get(modeStr);
  }


  /** Sets color of buttons. */
  public void setButtonColor(Color col) { btnCol_ = col; }

  /** Sets color of buttontext. */
  public void setButtonTextColor(Color col) { btnTxtCol_ = col; }

  /** Sets color of selected button. */
  public void setSelectedColor(Color col) { selectedCol_ = col; }


  /**
   * Handles clicks on the ModeButtons.
   * This method always returns false so that the
   * clicks are propagated further in the component
   * hierarchy thus allowing custom event handling.
   */
  public boolean action(Event evt, Object arg) {

    if(evt.target instanceof Button) {
      selectMode((String)arg);
    }
    return false;
  }


}