/* SpinnerUI.java --
   Copyright (C) 2003 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath 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, or (at your option)
any later version.

GNU Classpath 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 GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */

package javax.swing.plaf.basic;

import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Insets;
import java.awt.LayoutManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseAdapter;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JSpinner;
import javax.swing.Timer;
import javax.swing.UIDefaults;
import javax.swing.UIManager;
import javax.swing.plaf.SpinnerUI;
import javax.swing.plaf.ComponentUI;

/**
 * @since 1.4
 * @see javax.swing.JSpinner
 * @author Ka-Hing Cheung
 */
public class BasicSpinnerUI extends SpinnerUI
{
  /**
   * Creates a new <code>ComponentUI</code> for the specified 
   * <code>JComponent</code>
   *
   * @return a ComponentUI
   */
  public static ComponentUI createUI(JComponent c)
  {
    return new BasicSpinnerUI();
  }

  /**
   * Creates an editor component. Really, it just returns 
   * <code>JSpinner.getEditor()</code>
   *
   * @return a JComponent as an editor
   * @see javax.swing.JSpinner#getEditor
   */
  protected JComponent createEditor()
  {
    return spinner.getEditor();
  }

  /**
   * Creates a <code>LayoutManager</code> that layouts the sub components.
   * The subcomponents are identifies by the constraint "Next", "Previous" and
   * "Editor"
   *
   * @return a LayoutManager
   * @see java.awt.LayoutManager
   */  
  protected LayoutManager createLayout()
  {
    return new DefaultLayoutManager();
  }

  /**
   * Creates the "Next" button
   *
   * @return the next button component
   */
  protected Component createNextButton()
  {
    JButton button = new BasicArrowButton(BasicArrowButton.NORTH);
    return button;
  }

  /**
   * Creates the "Previous" button
   *
   * @return the previous button component
   */
  protected Component createPreviousButton()
  {
    JButton button = new BasicArrowButton(BasicArrowButton.SOUTH);
    return button;
  }

  /**
   * Creates the <code>PropertyChangeListener</code> that will be attached
   * by <code>installListeners</code>. It should watch for the "editor"
   * property, when it's changed, replace the old editor with the new one,
   * probably by calling <code>replaceEditor</code>
   *
   * @return a PropertyChangeListener
   * @see #replaceEditor
   */  
  protected PropertyChangeListener createPropertyChangeListener()
  {
    return new PropertyChangeListener()
      {
        public void propertyChange(PropertyChangeEvent evt)
        {
          if("editor".equals(evt.getPropertyName()))
            {
              BasicSpinnerUI.this.replaceEditor((JComponent)evt.getOldValue(),
                                                (JComponent)evt.getNewValue());
            }
        }
      };
  }

  /**
   * Called by <code>installUI</code>. This should set various defaults
   * obtained from <code>UIManager.getLookAndFeelDefaults</code>, as well as
   * set the layout obtained from <code>createLayout</code>
   *
   * @see #javax.swing.UIManager#getLookAndFeelDefaults
   * @see #createLayout
   * @see #installUI 
   */
  protected void installDefaults()
  {
    /* most of it copied from BasicLabelUI, I don't know what keys are
       available, so someone may want to update this. Hence: TODO
    */
    UIDefaults defaults = UIManager.getLookAndFeelDefaults();
    /*
    spinner.setForeground(defaults.getColor("Spinner.foreground"));
    spinner.setBackground(defaults.getColor("Spinner.background"));
    spinner.setFont(defaults.getFont("Spinner.font"));
    spinner.setBorder(defaults.getBorder("Spinner.border"));
    */    
    spinner.setLayout(createLayout());
  }

  /*
   * Called by <code>installUI</code>, which basically adds the
   * <code>PropertyChangeListener</code> created by
   * <code>createPropertyChangeListener</code>
   *
   * @see #createPropertyChangeListener
   * @see #installUI
   */
  protected void installListeners()
  {
    spinner.addPropertyChangeListener(listener);
  }

  /*
   * Install listeners to the next button so that it increments the model
   */
  protected void installNextButtonListeners(Component c)
  {
    c.addMouseListener(new MouseAdapter()
      {
        public void mousePressed(MouseEvent evt)
        {
          increment();
          timer.setInitialDelay(500);
          timer.start();
        }

        public void mouseReleased(MouseEvent evt)
        {
          timer.stop();
        }

        void increment()
        {
          Object next = BasicSpinnerUI.this.spinner.getNextValue();
          if(next != null)
            {
              BasicSpinnerUI.this.spinner.getModel().setValue(next);
            }
        }

        volatile boolean mouseDown = false;
        Timer timer = new Timer(50, new ActionListener()
          {
            public void actionPerformed(ActionEvent event)
            {
              increment();
            }
          });
      });
  }

  /*
   * Install listeners to the previous button so that it decrements the model
   */
  protected void installPreviousButtonListeners(Component c)
  {
    c.addMouseListener(new MouseAdapter()
      {
        public void mousePressed(MouseEvent evt)
        {
          decrement();
          timer.setInitialDelay(500);
          timer.start();
        }

        public void mouseReleased(MouseEvent evt)
        {
          timer.stop();
        }

        void decrement()
        {
          Object prev = BasicSpinnerUI.this.spinner.getPreviousValue();
          if(prev != null)
            {
              BasicSpinnerUI.this.spinner.getModel().setValue(prev);
            }
        }

        volatile boolean mouseDown = false;
        Timer timer = new Timer(50, new ActionListener()
          {
            public void actionPerformed(ActionEvent event)
            {
              decrement();
            }
          });
      });
  }

  /**
   * Install this UI to the <code>JComponent</code>, which in reality,
   * is a <code>JSpinner</code>. Calls <code>installDefaults</code>,
   * <code>installListeners</code>, and also adds the buttons and
   * editor.
   *
   * @see #installDefaults
   * @see #installListeners
   * @see #createNextButton
   * @see #createPreviousButton
   * @see #createEditor
   */
  public void installUI(JComponent c)
  {
    super.installUI(c);

    spinner = (JSpinner)c;

    installDefaults();
    installListeners();

    Component next = createNextButton(),
      previous = createPreviousButton();

    installNextButtonListeners(next);
    installPreviousButtonListeners(previous);

    c.add(createEditor(), "Editor");
    c.add(next, "Next");
    c.add(previous, "Previous");
  }

  /**
   * Replace the old editor with the new one
   *
   * @param oldEditor the old editor
   * @param newEditor the new one to replace with
   */
  protected void replaceEditor(JComponent oldEditor, JComponent newEditor)
  {
    spinner.remove(oldEditor);
    spinner.add(newEditor);
  }

  /**
   * The reverse of <code>installDefaults</code>. Called by
   * <code>uninstallUI</code>
   */
  protected void uninstallDefaults()
  {
    spinner.setLayout(null);
  }

  /**
   * The reverse of <code>installListeners</code>, called by
   * <code>uninstallUI</code>
   */
  protected void uninstallListeners()
  {
    spinner.removePropertyChangeListener(listener);    
  }

  /**
   * Called when the current L&F is replaced with another one, should call
   * <code>uninstallDefaults</code> and <code>uninstallListeners</code> as well
   * as remove the next/previous buttons and the editor
   */
  public void uninstallUI(JComponent c)
  {
    super.uninstallUI(c);

    uninstallDefaults();
    uninstallListeners();
    c.removeAll();
  }

  /**
   * The spinner for this UI
   */
  protected JSpinner spinner;
  private PropertyChangeListener listener = createPropertyChangeListener();

  private class DefaultLayoutManager implements LayoutManager
  {
    public void layoutContainer(Container parent)
    {

      synchronized(parent.getTreeLock())
        {
          Insets i = parent.getInsets();
          boolean l2r = parent.getComponentOrientation().isLeftToRight();
          /*
            --------------    --------------
            |        | n |    | n |        |
            |   e    | - | or | - |   e    |
            |        | p |    | p |        |
            --------------    --------------
          */

          Dimension e = minSize(editor);
          Dimension n = minSize(next);
          Dimension p = minSize(previous);
          Dimension s = spinner.getPreferredSize();

          int x = l2r ? i.left : i.right, y = i.top;
          int w = Math.max(p.width, n.width);
          int h = Math.max(p.height, n.height);
          h = Math.max(h, e.height / 2);
          int e_width = s.width - w;

          if(l2r)
            {
              setBounds(editor, x, y + (s.height - e.height) / 2, e_width, 
                        e.height);
              x += e_width;

              setBounds(next, x, y, w, h);
              y += h;

              setBounds(previous, x, y, w, h);
            }
          else
            {
              setBounds(next, x, y + (s.height - e.height) / 2, w, h);
              y += h;

              setBounds(previous, x, y, w, h);
              x += w;
              y -= h;

              setBounds(editor, x, y, e_width, e.height);
            }
        }
    }

    public Dimension minimumLayoutSize(Container parent)
    {
      Dimension d = new Dimension();

      if(editor != null) 
        {
          Dimension tmp = editor.getMinimumSize();
          d.width += tmp.width;
          d.height = tmp.height;
        }

      int nextWidth = 0;
      int previousWidth = 0;
      int otherHeight = 0;

      if(next != null)
        {
          Dimension tmp = next.getMinimumSize();
          nextWidth = tmp.width;
          otherHeight += tmp.height;
        }
      if(previous != null)
        {
          Dimension tmp = previous.getMinimumSize();
          previousWidth = tmp.width;
          otherHeight += tmp.height;
        }

      d.height = Math.max(d.height, otherHeight);
      d.width += Math.max(nextWidth, previousWidth);


      return d;
    }

    public Dimension preferredLayoutSize(Container parent)
    {
      Dimension d = new Dimension();

      if(editor != null) 
        {
          Dimension tmp = editor.getPreferredSize();
          d.width += Math.max(tmp.width, 40);
          d.height = tmp.height;
        }

      int nextWidth = 0;
      int previousWidth = 0;
      int otherHeight = 0;

      if(next != null)
        {
          Dimension tmp = next.getPreferredSize();
          nextWidth = tmp.width;
          otherHeight += tmp.height;
        }
      if(previous != null)
        {
          Dimension tmp = previous.getPreferredSize();
          previousWidth = tmp.width;
          otherHeight += tmp.height;
        }

      d.height = Math.max(d.height, otherHeight);
      d.width += Math.max(nextWidth, previousWidth);


      return d;
    }

    public void removeLayoutComponent(Component child) 
    {
      if(child == editor)
        editor = null;
      else if(child == next)
        next = null;
      else if(previous == child)
        previous = null;
    }

    public void addLayoutComponent(String name, Component child)
    {
      if("Editor".equals(name))
        editor = child;
      else if("Next".equals(name))
        next = child;
      else if("Previous".equals(name))
        previous = child;
    }

    private Dimension minSize(Component c)
    {
      if(c == null)
        return new Dimension();
      else
        return c.getMinimumSize();
    }

    private void setBounds(Component c, int x, int y, int w, int h)
    {
      if(c != null)
        c.setBounds(x, y, w, h);
    }

    private Component editor;
    private Component next;
    private Component previous;
  }

}