/* $Id: ZoomSliderButton.java 17841 2010-01-12 19:17:52Z linus $

  *****************************************************************************

  * Copyright (c) 2009 Contributors - see below

  * All rights reserved. This program and the accompanying materials

  * are made available under the terms of the Eclipse Public License v1.0

  * which accompanies this distribution, and is available at

  * http://www.eclipse.org/legal/epl-v10.html

  *

  * Contributors:

  *    tfmorris

  *****************************************************************************

  *

  * Some portions of this file was previously release using the BSD License:

  */

 // Copyright (c) 2003-2008 The Regents of the University of California. All

 // Rights Reserved. Permission to use, copy, modify, and distribute this

 // software and its documentation without fee, and without a written

 // agreement is hereby granted, provided that the above copyright notice

 // and this paragraph appear in all copies.  This software program and

 // documentation are copyrighted by The Regents of the University of

 // California. The software program and documentation are supplied "AS

 // IS", without any accompanying services from The Regents. The Regents

 // does not warrant that the operation of the program will be

 // uninterrupted or error-free. The end-user understands that the program

 // was developed for research purposes and is advised not to rely

 // exclusively on the program for any reason.  IN NO EVENT SHALL THE

 // UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,

 // SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,

 // ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF

 // THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF

 // SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY

 // WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF

 // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE

 // PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF

 // CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,

 // UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 package org.argouml.ui;

 import java.awt.BorderLayout;

 import java.awt.Component;

 import java.awt.Dimension;

 import java.awt.FlowLayout;

 import java.awt.Font;

 import java.awt.event.ActionEvent;

 import java.awt.event.ActionListener;

 import java.awt.event.FocusAdapter;

 import java.awt.event.FocusEvent;

 import java.awt.event.MouseEvent;

 import java.util.Enumeration;

 import javax.swing.AbstractAction;

 import javax.swing.Icon;

 import javax.swing.JLabel;

 import javax.swing.JPanel;

 import javax.swing.JPopupMenu;

 import javax.swing.JSlider;

 import javax.swing.JTextField;

 import javax.swing.event.ChangeEvent;

 import javax.swing.event.ChangeListener;

 import javax.swing.event.MouseInputAdapter;

 import javax.swing.event.PopupMenuEvent;

 import javax.swing.event.PopupMenuListener;

 import org.argouml.application.helpers.ResourceLoaderWrapper;

 import org.argouml.i18n.Translator;

 import org.tigris.swidgets.PopupButton;

 import org.tigris.gef.base.Editor;

 import org.tigris.gef.base.Globals;

 /**

  * A button that can be used to change the zoom magnification of the current

  * diagram. When the user presses the button, a popup is displayed which

  * contains a vertical slider representing the range of zoom magnifications.

  * Dragging the slider changes the zoom magnification for the current diagram.

  *

  * @author Jeremy Jones

  */

 public class ZoomSliderButton extends PopupButton {

     /**

      * Used for loading the zoom icon from the Zoom Reset action.

      */

     private static final String RESOURCE_NAME = "Zoom Reset";

     /**

      * Font used for the slider tick labels and for the current magnification

      * value label.

      */

     private static final Font LABEL_FONT = new Font("Dialog", Font.PLAIN, 10);

     /**

      * The minimum zoom slider value (as percentage).

      */

     public static final int MINIMUM_ZOOM = 25;

     /**

      * The maximum zoom slider value (as percentage).

      */

     public static final int MAXIMUM_ZOOM = 300;

     /**

      * The preferred height of the slider component.

      */

     private static final int SLIDER_HEIGHT = 250;

     /**

      * The slider component.

      */

     private JSlider slider = null;

     /**

      * The text field which shows the current zoom magnification value.

      */

     private JTextField currentValue = null;

     /**

      * Used to enable/disable the popup button.

      */

     private boolean popupButtonIsActive = true;

     /**

      * Indicates whether the popupmenu is showing or not.

      */

     private boolean popupMenuIsShowing = false;

     /**

      * Indicates whether the mouse is over the popup button or not.

      */

     private boolean mouseIsOverPopupButton = false;

     /**

      * Constructs a new ZoomSliderButton.

      */

     public ZoomSliderButton() {

         super();

         setAction(new AbstractAction() {

             public void actionPerformed(ActionEvent e) {

                 /* If action comes in with *no* modifiers, it is a pure

                  * keyboard event (e.g. spacebar), so do it.  Anything else

                  * is probably a mouse event, so ignore it. Mouse events are

                  * dealt with by mousePressed() instead (see bottom of page).

                  */ 

                 if (e.getModifiers() == 0) {

                     showPopup();

                 }

             }

         });

         Icon icon = ResourceLoaderWrapper.lookupIcon(RESOURCE_NAME);

         MyMouseListener myMouseListener = new MyMouseListener();

         addMouseMotionListener(myMouseListener);

         addMouseListener(myMouseListener);

         setIcon(icon);

         setToolTipText(Translator.localize("button.zoom"));

     }

     /**

      * Creates the slider popup component.

      */

     private void createPopupComponent() {

         slider =

             new JSlider(

                     JSlider.VERTICAL,

                     MINIMUM_ZOOM,

                     MAXIMUM_ZOOM,

                     MINIMUM_ZOOM);

         slider.setInverted(true);

         slider.setMajorTickSpacing(25);

         slider.setMinorTickSpacing(5);

         slider.setPaintTicks(true);

         slider.setPaintTrack(true);

         int sliderBaseWidth = slider.getPreferredSize().width;

         slider.setPaintLabels(true);

         for (Enumeration components = slider.getLabelTable().elements();

              components.hasMoreElements();) {

             ((Component) components.nextElement()).setFont(LABEL_FONT);

         }

         slider.setToolTipText(Translator.localize(

                 "button.zoom.slider-tooltip"));

         slider.addChangeListener(new ChangeListener() {

             public void stateChanged(ChangeEvent e) {

                 handleSliderValueChange();

             }

         });

         int labelWidth =

             slider.getFontMetrics(LABEL_FONT).stringWidth(

                     String.valueOf(MAXIMUM_ZOOM)) + 6;

         slider.setPreferredSize(new Dimension(

             sliderBaseWidth + labelWidth, SLIDER_HEIGHT));

         currentValue = new JTextField(5);

         currentValue.setHorizontalAlignment(JLabel.CENTER);

         currentValue.setFont(LABEL_FONT);

         currentValue.setToolTipText(Translator.localize(

             "button.zoom.current-zoom-magnification"));

         updateCurrentValueLabel();

         currentValue.addActionListener(new ActionListener() {

             public void actionPerformed(ActionEvent e) {

                 handleTextEntry();

             }

         });

         currentValue.addFocusListener(new FocusAdapter() {

             @Override

             public void focusLost(FocusEvent e) {

                 handleTextEntry();

             }

         });

         JPanel currentValuePanel =

             new JPanel(new FlowLayout(

                     FlowLayout.CENTER, 0, 0));

         currentValuePanel.add(currentValue);

         JPanel zoomPanel = new JPanel(new BorderLayout(0, 0));

         zoomPanel.add(slider, BorderLayout.CENTER);

         zoomPanel.add(currentValuePanel, BorderLayout.NORTH);

         setPopupComponent(zoomPanel);

     }

     /**

      * Update the slider value every time the popup is shown.

      */

     @Override

     protected void showPopup() {

         if (slider == null) {

             createPopupComponent();

         }

         Editor ed = Globals.curEditor();

         if (ed != null) {

             slider.setValue((int) (ed.getScale() * 100d));

         }

         if ( popupButtonIsActive ) {

             super.showPopup();

             JPopupMenu pm = (JPopupMenu) this.getPopupComponent().getParent();

             PopupMenuListener pml = new MyPopupMenuListener();

             pm.addPopupMenuListener(pml);

             popupMenuIsShowing = true;

         }

         slider.requestFocus();

     }

     /**

      * Called when the slider value changes.

      */

     private void handleSliderValueChange() {

         updateCurrentValueLabel();

         //if (!source.getValueIsAdjusting()) {

         double zoomPercentage = slider.getValue() / 100d;

         Editor ed = Globals.curEditor();

         if (ed == null || zoomPercentage <= 0.0) {

             return;

         }

         if (zoomPercentage != ed.getScale()) {

             ed.setScale(zoomPercentage);

             ed.damageAll();

         }

         //}

     }

     /**

      * Called when the text field value changes.

      */

     private void handleTextEntry() {

         String value = currentValue.getText();

         if (value.endsWith("%")) {

             value = value.substring(0, value.length() - 1);

         }

         try {

             int newZoom = Integer.parseInt(value);

             if (newZoom < MINIMUM_ZOOM || newZoom > MAXIMUM_ZOOM) {

                 throw new NumberFormatException();

             }

             slider.setValue(newZoom);

         } catch (NumberFormatException ex) {

             updateCurrentValueLabel();

         }

     }

     /**

      * Sets the current value label's text to the current slider value.

      */

     private void updateCurrentValueLabel() {

         currentValue.setText(String.valueOf(slider.getValue()) + '%');

     }

     private class MyPopupMenuListener extends AbstractAction implements

         PopupMenuListener {

         /**

          * Empty method to satisfy interface.

          */

         public void actionPerformed(ActionEvent e) {

         }

         /**

          * Method gets fired when the popup dies.

          * Conditionally re-enable the button depending on where the pointer 

          * is.

          */

         public void popupMenuCanceled(PopupMenuEvent e) {

             if (mouseIsOverPopupButton) {

                 popupButtonIsActive = false;

             } else {

                 popupButtonIsActive = true;

             }

             popupMenuIsShowing = false;

         }

         public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {

         }

         public void popupMenuWillBecomeVisible(PopupMenuEvent e) {

         }

     }

     private class MyMouseListener extends MouseInputAdapter {

         /**

          * Keeps track of mouseover status. 

          */

         @Override

         public void mouseEntered(MouseEvent me) {

             mouseIsOverPopupButton = true;

         }

         /**

          * Keeps track of mouseover status, and renables button if necessary.

          */

         @Override

         public void mouseExited(MouseEvent me) {

             mouseIsOverPopupButton = false;

             if (!popupButtonIsActive && !popupMenuIsShowing)

             {

                 popupButtonIsActive = true;

             }

         }

         /**

          * Catch the down stroke of mouse click to make the popup appear a tiny

          * bit earlier.

          */

         @Override

         public void mousePressed(MouseEvent me) {

             if (popupButtonIsActive) {

                 showPopup();

             }

             else if ( !popupMenuIsShowing )

             {

                 popupButtonIsActive = true;

             }

         }

     }

 }