/**

  * Copyright 2010 The Kuali Foundation Licensed under the

  * Educational Community License, Version 2.0 (the "License"); you may

  * not use this file except in compliance with the License. You may

  * obtain a copy of the License at

  *

  * http://www.osedu.org/licenses/ECL-2.0

  *

  * Unless required by applicable law or agreed to in writing,

  * software distributed under the License is distributed on an "AS IS"

  * BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express

  * or implied. See the License for the specific language governing

  * permissions and limitations under the License.

  */

 package org.kuali.student.common.ui.client.widgets.search;

 import org.kuali.student.common.ui.client.theme.Theme;

 import org.kuali.student.common.ui.client.widgets.KSButton;

 import org.kuali.student.common.ui.client.widgets.KSButtonAbstract.ButtonStyle;

 import org.kuali.student.common.ui.client.widgets.layout.HorizontalBlockFlowPanel;

 import org.kuali.student.common.ui.client.widgets.layout.VerticalFlowPanel;

 import com.google.gwt.animation.client.Animation;

 import com.google.gwt.event.dom.client.ClickEvent;

 import com.google.gwt.event.dom.client.ClickHandler;

 import com.google.gwt.user.client.DOM;

 import com.google.gwt.user.client.ui.Composite;

 import com.google.gwt.user.client.ui.DisclosurePanel;

 import com.google.gwt.user.client.ui.Image;

 import com.google.gwt.user.client.ui.SimplePanel;

 import com.google.gwt.user.client.ui.Widget;

 public class CollapsablePanel extends Composite{

         private KSButton label;

         private VerticalFlowPanel layout = new VerticalFlowPanel();

         private HorizontalBlockFlowPanel linkPanel = new HorizontalBlockFlowPanel();

         protected SimplePanel content = new SimplePanel();

         private boolean isOpen = false;

         private ContentAnimation animation = new ContentAnimation();

         private boolean withImages;

         private String buttonLabel;

         Image closedImage = Theme.INSTANCE.getCommonImages().getDisclosureClosedIcon();

     Image openedImage = Theme.INSTANCE.getCommonImages().getDisclosureOpenedIcon();

          private static class ContentAnimation extends Animation {

                     /**

                      * Whether the item is being opened or closed.

                      */

                     private boolean opening;

                     /**

                      * The {@link DisclosurePanel} being affected.

                      */

                     private CollapsablePanel curPanel;

                     /**

                      * Open or close the content.

                      *

                      * @param panel the panel to open or close

                      * @param animate true to animate, false to open instantly

                      */

                     public void setOpen(CollapsablePanel panel, boolean animate) {

                       // Immediately complete previous open

                       cancel();

                       // Open the new item

                       if (animate) {

                         curPanel = panel;

                         opening = panel.isOpen;

                         run(1000);

                       } else {

                         panel.content.setVisible(panel.isOpen);

                         if (panel.isOpen) {

                           // Special treatment on the visible case to ensure LazyPanel works

                           panel.content.setVisible(true);

                         }

                       }

                     }

                     @Override

                     protected void onComplete() {

                       if (!opening) {

                         curPanel.content.setVisible(false);

                       }

                       DOM.setStyleAttribute(curPanel.content.getElement(), "height",

                           "auto");

                       DOM.setStyleAttribute(curPanel.content.getElement(), "overflow", "visible");

                       curPanel = null;

                     }

                     @Override

                     protected void onStart() {

                       super.onStart();

                       DOM.setStyleAttribute(curPanel.content.getElement(), "overflow", "hidden");

                       if (opening) {

                         curPanel.content.setVisible(true);

                         // Special treatment on the visible case to ensure LazyPanel works

                         curPanel.content.setVisible(true);

                      }

                     }

                     @Override

                     protected void onUpdate(double progress) {

                       int scrollHeight = DOM.getElementPropertyInt(

                           curPanel.content.getElement(), "scrollHeight");

                       int height = (int) (progress * scrollHeight);

                       if (!opening) {

                         height = scrollHeight - height;

                       }

                       height = Math.max(height, 1);

                       DOM.setStyleAttribute(curPanel.content.getElement(), "height",

                           height + "px");

                       DOM.setStyleAttribute(curPanel.content.getElement(), "width",

                           "auto");

                     }

          }

                 public CollapsablePanel(String name, Widget content, boolean isOpen){

                         init(name, content, isOpen, true);

                 }

          public CollapsablePanel(String name, Widget content, boolean isOpen, boolean withImages){

                 init(name, content, isOpen, withImages);

         }

          private void init(String name, Widget content, boolean isOpen, boolean withImages){

                  this.withImages = withImages;

                         label = new KSButton(name, ButtonStyle.DEFAULT_ANCHOR);

                         this.content.setWidget(content);

                         label = new KSButton(name, ButtonStyle.DEFAULT_ANCHOR);

                         linkPanel.add(label);

                         if(!isOpen){

                                 this.content.setVisible(false);

                         if (this.withImages)

                                 linkPanel.add(closedImage);

                         }

                         else {

                         if (this.withImages)

                                 linkPanel.add(openedImage);

                         }

                         label.addClickHandler(new ClickHandler(){

                                 @Override

                                 public void onClick(ClickEvent event) {

                                         if(CollapsablePanel.this.isOpen){

                                                 CollapsablePanel.this.close();

                                         }

                                         else{

                                                 CollapsablePanel.this.open();

                                         }

                                 }

                         });

                         layout.add(linkPanel);

                         layout.add(this.content);

                         closedImage.addStyleName("ks-image-middle-alignment");

                         openedImage.addStyleName("ks-image-middle-alignment");

                         content.addStyleName("top-padding");

                         this.initWidget(layout);

          }

         public KSButton getLabel() {

         return label;

     }

     public boolean isOpen(){

                 return isOpen;

         }

         public void open(){

                 isOpen = true;

                 if (withImages) {

                         linkPanel.remove(closedImage);

                     linkPanel.add(openedImage);

                 }

                 animation.setOpen(this, true);

         }

         public void close(){

                 isOpen = false;

                 if (withImages) {

                     linkPanel.remove(openedImage);

                     linkPanel.add(closedImage);

                 }

                 animation.setOpen(this, true);

         }

 }