/*
    * Copyright 2000-2018 Vaadin Ltd.
    *
    * Licensed under the Apache 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.apache.org/licenses/LICENSE-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 com.vaadin.client.ui.panel;
  
  import com.google.gwt.dom.client.Element;
  import com.google.gwt.dom.client.NativeEvent;
  import com.google.gwt.dom.client.TextAreaElement;
  import com.google.gwt.event.dom.client.KeyCodes;
  import com.google.gwt.user.client.DOM;
  import com.google.gwt.user.client.Event;
  import com.vaadin.client.ApplicationConnection;
  import com.vaadin.client.Paintable;
  import com.vaadin.client.UIDL;
  import com.vaadin.client.ui.ClickEventHandler;
  import com.vaadin.client.ui.PostLayoutListener;
  import com.vaadin.client.ui.ShortcutActionHandler;
  import com.vaadin.client.ui.SimpleManagedLayout;
  import com.vaadin.client.ui.VPanel;
  import com.vaadin.client.ui.layout.MayScrollChildren;
  import com.vaadin.shared.MouseEventDetails;
  import com.vaadin.shared.ui.ComponentStateUtil;
  import com.vaadin.shared.ui.Connect;
  import com.vaadin.shared.ui.panel.PanelServerRpc;
  import com.vaadin.ui.Panel;
  
  @Connect(Panel.class)
  public class EnterFriendlyPanelConnector extends PanelConnector
          implements Paintable, SimpleManagedLayout, PostLayoutListener,
          MayScrollChildren {
  
      private Integer uidlScrollTop;
  
      private ClickEventHandler clickEventHandler = new ClickEventHandler(this) {
  
          @Override
          protected void fireClick(NativeEvent event,
                  MouseEventDetails mouseDetails) {
              getRpcProxy(PanelServerRpc.class).click(mouseDetails);
          }
      };
  
      private Integer uidlScrollLeft;
  
      @Override
      public void updateFromUIDL(UIDL uidl, ApplicationConnection client) {
          VPanel panel = getWidget();
          if (isRealUpdate(uidl)) {
  
              // Handle caption displaying and style names, prior generics.
              // Affects size calculations
  
              // Restore default stylenames
              panel.contentNode.setClassName(VPanel.CLASSNAME + "-content");
              panel.bottomDecoration
                      .setClassName(VPanel.CLASSNAME + "-deco");
              panel.captionNode.setClassName(VPanel.CLASSNAME + "-caption");
              boolean hasCaption = hasCaption();
              if (hasCaption) {
                  panel.setCaption(getState().caption);
              } else {
                  panel.setCaption("");
                  panel.captionNode
                          .setClassName(VPanel.CLASSNAME + "-nocaption");
              }
  
              // Add proper stylenames for all elements. This way we can prevent
              // unwanted CSS selector inheritance.
              final String captionBaseClass = VPanel.CLASSNAME
                      + (hasCaption ? "-caption" : "-nocaption");
              final String contentBaseClass = VPanel.CLASSNAME + "-content";
              final String decoBaseClass = VPanel.CLASSNAME + "-deco";
              String captionClass = captionBaseClass;
              String contentClass = contentBaseClass;
              String decoClass = decoBaseClass;
              if (ComponentStateUtil.hasStyles(getState())) {
                  for (String style : getState().styles) {
                      captionClass += " " + captionBaseClass + "-" + style;
                      contentClass += " " + contentBaseClass + "-" + style;
                      decoClass += " " + decoBaseClass + "-" + style;
                  }
              }
              panel.captionNode.setClassName(captionClass);
              panel.contentNode.setClassName(contentClass);
              panel.bottomDecoration.setClassName(decoClass);
  
              panel.makeScrollable();
         }
 
         if (!isRealUpdate(uidl)) {
             return;
         }
 
         clickEventHandler.handleEventHandlerRegistration();
 
         panel.client = client;
         panel.id = uidl.getId();
 
         if (getIconUri() != null) {
             panel.setIconUri(getIconUri(), client);
         } else {
             panel.setIconUri(null, client);
         }
 
         // We may have actions attached to this panel
         if (uidl.getChildCount() > 0) {
             final int cnt = uidl.getChildCount();
             for (int i = 0; i < cnt; i++) {
                 UIDL childUidl = uidl.getChildUIDL(i);
                 if (childUidl.getTag().equals("actions")) {
                     if (panel.shortcutHandler == null) {
                         panel.shortcutHandler = new EnterFriendlyShortcutActionHandler(
                                 getConnectorId(), client);
                     }
                     panel.shortcutHandler.updateActionMap(childUidl);
                 }
             }
         }
 
         if (getState().scrollTop != panel.scrollTop) {
             // Sizes are not yet up to date, so changing the scroll position
             // is deferred to after the layout phase
             uidlScrollTop = getState().scrollTop;
         }
 
         if (getState().scrollLeft != panel.scrollLeft) {
             // Sizes are not yet up to date, so changing the scroll position
             // is deferred to after the layout phase
             uidlScrollLeft = getState().scrollLeft;
         }
 
         // And apply tab index
         panel.contentNode.setTabIndex(getState().tabIndex);
     }
 
     /**
      * Detects if caption div should be visible.
      *
      * @return {@code true} if caption div should be shown
      */
     protected boolean hasCaption() {
         return getState().caption != null && !getState().caption.isEmpty();
     }
 
     @Override
     public void postLayout() {
         VPanel panel = getWidget();
         if (uidlScrollTop != null) {
             // IE / Safari fix for when scroll top is set to greater than panel
             // height
             int maxScroll = panel.getWidget().getOffsetHeight();
             if (uidlScrollTop > maxScroll) {
                 uidlScrollTop = maxScroll;
             }
             panel.contentNode.setScrollTop(uidlScrollTop.intValue());
 
             // Read actual value back to ensure update logic is correct
             // TODO Does this trigger reflows?
             panel.scrollTop = panel.contentNode.getScrollTop();
             uidlScrollTop = null;
         }
 
         if (uidlScrollLeft != null) {
             panel.contentNode.setScrollLeft(uidlScrollLeft.intValue());
             // Read actual value back to ensure update logic is correct
             // TODO Does this trigger reflows?
             panel.scrollLeft = panel.contentNode.getScrollLeft();
             uidlScrollLeft = null;
         }
     }
 
     /**
      * We override default {@link ShortcutActionHandler} to bypass shortcut handling when an 'ENTER' keyboard event comes from a text area.
      */
     private static class EnterFriendlyShortcutActionHandler extends ShortcutActionHandler {
 
         public EnterFriendlyShortcutActionHandler(String pid, ApplicationConnection c) {
             super(pid, c);
     }
 
         public void handleKeyboardEvent(Event event) {
             // ignore keyboard shortcut if enter was pressed within a textarea
             int keyCode = DOM.eventGetKeyCode(event);
             if (keyCode == KeyCodes.KEY_ENTER) {
                 Element el = DOM.eventGetTarget(event);
                 if (el.getTagName().equalsIgnoreCase(TextAreaElement.TAG)) {
                     return;
                 }
             }
             super.handleKeyboardEvent(event);
         }
     }
 }