/**
    * This file Copyright (c) 2010-2015 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.ui.vaadin.gwt.client.form.widget;
  
  import info.magnolia.ui.vaadin.gwt.client.form.formsection.widget.InlineMessageWidget;
  
  import com.google.gwt.event.dom.client.BlurEvent;
  import com.google.gwt.event.dom.client.BlurHandler;
  import com.google.gwt.event.dom.client.ClickEvent;
  import com.google.gwt.event.dom.client.ClickHandler;
  import com.google.gwt.event.dom.client.FocusEvent;
  import com.google.gwt.event.dom.client.FocusHandler;
  import com.google.gwt.event.dom.client.HasBlurHandlers;
  import com.google.gwt.event.dom.client.HasFocusHandlers;
  import com.google.gwt.event.shared.HandlerRegistration;
  import com.google.gwt.user.client.DOM;
  import com.google.gwt.user.client.Element;
  import com.google.gwt.user.client.ui.Button;
  import com.google.gwt.user.client.ui.FlowPanel;
  import com.google.gwt.user.client.ui.Widget;
  import com.google.gwt.user.client.ui.impl.FocusImpl;
  import com.vaadin.client.ui.aria.AriaHelper;
  
  /**
   * Wrapper widget that provides help and error indication.
   */
  public class FormFieldWrapper extends FlowPanel implements HasFocusHandlers, HasBlurHandlers {
  
      private Element label = DOM.createDiv();
  
      private Element fieldWrapper = DOM.createDiv();
  
      private Element root;
  
      private final HelpIconWidget helpButton = new HelpIconWidget();
  
      private Button errorAction = new Button();
  
      private InlineMessageWidget errorSection = null;
  
      private InlineMessageWidget helpSection = null;
  
      private String helpDescription = null;
  
      private Widget field = null;
  
      public FormFieldWrapper() {
          super();
          addStyleName("v-form-field-section");
          root = super.getElement();
          construct();
          setHelpEnabled(false);
  
          helpButton.addDomHandler(new ClickHandler() {
              @Override
              public void onClick(ClickEvent event) {
                  if (helpSection == null) {
                      showHelp();
                  } else {
                      hideHelp();
                  }
              }
          }, ClickEvent.getType());
  
      }
  
      public void hideHelp() {
          if (helpSection != null) {
             remove(helpSection);
         }
         helpSection = null;
         helpButton.setHighlighted(false);
     }
 
     public void showHelp() {
         if (helpDescription == null || "".equals(helpDescription)) {
             return;
         }
         helpSection = InlineMessageWidget.createHelpMessage();
         helpSection.setMessage(helpDescription);
         add(helpSection, root);
         helpButton.setHighlighted(true);
     }
 
     private void construct() {
         label.addClassName("v-form-field-label");
         fieldWrapper.addClassName("v-form-field-container");
         errorAction.addStyleName("action-validation");
 
         root.appendChild(label);
         root.appendChild(fieldWrapper);
         add(helpButton, fieldWrapper);
         add(errorAction, fieldWrapper);
     }
 
     public void showError(final String errorDescription) {
         helpButton.setVisible(false);
         errorAction.setVisible(true);
         fieldWrapper.addClassName("validation-highlight");
         if (errorSection == null) {
             errorSection = InlineMessageWidget.createErrorMessage();
         }
         errorSection.setMessage(errorDescription);
         add(errorSection, root);
     }
 
     public void setCaption(String caption) {
         label.setInnerHTML(caption);
         if (caption != null) {
             // let's show the caption as tooltip, too. This helps if the label is too long. it may contain <span class="requiredfield">*</span>
             String toolTip = caption.replaceAll("\\<.*?\\>", "");
             label.setTitle(toolTip);
         }
     }
 
     @Override
     public void add(Widget child) {
         add(child, fieldWrapper);
     }
 
     public void setField(Widget child) {
         if (this.field != null) {
             remove(field);
         }
         this.field = child;
         if (child != null) {
             child.removeFromParent();
             AriaHelper.bindCaption(child, label);
             getChildren().add(child);
             fieldWrapper.insertBefore(child.getElement(), helpButton.getElement());
             adopt(child);
         }
     }
 
     public boolean isDisplayingHelpSection() {
         return helpSection != null;
     }
 
     public void clearError() {
         if (errorSection != null) {
             remove(errorSection);
             errorSection = null;
         }
         fieldWrapper.removeClassName("validation-hilight");
         errorAction.setVisible(false);
         if (helpDescription != null && !"".equals(helpDescription)) {
             helpButton.setVisible(true);
         }
     }
 
     public void setHelpEnabled(boolean isHelpEnabled) {
         helpButton.setVisible(helpDescription != null && !"".equals(helpDescription) && !errorAction.isVisible());
         if (!isHelpEnabled && helpSection != null) {
             hideHelp();
             return;
         }
         if (isHelpEnabled && helpButton.isVisible() && helpSection == null) {
             showHelp();
         }
     }
 
     public void setHelpDescription(String description) {
         this.helpDescription = description;
         if (helpSection != null && getWidgetIndex(helpSection) >= 0) {
             helpSection.setMessage(helpDescription);
         }
         if (description != null && !"".equals(description)) {
             helpButton.setVisible(true);
         } else {
             helpButton.setVisible(false);
         }
     }
 
     public void focusField() {
         if (field != null) {
             FocusImpl.getFocusImplForWidget().focus(field.getElement());
         }
     }
 
     public Widget getField() {
         return field;
     }
 
     @Override
     public HandlerRegistration addFocusHandler(FocusHandler handler) {
         return field.addDomHandler(handler, FocusEvent.getType());
     }
 
     @Override
     public HandlerRegistration addBlurHandler(BlurHandler handler) {
         return field.addDomHandler(handler, BlurEvent.getType());
     }
 }