/*
 * Copyright 2008 Google Inc.
 * 
 * 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.google.gwt.user.client.ui.impl;

import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Node;

/**
 * IE6-specific implementation of rich-text editing.
 */
public class RichTextAreaImplIE6 extends RichTextAreaImplStandard {

  /**
   * Helper method to allow {@link #insertHTML(String)} code to invoke
   * {@link Node#isOrHasChild(Node)}, which is a JSO instance method.
   */
  private static boolean isOrHasChild(Node parent, Node child) {
    return parent.isOrHasChild(child);
  }

  @Override
  public Element createElement() {
    Element elem = super.createElement();
    elem.setPropertyString("src", "javascript:''");
    return elem;
  }

  @Override
  public native void initElement() /*-{
    var _this = this;
    _this.@com.google.gwt.user.client.ui.impl.RichTextAreaImplStandard::onElementInitializing()();

    setTimeout($entry(function() {
      if (_this.@com.google.gwt.user.client.ui.impl.RichTextAreaImplStandard::initializing == false) {
        return;
      }

      // Attempt to set the iframe document's body to 'contentEditable' mode.
      // There's no way to know when the body will actually be available, so
      // keep trying every so often until it is.
      // Note: The body seems to be missing only rarely, so please don't remove
      // this retry loop just because it's hard to reproduce.
      var elem = _this.@com.google.gwt.user.client.ui.impl.RichTextAreaImpl::elem;
      var doc = elem.contentWindow.document;
      if (!doc.body) {
        // Retry in 50 ms. Faster would run the risk of pegging the CPU. Slower
        // would increase the probability of a user-visible delay.
        setTimeout(arguments.callee, 50);
        return;
      }
      doc.body.contentEditable = true;

      // Send notification that the iframe has reached design mode.
      _this.@com.google.gwt.user.client.ui.impl.RichTextAreaImplStandard::onElementInitialized()();
    }, 1));
  }-*/;

  @Override
  public native void insertHTML(String html) /*-{
    try {
      var elem = this.@com.google.gwt.user.client.ui.impl.RichTextAreaImpl::elem;
      var doc = elem.contentWindow.document;
      doc.body.focus();
      var tr = doc.selection.createRange();
      if (tr == null) {
        return;
      }
      if (!@com.google.gwt.user.client.ui.impl.RichTextAreaImplIE6::isOrHasChild(*)(doc.body, tr.parentElement)) {
        return;
      }
      tr.pasteHTML(html);
    }
    catch (e) {
      return;
    }
  }-*/;

  @Override
  protected native String getTextImpl() /*-{
    var elem = this.@com.google.gwt.user.client.ui.impl.RichTextAreaImpl::elem;
    return elem.contentWindow.document.body.innerText;
  }-*/;

  @Override
  protected native void hookEvents() /*-{
    var elem = this.@com.google.gwt.user.client.ui.impl.RichTextAreaImpl::elem;
    var body = elem.contentWindow.document.body;

    var handler = $entry(function(evt) {
      // Weird: this code has the context of the script frame, but we need the
      // event from the edit iframe's window.
      // this code is shared with all IE implementations (see RichText.gwt.xml)
      // the event can be passed in as argument (IE9) or from the content window (IE8/7/6)
      evt = evt || elem.contentWindow.event;
      @com.google.gwt.user.client.DOM::dispatchEvent(Lcom/google/gwt/user/client/Event;Lcom/google/gwt/dom/client/Element;)(evt, elem);
    });

    body.onkeydown =
    body.onkeyup =
    body.onkeypress =
    body.onmousedown =
    body.onmouseup =
    body.onmousemove =
    body.onmouseover =
    body.onmouseout =
    body.onclick = handler;
    
    elem.contentWindow.onfocus =
    elem.contentWindow.onblur = handler;
  }-*/;

  @Override
  protected native boolean isEnabledImpl() /*-{
    var elem = this.@com.google.gwt.user.client.ui.impl.RichTextAreaImpl::elem;
    return elem.contentWindow.document.body.contentEditable.toLowerCase() == 'true'; 
  }-*/;

  @Override
  protected native void setEnabledImpl(boolean enabled) /*-{
    var elem = this.@com.google.gwt.user.client.ui.impl.RichTextAreaImpl::elem;
    elem.contentWindow.document.body.contentEditable = enabled;
  }-*/;

  @Override
  protected native void setTextImpl(String text) /*-{
    var elem = this.@com.google.gwt.user.client.ui.impl.RichTextAreaImpl::elem;
    elem.contentWindow.document.body.innerText = text;
  }-*/;

  @Override
  protected native void unhookEvents() /*-{
    var elem = this.@com.google.gwt.user.client.ui.impl.RichTextAreaImpl::elem;
    var body = elem.contentWindow.document.body;

    if (body) {
      // The body can be undefined in the relatively obscure case that the RTA
      // is attached and detached before it has a chance to finish initializing.
      body.onkeydown =
      body.onkeyup =
      body.onkeypress =
      body.onmousedown =
      body.onmouseup =
      body.onmousemove =
      body.onmouseover =
      body.onmouseout =
      body.onclick = null;

      elem.contentWindow.onfocus =
      elem.contentWindow.onblur = null;
    }
  }-*/;
}