DOMImplIE6


1   /*
2    * Copyright 2007 Google Inc.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License"); you may not
5    * use this file except in compliance with the License. You may obtain a copy of
6    * the License at
7    *
8    * http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13   * License for the specific language governing permissions and limitations under
14   * the License.
15   */
16  package com.google.gwt.user.client.impl;
17  
18  import com.google.gwt.core.client.JavaScriptObject;
19  import com.google.gwt.user.client.Element;
20  import com.google.gwt.user.client.Event;
21  
22  /**
23   * Internet Explorer 6 implementation of
24   * {@link com.google.gwt.user.client.impl.DOMImpl}.
25   */
26  class DOMImplIE6 extends DOMImpl {
27  
28    private static native int getBodyClientLeft() /*-{
29      // Standard mode uses $doc.documentElement.clientLeft
30      // Quirks mode uses $doc.body.clientLeft
31      return $doc.documentElement.clientLeft || $doc.body.clientLeft;
32    }-*/;
33  
34    private static native int getBodyClientTop() /*-{
35      // Standards mode uses $doc.documentElement.clientTop
36      // Quirks mode uses $doc.body.clientTop
37      return $doc.documentElement.clientTop || $doc.body.clientTop;
38    }-*/;
39  
40    /**
41     * A native map of image source URL strings to Image objects. All Image
42     * objects with values in this map are waiting on an asynchronous load to
43     * complete and have event handlers hooked. The moment the image finishes
44     * loading, it will be removed from this map.
45     */
46    JavaScriptObject srcImgMap;
47  
48    public native boolean compare(Element elem1, Element elem2) /*-{
49      if (!elem1 && !elem2)
50        return true;
51      else if (!elem1 || !elem2)
52        return false;
53      return (elem1.uniqueID == elem2.uniqueID);
54    }-*/;
55  
56    public native Element createInputRadioElement(String   group) /*-{
57      return $doc.createElement("<INPUT type='RADIO' name='" + group + "'>");
58    }-*/;
59  
60    /**
61     * Supports creating a select control with the multiple attribute to work
62     * around a bug in IE6 where changing the multiple attribute in a
63     * setAttribute call can cause subsequent setSelected calls to misbehave.
64     * Although this bug is fixed in IE7, this DOMImpl specialization is used
65     * for both IE6 and IE7, but it should be harmless.
66     */
67    public native Element createSelectElement(boolean multiple) /*-{
68      var html = multiple ? "<SELECT MULTIPLE>" : "<SELECT>"; 
69      return $doc.createElement(html);
70    }-*/;
71    
72    public native int eventGetClientX(Event evt) /*-{
73      return evt.clientX -
74          @com.google.gwt.user.client.impl.DOMImplIE6::getBodyClientLeft()();
75    }-*/;
76  
77    public native int eventGetClientY(Event evt) /*-{
78      return evt.clientY -
79          @com.google.gwt.user.client.impl.DOMImplIE6::getBodyClientTop()();
80    }-*/;
81  
82    public native Element eventGetFromElement(Event evt) /*-{
83      return evt.fromElement ? evt.fromElement : null;
84    }-*/;
85  
86    public native int eventGetMouseWheelVelocityY(Event evt) /*-{
87      return Math.round(-evt.wheelDelta / 40);
88    }-*/;
89  
90    public native Element eventGetTarget(Event evt) /*-{
91      return evt.srcElement || null;
92    }-*/;
93  
94    public native Element eventGetToElement(Event evt) /*-{
95      return evt.toElement || null;
96    }-*/;
97  
98    public native void eventPreventDefault(Event evt) /*-{
99      evt.returnValue = false;
100   }-*/;
101 
102   public native String   eventToString(Event evt) /*-{
103     if (evt.toString) return evt.toString();
104       return "[object Event]";
105   }-*/;
106 
107   public native int getAbsoluteLeft(Element elem) /*-{
108     // Standard mode || Quirks mode.
109     var scrollLeft = $doc.documentElement.scrollLeft || $doc.body.scrollLeft;
110     return (elem.getBoundingClientRect().left + scrollLeft)
111         - @com.google.gwt.user.client.impl.DOMImplIE6::getBodyClientLeft()();
112   }-*/;
113 
114   public native int getAbsoluteTop(Element elem) /*-{
115     // Standard mode || Quirks mode.
116     var scrollTop = $doc.documentElement.scrollTop || $doc.body.scrollTop;
117     return (elem.getBoundingClientRect().top + scrollTop)
118         - @com.google.gwt.user.client.impl.DOMImplIE6::getBodyClientTop()();
119    }-*/;
120 
121   public native Element getChild(Element elem, int index) /*-{
122     var child = elem.children[index];
123     return child || null;
124   }-*/;
125 
126   public native int getChildCount(Element elem) /*-{
127     return elem.children.length;
128   }-*/;
129 
130   public native int getChildIndex(Element parent, Element child) /*-{
131     var count = parent.children.length;
132     for (var i = 0; i < count; ++i) {
133       if (child.uniqueID == parent.children[i].uniqueID)
134         return i;
135     }
136     return -1;
137   }-*/;
138 
139   public native Element getFirstChild(Element elem) /*-{
140     var child = elem.firstChild;
141     return child || null;
142   }-*/;
143 
144   /*
145    * The src may not be set yet because of funky logic in setImgSrc(). See
146    * setImgSrc().
147    */
148   public native String   getImgSrc(Element img) /*-{
149     return img.__targetSrc || img.src;
150   }-*/;
151 
152   public native String   getInnerText(Element elem) /*-{
153     var ret = elem.innerText;
154     return (ret == null) ? null : ret;
155   }-*/;
156 
157   public native Element getNextSibling(Element elem) /*-{
158     var sib = elem.nextSibling;
159     return sib || null;
160   }-*/;
161 
162   public native Element getParent(Element elem) /*-{
163     var parent = elem.parentElement;
164     return parent || null;
165   }-*/;
166 
167   public native String   iframeGetSrc(Element elem) /*-{
168     return elem.src;
169   }-*/;
170 
171   public native void init() /*-{
172     // Fix IE background image refresh bug, present through IE6
173     // see http://www.mister-pixel.com/#Content__state=is_that_simple
174     // this only works with IE6 SP1+
175     try {
176       $doc.execCommand("BackgroundImageCache", false, true);
177     } catch (e) {
178       // ignore error on other browsers
179     }
180   
181     // Initialize the URL -> Image map.
182     this.@com.google.gwt.user.client.impl.DOMImplIE6::srcImgMap = {};
183 
184     // Set up event dispatchers.
185     $wnd.__dispatchEvent = function() {
186       if ($wnd.event.returnValue == null) {
187         $wnd.event.returnValue = true;
188         if (!@com.google.gwt.user.client.DOM::previewEvent(Lcom/google/gwt/user/client/Event;)($wnd.event))
189           return;
190       }
191 
192       if (this.__listener)
193         @com.google.gwt.user.client.DOM::dispatchEvent(Lcom/google/gwt/user/client/Event;Lcom/google/gwt/user/client/Element;Lcom/google/gwt/user/client/EventListener;)($wnd.event, this, this.__listener);
194     };
195 
196     $wnd.__dispatchDblClickEvent = function() {
197       var newEvent = $doc.createEventObject();
198       this.fireEvent('onclick', newEvent);
199       if (this.__eventBits & 2)
200         $wnd.__dispatchEvent.call(this);
201     };
202 
203     $doc.body.onclick       =
204     $doc.body.onmousedown   =
205     $doc.body.onmouseup     =
206     $doc.body.onmousemove   =
207     $doc.body.onmousewheel  =
208     $doc.body.onkeydown     =
209     $doc.body.onkeypress    =
210     $doc.body.onkeyup       =
211     $doc.body.onfocus       =
212     $doc.body.onblur        =
213     $doc.body.ondblclick    = $wnd.__dispatchEvent;
214   }-*/;
215 
216   public native void insertChild(Element parent, Element child, int index) /*-{
217     if (index >= parent.children.length)
218       parent.appendChild(child);
219     else
220       parent.insertBefore(child, parent.children[index]);
221   }-*/;
222 
223   public native void insertListItem(Element select, String   text, String   value,
224       int index) /*-{
225     // When we try to pass the populated option into this method, IE
226     // chokes, so we create the option here instead.
227     var newOption = document.createElement("Option");
228     if (index == -1) {
229       select.add(newOption);
230     } else{
231       select.add(newOption, index);
232     }
233     newOption.text = text;   // assumed not null
234     newOption.value = value; // assumed not null
235   }-*/;
236 
237   public native boolean isOrHasChild(Element parent, Element child) /*-{
238     while (child) {
239       if (parent.uniqueID == child.uniqueID)
240         return true;
241       child = child.parentElement;
242     }
243     return false;
244   }-*/;
245 
246   public native void releaseCapture(Element elem) /*-{
247     elem.releaseCapture();
248   }-*/;
249 
250   public native void setCapture(Element elem) /*-{
251     elem.setCapture();
252   }-*/;
253 
254   /*
255    * Works around an IE problem where multiple images trying to load at the same
256    * time will generate a request per image. We fix this by only allowing the
257    * first image of a given URL to set its source immediately, but simultaneous
258    * requests for the same URL don't actually get their source set until the
259    * original load is complete.
260    * 
261    * See comment on srcImgMap for the invariants that hold for the synthetic
262    * Image objects which are values in the map.
263    */
264   public native void setImgSrc(Element img, String   src) /*-{
265     // Grab the URL -> Image map.
266     var map = this.@com.google.gwt.user.client.impl.DOMImplIE6::srcImgMap;
267     
268     // See if there's already an image for this URL in the map (e.g. loading).
269     var queuedImg = map[src];
270     if (queuedImg) {
271       // just add myself to its array, it will set my source later
272       queuedImg.__kids.push(img);
273       // record the desired src so it can be retreived synchronously
274       img.__targetSrc = src;
275       return; 
276     }
277 
278     // No outstanding requests; load the image.
279     img.src = src;
280 
281     // If the image was in cache, the load may have just happened synchronously.
282     if (img.complete) {
283       // We're done
284       return;
285     }
286 
287     // Image is loading asynchronously; put in map for chaining.
288     var kids = img.__kids = [];
289     map[src] = img;
290 
291     // Store all the old handlers
292     var _onload = img.onload, _onerror = img.onerror, _onabort = img.onabort;
293 
294     // Same cleanup code matter what state we end up in.
295     img.onload = function() {
296       finish("onload");
297     }
298     img.onerror = function() {
299       finish("onerror");
300     }
301     img.onabort = function() {
302       finish("onabort");
303     }
304 
305     function finish(whichEvent) {
306       // Clean up: restore event handlers and remove from map.
307       img.onload = _onload; img.onerror = _onerror; img.onabort = _onabort;
308       delete map[src];
309       
310       // Set the source for all kids in a timer to ensure caching has happened.
311       window.setTimeout(function() {
312         for (var i = 0; i < kids.length; ++i) {
313           kids[i].src = img.src;
314           // clear the target src now that it's resolved
315           kids[i].__targetSrc = null;
316         }
317       }, 0);      
318       
319       // call the original handler, if any
320       if (img[whichEvent]) {
321         img[whichEvent]();
322       }
323     }
324   }-*/;
325 
326   public native void setInnerText(Element elem, String   text) /*-{
327     if (!text)
328       text = '';
329     elem.innerText = text;
330   }-*/;
331 
332   public native void sinkEvents(Element elem, int bits) /*-{
333     elem.__eventBits = bits;
334 
335     elem.onclick       = (bits & 0x00001) ? $wnd.__dispatchEvent : null;
336     // Add an ondblclick handler if onclick is desired to ensure that
337     // a user's double-click will result in two onclick events
338     elem.ondblclick    = (bits & (0x00001 | 0x00002)) ? $wnd.__dispatchDblClickEvent : null;
339     elem.onmousedown   = (bits & 0x00004) ? $wnd.__dispatchEvent : null;
340     elem.onmouseup     = (bits & 0x00008) ? $wnd.__dispatchEvent : null;
341     elem.onmouseover   = (bits & 0x00010) ? $wnd.__dispatchEvent : null;
342     elem.onmouseout    = (bits & 0x00020) ? $wnd.__dispatchEvent : null;
343     elem.onmousemove   = (bits & 0x00040) ? $wnd.__dispatchEvent : null;
344     elem.onkeydown     = (bits & 0x00080) ? $wnd.__dispatchEvent : null;
345     elem.onkeypress    = (bits & 0x00100) ? $wnd.__dispatchEvent : null;
346     elem.onkeyup       = (bits & 0x00200) ? $wnd.__dispatchEvent : null;
347     elem.onchange      = (bits & 0x00400) ? $wnd.__dispatchEvent : null;
348     elem.onfocus       = (bits & 0x00800) ? $wnd.__dispatchEvent : null;
349     elem.onblur        = (bits & 0x01000) ? $wnd.__dispatchEvent : null;
350     elem.onlosecapture = (bits & 0x02000) ? $wnd.__dispatchEvent : null;
351     elem.onscroll      = (bits & 0x04000) ? $wnd.__dispatchEvent : null;
352     elem.onload        = (bits & 0x08000) ? $wnd.__dispatchEvent : null;
353     elem.onerror       = (bits & 0x10000) ? $wnd.__dispatchEvent : null;
354     elem.onmousewheel  = (bits & 0x20000) ? $wnd.__dispatchEvent : null;
355   }-*/;
356 }
357
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