GWT

Google UI widget GWT 中的主JS文件代码

   1. // Copyright 2006 Google Inc. All Rights Reserved.
   2. // This startup script should be included in host pages.
   3. //
   4. //////////////////////////////////////////////////////////////////
   5. // Common
   6. //
   7. var __GWT_JS_INCLUDED;
   8. if (!__GWT_JS_INCLUDED) {
   9.   __GWT_JS_INCLUDED = true;
  10. var __gwt_retryWaitMs = 50;
  11. var __gwt_moduleNames = [];
  12. var __gwt_isHostPageLoaded = false;
  13. var __gwt_metaProps = {};
  14. var __gwt_onPropertyError = null;
  15. var __gwt_onLoadError = null;
  16. function __gwt_isHosted() {
  17.   if (window.external && window.external.gwtOnLoad) {
  18.   if (document.location.href.indexOf("gwt.hybrid") == -1) {
  19.   return true;
  20.   }
  21.   }
  22.   return false;
  23. }
  24. function __gwt_processMetas() {
  25.   var metas = document.getElementsByTagName("meta");
  26.   for (var i = 0, n = metas.length; i < n; ++i) {
  27.   var meta = metas[i];
  28.   var name = meta.getAttribute("name");
  29.   if (name) {
  30.   if (name == "gwt:module") {
  31.   var content = meta.getAttribute("content");
  32.   if (content) {
  33.   __gwt_moduleNames = __gwt_moduleNames.concat(content);
  34.   }
  35.   } else if (name == "gwt:property") {
  36.   var content = meta.getAttribute("content");
  37.   if (content) {
  38.   var name = content, value = "";
  39.   var eq = content.indexOf("=");
  40.   if (eq != -1) {
  41.   name = content.substring(0, eq);
  42.   value = content.substring(eq+1);
  43.   }
  44.   __gwt_metaProps[name] = value;
  45.   }
  46.   } else if (name == "gwt:onPropertyErrorFn") {
  47.   var content = meta.getAttribute("content");
  48.   if (content) {
  49.   try {
  50.   __gwt_onPropertyError = eval(content);
  51.   } catch (e) {
  52.   window.alert("Bad handler \"" + content + "\" for \"gwt:onPropertyErrorFn\"");
  53.   }
  54.   }
  55.   } else if (name == "gwt:onLoadErrorFn") {
  56.   var content = meta.getAttribute("content");
  57.   if (content) {
  58.   try {
  59.   __gwt_onLoadError = eval(content);
  60.   } catch (e) {
  61.   window.alert("Bad handler \"" + content + "\" for \"gwt:onLoadErrorFn\"");
  62.   }
  63.   }
  64.   }
  65.   }
  66.   }
  67. }
  68. function __gwt_getMetaProperty(name) {
  69.   var value = __gwt_metaProps[name];
  70.   if (value) {
  71.   return value;
  72.   } else {
  73.   return null;
  74.   }
  75. }
  76. function __gwt_forEachModule(lambda) {
  77.   for (var i = 0; i < __gwt_moduleNames.length; ++i) {
  78.   lambda(__gwt_moduleNames[i]);
  79.   }
  80. }
  81. // Called by the selection script when a property has a bad value or is missing.
  82. // 'allowedValues' is an array of strings.
  83. // Can be hooked in the host page.
  84. //
  85. function __gwt_onBadProperty(moduleName, propName, allowedValues, badValue) {
  86.   if (__gwt_onPropertyError) {
  87.   __gwt_onPropertyError(moduleName, propName, allowedValues, badValue);
  88.   return;
  89.   } else {
  90.   var msg = "While attempting to load module \"" + moduleName + "\", ";
  91.   if (badValue != null) {
  92.   msg += "property \"" + propName + "\" was set to the unexpected value \"" + badValue + "\"";
  93.   } else {
  94.   msg += "property \"" + propName + "\" was not specified";
  95.   }
  96.  
  97.   msg += "\n\nAllowed values: " + allowedValues;
  98.  
  99.   window.alert(msg);
100.   }
101. }
102. // Returns an array that splits the module name from the meta content into
103. // [0] the prefix url, if any, guaranteed to end with a slash
104. // [1] the dotted module name
105. //
106. function __gwt_splitModuleNameRef(moduleName) {
107.   var parts = ['', moduleName];
108.   var i = moduleName.lastIndexOf("=");
109.   if (i != -1) {
110.   parts[0] = moduleName.substring(0, i) + '/';
111.   parts[1] = moduleName.substring(i+1);
112.   }
113.   return parts;
114. }
115. //////////////////////////////////////////////////////////////////
116. // Called directly from compiled code
117. //
118. function __gwt_initHandlers(resize, beforeunload, unload) {
119.   var oldOnResize = window.onresize;
120.   window.onresize = function() {
121.   resize();
122.   if (oldOnResize)
123.   oldOnResize();
124.   };
125.   var oldOnBeforeUnload = window.onbeforeunload;
126.   window.onbeforeunload = function() {
127.   var ret = beforeunload();
128.   var oldRet;
129.   if (oldOnBeforeUnload)
130.   oldRet = oldOnBeforeUnload();
131.   if (ret !== null)
132.   return ret;
133.   return oldRet;
134.   };
135.   var oldOnUnload = window.onunload;
136.   window.onunload = function() {
137.   unload();
138.   if (oldOnUnload)
139.   oldOnUnload();
140.   };
141. }
142. //////////////////////////////////////////////////////////////////
143. // Web Mode
144. //
145. function __gwt_injectWebModeFrame(name) {
146.   if (document.body) {
147.   var parts = __gwt_splitModuleNameRef(name);
148.  
149.   // Insert an IFRAME
150.   var iframe = document.createElement("iframe");
151.   var selectorURL = parts[0] + parts[1] + ".nocache.html";
152.   iframe.src = selectorURL;
153.   iframe.style.border = '0px';
154.   iframe.style.width = '0px';
155.   iframe.style.height = '0px';
156.   if (document.body.firstChild) {
157.   document.body.insertBefore(iframe, document.body.firstChild);
158.   } else {
159.   document.body.appendChild(iframe);
160.   }
161.   } else {
162.   // Try again in a moment.
163.   //
164.   window.setTimeout(function() { __gwt_injectWebModeFrame(name); }, __gwt_retryWaitMs);
165.   }
166. }
167. // When nested IFRAMEs load, they reach up into the parent page to announce that
168. // they are ready to run. Because IFRAMEs load asynchronously relative to the
169. // host page, one of two things can happen when they reach up:
170. // (1) The host page's onload handler has not yet been called, in which case we
171. // retry until it has been called.
172. // (2) The host page's onload handler has already been called, in which case the
173. // nested IFRAME should be initialized immediately.
174. //
175. function __gwt_webModeFrameOnLoad(iframeWindow, name) {
176.   var moduleInitFn = iframeWindow.gwtOnLoad;
177.   if (__gwt_isHostPageLoaded && moduleInitFn) {
178.   var old = window.status;
179.   window.status = "Initializing module '" + name + "'";
180.   try {
181.   moduleInitFn(__gwt_onLoadError, name);
182.   } finally {
183.   window.status = old;
184.   }
185.   } else {
186.   setTimeout(function() { __gwt_webModeFrameOnLoad(iframeWindow, name); }, __gwt_retryWaitMs);
187.   }
188. }
189. function __gwt_hookOnLoad() {
190.   var oldHandler = window.onload;
191.   window.onload = function() {
192.   __gwt_isHostPageLoaded = true;
193.   if (oldHandler) {
194.   oldHandler();
195.   }
196.   };
197. }
198. //////////////////////////////////////////////////////////////////
199. // Hosted Mode
200. //
201. function __gwt_injectHostedModeFrame(name) {
202.   if (document.body) {
203.   // Insert an empty IFRAME
204.   var iframe = document.createElement("iframe");
205.   iframe.style.display = "none";
206.   document.body.insertBefore(iframe, document.body.firstChild);
207.   iframe.src = "gwt-hosted.html?" + name;
208.   } else {
209.   // Try again in a moment.
210.   //
211.   window.setTimeout(function() { __gwt_injectHostedModeFrame(name); }, __gwt_retryWaitMs);
212.   }
213. }
214. function __gwt_initHostedModeModule(moduleFrame, moduleName) {
215.   if (!window.external.gwtOnLoad(moduleFrame, moduleName)) {
216.   // Module failed to load.
217.   //
218.   if (__gwt_onLoadError) {
219.   __gwt_onLoadError(moduleName);
220.   } else {
221.   window.alert("Failed to load module '" + moduleName + "'.\nPlease see the log in the development shell for details.");
222.   }
223.   }
224. }
225. function __gwt_onUnload() {
226.   window.external.gwtOnLoad(null, null);
227.   if (__gwt_onUnload.oldUnloadHandler) {
228.   __gwt_onUnload.oldUnloadHandler();
229.   }
230. }
231. //////////////////////////////////////////////////////////////////
232. // Set it up
233. //
234. __gwt_processMetas();
235. if (__gwt_isHosted()) {
236.   __gwt_onUnload.oldUnloadHandler = window.onunload;
237.   window.onunload = __gwt_onUnload;
238.   __gwt_forEachModule(__gwt_injectHostedModeFrame);
239. }
240. else {
241.   __gwt_hookOnLoad();
242.   __gwt_forEachModule(__gwt_injectWebModeFrame);
243. }
244. } // __GWT_JS_INCLUDED