Page Speed Optimization Libraries
1.8.31.2
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00001 /* 00002 * Copyright 2011 Google Inc. 00003 * 00004 * Licensed under the Apache License, Version 2.0 (the "License"); 00005 * you may not use this file except in compliance with the License. 00006 * You may obtain a copy of the License at 00007 * 00008 * http:///www.apache.org/licenses/LICENSE-2.0 00009 * 00010 * Unless required by applicable law or agreed to in writing, software 00011 * distributed under the License is distributed on an "AS IS" BASIS, 00012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 00013 * See the License for the specific language governing permissions and 00014 * limitations under the License. 00015 */ 00016 00070 00071 #ifndef NET_INSTAWEB_REWRITER_PUBLIC_DELAY_IMAGES_FILTER_H_ 00072 #define NET_INSTAWEB_REWRITER_PUBLIC_DELAY_IMAGES_FILTER_H_ 00073 00074 #include "net/instaweb/rewriter/public/common_filter.h" 00075 #include "net/instaweb/util/public/basictypes.h" 00076 #include "net/instaweb/util/public/string_util.h" 00077 00078 namespace net_instaweb { 00079 00080 class HtmlElement; 00081 class RewriteDriver; 00082 class StaticAssetManager; 00083 class Statistics; 00084 00085 class DelayImagesFilter : public CommonFilter { 00086 public: 00087 static const char kDelayImagesSuffix[]; 00088 static const char kDelayImagesInlineSuffix[]; 00089 static const char kImageOnloadCode[]; 00090 static const char kImageOnloadJsSnippet[]; 00091 00092 explicit DelayImagesFilter(RewriteDriver* driver); 00093 virtual ~DelayImagesFilter(); 00094 00095 virtual void StartDocumentImpl(); 00096 virtual void StartElementImpl(HtmlElement* element) { } 00097 virtual void EndElementImpl(HtmlElement* element); 00098 00099 virtual void EndDocument(); 00100 00101 virtual const char* Name() const { return "DelayImages"; } 00102 00103 virtual void DetermineEnabled(); 00104 00105 static void InitStats(Statistics* statistics); 00106 static void Terminate(); 00107 00108 private: 00111 void MaybeAddImageOnloadJsSnippet(HtmlElement* element); 00112 00114 void InsertLowResImagesAndJs(HtmlElement* element, bool insert_after_element); 00115 00117 void InsertHighResJs(HtmlElement* element); 00118 00121 bool ShouldRewriteInplace() const; 00122 00123 RewriteDriver* driver_; 00124 StaticAssetManager* static_asset_manager_; 00125 00126 int num_low_res_inlined_images_; 00127 StringStringMap low_res_data_map_; 00128 00132 bool insert_low_res_images_inplace_; 00133 00138 bool lazyload_highres_images_; 00139 00140 bool is_script_inserted_; 00141 00142 bool added_image_onload_js_; 00143 00144 DISALLOW_COPY_AND_ASSIGN(DelayImagesFilter); 00145 }; 00146 00147 } 00148 00149 #endif ///< NET_INSTAWEB_REWRITER_PUBLIC_DELAY_IMAGES_FILTER_H_