Page Speed Optimization Libraries  1.8.31.2
net/instaweb/rewriter/public/css_util.h
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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 
00022 
00023 #ifndef NET_INSTAWEB_REWRITER_PUBLIC_CSS_UTIL_H_
00024 #define NET_INSTAWEB_REWRITER_PUBLIC_CSS_UTIL_H_
00025 
00026 #include <vector>
00027 
00028 #include "net/instaweb/util/public/basictypes.h"
00029 #include "net/instaweb/util/public/scoped_ptr.h"
00030 #include "net/instaweb/util/public/string.h"
00031 #include "net/instaweb/util/public/string_util.h"
00032 
00033 namespace Css {
00034 class Declarations;
00035 class MediaQueries;
00036 class MediaQuery;
00037 class Selector;
00038 }
00039 
00040 namespace net_instaweb {
00041 
00042 class HtmlElement;
00043 
00046 namespace css_util {
00047 
00048 static const char kAllMedia[] = "all";
00049 static const int kNoValue = -1;
00050 
00051 enum DimensionState {
00052   kNoDimensions,       
00053   kHasHeightOnly,      
00054   kHasWidthOnly,       
00055   kHasBothDimensions,  
00056   kNotParsable         
00057 };
00058 
00066 DimensionState GetDimensions(Css::Declarations* decls, int* width, int* height);
00067 
00068 class StyleExtractor {
00069  public:
00070   explicit StyleExtractor(HtmlElement* element);
00071   virtual ~StyleExtractor();
00072 
00073 
00074   DimensionState state() const { return state_; }
00075 
00077   int width() const { return width_px_; }
00078   int height() const { return height_px_; }
00079 
00082   bool HasAnyDimensions() { return (state_ != kNoDimensions); }
00083 
00084   DimensionState dimension_state() { return state_; }
00085 
00086  private:
00087   static Css::Declarations* GetDeclsFromElement(HtmlElement* element);
00088   scoped_ptr<Css::Declarations> decls_;
00089   int width_px_;
00090   int height_px_;
00091   DimensionState state_;
00092   DISALLOW_COPY_AND_ASSIGN(StyleExtractor);
00093 };
00094 
00099 
00104 void VectorizeMediaAttribute(const StringPiece& input_media,
00105                              StringVector* output_vector);
00106 
00111 GoogleString StringifyMediaVector(const StringVector& import_media);
00112 
00115 bool IsComplexMediaQuery(const Css::MediaQuery& query);
00116 
00122 bool ConvertMediaQueriesToStringVector(const Css::MediaQueries& in_vector,
00123                                        StringVector* out_vector);
00124 
00129 void ConvertStringVectorToMediaQueries(const StringVector& in_vector,
00130                                        Css::MediaQueries* out_vector);
00131 
00134 void ClearVectorIfContainsMediaAll(StringVector* media);
00135 
00137 bool CanMediaAffectScreen(const StringPiece& media);
00138 
00141 GoogleString JsDetectableSelector(const Css::Selector& selector);
00142 
00149 template<typename T>
00150 void EliminateElementsNotIn(std::vector<T>* sorted_inner,
00151                             const std::vector<T>& sorted_outer) {
00152   if (!sorted_outer.empty()) {
00153     if (sorted_inner->empty()) {
00154       *sorted_inner = sorted_outer;
00155     } else {
00156       typename std::vector<T>::const_iterator outer_iter = sorted_outer.begin();
00157       typename std::vector<T>::iterator inner_iter = sorted_inner->begin();
00158 
00159       while (inner_iter != sorted_inner->end()) {
00160         if (outer_iter == sorted_outer.end()) {
00162           inner_iter = sorted_inner->erase(inner_iter, sorted_inner->end());
00163         } else if (*outer_iter == *inner_iter) {
00165           ++outer_iter;
00166           ++inner_iter;
00167         } else if (*outer_iter < *inner_iter) {
00169           ++outer_iter;
00170         } else {
00172           inner_iter = sorted_inner->erase(inner_iter);
00173         }
00174       }
00175     }
00176   }
00177 }
00178 
00179 }  
00180 
00181 }  
00182 
00183 #endif  ///< NET_INSTAWEB_REWRITER_PUBLIC_CSS_UTIL_H_
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