| /* |
| * Copyright 2015 Google Inc. All Rights Reserved. |
| * |
| * 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. |
| */ |
| |
| #ifndef COBALT_CSSOM_SPECIFICITY_H_ |
| #define COBALT_CSSOM_SPECIFICITY_H_ |
| |
| #include "base/basictypes.h" |
| #include "base/logging.h" |
| |
| namespace cobalt { |
| namespace cssom { |
| |
| // A selector's specificity is calculated as follows: |
| // Count the number of ID selectors in the selector (A) |
| // Count the number of class selectors, attributes selectors, and |
| // pseudo-classes in the selector (B) |
| // Count the number of type selectors and pseudo-elements in the selector (C) |
| // https://www.w3.org/TR/selectors4/#specificity |
| // When adding two specificities, clampping the result at each field (A, B and |
| // C). |
| class Specificity { |
| public: |
| Specificity() { |
| v_[0] = 0; |
| v_[1] = 0; |
| v_[2] = 0; |
| } |
| |
| Specificity(int8 a, int8 b, int8 c) { |
| DCHECK_GE(a, 0) << "Specificity field cannot be negative."; |
| DCHECK_GE(b, 0) << "Specificity field cannot be negative."; |
| DCHECK_GE(c, 0) << "Specificity field cannot be negative."; |
| v_[0] = a; |
| v_[1] = b; |
| v_[2] = c; |
| } |
| |
| // Adds the value of another specificity to self. |
| void AddFrom(const Specificity& rhs); |
| |
| // Specificity fields are compared lexicographically. |
| bool operator<(const Specificity& rhs) const { |
| return v_[0] < rhs.v_[0] || |
| (v_[0] == rhs.v_[0] && |
| (v_[1] < rhs.v_[1] || (v_[1] == rhs.v_[1] && v_[2] < rhs.v_[2]))); |
| } |
| bool operator>(const Specificity& rhs) const { |
| return v_[0] > rhs.v_[0] || |
| (v_[0] == rhs.v_[0] && |
| (v_[1] > rhs.v_[1] || (v_[1] == rhs.v_[1] && v_[2] > rhs.v_[2]))); |
| } |
| bool operator==(const Specificity& rhs) const { |
| return v_[0] == rhs.v_[0] && v_[1] == rhs.v_[1] && v_[2] == rhs.v_[2]; |
| } |
| |
| private: |
| int8 v_[3]; |
| }; |
| |
| } // namespace cssom |
| } // namespace cobalt |
| |
| #endif // COBALT_CSSOM_SPECIFICITY_H_ |