1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CompositionUnderlineRangeFilter_h 6 #define CompositionUnderlineRangeFilter_h 7 8 #include "core/editing/CompositionUnderline.h" 9 #include "wtf/NotFound.h" 10 #include "wtf/Vector.h" 11 12 namespace WebCore { 13 14 // A visitor class to yield elements of a sorted (by startOffset) list of 15 // underlines, visiting only elements that intersect with specified *inclusive* 16 // range [indexLo, indexHi]. 17 class CompositionUnderlineRangeFilter { 18 WTF_MAKE_NONCOPYABLE(CompositionUnderlineRangeFilter); 19 public: 20 class ConstIterator { 21 public: 22 ConstIterator(): m_filter(nullptr), m_index(0) { } 23 const CompositionUnderline& operator*() 24 { 25 ASSERT(m_index != kNotFound); 26 return m_filter->m_underlines[m_index]; 27 } 28 ConstIterator& operator++() 29 { 30 if (m_index != kNotFound) 31 m_index = m_filter->seekValidIndex(m_index + 1); 32 return *this; 33 } 34 const CompositionUnderline* operator->() 35 { 36 ASSERT(m_index != kNotFound); 37 return &m_filter->m_underlines[m_index]; 38 } 39 bool operator==(const ConstIterator& other) 40 { 41 return other.m_index == m_index && other.m_filter == m_filter; 42 } 43 bool operator!=(const ConstIterator& other) { return !operator==(other); } 44 45 private: 46 friend class CompositionUnderlineRangeFilter; 47 48 ConstIterator(CompositionUnderlineRangeFilter* filter, size_t index) 49 : m_filter(filter) 50 , m_index(index) { } 51 CompositionUnderlineRangeFilter* m_filter; 52 size_t m_index; 53 }; 54 55 CompositionUnderlineRangeFilter(const Vector<CompositionUnderline>& underlines, size_t indexLo, size_t indexHi); 56 57 ConstIterator begin() { return ConstIterator(this, seekValidIndex(0)); } 58 const ConstIterator& end() { return m_theEnd; } 59 60 private: 61 friend class ConstIterator; 62 63 // Returns |index| if |m_underlines[index]| intersects with range 64 // [m_indexLo, m_indexHi]. Otherwise returns the index of the next 65 // intersecting interval, or END if there are none left. 66 size_t seekValidIndex(size_t index); 67 68 // Assume that elements of |m_underlines| are sorted by |.startOffset|. 69 const Vector<CompositionUnderline>& m_underlines; 70 // The "query range" is the inclusive range [m_indexLo, m_indexHi]. 71 const size_t m_indexLo; 72 const size_t m_indexHi; 73 const ConstIterator m_theEnd; 74 }; 75 76 } // namespace WebCore 77 78 #endif 79
