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b715d3f21d
Replaces selection_base() and selection_extent() with selection() and SetSelection(int, int) with SetSelection(range). This also adds the following convenience methods to TextRange: * reversed() * Contains(size_t position) * Contains(const TextRange& range) as well as operator== for use in unit tests. When Flutter migrates to C++20, we can replace that method with a default declaration.
71 lines
2.1 KiB
C++
71 lines
2.1 KiB
C++
// Copyright 2013 The Flutter Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include <algorithm>
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#include "flutter/fml/logging.h"
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// A directional range of text.
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//
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// A |TextRange| describes a range of text with |base| and |extent| positions.
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// In the case where |base| == |extent|, the range is said to be collapsed, and
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// when |base| > |extent|, the range is said to be reversed.
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class TextRange {
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public:
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explicit TextRange(size_t position) : base_(position), extent_(position) {}
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explicit TextRange(size_t base, size_t extent)
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: base_(base), extent_(extent) {}
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TextRange(const TextRange&) = default;
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TextRange& operator=(const TextRange&) = default;
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virtual ~TextRange() = default;
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// Returns the base position of the range.
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size_t base() const { return base_; }
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// Returns the extent position of the range.
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size_t extent() const { return extent_; }
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// Returns the lesser of the base and extent positions.
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size_t start() const { return std::min(base_, extent_); }
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// Returns the greater of the base and extent positions.
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size_t end() const { return std::max(base_, extent_); }
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// Returns the position of a collapsed range.
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//
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// Asserts that the range is of length 0.
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size_t position() const {
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FML_DCHECK(base_ == extent_);
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return extent_;
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}
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// Returns the length of the range.
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size_t length() const { return end() - start(); }
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// Returns true if the range is of length 0.
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bool collapsed() const { return base_ == extent_; }
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// Returns true if the base is greater than the extent.
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bool reversed() const { return base_ > extent_; }
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// Returns true if |position| is contained within the range.
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bool Contains(size_t position) const {
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return position >= start() && position <= end();
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}
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// Returns true if |range| is contained within the range.
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bool Contains(const TextRange& range) const {
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return range.start() >= start() && range.end() <= end();
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}
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bool operator==(const TextRange& other) const {
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return base_ == other.base_ && extent_ == other.extent_;
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}
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private:
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size_t base_;
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size_t extent_;
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};
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