123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145 |
- // Copyright (c) 2012 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- #ifndef UI_GFX_RANGE_RANGE_H_
- #define UI_GFX_RANGE_RANGE_H_
- #include <stddef.h>
- #include <stdint.h>
- #include <algorithm>
- #include <limits>
- #include <ostream>
- #include <string>
- #include "base/numerics/safe_conversions.h"
- #include "build/build_config.h"
- #include "ui/gfx/range/gfx_range_export.h"
- #if BUILDFLAG(IS_APPLE)
- #if __OBJC__
- #import <Foundation/Foundation.h>
- #else
- typedef struct _NSRange NSRange;
- #endif
- #endif // BUILDFLAG(IS_APPLE)
- namespace gfx {
- // This class represents either a forward range [min, max) or a reverse range
- // (max, min]. |start_| is always the first of these and |end_| the second; as a
- // result, the range is forward if (start_ <= end_). The zero-width range
- // [val, val) is legal, contains and intersects itself, and is contained by and
- // intersects any nonempty range [min, max) where min <= val < max.
- class GFX_RANGE_EXPORT Range {
- public:
- // Creates an empty range {0,0}.
- constexpr Range() : Range(0) {}
- // Initializes the range with a start and end.
- constexpr Range(size_t start, size_t end)
- : start_(base::checked_cast<uint32_t>(start)),
- end_(base::checked_cast<uint32_t>(end)) {}
- // Initializes the range with the same start and end positions.
- constexpr explicit Range(size_t position) : Range(position, position) {}
- // Platform constructors.
- #if BUILDFLAG(IS_APPLE)
- explicit Range(const NSRange& range);
- #endif
- // Returns a range that is invalid, which is {UINT32_MAX,UINT32_MAX}.
- static constexpr Range InvalidRange() {
- return Range(std::numeric_limits<uint32_t>::max());
- }
- // Checks if the range is valid through comparison to InvalidRange(). If this
- // is not valid, you must not call start()/end().
- constexpr bool IsValid() const { return *this != InvalidRange(); }
- // Getters and setters.
- constexpr size_t start() const { return start_; }
- void set_start(size_t start) { start_ = base::checked_cast<uint32_t>(start); }
- constexpr size_t end() const { return end_; }
- void set_end(size_t end) { end_ = base::checked_cast<uint32_t>(end); }
- // Returns the absolute value of the length.
- constexpr size_t length() const { return GetMax() - GetMin(); }
- constexpr bool is_reversed() const { return start() > end(); }
- constexpr bool is_empty() const { return start() == end(); }
- // Returns the minimum and maximum values.
- constexpr size_t GetMin() const {
- return start() < end() ? start() : end();
- }
- constexpr size_t GetMax() const {
- return start() > end() ? start() : end();
- }
- constexpr bool operator==(const Range& other) const {
- return start() == other.start() && end() == other.end();
- }
- constexpr bool operator!=(const Range& other) const {
- return !(*this == other);
- }
- constexpr bool EqualsIgnoringDirection(const Range& other) const {
- return GetMin() == other.GetMin() && GetMax() == other.GetMax();
- }
- // Returns true if this range intersects the specified |range|.
- constexpr bool Intersects(const Range& range) const {
- return Intersect(range).IsValid();
- }
- // Returns true if this range contains the specified |range|.
- constexpr bool Contains(const Range& range) const {
- return range.IsBoundedBy(*this) &&
- // A non-empty range doesn't contain the range [max, max).
- (range.GetMax() != GetMax() || range.is_empty() == is_empty());
- }
- // Returns true if this range is contained by the specified |range| or it is
- // an empty range and ending the range |range|.
- constexpr bool IsBoundedBy(const Range& range) const {
- return IsValid() && range.IsValid() && GetMin() >= range.GetMin() &&
- GetMax() <= range.GetMax();
- }
- // Computes the intersection of this range with the given |range|.
- // If they don't intersect, it returns an InvalidRange().
- // The returned range is always empty or forward (never reversed).
- constexpr Range Intersect(const Range& range) const {
- const size_t min = std::max(GetMin(), range.GetMin());
- const size_t max = std::min(GetMax(), range.GetMax());
- return (min < max || Contains(range) || range.Contains(*this))
- ? Range(min, max)
- : InvalidRange();
- }
- #if BUILDFLAG(IS_APPLE)
- Range& operator=(const NSRange& range);
- // NSRange does not store the directionality of a range, so if this
- // is_reversed(), the range will get flipped when converted to an NSRange.
- NSRange ToNSRange() const;
- #endif
- // GTK+ has no concept of a range.
- std::string ToString() const;
- private:
- // Note: we use uint32_t instead of size_t because this struct is sent over
- // IPC which could span 32 & 64 bit processes.
- uint32_t start_;
- uint32_t end_;
- };
- GFX_RANGE_EXPORT std::ostream& operator<<(std::ostream& os, const Range& range);
- } // namespace gfx
- #endif // UI_GFX_RANGE_RANGE_H_
|