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// Copyright 2016 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 THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SHAPING_SHAPE_RESULT_SPACING_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SHAPING_SHAPE_RESULT_SPACING_H_
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/text/character.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
namespace blink {
class FontDescription;
// A context object to apply letter-spacing, word-spacing, and justification to
// ShapeResult.
template <typename TextContainerType>
class PLATFORM_EXPORT ShapeResultSpacing final {
STACK_ALLOCATED();
public:
explicit ShapeResultSpacing(const TextContainerType& text,
bool allow_word_spacing_anywhere = false)
: text_(text),
letter_spacing_(0),
word_spacing_(0),
expansion_(0),
expansion_per_opportunity_(0),
expansion_opportunity_count_(0),
text_justify_(TextJustify::kAuto),
has_spacing_(false),
normalize_space_(false),
allow_tabs_(false),
is_after_expansion_(false),
allow_word_spacing_anywhere_(allow_word_spacing_anywhere) {}
const TextContainerType& Text() const { return text_; }
float LetterSpacing() const { return has_spacing_ ? letter_spacing_ : .0f; }
float WordSpacing() const { return has_spacing_ ? word_spacing_ : .0f; }
bool HasSpacing() const { return has_spacing_; }
bool HasExpansion() const { return expansion_opportunity_count_; }
unsigned ExpansionOppotunityCount() const {
return expansion_opportunity_count_;
}
// Set letter-spacing and word-spacing.
bool SetSpacing(const FontDescription&);
// Set the expansion for the justification.
void SetExpansion(float expansion,
TextDirection,
TextJustify,
bool allows_leading_expansion = false,
bool allows_trailing_expansion = false);
// Set letter-spacing, word-spacing, and
// justification. Available only for TextRun.
void SetSpacingAndExpansion(const FontDescription&);
// Compute the sum of all spacings for the specified |index|.
// The |index| is for the |TextContainerType| given in the constructor.
// For justification, this function must be called incrementally since it
// keeps states and counts consumed justification opportunities.
struct ComputeSpacingParameters {
unsigned index;
float original_advance = 0.0;
};
float ComputeSpacing(unsigned index, float& offset) {
return ComputeSpacing(ComputeSpacingParameters{.index = index}, offset);
}
float ComputeSpacing(const ComputeSpacingParameters& parameters,
float& offset);
private:
bool IsAfterExpansion() const { return is_after_expansion_; }
void ComputeExpansion(bool allows_leading_expansion,
bool allows_trailing_expansion,
TextDirection,
TextJustify);
float NextExpansion();
const TextContainerType& text_;
float letter_spacing_;
float word_spacing_;
float expansion_;
float expansion_per_opportunity_;
unsigned expansion_opportunity_count_;
TextJustify text_justify_;
bool has_spacing_;
bool normalize_space_;
bool allow_tabs_;
bool is_after_expansion_;
bool allow_word_spacing_anywhere_;
};
// Forward declare so no implicit instantiations happen before the
// first explicit instantiation (which would be a C++ violation).
template <>
void ShapeResultSpacing<TextRun>::SetSpacingAndExpansion(
const FontDescription&);
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SHAPING_SHAPE_RESULT_SPACING_H_
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