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// Copyright 2014 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.
#include "base/memory/scoped_ptr.h"
#include "base/memory/scoped_vector.h"
#include "third_party/harfbuzz-ng/src/hb.h"
#include "third_party/icu/source/common/unicode/ubidi.h"
#include "third_party/icu/source/common/unicode/uscript.h"
#include "ui/gfx/render_text.h"
namespace base {
namespace i18n {
class BreakIterator;
namespace gfx {
class Range;
class RangeF;
namespace internal {
// Applies std::round to the start and end values of the given RangeF.
GFX_EXPORT Range RoundRangeF(const RangeF& range_f);
struct GFX_EXPORT TextRunHarfBuzz {
// Returns the index of the first glyph that corresponds to the character at
// |pos|.
size_t CharToGlyph(size_t pos) const;
// Returns the corresponding glyph range of the given character range.
// |range| is in text-space (0 corresponds to |GetDisplayText()[0]|). Returned
// value is in run-space (0 corresponds to the first glyph in the run).
Range CharRangeToGlyphRange(const Range& range) const;
// Returns the number of missing glyphs in the shaped text run.
size_t CountMissingGlyphs() const;
// Writes the character and glyph ranges of the cluster containing |pos|.
void GetClusterAt(size_t pos, Range* chars, Range* glyphs) const;
// Returns the grapheme bounds at |text_index|. Handles multi-grapheme glyphs.
RangeF GetGraphemeBounds(base::i18n::BreakIterator* grapheme_iterator,
size_t text_index);
// Returns whether the given shaped run contains any missing glyphs.
bool HasMissingGlyphs() const;
float width;
float preceding_run_widths;
Range range;
bool is_rtl;
UBiDiLevel level;
UScriptCode script;
scoped_ptr<uint16[]> glyphs;
scoped_ptr<SkPoint[]> positions;
std::vector<uint32> glyph_to_char;
size_t glyph_count;
std::string family;
skia::RefPtr<SkTypeface> skia_face;
FontRenderParams render_params;
int font_size;
int baseline_offset;
int baseline_type;
int font_style;
bool strike;
bool diagonal_strike;
bool underline;
// Manages the list of TextRunHarfBuzz and its logical <-> visual index mapping.
class TextRunList {
size_t size() const { return runs_.size(); }
// Converts the index between logical and visual index.
size_t visual_to_logical(size_t index) const {
return visual_to_logical_[index];
size_t logical_to_visual(size_t index) const {
return logical_to_visual_[index];
const ScopedVector<TextRunHarfBuzz>& runs() const { return runs_; }
// Adds the new |run| to the run list.
void add(TextRunHarfBuzz* run) { runs_.push_back(run); }
// Reset the run list.
void Reset();
// Initialize the index mapping.
void InitIndexMap();
// Precomputes the offsets for all runs.
void ComputePrecedingRunWidths();
// Get the total width of runs, as if they were shown on one line.
// Do not use this when multiline is enabled.
float width() const { return width_; }
// Text runs in logical order.
ScopedVector<TextRunHarfBuzz> runs_;
// Maps visual run indices to logical run indices and vice versa.
std::vector<int32_t> visual_to_logical_;
std::vector<int32_t> logical_to_visual_;
float width_;
} // namespace internal
class GFX_EXPORT RenderTextHarfBuzz : public RenderText {
~RenderTextHarfBuzz() override;
// RenderText:
scoped_ptr<RenderText> CreateInstanceOfSameType() const override;
bool MultilineSupported() const override;
const base::string16& GetDisplayText() override;
Size GetStringSize() override;
SizeF GetStringSizeF() override;
SelectionModel FindCursorPosition(const Point& point) override;
std::vector<FontSpan> GetFontSpansForTesting() override;
Range GetGlyphBounds(size_t index) override;
// RenderText:
int GetDisplayTextBaseline() override;
SelectionModel AdjacentCharSelectionModel(
const SelectionModel& selection,
VisualCursorDirection direction) override;
SelectionModel AdjacentWordSelectionModel(
const SelectionModel& selection,
VisualCursorDirection direction) override;
std::vector<Rect> GetSubstringBounds(const Range& range) override;
size_t TextIndexToDisplayIndex(size_t index) override;
size_t DisplayIndexToTextIndex(size_t index) override;
bool IsValidCursorIndex(size_t index) override;
void OnLayoutTextAttributeChanged(bool text_changed) override;
void OnDisplayTextAttributeChanged() override;
void EnsureLayout() override;
void DrawVisualText(Canvas* canvas) override;
friend class RenderTextTest;
FRIEND_TEST_ALL_PREFIXES(RenderTextTest, Multiline_HorizontalAlignment);
FRIEND_TEST_ALL_PREFIXES(RenderTextTest, Multiline_NormalWidth);
FRIEND_TEST_ALL_PREFIXES(RenderTextTest, Multiline_WordWrapBehavior);
FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_RunDirection);
FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_HorizontalPositions);
FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_BreakRunsByUnicodeBlocks);
FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_BreakRunsByEmoji);
FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_SubglyphGraphemeCases);
FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_SubglyphGraphemePartition);
FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_NonExistentFont);
FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_UniscribeFallback);
FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_UnicodeFallback);
// Specify the width of a glyph for test. The width of glyphs is very
// platform-dependent and environment-dependent. Otherwise multiline test
// will become really flaky.
void set_glyph_width_for_test(float test_width) {
glyph_width_for_test_ = test_width;
// The actual implementation of the text drawing.
void DrawVisualTextInternal(internal::SkiaTextRenderer* renderer);
// Return the run index that contains the argument; or the length of the
// |runs_| vector if argument exceeds the text length or width.
size_t GetRunContainingCaret(const SelectionModel& caret);
size_t GetRunContainingXCoord(float x, float* offset) const;
// Given a |run|, returns the SelectionModel that contains the logical first
// or last caret position inside (not at a boundary of) the run.
// The returned value represents a cursor/caret position without a selection.
SelectionModel FirstSelectionModelInsideRun(
const internal::TextRunHarfBuzz* run);
SelectionModel LastSelectionModelInsideRun(
const internal::TextRunHarfBuzz* run);
// Break the text into logical runs and populate the visual <-> logical maps
// into |run_list_out|.
void ItemizeTextToRuns(const base::string16& string,
internal::TextRunList* run_list_out);
// Helper method for ShapeRun() that calls ShapeRunWithFont() with |text|,
// |run|, |family|, and |render_params|, returning true if the family provides
// all the glyphs needed for |run|, and false otherwise. Additionally updates
// |best_family|, |best_render_params|, and |best_missing_glyphs| if |family|
// has fewer than |best_missing_glyphs| missing glyphs.
bool CompareFamily(const base::string16& text,
const std::string& family,
const gfx::FontRenderParams& render_params,
internal::TextRunHarfBuzz* run,
std::string* best_family,
gfx::FontRenderParams* best_render_params,
size_t* best_missing_glyphs);
// Shape the glyphs of all runs in |run_list| using |text|.
void ShapeRunList(const base::string16& text,
internal::TextRunList* run_list);
// Shape the glyphs needed for the |run| within the |text|.
void ShapeRun(const base::string16& text,
internal::TextRunHarfBuzz* run);
bool ShapeRunWithFont(const base::string16& text,
const std::string& font_family,
const FontRenderParams& params,
internal::TextRunHarfBuzz* run);
// Makes sure that text runs for layout text are shaped.
void EnsureLayoutRunList();
// ICU grapheme iterator for the layout text. Can be NULL in case of an error.
base::i18n::BreakIterator* GetGraphemeIterator();
// Returns the current run list, |display_run_list_| if the text is
// elided, or |layout_run_list_| otherwise.
internal::TextRunList* GetRunList();
const internal::TextRunList* GetRunList() const;
// Text run list for |layout_text_| and |display_text_|.
// |display_run_list_| is created only when the text is elided.
internal::TextRunList layout_run_list_;
scoped_ptr<internal::TextRunList> display_run_list_;
bool update_layout_run_list_ : 1;
bool update_display_run_list_ : 1;
bool update_grapheme_iterator_ : 1;
bool update_display_text_ : 1;
// ICU grapheme iterator for the layout text. Use GetGraphemeIterator()
// to access the iterator.
scoped_ptr<base::i18n::BreakIterator> grapheme_iterator_;
// The total size of the layouted text.
SizeF total_size_;
// Fixed width of glyphs. This should only be set in test environments.
float glyph_width_for_test_;
} // namespace gfx