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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 "ui/gfx/render_text_harfbuzz.h"
#include <limits>
#include <set>
#include "base/command_line.h"
#include "base/feature_list.h"
#include "base/i18n/base_i18n_switches.h"
#include "base/i18n/bidi_line_iterator.h"
#include "base/i18n/break_iterator.h"
#include "base/i18n/char_iterator.h"
#include "base/macros.h"
#include "base/memory/ptr_util.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/trace_event/trace_event.h"
#include "build/build_config.h"
#include "third_party/icu/source/common/unicode/ubidi.h"
#include "third_party/icu/source/common/unicode/utf16.h"
#include "third_party/skia/include/core/SkColor.h"
#include "third_party/skia/include/core/SkTypeface.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/decorated_text.h"
#include "ui/gfx/font.h"
#include "ui/gfx/font_fallback.h"
#include "ui/gfx/font_render_params.h"
#include "ui/gfx/geometry/safe_integer_conversions.h"
#include "ui/gfx/harfbuzz_font_skia.h"
#include "ui/gfx/range/range_f.h"
#include "ui/gfx/skia_util.h"
#include "ui/gfx/switches.h"
#include "ui/gfx/text_utils.h"
#include "ui/gfx/utf16_indexing.h"
#if defined(OS_MACOSX)
#include "base/mac/mac_util.h"
#endif
#include <hb.h>
namespace gfx {
namespace {
// Text length limit. Longer strings are slow and not fully tested.
const size_t kMaxTextLength = 10000;
// The maximum number of scripts a Unicode character can belong to. This value
// is arbitrarily chosen to be a good limit because it is unlikely for a single
// character to belong to more scripts.
const size_t kMaxScripts = 5;
// Returns true if characters of |block_code| may trigger font fallback.
bool IsUnusualBlockCode(UBlockCode block_code) {
return block_code == UBLOCK_GEOMETRIC_SHAPES ||
block_code == UBLOCK_MISCELLANEOUS_SYMBOLS;
}
bool IsBracket(UChar32 character) {
static const char kBrackets[] = { '(', ')', '{', '}', '<', '>', };
static const char* kBracketsEnd = kBrackets + arraysize(kBrackets);
return std::find(kBrackets, kBracketsEnd, character) != kBracketsEnd;
}
// If the given scripts match, returns the one that isn't USCRIPT_INHERITED,
// i.e. the more specific one. Otherwise returns USCRIPT_INVALID_CODE. This
// function is used to split runs between characters of different script codes,
// unless either character has USCRIPT_INHERITED property. See crbug.com/448909.
UScriptCode ScriptIntersect(UScriptCode first, UScriptCode second) {
if (first == second || second == USCRIPT_INHERITED)
return first;
if (first == USCRIPT_INHERITED)
return second;
return USCRIPT_INVALID_CODE;
}
// Writes the script and the script extensions of the character with the
// Unicode |codepoint|. Returns the number of written scripts.
int GetScriptExtensions(UChar32 codepoint, UScriptCode* scripts) {
UErrorCode icu_error = U_ZERO_ERROR;
// ICU documentation incorrectly states that the result of
// |uscript_getScriptExtensions| will contain the regular script property.
// Write the character's script property to the first element.
scripts[0] = uscript_getScript(codepoint, &icu_error);
if (U_FAILURE(icu_error))
return 0;
// Fill the rest of |scripts| with the extensions.
int count = uscript_getScriptExtensions(codepoint, scripts + 1,
kMaxScripts - 1, &icu_error);
if (U_FAILURE(icu_error))
count = 0;
return count + 1;
}
// Intersects the script extensions set of |codepoint| with |result| and writes
// to |result|, reading and updating |result_size|.
void ScriptSetIntersect(UChar32 codepoint,
UScriptCode* result,
size_t* result_size) {
UScriptCode scripts[kMaxScripts] = { USCRIPT_INVALID_CODE };
int count = GetScriptExtensions(codepoint, scripts);
size_t out_size = 0;
for (size_t i = 0; i < *result_size; ++i) {
for (int j = 0; j < count; ++j) {
UScriptCode intersection = ScriptIntersect(result[i], scripts[j]);
if (intersection != USCRIPT_INVALID_CODE) {
result[out_size++] = intersection;
break;
}
}
}
*result_size = out_size;
}
// Returns true if |first_char| and |current_char| both have "COMMON" script
// property but only one of them is an ASCII character. By doing this ASCII
// characters will be put into a separate run and be rendered using its default
// font. See crbug.com/530021 and crbug.com/533721 for more details.
bool AsciiBreak(UChar32 first_char, UChar32 current_char) {
if (isascii(first_char) == isascii(current_char))
return false;
size_t scripts_size = 1;
UScriptCode scripts[kMaxScripts] = { USCRIPT_COMMON };
ScriptSetIntersect(first_char, scripts, &scripts_size);
if (scripts_size == 0)
return false;
ScriptSetIntersect(current_char, scripts, &scripts_size);
return scripts_size != 0;
}
// When a string of "unusual" characters ends, the run usually breaks. However,
// variation selectors should still attach to the run of unusual characters.
// Detect this situation so that FindRunBreakingCharacter() can continue
// tracking the unusual block. Otherwise, just returns |current|.
UBlockCode MaybeCombineUnusualBlock(UBlockCode preceding, UBlockCode current) {
return IsUnusualBlockCode(preceding) && current == UBLOCK_VARIATION_SELECTORS
? preceding
: current;
}
// Returns the boundary between a special and a regular character. Special
// characters are brackets or characters that satisfy |IsUnusualBlockCode|.
size_t FindRunBreakingCharacter(const base::string16& text,
size_t run_start,
size_t run_break) {
const int32_t run_length = static_cast<int32_t>(run_break - run_start);
base::i18n::UTF16CharIterator iter(text.c_str() + run_start, run_length);
const UChar32 first_char = iter.get();
// The newline character should form a single run so that the line breaker
// can handle them easily.
if (first_char == '\n')
return run_start + 1;
const UBlockCode first_block = ublock_getCode(first_char);
const bool first_block_unusual = IsUnusualBlockCode(first_block);
const bool first_bracket = IsBracket(first_char);
while (iter.Advance() && iter.array_pos() < run_length) {
const UChar32 current_char = iter.get();
const UBlockCode current_block =
MaybeCombineUnusualBlock(first_block, ublock_getCode(current_char));
const bool block_break = current_block != first_block &&
(first_block_unusual || IsUnusualBlockCode(current_block));
if (block_break || current_char == '\n' ||
first_bracket != IsBracket(current_char) ||
AsciiBreak(first_char, current_char)) {
return run_start + iter.array_pos();
}
}
return run_break;
}
// Find the longest sequence of characters from 0 and up to |length| that
// have at least one common UScriptCode value. Writes the common script value to
// |script| and returns the length of the sequence. Takes the characters' script
// extensions into account. http://www.unicode.org/reports/tr24/#ScriptX
//
// Consider 3 characters with the script values {Kana}, {Hira, Kana}, {Kana}.
// Without script extensions only the first script in each set would be taken
// into account, resulting in 3 runs where 1 would be enough.
int ScriptInterval(const base::string16& text,
size_t start,
size_t length,
UScriptCode* script) {
DCHECK_GT(length, 0U);
UScriptCode scripts[kMaxScripts] = { USCRIPT_INVALID_CODE };
base::i18n::UTF16CharIterator char_iterator(text.c_str() + start, length);
size_t scripts_size = GetScriptExtensions(char_iterator.get(), scripts);
*script = scripts[0];
while (char_iterator.Advance()) {
ScriptSetIntersect(char_iterator.get(), scripts, &scripts_size);
if (scripts_size == 0U)
return char_iterator.array_pos();
*script = scripts[0];
}
return length;
}
// A port of hb_icu_script_to_script because harfbuzz on CrOS is built without
// hb-icu. See http://crbug.com/356929
inline hb_script_t ICUScriptToHBScript(UScriptCode script) {
if (script == USCRIPT_INVALID_CODE)
return HB_SCRIPT_INVALID;
return hb_script_from_string(uscript_getShortName(script), -1);
}
// Whether |segment| corresponds to the newline character.
bool IsNewlineSegment(const base::string16& text,
const internal::LineSegment& segment) {
return text[segment.char_range.start()] == '\n';
}
// Helper template function for |TextRunHarfBuzz::GetClusterAt()|. |Iterator|
// can be a forward or reverse iterator type depending on the text direction.
// Returns true on success, or false if an error is encountered.
template <class Iterator>
bool GetClusterAtImpl(size_t pos,
Range range,
Iterator elements_begin,
Iterator elements_end,
bool reversed,
Range* chars,
Range* glyphs) {
Iterator element = std::upper_bound(elements_begin, elements_end, pos);
if (element == elements_begin) {
*chars = range;
*glyphs = Range();
return false;
}
chars->set_end(element == elements_end ? range.end() : *element);
glyphs->set_end(reversed ? elements_end - element : element - elements_begin);
while (--element != elements_begin && *element == *(element - 1));
chars->set_start(*element);
glyphs->set_start(
reversed ? elements_end - element : element - elements_begin);
if (reversed)
*glyphs = Range(glyphs->end(), glyphs->start());
DCHECK(!chars->is_reversed());
DCHECK(!chars->is_empty());
DCHECK(!glyphs->is_reversed());
DCHECK(!glyphs->is_empty());
return true;
}
// Returns the line segment index for the |line|, |text_x| pair. |text_x| is
// relative to text in the given line. Returns -1 if |text_x| is to the left
// of text in the line and |line|.segments.size() if it's to the right.
// |offset_relative_segment| will contain the offset of |text_x| relative to
// the start of the segment it is contained in.
int GetLineSegmentContainingXCoord(const internal::Line& line,
float line_x,
float* offset_relative_segment) {
DCHECK(offset_relative_segment);
*offset_relative_segment = 0;
if (line_x < 0)
return -1;
for (size_t i = 0; i < line.segments.size(); i++) {
const internal::LineSegment& segment = line.segments[i];
// segment.x_range is not used because it is in text space.
if (line_x < segment.width()) {
*offset_relative_segment = line_x;
return i;
}
line_x -= segment.width();
}
return line.segments.size();
}
// Internal class to generate Line structures. If |multiline| is true, the text
// is broken into lines at |words| boundaries such that each line is no longer
// than |max_width|. If |multiline| is false, only outputs a single Line from
// the given runs. |min_baseline| and |min_height| are the minimum baseline and
// height for each line.
// TODO(ckocagil): Expose the interface of this class in the header and test
// this class directly.
class HarfBuzzLineBreaker {
public:
HarfBuzzLineBreaker(size_t max_width,
int min_baseline,
float min_height,
WordWrapBehavior word_wrap_behavior,
const base::string16& text,
const BreakList<size_t>* words,
const internal::TextRunList& run_list)
: max_width_((max_width == 0) ? SK_ScalarMax : SkIntToScalar(max_width)),
min_baseline_(min_baseline),
min_height_(min_height),
word_wrap_behavior_(word_wrap_behavior),
text_(text),
words_(words),
run_list_(run_list),
max_descent_(0),
max_ascent_(0),
text_x_(0),
available_width_(max_width_) {
AdvanceLine();
}
// Constructs a single line for |text_| using |run_list_|.
void ConstructSingleLine() {
for (size_t i = 0; i < run_list_.size(); i++) {
const internal::TextRunHarfBuzz& run = *(run_list_.runs()[i]);
internal::LineSegment segment;
segment.run = i;
segment.char_range = run.range;
segment.x_range = RangeF(SkScalarToFloat(text_x_),
SkScalarToFloat(text_x_) + run.width);
AddLineSegment(segment);
}
}
// Constructs multiple lines for |text_| based on words iteration approach.
void ConstructMultiLines() {
DCHECK(words_);
for (auto iter = words_->breaks().begin(); iter != words_->breaks().end();
iter++) {
const Range word_range = words_->GetRange(iter);
std::vector<internal::LineSegment> word_segments;
SkScalar word_width = GetWordWidth(word_range, &word_segments);
// If the last word is '\n', we should advance a new line after adding
// the word to the current line.
bool new_line = false;
if (!word_segments.empty() &&
IsNewlineSegment(text_, word_segments.back())) {
new_line = true;
// Since the line should at least contain some information regarding the
// text range it corresponds to, don't pop the newline segment, if it's
// the only segment in the line. This ensures that every line has a non-
// empty segments vector (except the last in some cases). This segment
// won't be drawn though.
if (word_segments.size() != 1u || available_width_ != max_width_) {
word_width -= word_segments.back().width();
word_segments.pop_back();
}
}
// If the word is not the first word in the line and it can't fit into
// the current line, advance a new line.
if (word_width > available_width_ && available_width_ != max_width_)
AdvanceLine();
if (!word_segments.empty())
AddWordToLine(word_segments);
if (new_line)
AdvanceLine();
}
}
// Finishes line breaking and outputs the results. Can be called at most once.
void FinalizeLines(std::vector<internal::Line>* lines, SizeF* size) {
DCHECK(!lines_.empty());
// Add an empty line to finish the line size calculation and remove it.
AdvanceLine();
lines_.pop_back();
*size = total_size_;
lines->swap(lines_);
}
private:
// A (line index, segment index) pair that specifies a segment in |lines_|.
typedef std::pair<size_t, size_t> SegmentHandle;
internal::LineSegment* SegmentFromHandle(const SegmentHandle& handle) {
return &lines_[handle.first].segments[handle.second];
}
// Finishes the size calculations of the last Line in |lines_|. Adds a new
// Line to the back of |lines_|.
void AdvanceLine() {
if (!lines_.empty()) {
internal::Line* line = &lines_.back();
std::sort(line->segments.begin(), line->segments.end(),
[this](const internal::LineSegment& s1,
const internal::LineSegment& s2) -> bool {
return run_list_.logical_to_visual(s1.run) <
run_list_.logical_to_visual(s2.run);
});
line->size.set_height(std::max(min_height_, max_descent_ + max_ascent_));
line->baseline = std::max(min_baseline_, SkScalarRoundToInt(max_ascent_));
line->preceding_heights = std::ceil(total_size_.height());
total_size_.set_height(total_size_.height() + line->size.height());
total_size_.set_width(std::max(total_size_.width(), line->size.width()));
}
max_descent_ = 0;
max_ascent_ = 0;
available_width_ = max_width_;
lines_.push_back(internal::Line());
}
// Adds word to the current line. A word may contain multiple segments. If the
// word is the first word in line and its width exceeds |available_width_|,
// ignore/truncate/wrap it according to |word_wrap_behavior_|.
void AddWordToLine(const std::vector<internal::LineSegment>& word_segments) {
DCHECK(!lines_.empty());
DCHECK(!word_segments.empty());
bool has_truncated = false;
for (const internal::LineSegment& segment : word_segments) {
if (has_truncated)
break;
if (segment.width() <= available_width_ ||
word_wrap_behavior_ == IGNORE_LONG_WORDS) {
AddLineSegment(segment);
} else {
DCHECK(word_wrap_behavior_ == TRUNCATE_LONG_WORDS ||
word_wrap_behavior_ == WRAP_LONG_WORDS);
has_truncated = (word_wrap_behavior_ == TRUNCATE_LONG_WORDS);
const internal::TextRunHarfBuzz& run = *(run_list_.runs()[segment.run]);
internal::LineSegment remaining_segment = segment;
while (!remaining_segment.char_range.is_empty()) {
size_t cutoff_pos = GetCutoffPos(remaining_segment);
SkScalar width = run.GetGlyphWidthForCharRange(
Range(remaining_segment.char_range.start(), cutoff_pos));
if (width > 0) {
internal::LineSegment cut_segment;
cut_segment.run = remaining_segment.run;
cut_segment.char_range =
Range(remaining_segment.char_range.start(), cutoff_pos);
cut_segment.x_range = RangeF(SkScalarToFloat(text_x_),
SkScalarToFloat(text_x_ + width));
AddLineSegment(cut_segment);
// Updates old segment range.
remaining_segment.char_range.set_start(cutoff_pos);
remaining_segment.x_range.set_start(SkScalarToFloat(text_x_));
}
if (has_truncated)
break;
if (!remaining_segment.char_range.is_empty())
AdvanceLine();
}
}
}
}
// Add a line segment to the current line. Note that, in order to keep the
// visual order correct for ltr and rtl language, we need to merge segments
// that belong to the same run.
void AddLineSegment(const internal::LineSegment& segment) {
DCHECK(!lines_.empty());
internal::Line* line = &lines_.back();
const internal::TextRunHarfBuzz& run = *(run_list_.runs()[segment.run]);
if (!line->segments.empty()) {
internal::LineSegment& last_segment = line->segments.back();
// Merge segments that belong to the same run.
if (last_segment.run == segment.run) {
DCHECK_EQ(last_segment.char_range.end(), segment.char_range.start());
// Check there is less than a pixel between one run and the next.
DCHECK_LE(
std::abs(last_segment.x_range.end() - segment.x_range.start()),
1.0f);
last_segment.char_range.set_end(segment.char_range.end());
last_segment.x_range.set_end(SkScalarToFloat(text_x_) +
segment.width());
if (run.is_rtl && last_segment.char_range.end() == run.range.end())
UpdateRTLSegmentRanges();
line->size.set_width(line->size.width() + segment.width());
text_x_ += segment.width();
available_width_ -= segment.width();
return;
}
}
line->segments.push_back(segment);
line->size.set_width(line->size.width() + segment.width());
SkPaint paint;
paint.setTypeface(run.skia_face);
paint.setTextSize(SkIntToScalar(run.font_size));
paint.setAntiAlias(run.render_params.antialiasing);
SkPaint::FontMetrics metrics;
paint.getFontMetrics(&metrics);
// max_descent_ is y-down, fDescent is y-down, baseline_offset is y-down
max_descent_ = std::max(max_descent_, metrics.fDescent+run.baseline_offset);
// max_ascent_ is y-up, fAscent is y-down, baseline_offset is y-down
max_ascent_ = std::max(max_ascent_, -(metrics.fAscent+run.baseline_offset));
if (run.is_rtl) {
rtl_segments_.push_back(
SegmentHandle(lines_.size() - 1, line->segments.size() - 1));
// If this is the last segment of an RTL run, reprocess the text-space x
// ranges of all segments from the run.
if (segment.char_range.end() == run.range.end())
UpdateRTLSegmentRanges();
}
text_x_ += segment.width();
available_width_ -= segment.width();
}
// Finds the end position |end_pos| in |segment| where the preceding width is
// no larger than |available_width_|.
size_t GetCutoffPos(const internal::LineSegment& segment) const {
DCHECK(!segment.char_range.is_empty());
const internal::TextRunHarfBuzz& run =
*(run_list_.runs()[segment.run]).get();
size_t end_pos = segment.char_range.start();
SkScalar width = 0;
while (end_pos < segment.char_range.end()) {
const SkScalar char_width =
run.GetGlyphWidthForCharRange(Range(end_pos, end_pos + 1));
if (width + char_width > available_width_)
break;
width += char_width;
end_pos++;
}
const size_t valid_end_pos = std::max(
segment.char_range.start(),
static_cast<uint32_t>(FindValidBoundaryBefore(text_, end_pos)));
if (end_pos != valid_end_pos) {
end_pos = valid_end_pos;
width = run.GetGlyphWidthForCharRange(
Range(segment.char_range.start(), end_pos));
}
// |max_width_| might be smaller than a single character. In this case we
// need to put at least one character in the line. Note that, we should
// not separate surrogate pair or combining characters.
// See RenderTextHarfBuzzTest.Multiline_MinWidth for an example.
if (width == 0 && available_width_ == max_width_) {
end_pos = std::min(
segment.char_range.end(),
static_cast<uint32_t>(FindValidBoundaryAfter(text_, end_pos + 1)));
}
return end_pos;
}
// Gets the glyph width for |word_range|, and splits the |word| into different
// segments based on its runs.
SkScalar GetWordWidth(const Range& word_range,
std::vector<internal::LineSegment>* segments) const {
DCHECK(words_);
if (word_range.is_empty() || segments == nullptr)
return 0;
size_t run_start_index = run_list_.GetRunIndexAt(word_range.start());
size_t run_end_index = run_list_.GetRunIndexAt(word_range.end() - 1);
SkScalar width = 0;
for (size_t i = run_start_index; i <= run_end_index; i++) {
const internal::TextRunHarfBuzz& run = *(run_list_.runs()[i]);
const Range char_range = run.range.Intersect(word_range);
DCHECK(!char_range.is_empty());
const SkScalar char_width = run.GetGlyphWidthForCharRange(char_range);
width += char_width;
internal::LineSegment segment;
segment.run = i;
segment.char_range = char_range;
segment.x_range = RangeF(SkScalarToFloat(text_x_ + width - char_width),
SkScalarToFloat(text_x_ + width));
segments->push_back(segment);
}
return width;
}
// RTL runs are broken in logical order but displayed in visual order. To find
// the text-space coordinate (where it would fall in a single-line text)
// |x_range| of RTL segments, segment widths are applied in reverse order.
// e.g. {[5, 10], [10, 40]} will become {[35, 40], [5, 35]}.
void UpdateRTLSegmentRanges() {
if (rtl_segments_.empty())
return;
float x = SegmentFromHandle(rtl_segments_[0])->x_range.start();
for (size_t i = rtl_segments_.size(); i > 0; --i) {
internal::LineSegment* segment = SegmentFromHandle(rtl_segments_[i - 1]);
const float segment_width = segment->width();
segment->x_range = RangeF(x, x + segment_width);
x += segment_width;
}
rtl_segments_.clear();
}
const SkScalar max_width_;
const int min_baseline_;
const float min_height_;
const WordWrapBehavior word_wrap_behavior_;
const base::string16& text_;
const BreakList<size_t>* const words_;
const internal::TextRunList& run_list_;
// Stores the resulting lines.
std::vector<internal::Line> lines_;
float max_descent_;
float max_ascent_;
// Text space x coordinates of the next segment to be added.
SkScalar text_x_;
// Stores available width in the current line.
SkScalar available_width_;
// Size of the multiline text, not including the currently processed line.
SizeF total_size_;
// The current RTL run segments, to be applied by |UpdateRTLSegmentRanges()|.
std::vector<SegmentHandle> rtl_segments_;
DISALLOW_COPY_AND_ASSIGN(HarfBuzzLineBreaker);
};
// Function object for case insensitive string comparison.
struct CaseInsensitiveCompare {
bool operator() (const Font& a, const Font& b) const {
return base::CompareCaseInsensitiveASCII(a.GetFontName(), b.GetFontName()) <
0;
}
};
// Applies a forced text rendering direction if specified by a command-line
// switch.
void ApplyForcedDirection(UBiDiLevel* level) {
static bool has_switch = base::CommandLine::ForCurrentProcess()->HasSwitch(
switches::kForceTextDirection);
if (!has_switch)
return;
base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
if (command_line->HasSwitch(switches::kForceTextDirection)) {
std::string force_flag =
command_line->GetSwitchValueASCII(switches::kForceTextDirection);
if (force_flag == switches::kForceDirectionRTL)
*level = UBIDI_RTL;
if (force_flag == switches::kForceDirectionLTR)
*level = UBIDI_LTR;
}
}
} // namespace
namespace internal {
#if !defined(OS_MACOSX)
sk_sp<SkTypeface> CreateSkiaTypeface(const Font& font,
bool italic,
Font::Weight weight) {
SkFontStyle skia_style(
static_cast<int>(weight), SkFontStyle::kNormal_Width,
italic ? SkFontStyle::kItalic_Slant : SkFontStyle::kUpright_Slant);
return sk_sp<SkTypeface>(SkTypeface::MakeFromName(
font.GetFontName().c_str(), skia_style));
}
#endif
TextRunHarfBuzz::TextRunHarfBuzz(const Font& template_font)
: width(0.0f),
preceding_run_widths(0.0f),
is_rtl(false),
level(0),
script(USCRIPT_INVALID_CODE),
glyph_count(static_cast<size_t>(-1)),
font(template_font),
font_size(0),
baseline_offset(0),
baseline_type(0),
italic(false),
weight(Font::Weight::NORMAL),
strike(false),
underline(false),
heavy_underline(false) {}
TextRunHarfBuzz::~TextRunHarfBuzz() {}
Range TextRunHarfBuzz::CharRangeToGlyphRange(const Range& char_range) const {
DCHECK(range.Contains(char_range));
DCHECK(!char_range.is_reversed());
DCHECK(!char_range.is_empty());
Range start_glyphs;
Range end_glyphs;
Range temp_range;
GetClusterAt(char_range.start(), &temp_range, &start_glyphs);
GetClusterAt(char_range.end() - 1, &temp_range, &end_glyphs);
return is_rtl ? Range(end_glyphs.start(), start_glyphs.end()) :
Range(start_glyphs.start(), end_glyphs.end());
}
size_t TextRunHarfBuzz::CountMissingGlyphs() const {
static const int kMissingGlyphId = 0;
size_t missing = 0;
for (size_t i = 0; i < glyph_count; ++i)
missing += (glyphs[i] == kMissingGlyphId) ? 1 : 0;
return missing;
}
void TextRunHarfBuzz::GetClusterAt(size_t pos,
Range* chars,
Range* glyphs) const {
DCHECK(chars);
DCHECK(glyphs);
bool success = true;
if (glyph_count == 0 || !range.Contains(Range(pos, pos + 1))) {
*chars = range;
*glyphs = Range();
success = false;
}
if (is_rtl) {
success &= GetClusterAtImpl(pos, range, glyph_to_char.rbegin(),
glyph_to_char.rend(), true, chars, glyphs);
} else {
success &= GetClusterAtImpl(pos, range, glyph_to_char.begin(),
glyph_to_char.end(), false, chars, glyphs);
}
if (!success) {
std::string glyph_to_char_string;
for (size_t i = 0; i < glyph_count && i < glyph_to_char.size(); ++i) {
glyph_to_char_string += base::NumberToString(i) + "->" +
base::UintToString(glyph_to_char[i]) + ", ";
}
LOG(ERROR) << " TextRunHarfBuzz error, please report at crbug.com/724880:"
<< " range: " << range.ToString() << ", rtl: " << is_rtl << ","
<< " level: '" << level << "', script: " << script << ","
<< " font: '" << font.GetActualFontNameForTesting() << "',"
<< " glyph_count: " << glyph_count << ", pos: " << pos << ","
<< " glyph_to_char: " << glyph_to_char_string;
}
}
RangeF TextRunHarfBuzz::GetGraphemeBounds(RenderTextHarfBuzz* render_text,
size_t text_index) const {
DCHECK_LT(text_index, range.end());
if (glyph_count == 0)
return RangeF(preceding_run_widths, preceding_run_widths + width);
Range chars;
Range glyphs;
GetClusterAt(text_index, &chars, &glyphs);
const float cluster_begin_x = positions[glyphs.start()].x();
const float cluster_end_x = glyphs.end() < glyph_count ?
positions[glyphs.end()].x() : SkFloatToScalar(width);
DCHECK_LE(cluster_begin_x, cluster_end_x);
// A cluster consists of a number of code points and corresponds to a number
// of glyphs that should be drawn together. A cluster can contain multiple
// graphemes. In order to place the cursor at a grapheme boundary inside the
// cluster, we simply divide the cluster width by the number of graphemes.
// Note: The first call to GetGraphemeIterator() can be expensive, so avoid
// doing it unless it's actually needed (when |code_point_count| > 1).
ptrdiff_t code_point_count = UTF16IndexToOffset(render_text->GetDisplayText(),
chars.start(), chars.end());
if (code_point_count > 1 && render_text->GetGraphemeIterator()) {
int before = 0;
int total = 0;
base::i18n::BreakIterator* grapheme_iterator =
render_text->GetGraphemeIterator();
for (size_t i = chars.start(); i < chars.end(); ++i) {
if (grapheme_iterator->IsGraphemeBoundary(i)) {
if (i < text_index)
++before;
++total;
}
}
DCHECK_GT(total, 0);
// It's possible for |text_index| to point to a diacritical mark, at the end
// of |chars|. In this case all the grapheme boundaries come before it. Just
// provide the bounds of the last grapheme.
if (before == total)
--before;
if (total > 1) {
if (is_rtl)
before = total - before - 1;
DCHECK_GE(before, 0);
DCHECK_LT(before, total);
const float cluster_start = preceding_run_widths + cluster_begin_x;
const float average_width = (cluster_end_x - cluster_begin_x) / total;
return RangeF(cluster_start + average_width * before,
cluster_start + average_width * (before + 1));
}
}
return RangeF(preceding_run_widths + cluster_begin_x,
preceding_run_widths + cluster_end_x);
}
RangeF TextRunHarfBuzz::GetGraphemeSpanForCharRange(
RenderTextHarfBuzz* render_text,
const Range& char_range) const {
if (char_range.is_empty())
return RangeF();
DCHECK(!char_range.is_reversed());
DCHECK(range.Contains(char_range));
size_t left_index = char_range.start();
size_t right_index = gfx::UTF16OffsetToIndex(render_text->GetDisplayText(),
char_range.end(), -1);
DCHECK_LE(left_index, right_index);
if (is_rtl)
std::swap(left_index, right_index);
const RangeF left_span = GetGraphemeBounds(render_text, left_index);
return left_index == right_index
? left_span
: RangeF(left_span.start(),
GetGraphemeBounds(render_text, right_index).end());
}
SkScalar TextRunHarfBuzz::GetGlyphWidthForCharRange(
const Range& char_range) const {
if (char_range.is_empty())
return 0;
DCHECK(range.Contains(char_range));
Range glyph_range = CharRangeToGlyphRange(char_range);
// The |glyph_range| might be empty or invalid on Windows if a multi-character
// grapheme is divided into different runs (e.g., there are two font sizes or
// colors for a single glyph). In this case it might cause the browser crash,
// see crbug.com/526234.
if (glyph_range.start() >= glyph_range.end()) {
NOTREACHED() << "The glyph range is empty or invalid! Its char range: ["
<< char_range.start() << ", " << char_range.end()
<< "], and its glyph range: [" << glyph_range.start() << ", "
<< glyph_range.end() << "].";
return 0;
}
return ((glyph_range.end() == glyph_count)
? SkFloatToScalar(width)
: positions[glyph_range.end()].x()) -
positions[glyph_range.start()].x();
}
TextRunList::TextRunList() : width_(0.0f) {}
TextRunList::~TextRunList() {}
void TextRunList::Reset() {
runs_.clear();
width_ = 0.0f;
}
void TextRunList::InitIndexMap() {
if (runs_.size() == 1) {
visual_to_logical_ = logical_to_visual_ = std::vector<int32_t>(1, 0);
return;
}
const size_t num_runs = runs_.size();
std::vector<UBiDiLevel> levels(num_runs);
for (size_t i = 0; i < num_runs; ++i)
levels[i] = runs_[i]->level;
visual_to_logical_.resize(num_runs);
ubidi_reorderVisual(&levels[0], num_runs, &visual_to_logical_[0]);
logical_to_visual_.resize(num_runs);
ubidi_reorderLogical(&levels[0], num_runs, &logical_to_visual_[0]);
}
void TextRunList::ComputePrecedingRunWidths() {
// Precalculate run width information.
width_ = 0.0f;
for (size_t i = 0; i < runs_.size(); ++i) {
const auto& run = runs_[visual_to_logical_[i]];
run->preceding_run_widths = width_;
width_ += run->width;
}
}
size_t TextRunList::GetRunIndexAt(size_t position) const {
for (size_t i = 0; i < runs_.size(); ++i) {
if (runs_[i]->range.start() <= position && runs_[i]->range.end() > position)
return i;
}
return runs_.size();
}
} // namespace internal
RenderTextHarfBuzz::RenderTextHarfBuzz()
: RenderText(),
update_layout_run_list_(false),
update_display_run_list_(false),
update_grapheme_iterator_(false),
update_display_text_(false),
glyph_width_for_test_(0u) {
set_truncate_length(kMaxTextLength);
}
RenderTextHarfBuzz::~RenderTextHarfBuzz() {}
std::unique_ptr<RenderText> RenderTextHarfBuzz::CreateInstanceOfSameType()
const {
return base::WrapUnique(new RenderTextHarfBuzz);
}
bool RenderTextHarfBuzz::MultilineSupported() const {
return true;
}
const base::string16& RenderTextHarfBuzz::GetDisplayText() {
// TODO(krb): Consider other elision modes for multiline.
if ((multiline() && (max_lines() == 0 || elide_behavior() != ELIDE_TAIL)) ||
elide_behavior() == NO_ELIDE || elide_behavior() == FADE_TAIL) {
// Call UpdateDisplayText to clear |display_text_| and |text_elided_|
// on the RenderText class.
UpdateDisplayText(0);
update_display_text_ = false;
display_run_list_.reset();
return layout_text();
}
EnsureLayoutRunList();
DCHECK(!update_display_text_);
return text_elided() ? display_text() : layout_text();
}
Size RenderTextHarfBuzz::GetStringSize() {
const SizeF size_f = GetStringSizeF();
return Size(std::ceil(size_f.width()), size_f.height());
}
SizeF RenderTextHarfBuzz::GetStringSizeF() {
EnsureLayout();
return total_size_;
}
SelectionModel RenderTextHarfBuzz::FindCursorPosition(const Point& view_point) {
EnsureLayout();
DCHECK(!lines().empty());
int line_index = GetLineContainingYCoord((view_point - GetLineOffset(0)).y());
// Handle kDragToEndIfOutsideVerticalBounds above or below the text in a
// single-line by extending towards the mouse cursor.
if (RenderText::kDragToEndIfOutsideVerticalBounds && !multiline() &&
(line_index < 0 || line_index >= static_cast<int>(lines().size()))) {
SelectionModel selection_start = GetSelectionModelForSelectionStart();
bool left = view_point.x() < GetCursorBounds(selection_start, true).x();
return EdgeSelectionModel(left ? CURSOR_LEFT : CURSOR_RIGHT);
}
// Otherwise, clamp |line_index| to a valid value or drag to logical ends.
if (line_index < 0) {
if (RenderText::kDragToEndIfOutsideVerticalBounds)
return EdgeSelectionModel(GetVisualDirectionOfLogicalBeginning());
line_index = 0;
}
if (line_index >= static_cast<int>(lines().size())) {
if (RenderText::kDragToEndIfOutsideVerticalBounds)
return EdgeSelectionModel(GetVisualDirectionOfLogicalEnd());
line_index = lines().size() - 1;
}
const internal::Line& line = lines()[line_index];
float point_offset_relative_segment = 0;
const int segment_index = GetLineSegmentContainingXCoord(
line, (view_point - GetLineOffset(line_index)).x(),
&point_offset_relative_segment);
if (segment_index < 0)
return LineSelectionModel(line_index, CURSOR_LEFT);
if (segment_index >= static_cast<int>(line.segments.size()))
return LineSelectionModel(line_index, CURSOR_RIGHT);
const internal::LineSegment& segment = line.segments[segment_index];
const internal::TextRunHarfBuzz& run = *GetRunList()->runs()[segment.run];
const size_t segment_min_glyph_index =
run.CharRangeToGlyphRange(segment.char_range).GetMin();
const float segment_offset_relative_run =
segment_min_glyph_index != 0
? SkScalarToFloat(run.positions[segment_min_glyph_index].x())
: 0;
const float point_offset_relative_run =
point_offset_relative_segment + segment_offset_relative_run;
// TODO(crbug.com/676287): Use offset within the glyph to return the correct
// grapheme position within a multi-grapheme glyph.
for (size_t i = 0; i < run.glyph_count; ++i) {
const float end = i + 1 == run.glyph_count
? run.width
: SkScalarToFloat(run.positions[i + 1].x());
const float middle = (end + SkScalarToFloat(run.positions[i].x())) / 2;
const size_t index = DisplayIndexToTextIndex(run.glyph_to_char[i]);
if (point_offset_relative_run < middle) {
return run.is_rtl ? SelectionModel(
IndexOfAdjacentGrapheme(index, CURSOR_FORWARD),
CURSOR_BACKWARD)
: SelectionModel(index, CURSOR_FORWARD);
}
if (point_offset_relative_run < end) {
return run.is_rtl ? SelectionModel(index, CURSOR_FORWARD)
: SelectionModel(
IndexOfAdjacentGrapheme(index, CURSOR_FORWARD),
CURSOR_BACKWARD);
}
}
return LineSelectionModel(line_index, CURSOR_RIGHT);
}
bool RenderTextHarfBuzz::IsSelectionSupported() const {
return true;
}
std::vector<RenderText::FontSpan> RenderTextHarfBuzz::GetFontSpansForTesting() {
EnsureLayout();
internal::TextRunList* run_list = GetRunList();
std::vector<RenderText::FontSpan> spans;
for (const auto& run : run_list->runs()) {
spans.push_back(RenderText::FontSpan(
run->font, Range(DisplayIndexToTextIndex(run->range.start()),
DisplayIndexToTextIndex(run->range.end()))));
}
return spans;
}
Range RenderTextHarfBuzz::GetCursorSpan(const Range& text_range) {
DCHECK(!text_range.is_reversed());
EnsureLayout();
const size_t index = text_range.start();
const size_t run_index =
GetRunContainingCaret(SelectionModel(index, CURSOR_FORWARD));
internal::TextRunList* run_list = GetRunList();
// Return edge bounds if the index is invalid or beyond the layout text size.
if (run_index >= run_list->size())
return Range(GetStringSize().width());
internal::TextRunHarfBuzz* run = run_list->runs()[run_index].get();
Range display_range(TextIndexToDisplayIndex(text_range.start()),
TextIndexToDisplayIndex(text_range.end()));
// Although highly likely, there's no guarantee that a single text run is used
// for the entire cursor span. For example, Unicode Variation Selectors are
// incorrectly placed in the next run; see crbug.com/775404. (For these, the
// variation selector has zero width, so it's safe to ignore the second run).
// TODO(tapted): Change this to a DCHECK when crbug.com/775404 is fixed.
display_range = display_range.Intersect(run->range);
RangeF bounds = run->GetGraphemeSpanForCharRange(this, display_range);
// If cursor is enabled, extend the last glyph up to the rightmost cursor
// position since clients expect them to be contiguous.
if (cursor_enabled() && run_index == run_list->size() - 1 &&
index == (run->is_rtl ? run->range.start() : run->range.end() - 1))
bounds.set_end(std::ceil(bounds.end()));
return run->is_rtl ? RangeF(bounds.end(), bounds.start()).Round()
: bounds.Round();
}
base::i18n::BreakIterator* RenderTextHarfBuzz::GetGraphemeIterator() {
if (update_grapheme_iterator_) {
update_grapheme_iterator_ = false;
grapheme_iterator_.reset(new base::i18n::BreakIterator(
GetDisplayText(), base::i18n::BreakIterator::BREAK_CHARACTER));
if (!grapheme_iterator_->Init())
grapheme_iterator_.reset();
}
return grapheme_iterator_.get();
}
int RenderTextHarfBuzz::GetDisplayTextBaseline() {
EnsureLayout();
return lines()[0].baseline;
}
SelectionModel RenderTextHarfBuzz::AdjacentCharSelectionModel(
const SelectionModel& selection,
VisualCursorDirection direction) {
DCHECK(!update_display_run_list_);
internal::TextRunList* run_list = GetRunList();
internal::TextRunHarfBuzz* run;
size_t run_index = GetRunContainingCaret(selection);
if (run_index >= run_list->size()) {
// The cursor is not in any run: we're at the visual and logical edge.
SelectionModel edge = EdgeSelectionModel(direction);
if (edge.caret_pos() == selection.caret_pos())
return edge;
int visual_index = (direction == CURSOR_RIGHT) ? 0 : run_list->size() - 1;
run = run_list->runs()[run_list->visual_to_logical(visual_index)].get();
} else {
// If the cursor is moving within the current run, just move it by one
// grapheme in the appropriate direction.
run = run_list->runs()[run_index].get();
size_t caret = selection.caret_pos();
bool forward_motion = run->is_rtl == (direction == CURSOR_LEFT);
if (forward_motion) {
if (caret < DisplayIndexToTextIndex(run->range.end())) {
caret = IndexOfAdjacentGrapheme(caret, CURSOR_FORWARD);
return SelectionModel(caret, CURSOR_BACKWARD);
}
} else {
if (caret > DisplayIndexToTextIndex(run->range.start())) {
caret = IndexOfAdjacentGrapheme(caret, CURSOR_BACKWARD);
return SelectionModel(caret, CURSOR_FORWARD);
}
}
// The cursor is at the edge of a run; move to the visually adjacent run.
int visual_index = run_list->logical_to_visual(run_index);
visual_index += (direction == CURSOR_LEFT) ? -1 : 1;
if (visual_index < 0 || visual_index >= static_cast<int>(run_list->size()))
return EdgeSelectionModel(direction);
run = run_list->runs()[run_list->visual_to_logical(visual_index)].get();
}
bool forward_motion = run->is_rtl == (direction == CURSOR_LEFT);
return forward_motion ? FirstSelectionModelInsideRun(run) :
LastSelectionModelInsideRun(run);
}
SelectionModel RenderTextHarfBuzz::AdjacentWordSelectionModel(
const SelectionModel& selection,
VisualCursorDirection direction) {
if (obscured())
return EdgeSelectionModel(direction);
base::i18n::BreakIterator iter(text(), base::i18n::BreakIterator::BREAK_WORD);
bool success = iter.Init();
DCHECK(success);
if (!success)
return selection;
internal::TextRunList* run_list = GetRunList();
SelectionModel current(selection);
for (;;) {
current = AdjacentCharSelectionModel(current, direction);
size_t run = GetRunContainingCaret(current);
if (run == run_list->size())
break;
size_t cursor = current.caret_pos();
#if defined(OS_WIN)
// Windows generally advances to the start of a word in either direction.
// TODO: Break on the end of a word when the neighboring text is puctuation.
if (iter.IsStartOfWord(cursor))
break;
#else
const bool is_forward =
run_list->runs()[run]->is_rtl == (direction == CURSOR_LEFT);
if (is_forward ? iter.IsEndOfWord(cursor) : iter.IsStartOfWord(cursor))
break;
#endif // defined(OS_WIN)
}
return current;
}
std::vector<Rect> RenderTextHarfBuzz::GetSubstringBounds(const Range& range) {
DCHECK(!update_display_run_list_);
DCHECK(Range(0, text().length()).Contains(range));
const size_t start =
IsValidCursorIndex(range.GetMin())
? range.GetMin()
: IndexOfAdjacentGrapheme(range.GetMin(), CURSOR_BACKWARD);
const size_t end =
IsValidCursorIndex(range.GetMax())
? range.GetMax()
: IndexOfAdjacentGrapheme(range.GetMax(), CURSOR_FORWARD);
const Range display_range(TextIndexToDisplayIndex(start),
TextIndexToDisplayIndex(end));
DCHECK(Range(0, GetDisplayText().length()).Contains(display_range));
std::vector<Rect> rects;
if (display_range.is_empty())
return rects;
internal::TextRunList* run_list = GetRunList();
for (size_t line_index = 0; line_index < lines().size(); ++line_index) {
const internal::Line& line = lines()[line_index];
// Only the last line can be empty.
DCHECK(!line.segments.empty() || (line_index == lines().size() - 1));
const float line_start_x =
line.segments.empty()
? 0
: run_list->runs()[line.segments[0].run]->preceding_run_widths;
for (const internal::LineSegment& segment : line.segments) {
const Range intersection = segment.char_range.Intersect(display_range);
DCHECK(!intersection.is_reversed());
if (!intersection.is_empty()) {
const internal::TextRunHarfBuzz& run = *run_list->runs()[segment.run];
RangeF selected_span =
run.GetGraphemeSpanForCharRange(this, intersection);
int start_x = std::ceil(selected_span.start() - line_start_x);
int end_x = std::ceil(selected_span.end() - line_start_x);
gfx::Rect rect(start_x, 0, end_x - start_x,
std::ceil(line.size.height()));
rects.push_back(rect + GetLineOffset(line_index));
}
}
}
return rects;
}
size_t RenderTextHarfBuzz::TextIndexToDisplayIndex(size_t index) {
return TextIndexToGivenTextIndex(GetDisplayText(), index);
}
size_t RenderTextHarfBuzz::DisplayIndexToTextIndex(size_t index) {
if (!obscured())
return index;
const size_t text_index = UTF16OffsetToIndex(text(), 0, index);
DCHECK_LE(text_index, text().length());
return text_index;
}
bool RenderTextHarfBuzz::IsValidCursorIndex(size_t index) {
if (index == 0 || index == text().length())
return true;
if (!IsValidLogicalIndex(index))
return false;
base::i18n::BreakIterator* grapheme_iterator = GetGraphemeIterator();
return !grapheme_iterator || grapheme_iterator->IsGraphemeBoundary(index);
}
void RenderTextHarfBuzz::OnLayoutTextAttributeChanged(bool text_changed) {
update_layout_run_list_ = true;
OnDisplayTextAttributeChanged();
}
void RenderTextHarfBuzz::OnDisplayTextAttributeChanged() {
update_display_text_ = true;
update_grapheme_iterator_ = true;
}
void RenderTextHarfBuzz::EnsureLayout() {
EnsureLayoutRunList();
if (update_display_run_list_) {
DCHECK(text_elided());
const base::string16& display_text = GetDisplayText();
display_run_list_.reset(new internal::TextRunList);
if (!display_text.empty()) {
TRACE_EVENT0("ui", "RenderTextHarfBuzz:EnsureLayout1");
ItemizeTextToRuns(display_text, display_run_list_.get());
ShapeRunList(display_text, display_run_list_.get());
}
update_display_run_list_ = false;
std::vector<internal::Line> empty_lines;
set_lines(&empty_lines);
}
if (lines().empty()) {
internal::TextRunList* run_list = GetRunList();
const int height = std::max(font_list().GetHeight(), min_line_height());
HarfBuzzLineBreaker line_breaker(
display_rect().width(),
DetermineBaselineCenteringText(height, font_list()), height,
word_wrap_behavior(), GetDisplayText(),
multiline() ? &GetLineBreaks() : nullptr, *run_list);
if (multiline())
line_breaker.ConstructMultiLines();
else
line_breaker.ConstructSingleLine();
std::vector<internal::Line> lines;
line_breaker.FinalizeLines(&lines, &total_size_);
set_lines(&lines);
}
}
void RenderTextHarfBuzz::DrawVisualText(internal::SkiaTextRenderer* renderer) {
DCHECK(!update_layout_run_list_);
DCHECK(!update_display_run_list_);
DCHECK(!update_display_text_);
if (lines().empty())
return;
ApplyFadeEffects(renderer);
ApplyTextShadows(renderer);
ApplyCompositionAndSelectionStyles();
internal::TextRunList* run_list = GetRunList();
for (size_t i = 0; i < lines().size(); ++i) {
const internal::Line& line = lines()[i];
const Vector2d origin = GetLineOffset(i) + Vector2d(0, line.baseline);
SkScalar preceding_segment_widths = 0;
for (const internal::LineSegment& segment : line.segments) {
// Don't draw the newline glyph (crbug.com/680430).
if (IsNewlineSegment(GetDisplayText(), segment))
continue;
const internal::TextRunHarfBuzz& run = *run_list->runs()[segment.run];
renderer->SetTypeface(run.skia_face);
renderer->SetTextSize(SkIntToScalar(run.font_size));
renderer->SetFontRenderParams(run.render_params,
subpixel_rendering_suppressed());
Range glyphs_range = run.CharRangeToGlyphRange(segment.char_range);
std::unique_ptr<SkPoint[]> positions(new SkPoint[glyphs_range.length()]);
SkScalar offset_x = preceding_segment_widths -
((glyphs_range.GetMin() != 0)
? run.positions[glyphs_range.GetMin()].x()
: 0);
for (size_t j = 0; j < glyphs_range.length(); ++j) {
positions[j] = run.positions[(glyphs_range.is_reversed()) ?
(glyphs_range.start() - j) :
(glyphs_range.start() + j)];
positions[j].offset(SkIntToScalar(origin.x()) + offset_x,
SkIntToScalar(origin.y() + run.baseline_offset));
}
for (BreakList<SkColor>::const_iterator it =
colors().GetBreak(segment.char_range.start());
it != colors().breaks().end() &&
it->first < segment.char_range.end();
++it) {
const Range intersection =
colors().GetRange(it).Intersect(segment.char_range);
const Range colored_glyphs = run.CharRangeToGlyphRange(intersection);
// The range may be empty if a portion of a multi-character grapheme is
// selected, yielding two colors for a single glyph. For now, this just
// paints the glyph with a single style, but it should paint it twice,
// clipped according to selection bounds. See http://crbug.com/366786
if (colored_glyphs.is_empty())
continue;
renderer->SetForegroundColor(it->second);
renderer->DrawPosText(
&positions[colored_glyphs.start() - glyphs_range.start()],
&run.glyphs[colored_glyphs.start()], colored_glyphs.length());
int start_x = SkScalarRoundToInt(
positions[colored_glyphs.start() - glyphs_range.start()].x());
int end_x = SkScalarRoundToInt(
(colored_glyphs.end() == glyphs_range.end())
? (SkFloatToScalar(segment.width()) + preceding_segment_widths +
SkIntToScalar(origin.x()))
: positions[colored_glyphs.end() - glyphs_range.start()].x());
if (run.heavy_underline)
renderer->DrawUnderline(start_x, origin.y(), end_x - start_x, 2.0);
else if (run.underline)
renderer->DrawUnderline(start_x, origin.y(), end_x - start_x);
if (run.strike)
renderer->DrawStrike(start_x, origin.y(), end_x - start_x,
strike_thickness_factor());
}
preceding_segment_widths += SkFloatToScalar(segment.width());
}
}
UndoCompositionAndSelectionStyles();
}
size_t RenderTextHarfBuzz::GetRunContainingCaret(
const SelectionModel& caret) {
DCHECK(!update_display_run_list_);
size_t layout_position = TextIndexToDisplayIndex(caret.caret_pos());
LogicalCursorDirection affinity = caret.caret_affinity();
internal::TextRunList* run_list = GetRunList();
for (size_t i = 0; i < run_list->size(); ++i) {
internal::TextRunHarfBuzz* run = run_list->runs()[i].get();
if (RangeContainsCaret(run->range, layout_position, affinity))
return i;
}
return run_list->size();
}
SelectionModel RenderTextHarfBuzz::FirstSelectionModelInsideRun(
const internal::TextRunHarfBuzz* run) {
size_t position = DisplayIndexToTextIndex(run->range.start());
position = IndexOfAdjacentGrapheme(position, CURSOR_FORWARD);
return SelectionModel(position, CURSOR_BACKWARD);
}
SelectionModel RenderTextHarfBuzz::LastSelectionModelInsideRun(
const internal::TextRunHarfBuzz* run) {
size_t position = DisplayIndexToTextIndex(run->range.end());
position = IndexOfAdjacentGrapheme(position, CURSOR_BACKWARD);
return SelectionModel(position, CURSOR_FORWARD);
}
void RenderTextHarfBuzz::ItemizeTextToRuns(
const base::string16& text,
internal::TextRunList* run_list_out) {
DCHECK_NE(0U, text.length());
// If ICU fails to itemize the text, we create a run that spans the entire
// text. This is needed because leaving the runs set empty causes some clients
// to misbehave since they expect non-zero text metrics from a non-empty text.
base::i18n::BiDiLineIterator bidi_iterator;
base::i18n::BiDiLineIterator::CustomBehavior behavior =
base::i18n::BiDiLineIterator::CustomBehavior::NONE;
// If the feature flag is enabled, use the special URL behaviour on the Bidi
// algorithm, if this is a URL.
if (base::FeatureList::IsEnabled(features::kLeftToRightUrls) &&
directionality_mode() == DIRECTIONALITY_AS_URL) {
behavior = base::i18n::BiDiLineIterator::CustomBehavior::AS_URL;
}
if (!bidi_iterator.Open(text, GetTextDirection(text), behavior)) {
auto run = std::make_unique<internal::TextRunHarfBuzz>(
font_list().GetPrimaryFont());
run->range = Range(0, text.length());
run_list_out->Add(std::move(run));
run_list_out->InitIndexMap();
return;
}
// Temporarily apply composition underlines and selection colors.
ApplyCompositionAndSelectionStyles();
// Build the run list from the script items and ranged styles and baselines.
// Use an empty color BreakList to avoid breaking runs at color boundaries.
BreakList<SkColor> empty_colors;
empty_colors.SetMax(colors().max());
DCHECK_LE(text.size(), baselines().max());
for (const BreakList<bool>& style : styles())
DCHECK_LE(text.size(), style.max());
internal::StyleIterator style(empty_colors, baselines(),
font_size_overrides(), weights(), styles());
for (size_t run_break = 0; run_break < text.length();) {
auto run = std::make_unique<internal::TextRunHarfBuzz>(
font_list().GetPrimaryFont());
run->range.set_start(run_break);
run->italic = style.style(ITALIC);
run->baseline_type = style.baseline();
run->font_size = style.font_size_override();
run->strike = style.style(STRIKE);
run->underline = style.style(UNDERLINE);
run->heavy_underline = style.style(HEAVY_UNDERLINE);
run->weight = style.weight();
int32_t script_item_break = 0;
bidi_iterator.GetLogicalRun(run_break, &script_item_break, &run->level);
CHECK_GT(static_cast<size_t>(script_item_break), run_break);
ApplyForcedDirection(&run->level);
// Odd BiDi embedding levels correspond to RTL runs.
run->is_rtl = (run->level % 2) == 1;
// Find the length and script of this script run.
script_item_break = ScriptInterval(text, run_break,
script_item_break - run_break, &run->script) + run_break;
// Find the next break and advance the iterators as needed.
const size_t new_run_break = std::min(
static_cast<size_t>(script_item_break),
TextIndexToGivenTextIndex(text, style.GetRange().end()));
CHECK_GT(new_run_break, run_break)
<< "It must proceed! " << text << " " << run_break;
run_break = new_run_break;
// Break runs at certain characters that need to be rendered separately to
// prevent either an unusual character from forcing a fallback font on the
// entire run, or brackets from being affected by a fallback font.
// http://crbug.com/278913, http://crbug.com/396776
if (run_break > run->range.start())
run_break = FindRunBreakingCharacter(text, run->range.start(), run_break);
DCHECK(IsValidCodePointIndex(text, run_break));
style.UpdatePosition(DisplayIndexToTextIndex(run_break));
run->range.set_end(run_break);
run_list_out->Add(std::move(run));
}
// Undo the temporarily applied composition underlines and selection colors.
UndoCompositionAndSelectionStyles();
run_list_out->InitIndexMap();
}
bool RenderTextHarfBuzz::CompareFamily(
const base::string16& text,
const Font& font,
const FontRenderParams& render_params,
internal::TextRunHarfBuzz* run,
Font* best_font,
FontRenderParams* best_render_params,
size_t* best_missing_glyphs) {
if (!ShapeRunWithFont(text, font, render_params, run))
return false;
const size_t missing_glyphs = run->CountMissingGlyphs();
if (missing_glyphs < *best_missing_glyphs) {
*best_font = font;
*best_render_params = render_params;
*best_missing_glyphs = missing_glyphs;
}
return missing_glyphs == 0;
}
void RenderTextHarfBuzz::ShapeRunList(const base::string16& text,
internal::TextRunList* run_list) {
for (const auto& run : run_list->runs())
ShapeRun(text, run.get());
run_list->ComputePrecedingRunWidths();
}
void RenderTextHarfBuzz::ShapeRun(const base::string16& text,
internal::TextRunHarfBuzz* run) {
const Font& primary_font = font_list().GetPrimaryFont();
const std::string primary_family = primary_font.GetFontName();
if (run->font_size == 0)
run->font_size = primary_font.GetFontSize();
run->baseline_offset = 0;
if (run->baseline_type != NORMAL_BASELINE) {
// Calculate a slightly smaller font. The ratio here is somewhat arbitrary.
// Proportions from 5/9 to 5/7 all look pretty good.
const float ratio = 5.0f / 9.0f;
run->font_size = ToRoundedInt(primary_font.GetFontSize() * ratio);
switch (run->baseline_type) {
case SUPERSCRIPT:
run->baseline_offset =
primary_font.GetCapHeight() - primary_font.GetHeight();
break;
case SUPERIOR:
run->baseline_offset =
ToRoundedInt(primary_font.GetCapHeight() * ratio) -
primary_font.GetCapHeight();
break;
case SUBSCRIPT:
run->baseline_offset =
primary_font.GetHeight() - primary_font.GetBaseline();
break;
case INFERIOR: // Fall through.
default:
break;
}
}
Font best_font(primary_font);
FontRenderParams best_render_params;
size_t best_missing_glyphs = std::numeric_limits<size_t>::max();
for (const Font& font : font_list().GetFonts()) {
if (CompareFamily(text, font, font.GetFontRenderParams(), run, &best_font,
&best_render_params, &best_missing_glyphs))
return;
}
std::string preferred_fallback_family;
#if defined(OS_WIN) || defined(OS_MACOSX)
Font fallback_font(primary_font);
const base::char16* run_text = &(text[run->range.start()]);
if (GetFallbackFont(primary_font, run_text, run->range.length(),
&fallback_font)) {
preferred_fallback_family = fallback_font.GetFontName();
if (CompareFamily(text, fallback_font, fallback_font.GetFontRenderParams(),
run, &best_font, &best_render_params,
&best_missing_glyphs))
return;
}
#endif
std::vector<Font> fallback_font_list = GetFallbackFonts(primary_font);
#if defined(OS_WIN)
// Append fonts in the fallback list of the preferred fallback font.
// TODO(tapted): Investigate whether there's a case that benefits from this on
// Mac.
if (!preferred_fallback_family.empty()) {
std::vector<Font> fallback_fonts = GetFallbackFonts(fallback_font);
fallback_font_list.insert(fallback_font_list.end(), fallback_fonts.begin(),
fallback_fonts.end());
}
// Add Segoe UI and its associated linked fonts to the fallback font list to
// ensure that the fallback list covers the basic cases.
// http://crbug.com/467459. On some Windows configurations the default font
// could be a raster font like System, which would not give us a reasonable
// fallback font list.
if (!base::LowerCaseEqualsASCII(primary_font.GetFontName(), "segoe ui") &&
!base::LowerCaseEqualsASCII(preferred_fallback_family, "segoe ui")) {
std::vector<Font> default_fallback_families =
GetFallbackFonts(Font("Segoe UI", 13));
fallback_font_list.insert(fallback_font_list.end(),
default_fallback_families.begin(), default_fallback_families.end());
}
#endif
// Use a set to track the fallback fonts and avoid duplicate entries.
std::set<Font, CaseInsensitiveCompare> fallback_fonts;
// Try shaping with the fallback fonts.
for (const auto& font : fallback_font_list) {
std::string font_name = font.GetFontName();
if (font_name == primary_font.GetFontName() ||
font_name == preferred_fallback_family || fallback_fonts.count(font)) {
continue;
}
fallback_fonts.insert(font);
FontRenderParamsQuery query;
query.families.push_back(font_name);
query.pixel_size = run->font_size;
query.style = run->italic ? Font::ITALIC : 0;
FontRenderParams fallback_render_params = GetFontRenderParams(query, NULL);
if (CompareFamily(text, font, fallback_render_params, run, &best_font,
&best_render_params, &best_missing_glyphs))
return;
}
if (best_missing_glyphs != std::numeric_limits<size_t>::max() &&
(best_font.GetFontName() == run->font.GetFontName() ||
ShapeRunWithFont(text, best_font, best_render_params, run)))
return;
run->glyph_count = 0;
run->width = 0.0f;
}
bool RenderTextHarfBuzz::ShapeRunWithFont(const base::string16& text,
const Font& font,
const FontRenderParams& params,
internal::TextRunHarfBuzz* run) {
sk_sp<SkTypeface> skia_face(
internal::CreateSkiaTypeface(font, run->italic, run->weight));
if (!skia_face)
return false;
run->skia_face = skia_face;
run->font = font;
run->render_params = params;
hb_font_t* harfbuzz_font = CreateHarfBuzzFont(
run->skia_face, SkIntToScalar(run->font_size), run->render_params,
subpixel_rendering_suppressed());
// Create a HarfBuzz buffer and add the string to be shaped. The HarfBuzz
// buffer holds our text, run information to be used by the shaping engine,
// and the resulting glyph data.
hb_buffer_t* buffer = hb_buffer_create();
hb_buffer_add_utf16(buffer, reinterpret_cast<const uint16_t*>(text.c_str()),
text.length(), run->range.start(), run->range.length());
hb_buffer_set_script(buffer, ICUScriptToHBScript(run->script));
hb_buffer_set_direction(buffer,
run->is_rtl ? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
// TODO(ckocagil): Should we determine the actual language?
hb_buffer_set_language(buffer, hb_language_get_default());
// Shape the text.
hb_shape(harfbuzz_font, buffer, NULL, 0);
// Populate the run fields with the resulting glyph data in the buffer.
unsigned int glyph_count = 0;
hb_glyph_info_t* infos = hb_buffer_get_glyph_infos(buffer, &glyph_count);
run->glyph_count = glyph_count;
hb_glyph_position_t* hb_positions =
hb_buffer_get_glyph_positions(buffer, NULL);
run->glyphs.reset(new uint16_t[run->glyph_count]);
run->glyph_to_char.resize(run->glyph_count);
run->positions.reset(new SkPoint[run->glyph_count]);
run->width = 0.0f;
#if defined(OS_MACOSX)
// Mac 10.9 and 10.10 give a quirky offset for whitespace glyphs in RTL,
// which requires tests relying on the behavior of |glyph_width_for_test_|
// to also be given a zero x_offset, otherwise expectations get thrown off.
const bool force_zero_offset =
glyph_width_for_test_ > 0 && base::mac::IsAtMostOS10_10();
#else
constexpr bool force_zero_offset = false;
#endif
DCHECK(obscured() || glyph_spacing() == 0);
for (size_t i = 0; i < run->glyph_count; ++i) {
DCHECK_LE(infos[i].codepoint, std::numeric_limits<uint16_t>::max());
run->glyphs[i] = static_cast<uint16_t>(infos[i].codepoint);
run->glyph_to_char[i] = infos[i].cluster;
const SkScalar x_offset =
force_zero_offset ? 0
: HarfBuzzUnitsToSkiaScalar(hb_positions[i].x_offset);
const SkScalar y_offset =
HarfBuzzUnitsToSkiaScalar(hb_positions[i].y_offset);
run->positions[i].set(run->width + x_offset, -y_offset);
run->width +=
(glyph_width_for_test_ > 0)
? glyph_width_for_test_
: HarfBuzzUnitsToFloat(hb_positions[i].x_advance) + glyph_spacing();
// Round run widths if subpixel positioning is off to match native behavior.
if (!run->render_params.subpixel_positioning)
run->width = std::round(run->width);
}
hb_buffer_destroy(buffer);
hb_font_destroy(harfbuzz_font);
return true;
}
void RenderTextHarfBuzz::EnsureLayoutRunList() {
if (update_layout_run_list_) {
layout_run_list_.Reset();
const base::string16& text = layout_text();
if (!text.empty()) {
TRACE_EVENT0("ui", "RenderTextHarfBuzz:EnsureLayoutRunList");
ItemizeTextToRuns(text, &layout_run_list_);
ShapeRunList(text, &layout_run_list_);
}
display_run_list_.reset();
update_display_text_ = true;
update_layout_run_list_ = false;
}
if (update_display_text_) {
std::vector<internal::Line> empty_lines;
set_lines(&empty_lines);
UpdateDisplayText(multiline() ? 0 : layout_run_list_.width());
update_display_text_ = false;
update_display_run_list_ = text_elided();
}
}
// Returns the current run list, |display_run_list_| if the text is elided, or
// |layout_run_list_| otherwise.
internal::TextRunList* RenderTextHarfBuzz::GetRunList() {
DCHECK(!update_layout_run_list_);
DCHECK(!update_display_run_list_);
return text_elided() ? display_run_list_.get() : &layout_run_list_;
}
const internal::TextRunList* RenderTextHarfBuzz::GetRunList() const {
return const_cast<RenderTextHarfBuzz*>(this)->GetRunList();
}
bool RenderTextHarfBuzz::GetDecoratedTextForRange(
const Range& range,
DecoratedText* decorated_text) {
if (obscured())
return false;
EnsureLayout();
decorated_text->attributes.clear();
decorated_text->text = GetTextFromRange(range);
const internal::TextRunList* run_list = GetRunList();
for (size_t i = 0; i < run_list->size(); i++) {
const internal::TextRunHarfBuzz& run = *run_list->runs()[i];
const Range intersection = range.Intersect(run.range);
DCHECK(!intersection.is_reversed());
if (!intersection.is_empty()) {
int style = Font::NORMAL;
if (run.italic)
style |= Font::ITALIC;
if (run.underline || run.heavy_underline)
style |= Font::UNDERLINE;
// Get range relative to the decorated text.
DecoratedText::RangedAttribute attribute(
Range(intersection.start() - range.GetMin(),
intersection.end() - range.GetMin()),
run.font.Derive(0, style, run.weight));
attribute.strike = run.strike;
decorated_text->attributes.push_back(attribute);
}
}
return true;
}
void RenderTextHarfBuzz::SetGlyphWidthForTest(float test_width) {
glyph_width_for_test_ = test_width;
}
} // namespace gfx