blob: dabb4715beceaf1e77b6a1a39d7687703eaea35f [file] [log] [blame]
// 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/containers/mru_cache.h"
#include "base/containers/span.h"
#include "base/feature_list.h"
#include "base/hash/hash.h"
#include "base/i18n/base_i18n_switches.h"
#include "base/i18n/break_iterator.h"
#include "base/i18n/char_iterator.h"
#include "base/i18n/rtl.h"
#include "base/macros.h"
#include "base/memory/ptr_util.h"
#include "base/metrics/histogram_macros.h"
#include "base/no_destructor.h"
#include "base/numerics/safe_conversions.h"
#include "base/stl_util.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/strings/utf_string_conversions.h"
#include "base/task/current_thread.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/uscript.h"
#include "third_party/icu/source/common/unicode/utf16.h"
#include "third_party/skia/include/core/SkColor.h"
#include "third_party/skia/include/core/SkFontMetrics.h"
#include "third_party/skia/include/core/SkTypeface.h"
#include "ui/gfx/bidi_line_iterator.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/harfbuzz_font_skia.h"
#include "ui/gfx/platform_font.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_APPLE)
#include "base/mac/foundation_util.h"
#include "base/mac/mac_util.h"
#include "third_party/skia/include/ports/SkTypeface_mac.h"
#endif
#if defined(OS_ANDROID)
#include "base/android/locale_utils.h"
#endif // defined(OS_ANDROID)
#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 = 32;
// Font fallback mechanism used to Shape runs (see ShapeRuns(...)).
// These values are persisted to logs. Entries should not be renumbered and
// numeric values should never be reused.
enum class ShapeRunFallback {
FAILED = 0,
NO_FALLBACK = 1,
FALLBACK = 2,
FALLBACKS = 3,
kMaxValue = FALLBACKS
};
// Log the fallback font mechanism used for shaping to UMA (see ShapeRuns(...)).
void RecordShapeRunsFallback(ShapeRunFallback fallback) {
UMA_HISTOGRAM_ENUMERATION("RenderTextHarfBuzz.ShapeRunsFallback", fallback);
}
// Returns whether the codepoint has the 'extended pictographic' property.
bool IsExtendedPictographicCodepoint(UChar32 codepoint) {
return u_hasBinaryProperty(codepoint, UCHAR_EXTENDED_PICTOGRAPHIC);
}
// Returns whether the codepoint has emoji properties.
bool IsEmojiRelatedCodepoint(UChar32 codepoint) {
return u_hasBinaryProperty(codepoint, UCHAR_EMOJI) ||
u_hasBinaryProperty(codepoint, UCHAR_EMOJI_PRESENTATION) ||
u_hasBinaryProperty(codepoint, UCHAR_REGIONAL_INDICATOR);
}
// Returns true if |codepoint| is a bracket. This is used to avoid "matching"
// brackets picking different font fallbacks, thereby appearing mismatched.
bool IsBracket(UChar32 codepoint) {
return u_getIntPropertyValue(codepoint, UCHAR_BIDI_PAIRED_BRACKET_TYPE) !=
U_BPT_NONE;
}
// Writes the script and the script extensions of the Unicode |codepoint|.
// Returns the number of written scripts.
size_t GetScriptExtensions(UChar32 codepoint, UScriptCode* scripts) {
// Fill |scripts| with the script extensions.
UErrorCode icu_error = U_ZERO_ERROR;
size_t count =
uscript_getScriptExtensions(codepoint, scripts, kMaxScripts, &icu_error);
DCHECK_NE(icu_error, U_BUFFER_OVERFLOW_ERROR) << " #ext: " << count;
if (U_FAILURE(icu_error))
return 0;
return count;
}
// Intersects the script extensions set of |codepoint| with |result| and writes
// to |result|, reading and updating |result_size|. The output |result| will be
// a subset of the input |result| (thus |result_size| can only be smaller).
void ScriptSetIntersect(UChar32 codepoint,
UScriptCode* result,
size_t* result_size) {
// Each codepoint has a Script property and a Script Extensions (Scx)
// property.
//
// The implicit Script property values 'Common' and 'Inherited' indicate that
// a codepoint is widely used in many scripts, rather than being associated
// to a specific script.
//
// However, some codepoints that are assigned a value of 'Common' or
// 'Inherited' are not commonly used with all scripts, but rather only with a
// limited set of scripts. The Script Extension property is used to specify
// the set of script which borrow the codepoint.
//
// Calls to GetScriptExtensions(...) return the set of scripts where the
// codepoints can be used.
// (see table 7 from http://www.unicode.org/reports/tr24/tr24-29.html)
//
// Script Script Extensions -> Results
// 1) Common {Common} -> {Common}
// Inherited {Inherited} -> {Inherited}
// 2) Latin {Latn} -> {Latn}
// Inherited {Latn} -> {Latn}
// 3) Common {Hira Kana} -> {Hira Kana}
// Inherited {Hira Kana} -> {Hira Kana}
// 4) Devanagari {Deva Dogr Kthi Mahj} -> {Deva Dogr Kthi Mahj}
// Myanmar {Cakm Mymr Tale} -> {Cakm Mymr Tale}
//
// For most of the codepoints, the script extensions set contains only one
// element. For CJK codepoints, it's common to see 3-4 scripts. For really
// rare cases, the set can go above 20 scripts.
UScriptCode scripts[kMaxScripts] = { USCRIPT_INVALID_CODE };
size_t count = GetScriptExtensions(codepoint, scripts);
// Implicit script 'inherited' is inheriting scripts from preceding codepoint.
if (count == 1 && scripts[0] == USCRIPT_INHERITED)
return;
// Perform the intersection of both script set.
auto scripts_span = base::span<UScriptCode>(scripts, count);
DCHECK(!base::Contains(scripts_span, USCRIPT_INHERITED));
auto results_span = base::span<UScriptCode>(result, *result_size);
size_t out_size = 0;
for (UScriptCode current : results_span) {
if (base::Contains(scripts_span, current))
result[out_size++] = current;
}
*result_size = out_size;
}
struct GraphemeProperties {
bool has_control = false;
bool has_bracket = false;
bool has_pictographic = false;
bool has_emoji = false;
UBlockCode block = UBLOCK_NO_BLOCK;
};
// Returns the properties for the codepoints part of the given text.
GraphemeProperties RetrieveGraphemeProperties(const base::StringPiece16& text,
bool retrieve_block) {
GraphemeProperties properties;
bool first_char = true;
for (base::i18n::UTF16CharIterator iter(text); !iter.end(); iter.Advance()) {
const UChar32 codepoint = iter.get();
if (first_char) {
first_char = false;
if (retrieve_block)
properties.block = ublock_getCode(codepoint);
}
if (codepoint == '\n' || codepoint == ' ')
properties.has_control = true;
if (IsBracket(codepoint))
properties.has_bracket = true;
if (IsExtendedPictographicCodepoint(codepoint))
properties.has_pictographic = true;
if (IsEmojiRelatedCodepoint(codepoint))
properties.has_emoji = true;
}
return properties;
}
// Return whether the grapheme properties are compatible and the grapheme can
// be merge together in the same grapheme cluster.
bool AreGraphemePropertiesCompatible(const GraphemeProperties& first,
const GraphemeProperties& second) {
// There are 5 constrains to grapheme to be compatible.
// 1) The newline character and control characters should form a single run so
// that the line breaker can handle them easily.
// 2) Parentheses should be put in a separate run to avoid using different
// fonts while rendering matching parentheses (see http://crbug.com/396776).
// 3) Pictographic graphemes should be put in separate run to avoid altering
// fonts selection while rendering adjacent text (see
// http://crbug.com/278913).
// 4) Emoji graphemes should be put in separate run (see
// http://crbug.com/530021 and http://crbug.com/533721).
// 5) The 'COMMON' script needs to be split by unicode block. Codepoints are
// spread across blocks and supported with different fonts.
return !first.has_control && !second.has_control &&
first.has_bracket == second.has_bracket &&
first.has_pictographic == second.has_pictographic &&
first.has_emoji == second.has_emoji && first.block == second.block;
}
// Returns the end of the current grapheme cluster. This function is finding the
// breaking point where grapheme properties are no longer compatible
// (see: UNICODE TEXT SEGMENTATION (http://unicode.org/reports/tr29/).
// Breaks between |run_start| and |run_end| and force break after the grapheme
// starting at |run_break|.
size_t FindRunBreakingCharacter(const base::string16& text,
UScriptCode script,
size_t run_start,
size_t run_break,
size_t run_end) {
const size_t run_length = run_end - run_start;
const base::StringPiece16 run_text(text.c_str() + run_start, run_length);
const bool is_common_script = (script == USCRIPT_COMMON);
DCHECK(!run_text.empty());
// Create an iterator to split the text in graphemes.
base::i18n::BreakIterator grapheme_iterator(
run_text, base::i18n::BreakIterator::BREAK_CHARACTER);
if (!grapheme_iterator.Init() || !grapheme_iterator.Advance()) {
// In case of error, isolate the first character in a separate run.
NOTREACHED();
return run_start + 1;
}
// Retrieve the first grapheme and its codepoint properties.
const base::StringPiece16 first_grapheme_text =
grapheme_iterator.GetStringPiece();
const GraphemeProperties first_grapheme_properties =
RetrieveGraphemeProperties(first_grapheme_text, is_common_script);
// Append subsequent graphemes in this grapheme cluster if they are
// compatible, otherwise break the current run.
while (grapheme_iterator.Advance()) {
const base::StringPiece16 current_grapheme_text =
grapheme_iterator.GetStringPiece();
const GraphemeProperties current_grapheme_properties =
RetrieveGraphemeProperties(current_grapheme_text, is_common_script);
const size_t current_breaking_position =
run_start + grapheme_iterator.prev();
if (!AreGraphemePropertiesCompatible(first_grapheme_properties,
current_grapheme_properties)) {
return current_breaking_position;
}
// Break if the beginning of this grapheme is after |run_break|.
if (run_start + grapheme_iterator.prev() >= run_break) {
DCHECK_LE(current_breaking_position, run_end);
return current_breaking_position;
}
}
// Do not break this run, returns end of the text.
return run_end;
}
// 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.
size_t 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(
base::StringPiece16(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);
}
bool FontWasAlreadyTried(sk_sp<SkTypeface> typeface,
std::set<SkFontID>* fallback_fonts) {
return fallback_fonts->count(typeface->uniqueID()) != 0;
}
void MarkFontAsTried(sk_sp<SkTypeface> typeface,
std::set<SkFontID>* fallback_fonts) {
fallback_fonts->insert(typeface->uniqueID());
}
// Whether |segment| corresponds to the newline character.
bool IsNewlineSegment(const base::string16& text,
const internal::LineSegment& segment) {
const size_t offset = segment.char_range.start();
const size_t length = segment.char_range.length();
DCHECK_LT(segment.char_range.start() + length - 1, text.length());
return (length == 1 && (text[offset] == '\r' || text[offset] == '\n')) ||
(length == 2 && text[offset] == '\r' && text[offset + 1] == '\n');
}
// Returns the line index considering the newline character. Line index is
// incremented if the caret is right after the newline character, i.e, the
// cursor affinity is |CURSOR_BACKWARD| while containing the newline character.
size_t LineIndexForNewline(const size_t line_index,
const base::string16& text,
const internal::LineSegment& segment,
const SelectionModel& caret) {
bool at_newline = IsNewlineSegment(text, segment) &&
caret.caret_affinity() == CURSOR_BACKWARD;
return line_index + (at_newline ? 1 : 0);
}
// 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;
}
// 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,
float glyph_height_for_test,
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),
glyph_height_for_test_(glyph_height_for_test),
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.shape.width);
AddLineSegment(segment, false);
}
}
// 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;
// Subtract the width of newline segments, they are not drawn.
if (word_segments.size() != 1u || available_width_ != max_width_)
word_width -= word_segments.back().width();
}
// 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());
// If the last character of the text is a new line character, then the last
// line is any empty string, which contains no segments. This means that the
// display_text_index will not have been set in AdvanceLine. So here, set
// display_text_index to the text length, which is the true text index of
// the final line.
internal::Line* line = &lines_.back();
if (line->display_text_index == 0)
line->display_text_index = text_.size();
// 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();
// Compute the line start while the line segments are in the logical order
// so that the start of the line is the start of the char range,
// regardless of i18n.
if (!line->segments.empty())
line->display_text_index = line->segments[0].char_range.start();
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(
glyph_height_for_test_
? glyph_height_for_test_
: std::max(min_height_, max_descent_ + max_ascent_));
line->baseline = std::max(min_baseline_, SkScalarRoundToInt(max_ascent_));
line->preceding_heights = base::ClampCeil(total_size_.height());
// Subtract newline segment's width from |total_size_| because it's not
// drawn.
float line_width = line->size.width();
if (!line->segments.empty() &&
IsNewlineSegment(text_, line->segments.back())) {
line_width -= line->segments.back().width();
}
if (line->segments.size() > 1 &&
IsNewlineSegment(text_, line->segments.front())) {
line_width -= line->segments.front().width();
}
total_size_.set_height(total_size_.height() + line->size.height());
total_size_.set_width(std::max(total_size_.width(), line_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 (IsNewlineSegment(text_, segment) ||
segment.width() <= available_width_ ||
word_wrap_behavior_ == IGNORE_LONG_WORDS) {
AddLineSegment(segment, true);
} 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, true);
// 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, bool multiline) {
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.font_params.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());
// Newline characters are not drawn for multi-line, ignore their metrics.
if (!multiline || !IsNewlineSegment(text_, segment)) {
SkFont font(run.font_params.skia_face, run.font_params.font_size);
font.setEdging(run.font_params.render_params.antialiasing
? SkFont::Edging::kAntiAlias
: SkFont::Edging::kAlias);
SkFontMetrics metrics;
font.getMetrics(&metrics);
// max_descent_ is y-down, fDescent is y-down, baseline_offset is y-down
max_descent_ = std::max(
max_descent_, metrics.fDescent + run.font_params.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.font_params.baseline_offset));
}
if (run.font_params.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 float glyph_height_for_test_;
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);
};
// 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;
}
}
internal::TextRunHarfBuzz::FontParams CreateFontParams(
const Font& primary_font,
UBiDiLevel bidi_level,
UScriptCode script,
const internal::StyleIterator& style) {
internal::TextRunHarfBuzz::FontParams font_params(primary_font);
font_params.italic = style.style(TEXT_STYLE_ITALIC);
font_params.baseline_type = style.baseline();
font_params.font_size = style.font_size_override();
font_params.strike = style.style(TEXT_STYLE_STRIKE);
font_params.underline = style.style(TEXT_STYLE_UNDERLINE);
font_params.heavy_underline = style.style(TEXT_STYLE_HEAVY_UNDERLINE);
font_params.weight = style.weight();
font_params.level = bidi_level;
font_params.script = script;
// Odd BiDi embedding levels correspond to RTL runs.
font_params.is_rtl = (font_params.level % 2) == 1;
return font_params;
}
} // namespace
namespace internal {
sk_sp<SkTypeface> CreateSkiaTypeface(const Font& font,
bool italic,
Font::Weight weight) {
#if defined(OS_APPLE)
const Font::FontStyle style = italic ? Font::ITALIC : Font::NORMAL;
Font font_with_style = font.Derive(0, style, weight);
if (!font_with_style.GetNativeFont())
return nullptr;
return SkMakeTypefaceFromCTFont(
base::mac::NSToCFCast(font_with_style.GetNativeFont()));
#else
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::FontParams::FontParams(const Font& template_font)
: font(template_font) {}
TextRunHarfBuzz::FontParams::~FontParams() = default;
TextRunHarfBuzz::FontParams::FontParams(
const TextRunHarfBuzz::FontParams& other) = default;
TextRunHarfBuzz::FontParams& TextRunHarfBuzz::FontParams::operator=(
const TextRunHarfBuzz::FontParams& other) = default;
bool TextRunHarfBuzz::FontParams::operator==(const FontParams& other) const {
// Empirically, |script| and |weight| are the highest entropy members.
return script == other.script && weight == other.weight &&
skia_face == other.skia_face && render_params == other.render_params &&
font_size == other.font_size &&
baseline_offset == other.baseline_offset &&
baseline_type == other.baseline_type && italic == other.italic &&
strike == other.strike && underline == other.underline &&
heavy_underline == other.heavy_underline && is_rtl == other.is_rtl &&
level == other.level;
}
void TextRunHarfBuzz::FontParams::
ComputeRenderParamsFontSizeAndBaselineOffset() {
render_params = font.GetFontRenderParams();
if (font_size == 0)
font_size = font.GetFontSize();
baseline_offset = 0;
if (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;
font_size = base::ClampRound(font.GetFontSize() * ratio);
switch (baseline_type) {
case SUPERSCRIPT:
baseline_offset = font.GetCapHeight() - font.GetHeight();
break;
case SUPERIOR:
baseline_offset =
base::ClampRound(font.GetCapHeight() * ratio) - font.GetCapHeight();
break;
case SUBSCRIPT:
baseline_offset = font.GetHeight() - font.GetBaseline();
break;
case INFERIOR: // Fall through.
default:
break;
}
}
}
size_t TextRunHarfBuzz::FontParams::Hash::operator()(
const FontParams& key) const {
// In practice, |font|, |skia_face|, |render_params|, and |baseline_offset|
// have not yet been set when this is called.
return static_cast<size_t>(key.italic) << 0 ^
static_cast<size_t>(key.strike) << 1 ^
static_cast<size_t>(key.underline) << 2 ^
static_cast<size_t>(key.heavy_underline) << 3 ^
static_cast<size_t>(key.is_rtl) << 4 ^
static_cast<size_t>(key.weight) << 8 ^
static_cast<size_t>(key.font_size) << 12 ^
static_cast<size_t>(key.baseline_type) << 16 ^
static_cast<size_t>(key.level) << 20 ^
static_cast<size_t>(key.script) << 24;
}
bool TextRunHarfBuzz::FontParams::SetRenderParamsRematchFont(
const Font& new_font,
const FontRenderParams& new_render_params) {
// This takes the font family name from new_font, and calls
// SkTypeface::makeFromName() with that family name and the style information
// internal to this text run. So it triggers a new font match and looks for
// adjacent fonts in the family. This works for styling, e.g. styling a run in
// bold, italic or underline, but breaks font fallback in certain scenarios,
// as the fallback font may be of a different weight and style than the run's
// own, so this can lead to a failure of instantiating the correct fallback
// font.
sk_sp<SkTypeface> new_skia_face(
internal::CreateSkiaTypeface(new_font, italic, weight));
if (!new_skia_face)
return false;
skia_face = new_skia_face;
font = new_font;
render_params = new_render_params;
return true;
}
bool TextRunHarfBuzz::FontParams::SetRenderParamsOverrideSkiaFaceFromFont(
const Font& fallback_font,
const FontRenderParams& new_render_params) {
PlatformFont* platform_font = fallback_font.platform_font();
sk_sp<SkTypeface> new_skia_face = platform_font->GetNativeSkTypeface();
// If pass-through of the Skia native handle fails for PlatformFonts other
// than PlatformFontSkia, perform rematching.
if (!new_skia_face)
return SetRenderParamsRematchFont(fallback_font, new_render_params);
skia_face = new_skia_face;
font = fallback_font;
render_params = new_render_params;
return true;
}
TextRunHarfBuzz::ShapeOutput::ShapeOutput() = default;
TextRunHarfBuzz::ShapeOutput::~ShapeOutput() = default;
TextRunHarfBuzz::ShapeOutput::ShapeOutput(
const TextRunHarfBuzz::ShapeOutput& other) = default;
TextRunHarfBuzz::ShapeOutput& TextRunHarfBuzz::ShapeOutput::operator=(
const TextRunHarfBuzz::ShapeOutput& other) = default;
TextRunHarfBuzz::ShapeOutput::ShapeOutput(
TextRunHarfBuzz::ShapeOutput&& other) = default;
TextRunHarfBuzz::ShapeOutput& TextRunHarfBuzz::ShapeOutput::operator=(
TextRunHarfBuzz::ShapeOutput&& other) = default;
TextRunHarfBuzz::TextRunHarfBuzz(const Font& template_font)
: font_params(template_font) {}
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 font_params.is_rtl ? Range(end_glyphs.start(), start_glyphs.end())
: Range(start_glyphs.start(), end_glyphs.end());
}
size_t TextRunHarfBuzz::CountMissingGlyphs() const {
return shape.missing_glyph_count;
}
void TextRunHarfBuzz::GetClusterAt(size_t pos,
Range* chars,
Range* glyphs) const {
DCHECK(chars);
DCHECK(glyphs);
bool success = true;
if (shape.glyph_count == 0 || !range.Contains(Range(pos, pos + 1))) {
*chars = range;
*glyphs = Range();
success = false;
}
if (font_params.is_rtl) {
success &=
GetClusterAtImpl(pos, range, shape.glyph_to_char.rbegin(),
shape.glyph_to_char.rend(), true, chars, glyphs);
} else {
success &=
GetClusterAtImpl(pos, range, shape.glyph_to_char.begin(),
shape.glyph_to_char.end(), false, chars, glyphs);
}
if (!success) {
std::string glyph_to_char_string;
for (size_t i = 0; i < shape.glyph_count && i < shape.glyph_to_char.size();
++i) {
glyph_to_char_string += base::NumberToString(i) + "->" +
base::NumberToString(shape.glyph_to_char[i]) +
", ";
}
LOG(ERROR) << " TextRunHarfBuzz error, please report at crbug.com/724880:"
<< " range: " << range.ToString()
<< ", rtl: " << font_params.is_rtl << ","
<< " level: '" << font_params.level
<< "', script: " << font_params.script << ","
<< " font: '" << font_params.font.GetActualFontName() << "',"
<< " glyph_count: " << shape.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 (shape.glyph_count == 0)
return RangeF(preceding_run_widths, preceding_run_widths + shape.width);
Range chars;
Range glyphs;
GetClusterAt(text_index, &chars, &glyphs);
const float cluster_begin_x = shape.positions[glyphs.start()].x();
const float cluster_end_x = glyphs.end() < shape.glyph_count
? shape.positions[glyphs.end()].x()
: SkFloatToScalar(shape.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.
ptrdiff_t code_point_count = UTF16IndexToOffset(render_text->GetDisplayText(),
chars.start(), chars.end());
if (code_point_count > 1) {
int before = 0;
int total = 0;
for (size_t i = chars.start(); i < chars.end(); ++i) {
if (render_text->IsGraphemeBoundary(i)) {
if (i < text_index)
++before;
++total;
}
}
// With ICU 65.1, DCHECK_GT() below fails.
// See https://crbug.com/1017047 for more details.
//
// 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 (font_params.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 =
UTF16OffsetToIndex(render_text->GetDisplayText(), char_range.end(), -1);
DCHECK_LE(left_index, right_index);
if (font_params.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() == shape.glyph_count)
? SkFloatToScalar(shape.width)
: shape.positions[glyph_range.end()].x()) -
shape.positions[glyph_range.start()].x();
}
void TextRunHarfBuzz::UpdateFontParamsAndShape(
const FontParams& new_font_params,
const ShapeOutput& new_shape) {
if (new_shape.missing_glyph_count < shape.missing_glyph_count) {
font_params = new_font_params;
shape = new_shape;
// Note that |new_shape.glyph_to_char| is indexed from the beginning of
// |range|, while |shape.glyph_to_char| is indexed from the beginning of
// its embedding text.
for (size_t i = 0; i < shape.glyph_to_char.size(); ++i)
shape.glyph_to_char[i] += range.start();
}
}
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]->font_params.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->shape.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 {
// ShapeRunWithFont cache. Views makes repeated calls to ShapeRunWithFont
// with the same arguments in several places, and typesetting is very expensive.
// To compensate for this, encapsulate all of the input arguments to
// ShapeRunWithFont in ShapeRunWithFontInput, all of the output arguments in
// TextRunHarfBuzz::ShapeOutput, and add ShapeRunCache to map between the two.
// This is analogous to the blink::ShapeCache.
// https://crbug.com/826265
// Input for the stateless implementation of ShapeRunWithFont.
struct ShapeRunWithFontInput {
ShapeRunWithFontInput(const base::string16& full_text,
const TextRunHarfBuzz::FontParams& font_params,
Range full_range,
bool obscured,
float glyph_width_for_test,
int obscured_glyph_spacing,
bool subpixel_rendering_suppressed)
: skia_face(font_params.skia_face),
render_params(font_params.render_params),
script(font_params.script),
font_size(font_params.font_size),
obscured_glyph_spacing(obscured_glyph_spacing),
glyph_width_for_test(glyph_width_for_test),
is_rtl(font_params.is_rtl),
obscured(obscured),
subpixel_rendering_suppressed(subpixel_rendering_suppressed) {
// hb_buffer_add_utf16 will read the previous and next 5 unicode characters
// (which can have a maximum length of 2 uint16_t) as "context" that is used
// only for Arabic (which is RTL). Read the previous and next 10 uint16_ts
// to ensure that we capture all of this context if we're using RTL.
size_t kContextSize = is_rtl ? 10 : 0;
size_t context_start = full_range.start() < kContextSize
? 0
: full_range.start() - kContextSize;
size_t context_end =
std::min(full_text.length(), full_range.end() + kContextSize);
range = Range(full_range.start() - context_start,
full_range.end() - context_start);
text = full_text.substr(context_start, context_end - context_start);
// Pre-compute the hash to avoid having to re-hash at every comparison.
// Attempt to minimize collisions by including the typeface, script, font
// size, text and the text range.
hash = base::HashInts(hash, skia_face->uniqueID());
hash = base::HashInts(hash, script);
hash = base::HashInts(hash, font_size);
hash = base::Hash(text);
hash = base::HashInts(hash, range.start());
hash = base::HashInts(hash, range.length());
}
bool operator==(const ShapeRunWithFontInput& other) const {
return text == other.text && skia_face == other.skia_face &&
render_params == other.render_params &&
font_size == other.font_size && range == other.range &&
script == other.script && is_rtl == other.is_rtl &&
obscured == other.obscured &&
glyph_width_for_test == other.glyph_width_for_test &&
obscured_glyph_spacing == other.obscured_glyph_spacing &&
subpixel_rendering_suppressed == other.subpixel_rendering_suppressed;
}
struct Hash {
size_t operator()(const ShapeRunWithFontInput& key) const {
return key.hash;
}
};
sk_sp<SkTypeface> skia_face;
FontRenderParams render_params;
UScriptCode script;
int font_size;
int obscured_glyph_spacing;
float glyph_width_for_test;
bool is_rtl;
bool obscured;
bool subpixel_rendering_suppressed;
// The parts of the input text that may be read by hb_buffer_add_utf16.
base::string16 text;
// The conversion of the input range to a range within |text|.
Range range;
// The hash is cached to avoid repeated calls.
size_t hash = 0;
};
// An MRU cache of the results from calling ShapeRunWithFont. The maximum cache
// size used in blink::ShapeCache is 10k. A Finch experiment showed that
// reducing the cache size to 1k has no performance impact.
constexpr int kShapeRunCacheSize = 1000;
using ShapeRunCacheBase = base::HashingMRUCache<ShapeRunWithFontInput,
TextRunHarfBuzz::ShapeOutput,
ShapeRunWithFontInput::Hash>;
class ShapeRunCache : public ShapeRunCacheBase {
public:
ShapeRunCache() : ShapeRunCacheBase(kShapeRunCacheSize) {}
};
void ShapeRunWithFont(const ShapeRunWithFontInput& in,
TextRunHarfBuzz::ShapeOutput* out) {
TRACE_EVENT0("ui", "RenderTextHarfBuzz::ShapeRunWithFontInternal");
hb_font_t* harfbuzz_font =
CreateHarfBuzzFont(in.skia_face, SkIntToScalar(in.font_size),
in.render_params, in.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();
// Note that the value of the |item_offset| argument (here specified as
// |in.range.start()|) does affect the result, so we will have to adjust
// the computed offsets.
hb_buffer_add_utf16(
buffer, reinterpret_cast<const uint16_t*>(in.text.c_str()),
static_cast<int>(in.text.length()), in.range.start(), in.range.length());
hb_buffer_set_script(buffer, ICUScriptToHBScript(in.script));
hb_buffer_set_direction(buffer,
in.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);
out->glyph_count = glyph_count;
hb_glyph_position_t* hb_positions =
hb_buffer_get_glyph_positions(buffer, NULL);
out->glyphs.resize(out->glyph_count);
out->glyph_to_char.resize(out->glyph_count);
out->positions.resize(out->glyph_count);
out->width = 0.0f;
// Font on MAC like ".SF NS Text" may have a negative x_offset. Positive
// x_offset are also found on Windows (e.g. "Segoe UI"). It requires tests
// relying on the behavior of |glyph_width_for_test_| to also be given a zero
// x_offset, otherwise expectations get thrown off
// (see: http://crbug.com/1056220).
const bool force_zero_offset = in.glyph_width_for_test > 0;
constexpr uint16_t kMissingGlyphId = 0;
out->missing_glyph_count = 0;
for (size_t i = 0; i < out->glyph_count; ++i) {
DCHECK_LE(infos[i].codepoint, std::numeric_limits<uint16_t>::max());
uint16_t glyph = static_cast<uint16_t>(infos[i].codepoint);
out->glyphs[i] = glyph;
if (glyph == kMissingGlyphId)
out->missing_glyph_count += 1;
DCHECK_GE(infos[i].cluster, in.range.start());
out->glyph_to_char[i] = infos[i].cluster - in.range.start();
const SkScalar x_offset =
force_zero_offset ? 0
: HarfBuzzUnitsToSkiaScalar(hb_positions[i].x_offset);
const SkScalar y_offset =
HarfBuzzUnitsToSkiaScalar(hb_positions[i].y_offset);
out->positions[i].set(out->width + x_offset, -y_offset);
if (in.glyph_width_for_test == 0)
out->width += HarfBuzzUnitsToFloat(hb_positions[i].x_advance);
else if (hb_positions[i].x_advance) // Leave zero-width glyphs alone.
out->width += in.glyph_width_for_test;
if (in.obscured)
out->width += in.obscured_glyph_spacing;
// When subpixel positioning is not enabled, glyph width is rounded to avoid
// fractional width. Disable this conversion when a glyph width is provided
// for testing. Using an integral glyph width has the same behavior as
// disabling the subpixel positioning.
const bool force_subpixel_for_test = in.glyph_width_for_test != 0;
// Round run widths if subpixel positioning is off to match native behavior.
if (!in.render_params.subpixel_positioning && !force_subpixel_for_test)
out->width = std::round(out->width);
}
hb_buffer_destroy(buffer);
hb_font_destroy(harfbuzz_font);
}
std::string GetApplicationLocale() {
#if defined(OS_ANDROID)
// TODO(etienneb): Android locale should work the same way than base locale.
return base::android::GetDefaultLocaleString();
#else
return base::i18n::GetConfiguredLocale();
#endif
}
} // namespace
} // namespace internal
RenderTextHarfBuzz::RenderTextHarfBuzz()
: RenderText(),
update_layout_run_list_(false),
update_display_run_list_(false),
update_display_text_(false),
locale_(internal::GetApplicationLocale()) {
set_truncate_length(kMaxTextLength);
}
RenderTextHarfBuzz::~RenderTextHarfBuzz() {}
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 GetLayoutText();
}
EnsureLayoutRunList();
DCHECK(!update_display_text_);
return text_elided() ? display_text() : GetLayoutText();
}
SizeF RenderTextHarfBuzz::GetStringSizeF() {
EnsureLayout();
return total_size_;
}
SizeF RenderTextHarfBuzz::GetLineSizeF(const SelectionModel& caret) {
const internal::ShapedText* shaped_text = GetShapedText();
const auto& caret_run = GetRunContainingCaret(caret);
for (const auto& line : shaped_text->lines()) {
for (const internal::LineSegment& segment : line.segments) {
if (segment.run == caret_run)
return line.size;
}
}
return shaped_text->lines().back().size;
}
std::vector<Rect> RenderTextHarfBuzz::GetSubstringBounds(const Range& range) {
EnsureLayout();
DCHECK(!update_display_run_list_);
DCHECK(Range(0, text().length()).Contains(range));
const Range grapheme_range = ExpandRangeToGraphemeBoundary(range);
const Range display_range(TextIndexToDisplayIndex(grapheme_range.start()),
TextIndexToDisplayIndex(grapheme_range.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();
const internal::ShapedText* shaped_text = GetShapedText();
for (size_t line_index = 0; line_index < shaped_text->lines().size();
++line_index) {
const internal::Line& line = shaped_text->lines()[line_index];
// Only the last line can be empty.
DCHECK(!line.segments.empty() ||
(line_index == shaped_text->lines().size() - 1));
float line_start_x =
line.segments.empty()
? 0
: run_list->runs()[line.segments[0].run]->preceding_run_widths;
if (line.segments.size() > 1 && IsNewlineSegment(line.segments[0]))
line_start_x += line.segments[0].width();
std::vector<Rect> current_line_rects;
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);
DCHECK(!selected_span.is_reversed());
int start_x = base::ClampFloor(selected_span.start() - line_start_x);
int end_x = base::ClampCeil(selected_span.end() - line_start_x);
Rect rect(start_x, 0, end_x - start_x,
base::ClampCeil(line.size.height()));
current_line_rects.push_back(rect + GetLineOffset(line_index));
}
}
MergeIntersectingRects(current_line_rects);
rects.insert(rects.end(), current_line_rects.begin(),
current_line_rects.end());
}
return rects;
}
RangeF RenderTextHarfBuzz::GetCursorSpan(const Range& text_range) {
DCHECK(!text_range.is_reversed());
EnsureLayout();
const size_t index = text_range.start();
size_t run_index =
GetRunContainingCaret(SelectionModel(index, CURSOR_FORWARD));
internal::TextRunList* run_list = GetRunList();
// Return zero if the text is empty.
if (run_list->size() == 0 || text().empty())
return RangeF(0);
// Use the last run if the index is invalid or beyond the layout text size.
Range valid_range(text_range.start(), text_range.end());
if (run_index >= run_list->size()) {
valid_range = Range(text().length() - 1, text().length());
run_index = run_list->size() - 1;
}
internal::TextRunHarfBuzz* run = run_list->runs()[run_index].get();
size_t next_grapheme_start = valid_range.end();
if (!IsValidCursorIndex(next_grapheme_start)) {
next_grapheme_start =
IndexOfAdjacentGrapheme(next_grapheme_start, CURSOR_FORWARD);
}
Range display_range(TextIndexToDisplayIndex(valid_range.start()),
TextIndexToDisplayIndex(next_grapheme_start));
// 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);
return run->font_params.is_rtl ? RangeF(bounds.end(), bounds.start())
: bounds;
}
size_t RenderTextHarfBuzz::GetLineContainingCaret(const SelectionModel& caret) {
EnsureLayout();
if (caret.caret_pos() == 0)
return 0;
if (!multiline()) {
DCHECK_EQ(1u, GetShapedText()->lines().size());
return 0;
}
size_t layout_position = TextIndexToDisplayIndex(caret.caret_pos());
LogicalCursorDirection affinity = caret.caret_affinity();
const internal::ShapedText* shaped_text = GetShapedText();
for (size_t line_index = 0; line_index < shaped_text->lines().size();
++line_index) {
const internal::Line& line = shaped_text->lines()[line_index];
for (const internal::LineSegment& segment : line.segments) {
if (RangeContainsCaret(segment.char_range, layout_position, affinity))
return LineIndexForNewline(line_index, text(), segment, caret);
}
}
return shaped_text->lines().size() - 1;
}
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->font_params.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->font_params.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
// punctuation.
if (iter.IsStartOfWord(cursor))
break;
#else
const bool is_forward =
run_list->runs()[run]->font_params.is_rtl == (direction == CURSOR_LEFT);
if (is_forward ? iter.IsEndOfWord(cursor) : iter.IsStartOfWord(cursor))
break;
#endif // defined(OS_WIN)
}
return current;
}
SelectionModel RenderTextHarfBuzz::AdjacentLineSelectionModel(
const SelectionModel& selection,
VisualCursorDirection direction) {
DCHECK(direction == CURSOR_UP || direction == CURSOR_DOWN);
size_t line = GetLineContainingCaret(selection);
if (line == 0 && direction == CURSOR_UP) {
reset_cached_cursor_x();
return SelectionModel(0, CURSOR_BACKWARD);
}
if (line == GetShapedText()->lines().size() - 1 && direction == CURSOR_DOWN) {
reset_cached_cursor_x();
return SelectionModel(text().length(), CURSOR_FORWARD);
}
direction == CURSOR_UP ? --line : ++line;
Rect bounds = GetCursorBounds(selection, true);
Point target = bounds.origin();
if (cached_cursor_x())
target.set_x(cached_cursor_x().value());
else
set_cached_cursor_x(target.x());
if (direction == CURSOR_UP)
target.Offset(0, -bounds.size().height() / 2);
else
target.Offset(0, bounds.size().height() * 3 / 2);
SelectionModel next = FindCursorPosition(target, Point());
size_t next_line = GetLineContainingCaret(next);
// If the |target| position is at the newline character, the caret is drawn to
// the next line. e.g., when the caret is at the beginning of the line in RTL
// text. Move the caret to the position of the previous character to move the
// caret to the previous line.
if (next_line == line + 1)
next = SelectionModel(next.caret_pos() - 1, next.caret_affinity());
return next;
}
void RenderTextHarfBuzz::OnLayoutTextAttributeChanged(bool text_changed) {
RenderText::OnLayoutTextAttributeChanged(text_changed);
update_layout_run_list_ = true;
OnDisplayTextAttributeChanged();
}
void RenderTextHarfBuzz::OnDisplayTextAttributeChanged() {
update_display_text_ = true;
set_shaped_text(nullptr);
}
void RenderTextHarfBuzz::EnsureLayout() {
EnsureLayoutRunList();
if (update_display_run_list_) {
DCHECK(text_elided());
const base::string16& display_text = GetDisplayText();
display_run_list_ = std::make_unique<internal::TextRunList>();
if (!display_text.empty())
ItemizeAndShapeText(display_text, display_run_list_.get());
update_display_run_list_ = false;
set_shaped_text(nullptr);
}
if (!has_shaped_text()) {
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,
glyph_height_for_test_, 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_);
if (multiline() && max_lines()) {
// TODO(crbug.com/866720): no more than max_lines() should be rendered.
// Remove the IsHomogeneous() condition for the following DCHECK when the
// bug is fixed.
if (IsHomogeneous()) {
DCHECK_LE(lines.size(), max_lines());
}
}
set_shaped_text(std::make_unique<internal::ShapedText>(lines));
}
}
void RenderTextHarfBuzz::DrawVisualText(internal::SkiaTextRenderer* renderer,
const std::vector<Range>& selections) {
DCHECK(!update_layout_run_list_);
DCHECK(!update_display_run_list_);
DCHECK(!update_display_text_);
const internal::ShapedText* shaped_text = GetShapedText();
if (shaped_text->lines().empty())
return;
ApplyFadeEffects(renderer);
ApplyTextShadows(renderer);
// Apply the selected text color to the [un-reversed] selection range.
BreakList<SkColor> colors = layout_colors();
for (auto selection : selections) {
if (!selection.is_empty()) {
const Range grapheme_range = ExpandRangeToGraphemeBoundary(selection);
colors.ApplyValue(
selection_color(),
Range(TextIndexToDisplayIndex(grapheme_range.GetMin()),
TextIndexToDisplayIndex(grapheme_range.GetMax())));
}
}
internal::TextRunList* run_list = GetRunList();
const base::string16& display_text = GetDisplayText();
for (size_t i = 0; i < shaped_text->lines().size(); ++i) {
const internal::Line& line = shaped_text->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(display_text, segment))
continue;
const internal::TextRunHarfBuzz& run = *run_list->runs()[segment.run];
renderer->SetTypeface(run.font_params.skia_face);
renderer->SetTextSize(SkIntToScalar(run.font_params.font_size));
renderer->SetFontRenderParams(run.font_params.render_params,
subpixel_rendering_suppressed());
Range glyphs_range = run.CharRangeToGlyphRange(segment.char_range);
std::vector<SkPoint> positions(glyphs_range.length());
SkScalar offset_x = preceding_segment_widths -
((glyphs_range.GetMin() != 0)
? run.shape.positions[glyphs_range.GetMin()].x()
: 0);
for (size_t j = 0; j < glyphs_range.length(); ++j) {
positions[j] = run.shape.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.font_params.baseline_offset));
}
for (auto 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.shape.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.font_params.heavy_underline)
renderer->DrawUnderline(start_x, origin.y(), end_x - start_x, 2.0);
else if (run.font_params.underline)
renderer->DrawUnderline(start_x, origin.y(), end_x - start_x);
if (run.font_params.strike)
renderer->DrawStrike(start_x, origin.y(), end_x - start_x,
strike_thickness_factor());
}
preceding_segment_widths += SkFloatToScalar(segment.width());
}
}
}
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::ItemizeAndShapeText(const base::string16& text,
internal::TextRunList* run_list) {
CommonizedRunsMap commonized_run_map;
ItemizeTextToRuns(text, run_list, &commonized_run_map);
for (auto iter = commonized_run_map.begin(); iter != commonized_run_map.end();
++iter) {
internal::TextRunHarfBuzz::FontParams font_params = iter->first;
font_params.ComputeRenderParamsFontSizeAndBaselineOffset();
ShapeRuns(text, font_params, std::move(iter->second));
}
run_list->InitIndexMap();
run_list->ComputePrecedingRunWidths();
}
void RenderTextHarfBuzz::ItemizeTextToRuns(
const base::string16& text,
internal::TextRunList* out_run_list,
CommonizedRunsMap* out_commonized_run_map) {
TRACE_EVENT1("ui", "RenderTextHarfBuzz::ItemizeTextToRuns", "text_length",
text.length());
DCHECK(!text.empty());
const Font& primary_font = font_list().GetPrimaryFont();
// 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.
ui::gfx::BiDiLineIterator bidi_iterator;
if (!bidi_iterator.Open(text, GetTextDirectionForGivenText(text))) {
auto run = std::make_unique<internal::TextRunHarfBuzz>(
font_list().GetPrimaryFont());
run->range = Range(0, text.length());
internal::TextRunHarfBuzz::FontParams font_params(primary_font);
(*out_commonized_run_map)[font_params].push_back(run.get());
out_run_list->Add(std::move(run));
return;
}
// Iterator to split ranged styles and baselines. The color attributes don't
// break text runs to keep ligature between graphemes (e.g. Arabic word).
internal::StyleIterator style = GetLayoutTextStyleIterator();
// Split the original text by logical runs, then each logical run by common
// script and each sequence at special characters and style boundaries. This
// invariant holds: bidi_run_start <= script_run_start <= breaking_run_start
// <= breaking_run_end <= script_run_end <= bidi_run_end
for (size_t bidi_run_start = 0; bidi_run_start < text.length();) {
// Determine the longest logical run (e.g. same bidi direction) from this
// point.
int32_t bidi_run_break = 0;
UBiDiLevel bidi_level = 0;
bidi_iterator.GetLogicalRun(bidi_run_start, &bidi_run_break, &bidi_level);
size_t bidi_run_end = static_cast<size_t>(bidi_run_break);
DCHECK_LT(bidi_run_start, bidi_run_end);
ApplyForcedDirection(&bidi_level);
for (size_t script_run_start = bidi_run_start;
script_run_start < bidi_run_end;) {
// Find the longest sequence of characters that have at least one common
// UScriptCode value.
UScriptCode script = USCRIPT_INVALID_CODE;
size_t script_run_end =
ScriptInterval(text, script_run_start,
bidi_run_end - script_run_start, &script) +
script_run_start;
DCHECK_LT(script_run_start, script_run_end);
for (size_t breaking_run_start = script_run_start;
breaking_run_start < script_run_end;) {
// Find the break boundary for style. The style won't break a grapheme
// since the style of the first character is applied to the whole
// grapheme.
style.IncrementToPosition(breaking_run_start);
size_t text_style_end = style.GetTextBreakingRange().end();
// Break runs at certain characters that need to be rendered separately
// to prevent an unusual character from forcing a fallback font on the
// entire run. After script intersection, many codepoints end up in the
// script COMMON but can't be rendered together.
size_t breaking_run_end = FindRunBreakingCharacter(
text, script, breaking_run_start, text_style_end, script_run_end);
DCHECK_LT(breaking_run_start, breaking_run_end);
DCHECK(IsValidCodePointIndex(text, breaking_run_end));
// Set the font params for the current run for the current run break.
internal::TextRunHarfBuzz::FontParams font_params =
CreateFontParams(primary_font, bidi_level, script, style);
// Create the current run from [breaking_run_start, breaking_run_end[.
auto run = std::make_unique<internal::TextRunHarfBuzz>(primary_font);
run->range = Range(breaking_run_start, breaking_run_end);
// Add the created run to the set of runs.
(*out_commonized_run_map)[font_params].push_back(run.get());
out_run_list->Add(std::move(run));
// Move to the next run.
breaking_run_start = breaking_run_end;
}
// Move to the next script sequence.
script_run_start = script_run_end;
}
// Move to the next direction sequence.
bidi_run_start = bidi_run_end;
}
// Add trace event to track incorrect usage of fallback fonts.
// TODO(https://crbug.com/995789): Remove the following code when the issue
// is fixed.
bool tracing_enabled;
TRACE_EVENT_CATEGORY_GROUP_ENABLED("fonts", &tracing_enabled);
if (tracing_enabled) {
std::string logging_str;
for (const auto& iter : *out_commonized_run_map) {
const internal::TextRunHarfBuzz::FontParams& font_params = iter.first;
for (const auto* run : iter.second) {
base::i18n::UTF16CharIterator text_iter(base::StringPiece16(
text.c_str() + run->range.start(), run->range.length()));
const UChar32 first_char = text_iter.get();
const UBlockCode first_block = ublock_getCode(first_char);
const char* script_name = uscript_getShortName(font_params.script);
base::StringAppendF(&logging_str, "block=%d script=%s\n",
static_cast<int>(first_block),
script_name ? script_name : "");
}
}
TRACE_EVENT_INSTANT1("fonts", "RenderTextHarfBuzz::ItemizeTextToRuns::Runs",
TRACE_EVENT_SCOPE_THREAD, "runs", logging_str);
}
}
void RenderTextHarfBuzz::ShapeRuns(
const base::string16& text,
const internal::TextRunHarfBuzz::FontParams& font_params,
std::vector<internal::TextRunHarfBuzz*> runs) {
TRACE_EVENT1("ui", "RenderTextHarfBuzz::ShapeRuns", "run_count", runs.size());
// Runs with a single newline character should be skipped since they can't be
// rendered (see http://crbug/680430). The following code sets the runs
// shaping output to report report the missing glyph and removes the runs from
// the vector of runs to shape. The newline character doesn't have a
// glyph, which otherwise forces this function to go through the expensive
// font fallbacks before reporting a missing glyph (see http://crbug/972090).
std::vector<internal::TextRunHarfBuzz*> need_shaping_runs;
for (internal::TextRunHarfBuzz*& run : runs) {
if ((run->range.length() == 1 && (text[run->range.start()] == '\r' ||
text[run->range.start()] == '\n')) ||
(run->range.length() == 2 && text[run->range.start()] == '\r' &&
text[run->range.start() + 1] == '\n')) {
// Newline runs can't be shaped. Shape this run as if the glyph is
// missing.
run->font_params = font_params;
run->shape.missing_glyph_count = 1;
run->shape.glyph_count = 1;
run->shape.glyphs.resize(run->shape.glyph_count);
run->shape.glyph_to_char.resize(run->shape.glyph_count);
run->shape.positions.resize(run->shape.glyph_count);
run->shape.width = glyph_width_for_test_;
} else {
// This run needs shaping.
need_shaping_runs.push_back(run);
}
}
runs.swap(need_shaping_runs);
if (runs.empty()) {
RecordShapeRunsFallback(ShapeRunFallback::NO_FALLBACK);
return;
}
// Keep a set of fonts already tried for shaping runs.
std::set<SkFontID> fallback_fonts_already_tried;
std::vector<Font> fallback_font_candidates;
// Shaping with primary configured fonts from font_list().
for (const Font& font : font_list().GetFonts()) {
internal::TextRunHarfBuzz::FontParams test_font_params = font_params;
if (test_font_params.SetRenderParamsRematchFont(
font, font.GetFontRenderParams()) &&
!FontWasAlreadyTried(test_font_params.skia_face,
&fallback_fonts_already_tried)) {
ShapeRunsWithFont(text, test_font_params, &runs);
MarkFontAsTried(test_font_params.skia_face,
&fallback_fonts_already_tried);
fallback_font_candidates.push_back(font);
}
if (runs.empty()) {
RecordShapeRunsFallback(ShapeRunFallback::NO_FALLBACK);
return;
}
}
const Font& primary_font = font_list().GetPrimaryFont();
// Find fallback fonts for the remaining runs using a worklist algorithm. Try
// to shape the first run by using GetFallbackFont(...) and then try shaping
// other runs with the same font. If the first font can't be shaped, remove it
// and continue with the remaining runs until the worklist is empty. The
// fallback font returned by GetFallbackFont(...) depends on the text of the
// run and the results may differ between runs.
std::vector<internal::TextRunHarfBuzz*> remaining_unshaped_runs;
while (!runs.empty()) {
Font fallback_font(primary_font);
bool fallback_found;
internal::TextRunHarfBuzz* current_run = *runs.begin();
{
SCOPED_UMA_HISTOGRAM_LONG_TIMER("RenderTextHarfBuzz.GetFallbackFontTime");
TRACE_EVENT1("ui", "RenderTextHarfBuzz::GetFallbackFont", "script",
TRACE_STR_COPY(uscript_getShortName(font_params.script)));
const base::StringPiece16 run_text(&text[current_run->range.start()],
current_run->range.length());
fallback_found =
GetFallbackFont(primary_font, locale_, run_text, &fallback_font);
}
if (fallback_found) {
internal::TextRunHarfBuzz::FontParams test_font_params = font_params;
if (test_font_params.SetRenderParamsOverrideSkiaFaceFromFont(
fallback_font, fallback_font.GetFontRenderParams()) &&
!FontWasAlreadyTried(test_font_params.skia_face,
&fallback_fonts_already_tried)) {
ShapeRunsWithFont(text, test_font_params, &runs);
MarkFontAsTried(test_font_params.skia_face,
&fallback_fonts_already_tried);
}
}
// Remove the first run if not fully shaped with its associated fallback
// font.
if (!runs.empty() && runs[0] == current_run) {
remaining_unshaped_runs.push_back(current_run);
runs.erase(runs.begin());
}
}
runs.swap(remaining_unshaped_runs);
if (runs.empty()) {
RecordShapeRunsFallback(ShapeRunFallback::FALLBACK);
return;
}
std::vector<Font> fallback_font_list;
{
SCOPED_UMA_HISTOGRAM_LONG_TIMER("RenderTextHarfBuzz.GetFallbackFontsTime");
TRACE_EVENT1("ui", "RenderTextHarfBuzz::GetFallbackFonts", "script",
TRACE_STR_COPY(uscript_getShortName(font_params.script)));
fallback_font_list = GetFallbackFonts(primary_font);
#if defined(OS_WIN)
// Append fonts in the fallback list of the fallback fonts.
// TODO(tapted): Investigate whether there's a case that benefits from this
// on Mac.
for (const auto& fallback_font : fallback_font_candidates) {
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.
Font segoe("Segoe UI", 13);
if (!FontWasAlreadyTried(segoe.platform_font()->GetNativeSkTypeface(),
&fallback_fonts_already_tried)) {
std::vector<Font> default_fallback_families = GetFallbackFonts(segoe);
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.
SCOPED_UMA_HISTOGRAM_LONG_TIMER(
"RenderTextHarfBuzz.ShapeRunsWithFallbackFontsTime");
TRACE_EVENT1("ui", "RenderTextHarfBuzz::ShapeRunsWithFallbackFonts",
"fonts_count", fallback_font_list.size());
// Try shaping with the fallback fonts.
for (const auto& font : fallback_font_list) {
std::string font_name = font.GetFontName();
FontRenderParamsQuery query;
query.families.push_back(font_name);
query.pixel_size = font_params.font_size;
query.style = font_params.italic ? Font::ITALIC : 0;
FontRenderParams fallback_render_params = GetFontRenderParams(query, NULL);
internal::TextRunHarfBuzz::FontParams test_font_params = font_params;
if (test_font_params.SetRenderParamsOverrideSkiaFaceFromFont(
font, fallback_render_params) &&
!FontWasAlreadyTried(test_font_params.skia_face,
&fallback_fonts_already_tried)) {
ShapeRunsWithFont(text, test_font_params, &runs);
MarkFontAsTried(test_font_params.skia_face,
&fallback_fonts_already_tried);
}
if (runs.empty()) {
TRACE_EVENT_INSTANT2("ui", "RenderTextHarfBuzz::FallbackFont",
TRACE_EVENT_SCOPE_THREAD, "font_name",
TRACE_STR_COPY(font_name.c_str()),
"primary_font_name", primary_font.GetFontName());
RecordShapeRunsFallback(ShapeRunFallback::FALLBACKS);
return;
}
}
for (internal::TextRunHarfBuzz*& run : runs) {
if (run->shape.missing_glyph_count == std::numeric_limits<size_t>::max()) {
run->shape.glyph_count = 0;
run->shape.width = 0.0f;
}
}
RecordShapeRunsFallback(ShapeRunFallback::FAILED);
}
void RenderTextHarfBuzz::ShapeRunsWithFont(
const base::string16& text,
const internal::TextRunHarfBuzz::FontParams& font_params,
std::vector<internal::TextRunHarfBuzz*>* in_out_runs) {
// ShapeRunWithFont can be extremely slow, so use cached results if possible.
// Only do this on the UI thread, to avoid synchronization overhead (and
// because almost all calls are on the UI thread. Also avoid caching long
// strings, to avoid blowing up the cache size.
constexpr size_t kMaxRunLengthToCache = 25;
static base::NoDestructor<internal::ShapeRunCache> cache;
std::vector<internal::TextRunHarfBuzz*> runs_with_missing_glyphs;
for (internal::TextRunHarfBuzz*& run : *in_out_runs) {
// First do a cache lookup.
bool can_use_cache = base::CurrentUIThread::IsSet() &&
run->range.length() <= kMaxRunLengthToCache;
bool found_in_cache = false;
const internal::ShapeRunWithFontInput cache_key(
text, font_params, run->range, obscured(), glyph_width_for_test_,
obscured_glyph_spacing(), subpixel_rendering_suppressed());
if (can_use_cache) {
auto found = cache.get()->Get(cache_key);
if (found != cache.get()->end()) {
run->UpdateFontParamsAndShape(font_params, found->second);
found_in_cache = true;
}
}
// If that fails, compute the shape of the run, and add the result to the
// cache.
// TODO(ccameron): Coalesce calls to ShapeRunsWithFont when possible.
if (!found_in_cache) {
internal::TextRunHarfBuzz::ShapeOutput output;
ShapeRunWithFont(cache_key, &output);
run->UpdateFontParamsAndShape(font_params, output);
if (can_use_cache)
cache.get()->Put(cache_key, output);
}
// Check to see if we still have missing glyphs.
if (run->shape.missing_glyph_count)
runs_with_missing_glyphs.push_back(run);
}
in_out_runs->swap(runs_with_missing_glyphs);
}
void RenderTextHarfBuzz::EnsureLayoutRunList() {
// Update layout run list if the device scale factor has changed since the
// layout run list was last updated, as changes in device scale factor change
// subpixel positioning, at least on Linux and Chrome OS.
const float device_scale_factor = GetFontRenderParamsDeviceScaleFactor();
if (update_layout_run_list_ || device_scale_factor_ != device_scale_factor) {
device_scale_factor_ = device_scale_factor;
layout_run_list_.Reset();
const base::string16& text = GetLayoutText();
if (!text.empty())
ItemizeAndShapeText(text, &layout_run_list_);
display_run_list_.reset();
update_display_text_ = true;
update_layout_run_list_ = false;
}
if (update_display_text_) {
set_shaped_text(nullptr);
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.font_params.italic)
style |= Font::ITALIC;
if (run.font_params.underline || run.font_params.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_params.font.Derive(0, style, run.font_params.weight));
attribute.strike = run.font_params.strike;
decorated_text->attributes.push_back(attribute);
}
}
return true;
}
} // namespace gfx