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-rw-r--r--ui/gfx/render_text_win.cc40
1 files changed, 33 insertions, 7 deletions
diff --git a/ui/gfx/render_text_win.cc b/ui/gfx/render_text_win.cc
index 8413ccf..2415060 100644
--- a/ui/gfx/render_text_win.cc
+++ b/ui/gfx/render_text_win.cc
@@ -7,11 +7,13 @@
#include <algorithm>
#include "base/i18n/break_iterator.h"
+#include "base/i18n/char_iterator.h"
#include "base/i18n/rtl.h"
#include "base/logging.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/win/windows_version.h"
+#include "third_party/icu/source/common/unicode/uchar.h"
#include "ui/base/text/utf16_indexing.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/font_fallback_win.h"
@@ -543,13 +545,14 @@ void RenderTextWin::ItemizeLogicalText() {
script_state_.uBidiLevel =
(GetTextDirection() == base::i18n::RIGHT_TO_LEFT) ? 1 : 0;
- if (text().empty())
+ const base::string16& layout_text = GetLayoutText();
+ if (layout_text.empty())
return;
HRESULT hr = E_OUTOFMEMORY;
int script_items_count = 0;
std::vector<SCRIPT_ITEM> script_items;
- const size_t layout_text_length = GetLayoutText().length();
+ const size_t layout_text_length = layout_text.length();
// Ensure that |kMaxRuns| is attempted and the loop terminates afterward.
for (size_t runs = kGuessRuns; hr == E_OUTOFMEMORY && runs <= kMaxRuns;
runs = std::max(runs + 1, std::min(runs * 2, kMaxRuns))) {
@@ -557,9 +560,9 @@ void RenderTextWin::ItemizeLogicalText() {
// ScriptItemize always adds a terminal array item so that the length of
// the last item can be derived from the terminal SCRIPT_ITEM::iCharPos.
script_items.resize(runs);
- hr = ScriptItemize(GetLayoutText().c_str(), layout_text_length,
- runs - 1, &script_control_, &script_state_,
- &script_items[0], &script_items_count);
+ hr = ScriptItemize(layout_text.c_str(), layout_text_length, runs - 1,
+ &script_control_, &script_state_, &script_items[0],
+ &script_items_count);
}
DCHECK(SUCCEEDED(hr));
if (!SUCCEEDED(hr) || script_items_count <= 0)
@@ -571,7 +574,7 @@ void RenderTextWin::ItemizeLogicalText() {
// Build the list of runs from the script items and ranged styles. Use an
// empty color BreakList to avoid breaking runs at color boundaries.
BreakList<SkColor> empty_colors;
- empty_colors.SetMax(text().length());
+ empty_colors.SetMax(layout_text_length);
internal::StyleIterator style(empty_colors, styles());
SCRIPT_ITEM* script_item = &script_items[0];
const size_t max_run_length = kMaxGlyphs / 2;
@@ -592,9 +595,32 @@ void RenderTextWin::ItemizeLogicalText() {
const size_t script_item_break = (script_item + 1)->iCharPos;
run_break = std::min(script_item_break,
TextIndexToLayoutIndex(style.GetRange().end()));
+
// Clamp run lengths to avoid exceeding the maximum supported glyph count.
- if ((run_break - run->range.start()) > max_run_length)
+ if ((run_break - run->range.start()) > max_run_length) {
run_break = run->range.start() + max_run_length;
+ if (!ui::IsValidCodePointIndex(layout_text, run_break))
+ --run_break;
+ }
+
+ // Break runs between characters in different code blocks. This avoids using
+ // fallback fonts for more characters than needed. http://crbug.com/278913
+ if (run_break > run->range.start()) {
+ const size_t run_start = run->range.start();
+ const int32 run_length = static_cast<int32>(run_break - run_start);
+ base::i18n::UTF16CharIterator iter(layout_text.c_str() + run_start,
+ run_length);
+ const UBlockCode first_block_code = ublock_getCode(iter.get());
+ while (iter.Advance() && iter.array_pos() < run_length) {
+ if (ublock_getCode(iter.get()) != first_block_code) {
+ run_break = run_start + iter.array_pos();
+ break;
+ }
+ }
+ }
+
+ DCHECK(ui::IsValidCodePointIndex(layout_text, run_break));
+
style.UpdatePosition(LayoutIndexToTextIndex(run_break));
if (script_item_break == run_break)
script_item++;