Move allow_character_break property to RenderText.

ui/gfx/render_text_harfbuzz.cc

 // 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 "base/i18n/bidi_line_iterator.h"
 #include "base/i18n/break_iterator.h"
@@ skipping 205 matching lines @@
 // 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,
                       bool multiline,
+                      bool allow_character_break,
                       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),
         multiline_(multiline),
+        allow_character_break_(allow_character_break),
         text_(text),
         words_(words),
         run_list_(run_list),
         text_x_(0),
         line_x_(0),
         max_descent_(0),
         max_ascent_(0) {
     DCHECK_EQ(multiline_, (words_ != nullptr));
     AdvanceLine();
   }
@@ skipping 85 matching lines @@
       Range glyph_range = run.CharRangeToGlyphRange(Range(i, i + 1));
       SkScalar char_width = ((glyph_range.end() >= run.glyph_count)
                                  ? SkFloatToScalar(run.width)
                                  : run.positions[glyph_range.end()].x()) -
                             run.positions[glyph_range.start()].x();
 
       *width += char_width;
       word_width += char_width;
 
       if (*width > available_width) {
-        if (line_x_ != 0 || word_width < *width) {
+        if (!allow_character_break_ && (line_x_ != 0 || word_width < *width)) {

[msw, 2015/03/25 20:54:15]

I don't think this matches the current Label behavior of toggling between
gfx::WRAP_LONG_WORDS and gfx::TRUNCATE_LONG_WORDS...

Afaict, this is the expected behavior, can you confirm?
1) TRUNCATE_LONG_WORDS (allow_character_break_ == false): Move long words to a
new line (if there is preceding text on the current line), then *truncate any
word content beyond the width of a full line*.
2) WRAP_LONG_WORDS (allow_character_break_ == true): Move long words to a new
line (if there is preceding text on the current line), then *continually wrap
the word content as needed onto subsequent lines.*
3) RenderText ToT: Matches WRAP_LONG_WORDS (allow_character_break_ == true)?
4) With this change: *Never move long words onto new lines* (WRONG), just
continually wrap the word content as needed...

We should clarify the gfx::WordWrapBehavior enums comments and add more testing.

[Jun Mukai, 2015/03/26 01:35:08]

Rewritten the logic, and enriched the tests. PTAL.

           // Roll back one word.
           *width -= word_width;
           *next_char = std::max(word->first, start_char);
         } else if (char_width < *width) {
           // Roll back one character.
           *width -= char_width;
           *next_char = i;
         } else {
           // Continue from the next character.
           *next_char = i + 1;
@@ skipping 88 matching lines @@
         UpdateRTLSegmentRanges();
     }
     text_x_ += SkFloatToScalar(width);
     line_x_ += SkFloatToScalar(width);
   }
 
   const SkScalar max_width_;
   const int min_baseline_;
   const float min_height_;
   const bool multiline_;
+  const bool allow_character_break_;
   const base::string16& text_;
   const BreakList<size_t>* const words_;
   const internal::TextRunList& run_list_;
 
   // Stores the resulting lines.
   std::vector<internal::Line> lines_;
 
   // Text space and line space x coordinates of the next segment to be added.
   SkScalar text_x_;
   SkScalar line_x_;
@@ skipping 522 matching lines @@
   if (lines().empty()) {
     // TODO(vadimt): Remove ScopedTracker below once crbug.com/431326 is fixed.
     tracked_objects::ScopedTracker tracking_profile2(
         FROM_HERE_WITH_EXPLICIT_FUNCTION(
             "431326 RenderTextHarfBuzz::EnsureLayout2"));
 
     internal::TextRunList* run_list = GetRunList();
     HarfBuzzLineBreaker line_breaker(
         display_rect().width(), font_list().GetBaseline(),
         std::max(font_list().GetHeight(), min_line_height()), multiline(),
-        GetDisplayText(), multiline() ? &GetLineBreaks() : nullptr, *run_list);
+        allow_character_break(), GetDisplayText(),
+        multiline() ? &GetLineBreaks() : nullptr, *run_list);
 
     // TODO(vadimt): Remove ScopedTracker below once crbug.com/431326 is fixed.
     tracked_objects::ScopedTracker tracking_profile3(
         FROM_HERE_WITH_EXPLICIT_FUNCTION(
             "431326 RenderTextHarfBuzz::EnsureLayout3"));
 
     for (size_t i = 0; i < run_list->size(); ++i)
       line_breaker.AddRun(i);
     std::vector<internal::Line> lines;
     line_breaker.Finalize(&lines, &total_size_);
@@ skipping 519 matching lines @@
   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();
 }
 
 }  // namespace gfx