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 <set>
 
 #include "base/i18n/bidi_line_iterator.h"
@@ skipping 206 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,
+                      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),
         multiline_(multiline),
+        word_wrap_behavior_(word_wrap_behavior),
         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 34 matching lines @@
   // them. Adds a new Line to the back of |lines_| whenever a new segment can't
   // be added without the Line's width exceeding |max_width_|.
   void BreakRun(int run_index) {
     const internal::TextRunHarfBuzz& run = *(run_list_.runs()[run_index]);
     SkScalar width = 0;
     size_t next_char = run.range.start();
 
     // Break the run until it fits the current line.
     while (next_char < run.range.end()) {
       const size_t current_char = next_char;
+      size_t end_char = next_char;
       const bool skip_line =
-          BreakRunAtWidth(run, current_char, &width, &next_char);
-      AddSegment(run_index, Range(current_char, next_char),
+          BreakRunAtWidth(run, current_char, &width, &end_char, &next_char);
+      AddSegment(run_index, Range(current_char, end_char),
                  SkScalarToFloat(width));
       if (skip_line)
         AdvanceLine();
     }
   }
 
   // Starting from |start_char|, finds a suitable line break position at or
   // before available width using word break. If the current position is at the
   // beginning of a line, this function will not roll back to |start_char| and
   // |*next_char| will be greater than |start_char| (to avoid constructing empty
-  // lines).
+  // lines). It stores the end of the segment range to |end_char|, which can be
+  // smaller than |*next_char| for certain word wrapping behavior.
   // Returns whether to skip the line before |*next_char|.
   // TODO(ckocagil): We might have to reshape after breaking at ligatures.
   //                 See whether resolving the TODO above resolves this too.
   // TODO(ckocagil): Do not reserve width for whitespace at the end of lines.
   bool BreakRunAtWidth(const internal::TextRunHarfBuzz& run,
                        size_t start_char,
                        SkScalar* width,
+                       size_t* end_char,
                        size_t* next_char) {
     DCHECK(words_);
     DCHECK(run.range.Contains(Range(start_char, start_char + 1)));
     SkScalar available_width = max_width_ - line_x_;
     BreakList<size_t>::const_iterator word = words_->GetBreak(start_char);
     BreakList<size_t>::const_iterator next_word = word + 1;
     // Width from |std::max(word->first, start_char)| to the current character.
     SkScalar word_width = 0;
     *width = 0;
 
     Range char_range;
     for (size_t i = start_char; i < run.range.end(); i += char_range.length()) {
       // |word| holds the word boundary at or before |i|, and |next_word| holds
       // the word boundary right after |i|. Advance both |word| and |next_word|
       // when |i| reaches |next_word|.
       if (next_word != words_->breaks().end() && i >= next_word->first) {
+        if (*width > available_width) {
+          DCHECK_NE(WRAP_LONG_WORDS, word_wrap_behavior_);
+          *next_char = i;
+          if (word_wrap_behavior_ != TRUNCATE_LONG_WORDS)
+            *end_char = *next_char;
+          return true;
+        }
         word = next_word++;
         word_width = 0;
       }
 
       Range glyph_range;
       run.GetClusterAt(i, &char_range, &glyph_range);
       DCHECK_LT(0U, char_range.length());
 
       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;
 
+      // TODO(mukai): implement ELIDE_LONG_WORDS.
       if (*width > available_width) {
         if (line_x_ != 0 || word_width < *width) {
           // 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 + char_range.length();
+          *end_char = *next_char;
+          return true;
+        } else if (word_wrap_behavior_ == WRAP_LONG_WORDS) {
+          if (char_width < *width) {
+            // Roll back one character.
+            *width -= char_width;
+            *next_char = i;
+          } else {
+            // Continue from the next character.
+            *next_char = i + char_range.length();
+          }
+          *end_char = *next_char;
+          return true;
         }
-        return true;
+      } else {
+        *end_char = char_range.end();
       }
     }
 
     *next_char = run.range.end();
+    *end_char = *next_char;

[msw, 2015/03/27 01:45:27]

optional nit: "*end_char = *next_char = run.range.end();" or "*end_char =
run.range.end();"

[Jun Mukai, 2015/03/27 16:36:12]

Done.

     return false;
   }
 
   // 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;
@@ skipping 72 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 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_;
 
   // Text space and line space x coordinates of the next segment to be added.
   SkScalar text_x_;
   SkScalar line_x_;
@@ skipping 529 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);
+        word_wrap_behavior(), 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 514 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