Clean up of SelectionModel

ui/gfx/render_text.cc

 // Copyright (c) 2011 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.h"
 
 #include <algorithm>
 
 #include "base/i18n/break_iterator.h"
 #include "base/logging.h"
@@ skipping 202 matching lines @@
   return changed;
 }
 
 bool RenderText::MoveCursorTo(const Point& point, bool select) {
   SelectionModel selection = FindCursorPosition(point);
   if (select)
     selection.set_selection_start(GetSelectionStart());
   return MoveCursorTo(selection);
 }
 
+bool RenderText::SelectRange(const ui::Range& range) {
+  size_t text_length = text().length();
+  size_t start = std::min(range.start(), text_length);
+  size_t end = std::min(range.end(), text_length);
+
+  if (!IsCursorablePosition(start) || !IsCursorablePosition(end))
+    return false;
+
+  size_t pos = end;
+  SelectionModel::CaretPlacement placement = SelectionModel::LEADING;
+  if (start < end) {
+    pos = GetIndexOfPreviousGrapheme(end);
+    DCHECK_LT(pos, end);
+    placement = SelectionModel::TRAILING;
+  } else if (end == text_length) {
+    SelectionModel boundary = GetTextDirection() == base::i18n::RIGHT_TO_LEFT ?
+        LeftEndSelectionModel() : RightEndSelectionModel();
+    pos = boundary.caret_pos();
+    placement = boundary.caret_placement();
+  }
+  SetSelectionModel(SelectionModel(start, end, pos, placement));
+  return true;
+}
+
 bool RenderText::IsPointInSelection(const Point& point) {
   if (EmptySelection())
     return false;
   // TODO(xji): should this check whether the point is inside the visual
   // selection bounds? In case of "abcFED", if "ED" is selected, |point| points
   // to the right half of 'c', is the point in selection?
   size_t pos = FindCursorPosition(point).selection_end();
   return (pos >= MinOfSelection() && pos < MaxOfSelection());
 }
 
@@ skipping 210 matching lines @@
 }
 
 const Point& RenderText::GetUpdatedDisplayOffset() {
   UpdateCachedBoundsAndOffset();
   return display_offset_;
 }
 
 SelectionModel RenderText::GetLeftSelectionModel(const SelectionModel& current,
                                                  BreakType break_type) {
   if (break_type == LINE_BREAK)
-    return SelectionModel(0, 0, SelectionModel::LEADING);
+    return LeftEndSelectionModel();
   size_t pos = std::max(static_cast<long>(current.selection_end() - 1),
                         static_cast<long>(0));
   if (break_type == CHARACTER_BREAK)
     return SelectionModel(pos, pos, SelectionModel::LEADING);
 
   // Notes: We always iterate words from the beginning.
   // This is probably fast enough for our usage, but we may
   // want to modify WordIterator so that it can start from the
   // middle of string and advance backwards.
   base::i18n::BreakIterator iter(text(), base::i18n::BreakIterator::BREAK_WORD);
@@ skipping 20 matching lines @@
   }
 
   return SelectionModel(pos, pos, SelectionModel::LEADING);
 }
 
 SelectionModel RenderText::GetRightSelectionModel(const SelectionModel& current,
                                                   BreakType break_type) {
   if (text_.empty())
     return SelectionModel(0, 0, SelectionModel::LEADING);
   if (break_type == LINE_BREAK)
-    return SelectionModel(text().length(),
-        GetIndexOfPreviousGrapheme(text().length()), SelectionModel::TRAILING);
+    return RightEndSelectionModel();
   size_t pos = std::min(current.selection_end() + 1, text().length());
   if (break_type == CHARACTER_BREAK)
     return SelectionModel(pos, pos, SelectionModel::LEADING);
 
   base::i18n::BreakIterator iter(text(), base::i18n::BreakIterator::BREAK_WORD);
   bool success = iter.Init();
   DCHECK(success);
   if (!success)
     return current;
   while (iter.Advance()) {
@@ skipping 124 matching lines @@
     // LTR character.
     //
     // Pan to show the cursor when it overflows to the left.
     delta_offset = display_rect_.x() - cursor_bounds_.x();
   }
   display_offset_.Offset(delta_offset, 0);
   cursor_bounds_.Offset(delta_offset, 0);
 }
 
 }  // namespace gfx