Add RenderText DirectionalityMode enum and support; etc.

ui/gfx/render_text.cc

 // Copyright (c) 2012 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"
 #include "base/stl_util.h"
 #include "third_party/skia/include/core/SkTypeface.h"
 #include "third_party/skia/include/effects/SkGradientShader.h"
 #include "ui/base/text/utf16_indexing.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/insets.h"
 #include "ui/gfx/skia_util.h"
+#include "ui/gfx/text_constants.h"
 
 namespace {
 
 // All chars are replaced by this char when the password style is set.
 // TODO(benrg): GTK uses the first of U+25CF, U+2022, U+2731, U+273A, '*'
 // that's available in the font (find_invisible_char() in gtkentry.c).
 const char16 kPasswordReplacementChar = '*';
 
 // Default color used for the cursor.
 const SkColor kDefaultCursorColor = SK_ColorBLACK;
@@ skipping 359 matching lines @@
   }
 #ifndef NDEBUG
   CheckStyleRanges(style_ranges_, text_.length());
 #endif
   cached_bounds_and_offset_valid_ = false;
 
   // Reset selection model. SetText should always followed by SetSelectionModel
   // or SetCursorPosition in upper layer.
   SetSelectionModel(SelectionModel());
 
+  // Invalidate the cached text direction if it depends on the text contents.
+  if (directionality_mode_ == DIRECTIONALITY_FROM_TEXT)
+    text_direction_ = base::i18n::UNKNOWN_DIRECTION;
+
   ResetLayout();
 }
 
 void RenderText::SetHorizontalAlignment(HorizontalAlignment alignment) {
   if (horizontal_alignment_ != alignment) {
     horizontal_alignment_ = alignment;
     display_offset_ = Point();
     cached_bounds_and_offset_valid_ = false;
   }
 }
@@ skipping 182 matching lines @@
 
 void RenderText::ApplyDefaultStyle() {
   style_ranges_.clear();
   StyleRange style = StyleRange(default_style_);
   style.range.set_end(text_.length());
   style_ranges_.push_back(style);
   cached_bounds_and_offset_valid_ = false;
   ResetLayout();
 }
 
+void RenderText::SetDirectionalityMode(DirectionalityMode mode) {
+  if (mode == directionality_mode_)
+    return;
+
+  directionality_mode_ = mode;
+  text_direction_ = base::i18n::UNKNOWN_DIRECTION;
+  ResetLayout();
+}
+
+base::i18n::TextDirection RenderText::GetTextDirection() {
+  if (text_direction_ == base::i18n::UNKNOWN_DIRECTION) {
+    switch (directionality_mode_) {
+      case DIRECTIONALITY_FROM_TEXT:
+        // Derive the direction from the display text, which differs from text()
+        // in the case of obscured (password) textfields.
+        text_direction_ =
+            base::i18n::GetFirstStrongCharacterDirection(GetDisplayText());
+        break;
+      case DIRECTIONALITY_FROM_UI:
+        text_direction_ = base::i18n::IsRTL() ? base::i18n::RIGHT_TO_LEFT :
+                                                base::i18n::LEFT_TO_RIGHT;
+        break;
+      case DIRECTIONALITY_FORCE_LTR:
+        text_direction_ = base::i18n::LEFT_TO_RIGHT;
+        break;
+      case DIRECTIONALITY_FORCE_RTL:
+        text_direction_ = base::i18n::RIGHT_TO_LEFT;
+        break;
+      default:
+        NOTREACHED();
+    }
+  }
+
+  return text_direction_;
+}
+
 VisualCursorDirection RenderText::GetVisualDirectionOfLogicalEnd() {
   return GetTextDirection() == base::i18n::LEFT_TO_RIGHT ?
       CURSOR_RIGHT : CURSOR_LEFT;
 }
 
 void RenderText::Draw(Canvas* canvas) {
   EnsureLayout();
 
   if (clip_to_display_rect()) {
     gfx::Rect clip_rect(display_rect());
@@ skipping 85 matching lines @@
   return SelectionModel(sel.start(),
                         sel.is_reversed() ? CURSOR_BACKWARD : CURSOR_FORWARD);
 }
 
 void RenderText::SetTextShadows(const ShadowValues& shadows) {
   text_shadows_ = shadows;
 }
 
 RenderText::RenderText()
     : horizontal_alignment_(base::i18n::IsRTL() ? ALIGN_RIGHT : ALIGN_LEFT),
+      directionality_mode_(DIRECTIONALITY_FROM_TEXT),
+      text_direction_(base::i18n::UNKNOWN_DIRECTION),
       cursor_enabled_(true),
       cursor_visible_(false),
       insert_mode_(true),
       cursor_color_(kDefaultCursorColor),
       selection_color_(kDefaultSelectionColor),
       selection_background_focused_color_(kDefaultSelectionBackgroundColor),
       selection_background_unfocused_color_(kDefaultSelectionBackgroundColor),
       focused_(false),
       composition_range_(ui::Range::InvalidRange()),
       obscured_(false),
@@ skipping 252 matching lines @@
   if (cursor_enabled() && cursor_visible() && focused()) {
     const Rect& bounds = GetUpdatedCursorBounds();
     if (bounds.width() != 0)
       canvas->FillRect(bounds, cursor_color_);
     else
       canvas->DrawRect(bounds, cursor_color_);
   }
 }
 
 }  // namespace gfx