Add RenderText DirectionalityMode enum and support; etc.

ui/gfx/text_constants.h

+
+// 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.
+
+#ifndef UI_GFX_TEXT_CONSTANTS_H_
+#define UI_GFX_TEXT_CONSTANTS_H_
+
+namespace gfx {
+
+// TODO(msw): Distinguish between logical character stops and glyph stops?
+// TODO(msw): Merge with base::i18n::BreakIterator::BreakType.
+enum BreakType {
+  CHARACTER_BREAK = 0, // Stop cursor movement on neighboring characters.

[Alexei Svitkine (slow), 2012/07/30 22:29:16]

Nit: Please put comments on the preceding line. I think there's a preference for
that style in gfx/ - I know sky has given that comment to me before.

[msw, 2012/07/31 03:03:06]

Done.

+  WORD_BREAK,          // Stop cursor movement on nearest word boundaries.
+  LINE_BREAK,          // Stop cursor movement on line ends as shown on screen.
+};
+
+// Horizontal text alignment modes.
+enum HorizontalAlignment {
+  ALIGN_LEFT = 0, // Align the text's left edge with that of its display area.
+  ALIGN_CENTER,   // Align the text's center with that of its display area.
+  ALIGN_RIGHT,    // Align the text's right edge with that of its display area.
+};
+
+// The directionality modes used to determine the base text direction.
+enum DirectionalityMode {
+  DIRECTIONALITY_FROM_TEXT = 0, // Use the first strong character's direction.
+  DIRECTIONALITY_FROM_UI,       // Use the UI locale's text reading direction.
+  DIRECTIONALITY_FORCE_LTR,     // Use LTR regardless of content or UI locale.
+  DIRECTIONALITY_FORCE_RTL,     // Use RTL regardless of content or UI locale.
+};
+
+}  // namespace gfx
+
+#endif  // UI_GFX_TEXT_CONSTANTS_H_