Views Textfield: Handle Ctrl+Shift direction and layout changes.

Implement NativeTextfieldViews::ChangeTextDirectionAndLayoutAlignment.
(already called by Windows IMEs InputMethodWin/InputMethodBridge)
Change the RenderText's directionality and schedule paint.
(no alignment changes are made, as per aharon's suggestion)

Force LTR/RTL directionality modes as indicated, except:
Restore text directionality when indicated == current forced.
(helps manage BiDi layout without getting stuck in forced LTR/RTL)
This behavior is nuanced and I'll gladly consider other suggestions.

Expose RenderText::directionality_mode; clobber bounds on changes.
(for clever directionality handling, and updating cursor bounds)

Fix IMM32Manager::IsCtrlShiftPressed code for odd F-22 behavior.
Pressing F-10 in another app causes F-22 to get stuck 'pressed'?
(without this, textfields could get stuck in forced LTR/RTL mode)

TODO(followup): Fix IME calling on ChromeOS and Linux Aura.

BUG=310313
TEST=Ctrl+[Left-|Right-]Shift changes text in textfields and the omnibox.
R=pkasting@chromium.org,nona@chromium.org,yukawa@chromium.org,aharon@chromium.org

Review URL: https://codereview.chromium.org/60743002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233754 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 20 insertions, 3 deletions

diff --git a/ui/base/ime/win/imm32_manager.cc b/ui/base/ime/win/imm32_manager.cc
index d418f61..093b010 100644
--- a/ui/base/ime/win/imm32_manager.cc
+++ b/ui/base/ime/win/imm32_manager.cc
@@ -605,6 +605,10 @@ bool IMM32Manager::IsCtrlShiftPressed(base::i18n::TextDirection* direction) {
   keystate[VK_CONTROL] = 0;
   keystate[VK_RCONTROL] = 0;
   keystate[VK_LCONTROL] = 0;
+  // Oddly, pressing F10 in another application seemingly breaks all subsequent
+  // calls to GetKeyboardState regarding the state of the F22 key. Perhaps this
+  // defect is limited to my keyboard driver, but ignoring F22 should be okay.
+  keystate[VK_F22] = 0;
   for (int i = 0; i <= VK_PACKET; ++i) {
     if (keystate[i] & kKeyDownMask)
       return false;
diff --git a/ui/gfx/render_text.cc b/ui/gfx/render_text.cc
index 4761538..2c062a5 100644
--- a/ui/gfx/render_text.cc
+++ b/ui/gfx/render_text.cc
@@ -626,6 +626,7 @@ void RenderText::SetDirectionalityMode(DirectionalityMode mode) {
 
   directionality_mode_ = mode;
   text_direction_ = base::i18n::UNKNOWN_DIRECTION;
+  cached_bounds_and_offset_valid_ = false;
   ResetLayout();
 }
 
diff --git a/ui/gfx/render_text.h b/ui/gfx/render_text.h
index 6d998de..09e8e88 100644
--- a/ui/gfx/render_text.h
+++ b/ui/gfx/render_text.h
@@ -307,8 +307,11 @@ class GFX_EXPORT RenderText {
   // RenderText.
   bool GetStyle(TextStyle style) const;
 
-  // Set the text directionality mode and get the text direction yielded.
+  // Set or get the text directionality mode and get the text direction yielded.
   void SetDirectionalityMode(DirectionalityMode mode);
+  DirectionalityMode directionality_mode() const {
+      return directionality_mode_;
+  }
   base::i18n::TextDirection GetTextDirection();
 
   // Returns the visual movement direction corresponding to the logical end
diff --git a/ui/views/controls/textfield/native_textfield_views.cc b/ui/views/controls/textfield/native_textfield_views.cc
index 749de28..6d4199a 100644
--- a/ui/views/controls/textfield/native_textfield_views.cc
+++ b/ui/views/controls/textfield/native_textfield_views.cc
@@ -1090,8 +1090,17 @@ void NativeTextfieldViews::OnInputMethodChanged() {
 
 bool NativeTextfieldViews::ChangeTextDirectionAndLayoutAlignment(
     base::i18n::TextDirection direction) {
-  NOTIMPLEMENTED();
-  return false;
+  // Restore text directionality mode when the indicated direction matches the
+  // current forced mode; otherwise, force the mode indicated. This helps users
+  // manage BiDi text layout without getting stuck in forced LTR or RTL modes.
+  const gfx::DirectionalityMode mode = direction == base::i18n::RIGHT_TO_LEFT ?
+      gfx::DIRECTIONALITY_FORCE_RTL : gfx::DIRECTIONALITY_FORCE_LTR;
+  if (mode == GetRenderText()->directionality_mode())
+    GetRenderText()->SetDirectionalityMode(gfx::DIRECTIONALITY_FROM_TEXT);
+  else
+    GetRenderText()->SetDirectionalityMode(mode);
+  SchedulePaint();
+  return true;
 }
 
 void NativeTextfieldViews::ExtendSelectionAndDelete(