This CL fixes issue 6099 -- bad display of multi-line English message in pop ups.

(http://crbug.com/6099)

Currently, in RTL locales, a pure *multi-line* English message is displayed as right aligned and has RTL directionality (such as the ending punctuation appears at the very left).

Single-line message works fine.

I do not know why, but simply putting LRE-PDF around a multi-line English text which has the following flags 
DT_WORDBREAK | DT_RTLREADING 
wont render the English message as LTR.
We have to remove the DT_RTLREADING to render multi-line English message correctly in LTR direction.


The fix is that in RTL locales, for JavaScript message, if the message is pure English, the alignment is set to be left-aligned, and the directionality is set to be left-to-right. If the message is mixed BiDi text, the alignment and the directionality is determined by the directionality of the first character with strong directionality in the text. 

JavaScript message is a MessageBoxView, and the message is a view::Label. Both MessageBoxView and Label are used by Chrome's UI  as well.
If the message is one of Chrome UI's, the alignment and directionality of the message should be taken from that of the UI's.

In order to distinguish where the message comes from, a new flag kFlagWebMessage is introduced in MessageBoxView, and a new argument is introduced in Label::SetHorizontalAlignment() to control whether the alignment need to be flipped or not for RTL locales.

Consequently, quite a few files which calls Label::SetHorizontalAlignment() are changed.

The main changes are in 5 areas. Other files are changed due to the signature change of Label::SetHorizontalAlignment().

1. jsmessage_box_handler.cc: pass in extra flag kFlagWebPage when creating MessageBoxView to indicate the message box is one from a web page, not from Chrome UI.

2. l10n_util.h/.cc
added function GetFirstStrongDirection()

3. label.h/.cc
a new argument is introduced in Label::SetHorizontalAlignment() to control whether the alignment need to be flipped or not for RTL locales.

4. message_box_view.cc
when init message box view, if the flag is kFlagWebPage, get the text directionality from the text itself (not Chrome UI's) and calls Label::SetHorizontalAlignment() to not resetting the flag for RTL locales.

5. chrome_canvas_win.cc
5.1 ComputeFormatFlags()
only set flag DT_RTLREADING for RTL locales if the text contains strong RTL characters and the alignment is RIGHT aligned. All labels of Chrome's UI and other Chrome UI components in RTL locales have been set as (or flipped to) RIGHT aligned. 

5.2 DoDrawText()
Only adjust string for locale is the reading direction is DT_RTLREADING.



Review URL: http://codereview.chromium.org/18863

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@10178 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 16 insertions, 0 deletions

diff --git a/chrome/views/message_box_view.h b/chrome/views/message_box_view.h
index a8f0dca..e71db2c 100644
--- a/chrome/views/message_box_view.h
+++ b/chrome/views/message_box_view.h
@@ -25,6 +25,22 @@ class MessageBoxView : public views::View {
   static const int kFlagHasPromptField = 0x4;
   static const int kFlagHasMessage = 0x8;
 
+  // The following flag is used to indicate whether the message's alignment
+  // should be autodetected or inherited from Chrome UI. Callers should pass
+  // the correct flag based on the origin of the message. If the message is
+  // from a web page (such as the JavaScript alert message), its alignment and
+  // directionality are based on the first character with strong directionality
+  // in the message. Chrome UI strings are localized string and therefore they
+  // should have the same alignment and directionality as those of the Chrome
+  // UI. For example, in RTL locales, even though some strings might begin with
+  // an English character, they should still be right aligned and be displayed
+  // Right-To-Left.
+  //
+  // TODO(xji): If the message is from a web page, then the message
+  // directionality should be determined based on the directionality of the web
+  // page. Please refer to http://crbug.com/7166 for more information.
+  static const int kAutoDetectAlignment = 0x10;
+
   static const int kIsConfirmMessageBox = kFlagHasMessage |
                                           kFlagHasOKButton |
                                           kFlagHasCancelButton;