Enforce the page title direction

content/renderer/render_view.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 "content/renderer/render_view.h"
 
 #include <algorithm>
 #include <cmath>
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
+#include "base/i18n/rtl.h"
 #include "base/json/json_writer.h"
 #include "base/lazy_instance.h"
 #include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/string_piece.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
@@ skipping 210 matching lines @@
 using base::TimeDelta;
 using webkit_glue::AltErrorPageResourceFetcher;
 using webkit_glue::FormField;
 using webkit_glue::PasswordForm;
 using webkit_glue::PasswordFormDomManager;
 using webkit_glue::ResourceFetcher;
 using webkit_glue::WebAccessibility;
 
 //-----------------------------------------------------------------------------
 
+namespace {
+
+// Return true if the character is known to be a strong LTR character.
+// A false return value can mean it's not an LTR character or just that
+// it's a strongly LTR character not in the set we test.
+// Used as a fast-path for the common case of LTR text.
+bool IsStronglyLTR(char16 ch) {

[brettw, 2011/07/29 17:14:00]

If the check in rtl.h is slow, it seems like it might be worthwhile to move this
function in there so everybody calling the Wrap function can take advantage of
the fast path.

It might also be nice to name this "Fast" or something since it doesn't actually
do a real check for strong LTR (which would be more complex & slow).

[Evan Martin, 2011/07/30 00:05:15]

It's more that the function in rtl.h actually scans the string looking for a
strongly directional character, while in this code I'm interested in whether the
*first* character is strongly RTL.

I will try to think of a better name.

+  return (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z');
+}
+
+}  // namespace
+
 typedef std::map<WebKit::WebView*, RenderView*> ViewMap;
 static base::LazyInstance<ViewMap> g_view_map(base::LINKER_INITIALIZED);
 
 // Time, in seconds, we delay before sending content state changes (such as form
 // state and scroll position) to the browser. We delay sending changes to avoid
 // spamming the browser.
 // To avoid having tab/session restore require sending a message to get the
 // current content state during tab closing we use a shorter timeout for the
 // foreground renderer. This means there is a small window of time from which
 // content state is modified and not sent to session restore, but this is
@@ skipping 915 matching lines @@
 
   // Check if the navigation was within the same page, in which case we don't
   // want to clear the accessibility cache.
   if (accessibility_.get() && !navigation_state->was_within_same_page()) {
     accessibility_.reset();
     pending_accessibility_notifications_.clear();
   }
 }
 
 // Tell the embedding application that the title of the active page has changed
-void RenderView::UpdateTitle(WebFrame* frame, const string16& title) {
-  // Ignore all but top level navigations...
-  if (!frame->parent()) {
-    Send(new ViewHostMsg_UpdateTitle(
-        routing_id_,
-        page_id_,
-        title.length() > content::kMaxTitleChars ?
-            title.substr(0, content::kMaxTitleChars) : title));
+void RenderView::UpdateTitle(WebFrame* frame, const string16& title,
+                             WebTextDirection title_direction) {
+  // Ignore all but top level navigations.
+  if (frame->parent())
+    return;
+
+  string16 fixed_title = title.substr(0, content::kMaxTitleChars);
+
+  // Wrap with extra Unicode formatting to make the title strongly directional.
+  if (!fixed_title.empty()) {
+    if (title_direction == WebKit::WebTextDirectionLeftToRight) {
+      // To avoid needing to complicate tests that only use ASCII characters,
+      // special-case out some known strongly directional characters.
+      if (!IsStronglyLTR(title[0]))
+        base::i18n::WrapStringWithLTRFormatting(&fixed_title);
+    } else {
+      base::i18n::WrapStringWithRTLFormatting(&fixed_title);
+    }
   }
+
+  Send(new ViewHostMsg_UpdateTitle(routing_id_, page_id_, fixed_title));
 }
 
 void RenderView::UpdateEncoding(WebFrame* frame,
                                 const std::string& encoding_name) {
   // Only update main frame's encoding_name.
   if (webview()->mainFrame() == frame &&
       last_encoding_name_ != encoding_name) {
     // Save the encoding name for later comparing.
     last_encoding_name_ = encoding_name;
 
@@ skipping 1324 matching lines @@
     if (frame == webview()->mainFrame())
       Send(new ViewHostMsg_DocumentAvailableInMainFrame(routing_id_));
   }
 
   FOR_EACH_OBSERVER(RenderViewObserver, observers_,
                     DidCreateDocumentElement(frame));
 }
 
 void RenderView::didReceiveTitle(WebFrame* frame, const WebString& title,
                                  WebTextDirection direction) {
-  // TODO: pass direction through various APIs.
-  // http://code.google.com/p/chromium/issues/detail?id=79903
-  UpdateTitle(frame, title);
+  UpdateTitle(frame, title, direction);
 
   // Also check whether we have new encoding name.
   UpdateEncoding(frame, frame->view()->pageEncoding().utf8());
 }
 
 void RenderView::didChangeIcon(WebFrame* frame, WebIconURL::Type type) {
   FOR_EACH_OBSERVER(RenderViewObserver, observers_,
                     DidChangeIcon(frame, type));
 }
 
@@ skipping 44 matching lines @@
   // existing navigation state to a content-initiated navigation state.
   // DidCreateDataSource conveniently takes care of this for us.
   didCreateDataSource(frame, frame->dataSource());
 
   NavigationState* new_state =
       NavigationState::FromDataSource(frame->dataSource());
   new_state->set_was_within_same_page(true);
 
   didCommitProvisionalLoad(frame, is_new_navigation);
 
-  UpdateTitle(frame, frame->view()->mainFrame()->dataSource()->pageTitle());
+  // TODO(evan): update this to use ->pageTitleDirection() once we pull in new
+  // WebKit.
+  // http://code.google.com/p/chromium/issues/detail?id=27094
+  UpdateTitle(frame, frame->view()->mainFrame()->dataSource()->pageTitle(),
+              WebKit::WebTextDirectionLeftToRight);
 }
 
 void RenderView::didUpdateCurrentHistoryItem(WebFrame* frame) {
   StartNavStateSyncTimerIfNecessary();
 }
 
 void RenderView::assignIdentifierToRequest(
     WebFrame* frame, unsigned identifier, const WebURLRequest& request) {
   // Ignore
 }
@@ skipping 1778 matching lines @@
 }
 #endif
 
 void RenderView::OnContextMenuClosed(
     const webkit_glue::CustomContextMenuContext& custom_context) {
   if (custom_context.is_pepper_menu)
     pepper_delegate_.OnContextMenuClosed(custom_context);
   else
     context_menu_node_.reset();
 }