Enabling overscroll/GestureNav for Athena.

athena/content/web_activity.cc

 // Copyright 2014 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 "athena/content/web_activity.h"
 
 #include "athena/activity/public/activity_factory.h"
 #include "athena/activity/public/activity_manager.h"
 #include "athena/input/public/accelerator_manager.h"
+#include "base/command_line.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/public/browser/native_web_keyboard_event.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_delegate.h"
+#include "content/public/common/content_switches.h"
 #include "ui/views/controls/webview/unhandled_keyboard_event_handler.h"
 #include "ui/views/controls/webview/webview.h"
 #include "ui/views/focus/focus_manager.h"
 #include "ui/views/widget/widget.h"
 
 namespace athena {
 namespace {
 
 class WebActivityController : public AcceleratorHandler {
  public:
@@ skipping 188 matching lines @@
                                                       params.url));
         break;
       }
       default:
         break;
     }
     // NULL is returned if the URL wasn't opened immediately.
     return NULL;
   }
 
+  virtual bool CanOverscrollContent() const OVERRIDE {
+    const std::string value = CommandLine::ForCurrentProcess()->
+        GetSwitchValueASCII(switches::kOverscrollHistoryNavigation);
+    return value != "0";

[oshima, 2014/08/29 20:00:37]

just out of curiosity, do you know why this flag uses 1/0 value instead of just
a flag?

[mfomitchev, 2014/08/29 20:40:50]

It's actually 0/1/2.
0 = off
1 = on, default screenshot-based UI
2 = on, simple UI with no screenshots used. It shows navigation arrows that
slide in on the side when overscrolling.

[oshima, 2014/08/29 20:53:49]

I see. Would you mind updating the comment in


https://code.google.com/p/chromium/codesearch#chromium/src/content/public/com...

in separate CL?

[mfomitchev, 2014/08/29 21:15:21]

Done: https://codereview.chromium.org/519143002/

+  }
+
   virtual void AddNewContents(content::WebContents* source,
                               content::WebContents* new_contents,
                               WindowOpenDisposition disposition,
                               const gfx::Rect& initial_pos,
                               bool user_gesture,
                               bool* was_blocked) OVERRIDE {
     ActivityManager::Get()->AddActivity(
         new WebActivity(new AthenaWebView(new_contents)));
   }
 
@@ skipping 174 matching lines @@
 void WebActivity::DidUpdateFaviconURL(
     const std::vector<content::FaviconURL>& candidates) {
   ActivityManager::Get()->UpdateActivity(this);
 }
 
 void WebActivity::DidChangeThemeColor(SkColor theme_color) {
   title_color_ = theme_color;
 }
 
 }  // namespace athena