Implement sidebar support for extension action popups

chrome/browser/extensions/sidebar_manager.h

+// Copyright (c) 2015 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 CHROME_BROWSER_EXTENSIONS_SIDEBAR_MANAGER_H_
+#define CHROME_BROWSER_EXTENSIONS_SIDEBAR_MANAGER_H_
+
+#include <map>
+#include <string>
+
+#include "base/observer_list.h"
+#include "base/strings/string16.h"
+#include "chrome/browser/extensions/sidebar_container.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+
+class GURL;
+class SidebarContainer;
+class SidebarManagerObserver;
+
+namespace content {
+class BrowserContext;
+class WebContents;
+}
+
+namespace extensions {
+///////////////////////////////////////////////////////////////////////////////
+// SidebarManager
+//
+//  This class is a singleton that manages SidebarContainer instances and
+//  maintains a connection between tabs and sidebars.
+//
+class SidebarManager : public content::NotificationObserver {
+ public:
+  // Returns SidebarManager instance registered with BrowserContext.
+  static SidebarManager* GetFromContext(content::BrowserContext* context);
+
+  SidebarManager();
+
+  // Returns SidebarContainer registered for |tab| or nullptr if there is no
+  // SidebarContainer registered for |tab|.
+  SidebarContainer* GetSidebarContainerFor(content::WebContents* tab);
+
+  // Sends sidebar state change notification to extensions.
+  void NotifyStateChanges(content::WebContents* was_active_sidebar_contents,

[Devlin, 2015/06/16 17:56:12]

When is this used?

+                          content::WebContents* active_sidebar_contents);
+
+  // Creates a new sidebar identified by |tab| (adds sidebar's mini tab).
+  void CreateSidebar(content::WebContents* tab,
+                     const GURL& url,
+                     Browser* browser);
+
+  // Hides and destroys sidebar identified by |tab| (removes sidebar's mini
+  // tab).
+  void HideSidebar(content::WebContents* tab);
+
+  // Check if |tab| has a sidebar assigned.
+  bool HasSidebar(content::WebContents* tab);
+
+  void AddObserver(SidebarManagerObserver* observer);
+  void RemoveObserver(SidebarManagerObserver* observer);
+
+  ~SidebarManager() override;
+
+ private:
+  // Overridden from content::NotificationObserver.
+  void Observe(int type,
+               const content::NotificationSource& source,
+               const content::NotificationDetails& details) override;
+
+  // Returns SidebarContainer corresponding to |sidebar_contents|.
+  SidebarContainer* FindSidebarContainerFor(
+      content::WebContents* sidebar_contents);
+
+  // Records the link between |tab| and |container|.
+  void BindSidebarContainer(content::WebContents* tab,
+                            SidebarContainer* container);
+
+  // Forgets the link between |tab| and |container|.
+  void UnbindSidebarContainer(content::WebContents* tab,
+                              SidebarContainer* container);
+
+  content::NotificationRegistrar registrar_;
+
+  // This map stores sidebars linked to a particular tab. Sidebars are
+  // identified by their unique content id (string).
+  typedef std::map<std::string, SidebarContainer*>
+      ContentIdToSidebarContainerMap;
+
+  // These two maps are for tracking dependencies between tabs and
+  // their SidebarContainers.
+  //
+  // SidebarManager start listening to SidebarContainers when they are put
+  // into these maps and removes them when they are closing.
+  typedef std::map<content::WebContents*, SidebarContainer*>

[Devlin, 2015/06/16 17:56:12]

Having two maps is probably excessive, since most users won't have that many
sidebars open, and keeping everything up to date is a bit of a pain.  I'd just
have one map, keyed on web contents, and then if you need to look up a
particular sidebar, you can just traverse it (since it will be small).

+      TabToSidebarContainerMap;
+  TabToSidebarContainerMap tab_to_sidebar_container_;
+
+  typedef std::map<SidebarContainer*, content::WebContents*>
+      SidebarContainerToTabMap;
+  SidebarContainerToTabMap sidebar_container_to_tab_;
+
+  base::ObserverList<SidebarManagerObserver> observer_list_;
+
+  DISALLOW_COPY_AND_ASSIGN(SidebarManager);
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_SIDEBAR_MANAGER_H_