extensions/browser/extension_web_contents_observer.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef EXTENSIONS_BROWSER_EXTENSION_WEB_CONTENTS_OBSERVER_H_
   6 #define EXTENSIONS_BROWSER_EXTENSION_WEB_CONTENTS_OBSERVER_H_
   7
   8 #include <string>
   9
  10 #include "base/compiler_specific.h"
  11 #include "base/macros.h"
  12 #include "content/public/browser/web_contents_observer.h"
  13 #include "extensions/browser/extension_function_dispatcher.h"
  14
  15 namespace content {
  16 class BrowserContext;
  17 class RenderViewHost;
  18 class WebContents;
  19 }
  20
  21 namespace extensions {
  22 class Extension;
  23
  24 // A web contents observer used for renderer and extension processes. Grants the
  25 // renderer access to certain URL scheme patterns for extensions and notifies
  26 // the renderer that the extension was loaded.
  27 //
  28 // Extension system embedders must create an instance for every extension
  29 // WebContents. It must be a subclass so that creating an instance via
  30 // content::WebContentsUserData::CreateForWebContents() provides an object of
  31 // the correct type. For an example, see ChromeExtensionWebContentsObserver.
  32 class ExtensionWebContentsObserver
  33     : public content::WebContentsObserver,
  34       public ExtensionFunctionDispatcher::Delegate {
  35  public:
  36   // Returns the ExtensionWebContentsObserver for the given |web_contents|.
  37   static ExtensionWebContentsObserver* GetForWebContents(
  38       content::WebContents* web_contents);
  39
  40   ExtensionFunctionDispatcher* dispatcher() { return &dispatcher_; }
  41
  42  protected:
  43   explicit ExtensionWebContentsObserver(content::WebContents* web_contents);
  44   ~ExtensionWebContentsObserver() override;
  45
  46   content::BrowserContext* browser_context() { return browser_context_; }
  47
  48   // Initializes a new render frame. Subclasses should invoke this
  49   // implementation if extending.
  50   virtual void InitializeRenderFrame(
  51       content::RenderFrameHost* render_frame_host);
  52
  53   // ExtensionFunctionDispatcher::Delegate overrides.
  54   content::WebContents* GetAssociatedWebContents() const override;
  55
  56   // content::WebContentsObserver overrides.
  57
  58   // A subclass should invoke this method to finish extension process setup.
  59   void RenderViewCreated(content::RenderViewHost* render_view_host) override;
  60
  61   void RenderFrameCreated(content::RenderFrameHost* render_frame_host) override;
  62   void RenderFrameDeleted(content::RenderFrameHost* render_frame_host) override;
  63
  64   // Subclasses should call this first before doing their own message handling.
  65   bool OnMessageReceived(const IPC::Message& message,
  66                          content::RenderFrameHost* render_frame_host) override;
  67
  68   // Per the documentation in WebContentsObserver, these two methods are invoked
  69   // when a Pepper plugin instance is attached/detached in the page DOM.
  70   void PepperInstanceCreated() override;
  71   void PepperInstanceDeleted() override;
  72
  73   // Returns the extension id associated with the given |render_frame_host|, or
  74   // the empty string if there is none.
  75   std::string GetExtensionIdFromFrame(
  76       content::RenderFrameHost* render_frame_host) const;
  77
  78   // Returns the extension associated with the given |render_frame_host|, or
  79   // null if there is none.
  80   const Extension* GetExtensionFromFrame(
  81       content::RenderFrameHost* render_frame_host) const;
  82
  83   // TODO(devlin): Remove these once callers are updated to use the FromFrame
  84   // equivalents.
  85   // Returns the extension or app associated with a render view host. Returns
  86   // NULL if the render view host is not for a valid extension.
  87   const Extension* GetExtension(content::RenderViewHost* render_view_host);
  88   // Returns the extension or app ID associated with a render view host. Returns
  89   // the empty string if the render view host is not for a valid extension.
  90   static std::string GetExtensionId(content::RenderViewHost* render_view_host);
  91
  92  private:
  93   void OnRequest(content::RenderFrameHost* render_frame_host,
  94                  const ExtensionHostMsg_Request_Params& params);
  95
  96   // A helper function for initializing render frames at the creation of the
  97   // observer.
  98   void InitializeFrameHelper(content::RenderFrameHost* render_frame_host);
  99
 100   // The BrowserContext associated with the WebContents being observed.
 101   content::BrowserContext* browser_context_;
 102
 103   ExtensionFunctionDispatcher dispatcher_;
 104
 105   DISALLOW_COPY_AND_ASSIGN(ExtensionWebContentsObserver);
 106 };
 107
 108 }  // namespace extensions
 109
 110 #endif  // EXTENSIONS_BROWSER_EXTENSION_WEB_CONTENTS_OBSERVER_H_