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.
5 #ifndef EXTENSIONS_RENDERER_OBJECT_BACKED_NATIVE_HANDLER_H_
6 #define EXTENSIONS_RENDERER_OBJECT_BACKED_NATIVE_HANDLER_H_
11 #include "base/bind.h"
12 #include "base/memory/linked_ptr.h"
13 #include "extensions/renderer/native_handler.h"
14 #include "v8/include/v8-util.h"
15 #include "v8/include/v8.h"
17 namespace extensions
{
20 // An ObjectBackedNativeHandler is a factory for JS objects with functions on
21 // them that map to native C++ functions. Subclasses should call RouteFunction()
22 // in their constructor to define functions on the created JS objects.
23 class ObjectBackedNativeHandler
: public NativeHandler
{
25 explicit ObjectBackedNativeHandler(ScriptContext
* context
);
26 ~ObjectBackedNativeHandler() override
;
28 // Create an object with bindings to the native functions defined through
30 v8::Handle
<v8::Object
> NewInstance() override
;
32 v8::Isolate
* GetIsolate() const;
35 typedef base::Callback
<void(const v8::FunctionCallbackInfo
<v8::Value
>&)>
38 // Installs a new 'route' from |name| to |handler_function|. This means that
39 // NewInstance()s of this ObjectBackedNativeHandler will have a property
40 // |name| which will be handled by |handler_function|.
41 void RouteFunction(const std::string
& name
,
42 const HandlerFunction
& handler_function
);
44 ScriptContext
* context() const { return context_
; }
46 void Invalidate() override
;
49 // Callback for RouteFunction which routes the V8 call to the correct
50 // base::Bound callback.
51 static void Router(const v8::FunctionCallbackInfo
<v8::Value
>& args
);
53 // When RouteFunction is called we create a v8::Object to hold the data we
54 // need when handling it in Router() - this is the base::Bound function to
57 // We need a v8::Object because it's possible for v8 to outlive the
58 // base::Bound function; the lifetime of an ObjectBackedNativeHandler is the
59 // lifetime of webkit's involvement with it, not the life of the v8 context.
60 // A scenario when v8 will outlive us is if a frame holds onto the
61 // contentWindow of an iframe after it's removed.
63 // So, we use v8::Objects here to hold that data, effectively refcounting
64 // the data. When |this| is destroyed we remove the base::Bound function from
65 // the object to indicate that it shoudn't be called.
66 typedef v8::PersistentValueVector
<v8::Object
> RouterData
;
67 RouterData router_data_
;
69 ScriptContext
* context_
;
71 v8::Global
<v8::ObjectTemplate
> object_template_
;
73 DISALLOW_COPY_AND_ASSIGN(ObjectBackedNativeHandler
);
76 } // namespace extensions
78 #endif // EXTENSIONS_RENDERER_OBJECT_BACKED_NATIVE_HANDLER_H_