Lazy load chrome.* APIs

chrome/renderer/extensions/native_handler.h

 // Copyright (c) 2012 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_RENDERER_EXTENSIONS_NATIVE_HANDLER_H_
 #define CHROME_RENDERER_EXTENSIONS_NATIVE_HANDLER_H_
 
-#include "base/bind.h"
-#include "base/memory/linked_ptr.h"
-#include "chrome/renderer/extensions/scoped_persistent.h"
+#include "base/basictypes.h"
 #include "v8/include/v8.h"
 
-#include <string>
-#include <vector>
-
 namespace extensions {
 
-// A NativeHandler is a factory for JS objects with functions on them that map
-// to native C++ functions. Subclasses should call RouteFunction() in their
-// constructor to define functions on the created JS objects.
-//
 // NativeHandlers are intended to be used with a ModuleSystem. The ModuleSystem
 // will assume ownership of the NativeHandler, and as a ModuleSystem is tied to
 // a single v8::Context, this implies that NativeHandlers will also be tied to
-// a single v8::context.
+// a single v8::Context.
 // TODO(koz): Rename this to NativeJavaScriptModule.
 class NativeHandler {
  public:
-  explicit NativeHandler(v8::Isolate* isolate);
+  NativeHandler();
   virtual ~NativeHandler();
 
-  // Create an object with bindings to the native functions defined through
-  // RouteFunction().
-  virtual v8::Handle<v8::Object> NewInstance();
+  // Create a new instance of the object this handler specifies.
+  virtual v8::Handle<v8::Object> NewInstance() = 0;
+
+  // Invalidate this object so it cannot be used any more. This is needed
+  // because it's possible for this to outlive its owner context. Invalidate
+  // must be called before this happens.
+  //
+  // Subclasses should override to invalidate their own V8 state. If they do
+  // they must call their superclass' Invalidate().
+  virtual void Invalidate();
 
  protected:
-  typedef v8::Handle<v8::Value> (*HandlerFunc)(const v8::Arguments&);
-  typedef base::Callback<v8::Handle<v8::Value>(const v8::Arguments&)>
-      HandlerFunction;
-
-  // Installs a new 'route' from |name| to |handler_function|. This means that
-  // NewInstance()s of this NativeHandler will have a property |name| which
-  // will be handled by |handler_function|.
-  void RouteFunction(const std::string& name,
-                     const HandlerFunction& handler_function);
-
-  void RouteStaticFunction(const std::string& name,
-                           const HandlerFunc handler_func);
+  // Allow subclasses to query valid state.
+  bool is_valid() { return is_valid_; }
 
  private:
-  static v8::Handle<v8::Value> Router(const v8::Arguments& args);
-
-  std::vector<linked_ptr<HandlerFunction> > handler_functions_;
-  ScopedPersistent<v8::ObjectTemplate> object_template_;
+  bool is_valid_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeHandler);
 };
 
 }  // extensions
 
 #endif  // CHROME_RENDERER_EXTENSIONS_NATIVE_HANDLER_H_