Add JavaBoundObject

content/browser/renderer_host/java_bound_object.h

+// Copyright (c) 2011 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 CONTENT_BROWSER_RENDERER_HOST_JAVA_BOUND_OBJECT_H_
+#define CONTENT_BROWSER_RENDERER_HOST_JAVA_BOUND_OBJECT_H_
+
+#if defined(ENABLE_JAVA_BRIDGE)

[jam, 2011/11/10 17:30:20]

is this really needed? if ENABLE_JAVA_BRIDGE is not defined, then even if this
file is included, no functions of it should be used

[Steve Block, 2011/11/10 18:17:55]

I guess it's not strictly required, because the gypi excludes these files when
JAVA_BRIDGE is not defined.

The reason I used a guard is that these files use JNI and Android-specific
headers. There shouldn't be a problem, because Android should be the only
platform to enable JAVA_BRIDGE, but is this a reasonable pattern?

+
+#include <jni.h>
+#include <map>
+#include <string>
+
+#include "base/android/scoped_java_ref.h"
+#include "base/memory/linked_ptr.h"
+#include "content/browser/renderer_host/java_method.h"
+#include "third_party/npapi/bindings/npruntime.h"
+
+// Represents a Java object for use in the Java bridge. Holds a global ref to
+// the Java object and provides the ability to invoke methods on it.
+// Interrogation of the Java object for its methods is done lazily. This class
+// is not generally threadsafe. However, it does allow for instances to be
+// created and destroyed on different threads.
+class JavaBoundObject {
+ public:
+  // Takes a Java object and creates a JavaBoundObject around it. Returns an
+  // NPObject with a ref count of one which owns the JavaBoundObject.
+  static NPObject* Create(const base::android::JavaRef<jobject>& object);
+
+  virtual ~JavaBoundObject();
+
+  // Gets the underlying JavaObject from a JavaBoundObject wrapped as an
+  // NPObject.
+  static jobject GetJavaObject(NPObject* object);
+
+  // Methods to implement the NPObject callbacks.
+  bool HasMethod(const std::string& name) const;
+  bool Invoke(const std::string& name, const NPVariant* args, size_t arg_count,
+              NPVariant* result);
+
+ private:
+  explicit JavaBoundObject(const base::android::JavaRef<jobject>& object);
+
+  void EnsureMethodsAreSetUp();
+
+  base::android::ScopedJavaGlobalRef<jobject> java_object_;
+  bool are_methods_set_up_;
+
+  // A map containing the public methods of this Java object. We map from
+  // method name to Method instance. We support overloaded methods, so multiple
+  // entries in the map may have the same key. Note that we can't use
+  // scoped_ptr in STL containers as we can't copy it.
+  typedef std::multimap<std::string, linked_ptr<JavaMethod> > JavaMethodMap;
+  JavaMethodMap methods_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JavaBoundObject);
+};
+
+#endif  // defined(ENABLE_JAVA_BRIDGE)
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_JAVA_BOUND_OBJECT_H_