Add ContentViewDelegate

android_webview/native/aw_contents_io_thread_delegate.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 ANDROID_WEBVIEW_NATIVE_AW_CONTENTS_IO_THREAD_DELEGATE_H_
+#define ANDROID_WEBVIEW_NATIVE_AW_CONTENTS_IO_THREAD_DELEGATE_H_
+
+#include "base/android/scoped_java_ref.h"
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+
+class GURL;
+class InterceptedRequestData;
+class JavaDelegateMapMaintainer;
+
+namespace content {
+class RenderViewHost;
+struct Referrer;
+class WebContents;
+}
+
+namespace net {
+class URLRequest;
+}
+
+// This lets us implement URLRequest intercepting in a way that lets the
+// embedder associate URLRequests with the WebContents that the URLRequest
+// is made for.
+//
+// It is preferable to use the static getter methods to obtain a new instance
+// of the class rather than holding on to one for prolonged periods of time
+// (see note for more details).
+//
+// Note: The native AwWebContentsIoThreadDelegate instance has a Global ref to
+// the Java object. By keeping the native AwWebContentsIoThreadDelegate
+// instance alive you're also prolonging the lifetime of the Java instance, so
+// don't keep a AwWebContentsIoThreadDelegate if you don't need to.
+// It is also possible that AwWebContentsIoThreadDelegate becomes invalid when
+// you're holding on to it. This could happen if the WebContents is destroyed.
+// In that case the instance methods will noop and return default/null values.
+class AwWebContentsIoThreadDelegate {

[joth, 2012/09/11 02:06:50]

OK getting my head around this now.

I think future readers will be confused that AwWebContentsIoThreadDelegate java
& native parts have such different lifetimes. (and that one java instance will
be referenced by thousands of native instances over its lifetime). Can we think
of a different name for the native object to reflect this? FooHandle or
FooReference (or if nothing else FooProxy or FooAccessor) might be a starting
point.

[mkosiba (inactive), 2012/09/13 01:48:26]

added some comments

+ public:
+  // This will attempt to fetch the AwWebContentsIoThreadDelegate for the given
+  // |render_process_id|, |render_view_id| pair.
+  // This method can be called from any thread.
+  // An empty scoped_ptr is a valid return value.
+  static scoped_ptr<AwWebContentsIoThreadDelegate>
+      FromID(int render_process_id, int render_view_id);
+
+  static bool RegisterAwWebContentsIoThreadDelegate(JNIEnv* env);
+
+  // This method is called on the IO thread only.
+  scoped_ptr<InterceptedRequestData> ShouldInterceptRequest(
+      const net::URLRequest* request);
+
+  ~AwWebContentsIoThreadDelegate();
+
+ private:
+  friend class JavaDelegateMapMaintainer;
+
+  AwWebContentsIoThreadDelegate(const base::android::JavaRef<jobject>& obj);
+
+  // This method is called on the UI thread only.
+  void OnWebContentsDestroyed();
+
+  base::android::ScopedJavaGlobalRef<jobject> java_object_;
+
+  DISALLOW_COPY_AND_ASSIGN(AwWebContentsIoThreadDelegate);
+};
+
+#endif  // ANDROID_WEBVIEW_NATIVE_AW_CONTENTS_IO_THREAD_DELEGATE_H_