browser_cld_data_provider.h revision 116680a4aac90f2aa7413d9095a592090648e557 
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 COMPONENTS_TRANSLATE_CONTENT_BROWSER_BROWSER_CLD_DATA_PROVIDER_H_
6#define COMPONENTS_TRANSLATE_CONTENT_BROWSER_BROWSER_CLD_DATA_PROVIDER_H_
7
8#include "ipc/ipc_listener.h"
9
10namespace IPC {
11class Message;
12}
13
14namespace content {
15class WebContents;
16}
17
18namespace translate {
19
20// Browser-side interface responsible for providing CLD data.
21// The implementation must be paired with a renderer-side implementation of
22// the RendererCldDataProvider class:
23//
24//   components/translate/content/renderer/renderer_cld_data_provider.h
25//
26// ... and the glue between them is typically a pair of request/response IPC
27// messages using the CldDataProviderMsgStart IPCMessageStart enumerated
28// constant from ipc_message_start.h
29class BrowserCldDataProvider : public IPC::Listener {
30 public:
31  virtual ~BrowserCldDataProvider() {}
32
33  // IPC::Listener implementation:
34  // If the specified message is a request for CLD data, invokes
35  // OnCldDataRequest() and returns true. In all other cases, this method does
36  // nothing. This method is defined as virtual in order to force the
37  // implementation to define the specific IPC message(s) that it handles.
38  virtual bool OnMessageReceived(const IPC::Message&) = 0;
39
40  // Called when the browser process receives an appropriate message in
41  // OnMessageReceived, above. The implementation should attempt to locate
42  // the CLD data, cache any metadata required for accessing that data, and
43  // ultimately trigger a response by invoking SendCldDataResponse.
44  //
45  // The renderer process may poll for data, in which case this method may be
46  // repeatedly invoked. The implementation must be safe to call any number
47  // of times.
48  virtual void OnCldDataRequest() = 0;
49
50  // Invoked when OnCldDataRequest, above, results in a successful lookup or
51  // the data is already cached and ready to respond to. The implementation
52  // should take whatever action is appropriate for responding to the paired
53  // RendererCldDataProvider, typically by sending an IPC response.
54  virtual void SendCldDataResponse() = 0;
55};
56
57// Static factory function defined by the implementation that produces a new
58// provider for the specified WebContents.
59BrowserCldDataProvider* CreateBrowserCldDataProviderFor(
60    content::WebContents*);
61
62}  // namespace translate
63
64#endif  // COMPONENTS_TRANSLATE_CONTENT_BROWSER_BROWSER_CLD_DATAP_PROVIDER_H_
65