src/content/browser/media/capture/web_contents_tracker.cc

   1 // Copyright (c) 2013 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 #include "content/browser/media/capture/web_contents_tracker.h"
   6
   7 #include "base/message_loop/message_loop_proxy.h"
   8 #include "content/public/browser/browser_thread.h"
   9 #include "content/public/browser/render_process_host.h"
  10 #include "content/public/browser/render_view_host.h"
  11 #include "content/public/browser/web_contents.h"
  12
  13 namespace content {
  14
  15 WebContentsTracker::WebContentsTracker() {}
  16
  17 WebContentsTracker::~WebContentsTracker() {
  18   DCHECK(!web_contents()) << "BUG: Still observering!";
  19 }
  20
  21 void WebContentsTracker::Start(int render_process_id, int render_view_id,
  22                                const ChangeCallback& callback) {
  23   DCHECK(!message_loop_.get() || message_loop_->BelongsToCurrentThread());
  24
  25   message_loop_ = base::MessageLoopProxy::current();
  26   DCHECK(message_loop_.get());
  27   callback_ = callback;
  28
  29   BrowserThread::PostTask(
  30       BrowserThread::UI, FROM_HERE,
  31       base::Bind(&WebContentsTracker::LookUpAndObserveWebContents, this,
  32                  render_process_id, render_view_id));
  33 }
  34
  35 void WebContentsTracker::Stop() {
  36   DCHECK(message_loop_->BelongsToCurrentThread());
  37
  38   callback_.Reset();
  39
  40   BrowserThread::PostTask(
  41       BrowserThread::UI, FROM_HERE,
  42       base::Bind(&WebContentsTracker::Observe, this,
  43                  static_cast<WebContents*>(NULL)));
  44 }
  45
  46 void WebContentsTracker::OnWebContentsChangeEvent() {
  47   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  48
  49   WebContents* const wc = web_contents();
  50   RenderViewHost* const rvh = wc ? wc->GetRenderViewHost() : NULL;
  51   RenderProcessHost* const rph = rvh ? rvh->GetProcess() : NULL;
  52
  53   const int render_process_id = rph ? rph->GetID() : MSG_ROUTING_NONE;
  54   const int render_view_id = rvh ? rvh->GetRoutingID() : MSG_ROUTING_NONE;
  55
  56   message_loop_->PostTask(FROM_HERE,
  57       base::Bind(&WebContentsTracker::MaybeDoCallback, this,
  58                  render_process_id, render_view_id));
  59 }
  60
  61 void WebContentsTracker::MaybeDoCallback(int render_process_id,
  62                                          int render_view_id) {
  63   DCHECK(message_loop_->BelongsToCurrentThread());
  64
  65   if (!callback_.is_null())
  66     callback_.Run(render_process_id, render_view_id);
  67 }
  68
  69 void WebContentsTracker::LookUpAndObserveWebContents(int render_process_id,
  70                                                      int render_view_id) {
  71   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  72
  73   RenderViewHost* const rvh =
  74       RenderViewHost::FromID(render_process_id, render_view_id);
  75   DVLOG_IF(1, !rvh) << "RenderViewHost::FromID("
  76                     << render_process_id << ", " << render_view_id
  77                     << ") returned NULL.";
  78   Observe(rvh ? WebContents::FromRenderViewHost(rvh) : NULL);
  79   DVLOG_IF(1, !web_contents())
  80       << "WebContents::FromRenderViewHost(" << rvh << ") returned NULL.";
  81
  82   OnWebContentsChangeEvent();
  83 }
  84
  85 void WebContentsTracker::RenderViewReady() {
  86   OnWebContentsChangeEvent();
  87 }
  88
  89 void WebContentsTracker::AboutToNavigateRenderView(RenderViewHost* rvh) {
  90   OnWebContentsChangeEvent();
  91 }
  92
  93 void WebContentsTracker::DidNavigateMainFrame(
  94     const LoadCommittedDetails& details, const FrameNavigateParams& params) {
  95   OnWebContentsChangeEvent();
  96 }
  97
  98 void WebContentsTracker::WebContentsDestroyed() {
  99   OnWebContentsChangeEvent();
 100 }
 101
 102 }  // namespace content