content/renderer/load_progress_tracker.cc

   1 // Copyright (c) 2012 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/renderer/load_progress_tracker.h"
   6
   7 #include "base/bind.h"
   8 #include "base/message_loop/message_loop.h"
   9 #include "content/common/view_messages.h"
  10 #include "content/renderer/render_view_impl.h"
  11
  12 namespace content {
  13 namespace {
  14
  15 const int kMinimumDelayBetweenUpdatesMS = 100;
  16
  17 }
  18
  19 LoadProgressTracker::LoadProgressTracker(RenderViewImpl* render_view)
  20     : render_view_(render_view),
  21       tracked_frame_(NULL),
  22       progress_(0.0),
  23       weak_factory_(this) {
  24 }
  25
  26 LoadProgressTracker::~LoadProgressTracker() {
  27 }
  28
  29 void LoadProgressTracker::DidStopLoading() {
  30   if (!tracked_frame_)
  31     return;
  32
  33   // Load stopped while we were still tracking load.  Make sure we notify the
  34   // browser that load is complete.
  35   progress_ = 1.0;
  36   SendChangeLoadProgress();
  37   // Then we clean-up our states.
  38   ResetStates();
  39 }
  40
  41 void LoadProgressTracker::DidChangeLoadProgress(WebKit::WebFrame* frame,
  42                                                 double progress) {
  43   if (tracked_frame_ && frame != tracked_frame_)
  44     return;
  45
  46   if (!tracked_frame_)
  47     tracked_frame_ = frame;
  48
  49   progress_ = progress;
  50
  51   // We send the progress change to the browser immediately for the first and
  52   // last updates.  Also, since the message loop may be pretty busy when a page
  53   // is loaded, it might not execute a posted task in a timely manner so we make
  54   // sure to immediately send progress report if enough time has passed.
  55   base::TimeDelta min_delay =
  56       base::TimeDelta::FromMilliseconds(kMinimumDelayBetweenUpdatesMS);
  57   if (progress == 1.0 || last_time_progress_sent_.is_null() ||
  58       base::TimeTicks::Now() - last_time_progress_sent_ >
  59       min_delay) {
  60     // If there is a pending task to send progress, it is now obsolete.
  61     weak_factory_.InvalidateWeakPtrs();
  62     SendChangeLoadProgress();
  63     if (progress == 1.0)
  64       ResetStates();
  65     return;
  66   }
  67
  68   if (weak_factory_.HasWeakPtrs())
  69     return;
  70
  71   base::MessageLoop::current()->PostDelayedTask(
  72       FROM_HERE,
  73       base::Bind(&LoadProgressTracker::SendChangeLoadProgress,
  74                  weak_factory_.GetWeakPtr()),
  75       min_delay);
  76 }
  77
  78 void LoadProgressTracker::SendChangeLoadProgress() {
  79   last_time_progress_sent_ = base::TimeTicks::Now();
  80   render_view_->Send(
  81       new ViewHostMsg_DidChangeLoadProgress(render_view_->routing_id(),
  82                                             progress_));
  83 }
  84
  85 void LoadProgressTracker::ResetStates() {
  86   tracked_frame_ = NULL;
  87   progress_ = 0.0;
  88   weak_factory_.InvalidateWeakPtrs();
  89   last_time_progress_sent_ = base::TimeTicks();
  90 }
  91
  92 }  // namespace content