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
12namespace content {
13namespace {
14
15const int kMinimumDelayBetweenUpdatesMS = 100;
16
17}
18
19LoadProgressTracker::LoadProgressTracker(RenderViewImpl* render_view)
20    : render_view_(render_view),
21      tracked_frame_(NULL),
22      progress_(0.0),
23      weak_factory_(this) {
24}
25
26LoadProgressTracker::~LoadProgressTracker() {
27}
28
29void 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
41void 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
78void 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
85void 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
93