1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
|
// 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.
#include "content/browser/device_orientation/orientation.h"
#include <cmath>
#include "content/common/device_orientation_messages.h"
namespace content {
Orientation::Orientation()
: can_provide_alpha_(false),
can_provide_beta_(false),
can_provide_gamma_(false),
can_provide_absolute_(false) {
}
Orientation::~Orientation() {
}
IPC::Message* Orientation::CreateIPCMessage(int render_view_id) const {
DeviceOrientationMsg_Updated_Params params;
params.can_provide_alpha = can_provide_alpha_;
params.alpha = alpha_;
params.can_provide_beta = can_provide_beta_;
params.beta = beta_;
params.can_provide_gamma = can_provide_gamma_;
params.gamma = gamma_;
params.can_provide_absolute = can_provide_absolute_;
params.absolute = absolute_;
return new DeviceOrientationMsg_Updated(render_view_id, params);
}
// Returns true if two orientations are considered different enough that
// observers should be notified of the new orientation.
bool Orientation::ShouldFireEvent(const DeviceData* old_data) const {
scoped_refptr<const Orientation> old_orientation(
static_cast<const Orientation*>(old_data));
return IsElementSignificantlyDifferent(can_provide_alpha_,
old_orientation->can_provide_alpha(),
alpha_,
old_orientation->alpha()) ||
IsElementSignificantlyDifferent(can_provide_beta_,
old_orientation->can_provide_beta(),
beta_,
old_orientation->beta()) ||
IsElementSignificantlyDifferent(can_provide_gamma_,
old_orientation->can_provide_gamma(),
gamma_,
old_orientation->gamma()) ||
can_provide_absolute_ != old_orientation->can_provide_absolute() ||
absolute_ != old_orientation->absolute();
}
bool Orientation::IsElementSignificantlyDifferent(bool can_provide_element1,
bool can_provide_element2, double element1, double element2) {
const double kThreshold = 0.1;
if (can_provide_element1 != can_provide_element2)
return true;
if (can_provide_element1 && std::fabs(element1 - element2) >= kThreshold)
return true;
return false;
}
} // namespace content
|
