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
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
// Copyright 2013 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/renderer_host/input/synthetic_pinch_gesture.h"
#include <cmath>
#include "base/logging.h"
#include "ui/events/latency_info.h"
namespace content {
SyntheticPinchGesture::SyntheticPinchGesture(
const SyntheticPinchGestureParams& params)
: params_(params),
start_y_0_(0.0f),
start_y_1_(0.0f),
gesture_source_type_(SyntheticGestureParams::DEFAULT_INPUT),
state_(SETUP) {
DCHECK_GE(params_.total_num_pixels_covered, 0);
}
SyntheticPinchGesture::~SyntheticPinchGesture() {}
SyntheticGesture::Result SyntheticPinchGesture::ForwardInputEvents(
const base::TimeTicks& timestamp, SyntheticGestureTarget* target) {
if (state_ == SETUP) {
gesture_source_type_ = params_.gesture_source_type;
if (gesture_source_type_ == SyntheticGestureParams::DEFAULT_INPUT)
gesture_source_type_ = target->GetDefaultSyntheticGestureSourceType();
if (!target->SupportsSyntheticGestureSourceType(gesture_source_type_))
return SyntheticGesture::GESTURE_SOURCE_TYPE_NOT_SUPPORTED_BY_PLATFORM;
state_ = STARTED;
start_time_ = timestamp;
}
DCHECK_NE(gesture_source_type_, SyntheticGestureParams::DEFAULT_INPUT);
if (gesture_source_type_ == SyntheticGestureParams::TOUCH_INPUT)
ForwardTouchInputEvents(timestamp, target);
else
return SyntheticGesture::GESTURE_SOURCE_TYPE_NOT_IMPLEMENTED;
return (state_ == DONE) ? SyntheticGesture::GESTURE_FINISHED
: SyntheticGesture::GESTURE_RUNNING;
}
void SyntheticPinchGesture::ForwardTouchInputEvents(
const base::TimeTicks& timestamp, SyntheticGestureTarget* target) {
switch (state_) {
case STARTED:
// Check for an early finish.
if (params_.total_num_pixels_covered == 0) {
state_ = DONE;
break;
}
SetupCoordinatesAndStopTime(target);
PressTouchPoints(target, timestamp);
state_ = MOVING;
break;
case MOVING: {
base::TimeTicks event_timestamp = ClampTimestamp(timestamp);
float delta = GetDeltaForPointer0AtTime(event_timestamp);
MoveTouchPoints(target, delta, event_timestamp);
if (HasReachedTarget(event_timestamp)) {
ReleaseTouchPoints(target, event_timestamp);
state_ = DONE;
}
} break;
case SETUP:
NOTREACHED() << "State SETUP invalid for synthetic pinch.";
case DONE:
NOTREACHED() << "State DONE invalid for synthetic pinch.";
}
}
void SyntheticPinchGesture::PressTouchPoints(SyntheticGestureTarget* target,
const base::TimeTicks& timestamp) {
touch_event_.PressPoint(params_.anchor.x(), start_y_0_);
touch_event_.PressPoint(params_.anchor.x(), start_y_1_);
ForwardTouchEvent(target, timestamp);
}
void SyntheticPinchGesture::MoveTouchPoints(SyntheticGestureTarget* target,
float delta,
const base::TimeTicks& timestamp) {
// The two pointers move in opposite directions.
float current_y_0 = start_y_0_ + delta;
float current_y_1 = start_y_1_ - delta;
// The current pointer positions are stored as float but the pointer
// coordinates of the input event are integers. Floor both positions so that
// in case of an odd distance one of the pointers (the one whose position goes
// down) moves one pixel further than the other. The explicit flooring is only
// needed for negative values.
touch_event_.MovePoint(0, params_.anchor.x(), floor(current_y_0));
touch_event_.MovePoint(1, params_.anchor.x(), floor(current_y_1));
ForwardTouchEvent(target, timestamp);
}
void SyntheticPinchGesture::ReleaseTouchPoints(
SyntheticGestureTarget* target, const base::TimeTicks& timestamp) {
touch_event_.ReleasePoint(0);
touch_event_.ReleasePoint(1);
ForwardTouchEvent(target, timestamp);
}
void SyntheticPinchGesture::ForwardTouchEvent(
SyntheticGestureTarget* target, const base::TimeTicks& timestamp) {
touch_event_.timeStampSeconds = ConvertTimestampToSeconds(timestamp);
target->DispatchInputEventToPlatform(touch_event_);
}
void SyntheticPinchGesture::SetupCoordinatesAndStopTime(
SyntheticGestureTarget* target) {
const int kTouchSlopInDips = target->GetTouchSlopInDips();
params_.total_num_pixels_covered += 2 * kTouchSlopInDips;
float inner_distance_to_anchor = 2 * kTouchSlopInDips;
float outer_distance_to_anchor =
inner_distance_to_anchor + params_.total_num_pixels_covered / 2.0f;
// Move pointers away from each other to zoom in
// or towards each other to zoom out.
if (params_.zoom_in) {
start_y_0_ = params_.anchor.y() - inner_distance_to_anchor;
start_y_1_ = params_.anchor.y() + inner_distance_to_anchor;
} else {
start_y_0_ = params_.anchor.y() - outer_distance_to_anchor;
start_y_1_ = params_.anchor.y() + outer_distance_to_anchor;
}
int64 total_duration_in_us = static_cast<int64>(
1e6 * (static_cast<double>(params_.total_num_pixels_covered) /
params_.relative_pointer_speed_in_pixels_s));
DCHECK_GT(total_duration_in_us, 0);
stop_time_ =
start_time_ + base::TimeDelta::FromMicroseconds(total_duration_in_us);
}
float SyntheticPinchGesture::GetDeltaForPointer0AtTime(
const base::TimeTicks& timestamp) const {
float total_abs_delta;
// Make sure the final delta is correct. Using the computation below can lead
// to issues with floating point precision.
if (HasReachedTarget(timestamp))
total_abs_delta = params_.total_num_pixels_covered;
else
total_abs_delta = params_.relative_pointer_speed_in_pixels_s *
(timestamp - start_time_).InSecondsF();
float abs_delta_pointer_0 = total_abs_delta / 2.0f;
return params_.zoom_in ? -abs_delta_pointer_0 : abs_delta_pointer_0;
}
base::TimeTicks SyntheticPinchGesture::ClampTimestamp(
const base::TimeTicks& timestamp) const {
return std::min(timestamp, stop_time_);
}
bool SyntheticPinchGesture::HasReachedTarget(const base::TimeTicks& timestamp)
const {
return timestamp >= stop_time_;
}
} // namespace content
|
