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
169
170
171
|
/*
* Copyright (C) 2008-2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.gesture;
import android.view.MotionEvent;
import android.view.View;
import java.util.ArrayList;
import java.lang.ref.WeakReference;
/**
* TouchThroughGesturing implements the interaction behavior that allows a user
* to gesture over a regular UI widget such as ListView and at the same time,
* still allows a user to perform basic interactions (clicking, scrolling and panning)
* with the underlying widget.
*/
public class TouchThroughGestureListener implements GestureOverlayView.OnGestureListener {
public static final int SINGLE_STROKE = 0;
public static final int MULTIPLE_STROKE = 1;
// TODO: Add properties for all these
private static final float STROKE_LENGTH_THRESHOLD = 30;
private static final float SQUARENESS_THRESHOLD = 0.275f;
private static final float ANGLE_THRESHOLD = 40;
private boolean mIsGesturing = false;
private float mTotalLength;
private float mX;
private float mY;
private WeakReference<View> mModel;
private int mGestureType = SINGLE_STROKE;
// TODO: Use WeakReferences
private final ArrayList<OnGesturePerformedListener> mPerformedListeners =
new ArrayList<OnGesturePerformedListener>();
private boolean mStealEvents = false;
public TouchThroughGestureListener(View model) {
this(model, false);
}
public TouchThroughGestureListener(View model, boolean stealEvents) {
mModel = new WeakReference<View>(model);
mStealEvents = stealEvents;
}
/**
*
* @param type SINGLE_STROKE or MULTIPLE_STROKE
*/
public void setGestureType(int type) {
mGestureType = type;
}
public void onGestureStarted(GestureOverlayView overlay, MotionEvent event) {
if (mGestureType == MULTIPLE_STROKE) {
overlay.cancelFadingOut();
}
mX = event.getX();
mY = event.getY();
mTotalLength = 0;
mIsGesturing = false;
if (mGestureType == SINGLE_STROKE || overlay.getCurrentGesture() == null
|| overlay.getCurrentGesture().getStrokesCount() == 0) {
overlay.setGestureDrawingColor(overlay.getUncertainGestureColor());
}
dispatchEventToModel(event);
}
private void dispatchEventToModel(MotionEvent event) {
View v = mModel.get();
if (v != null) v.dispatchTouchEvent(event);
}
public void onGesture(GestureOverlayView overlay, MotionEvent event) {
//noinspection PointlessBooleanExpression
if (!mStealEvents) {
dispatchEventToModel(event);
}
if (mIsGesturing) {
return;
}
final float x = event.getX();
final float y = event.getY();
final float dx = x - mX;
final float dy = y - mY;
mTotalLength += (float) Math.sqrt(dx * dx + dy * dy);
mX = x;
mY = y;
if (mTotalLength > STROKE_LENGTH_THRESHOLD) {
final OrientedBoundingBox box =
GestureUtilities.computeOrientedBoundingBox(overlay.getCurrentStroke());
float angle = Math.abs(box.orientation);
if (angle > 90) {
angle = 180 - angle;
}
if (box.squareness > SQUARENESS_THRESHOLD || angle < ANGLE_THRESHOLD) {
mIsGesturing = true;
overlay.setGestureDrawingColor(overlay.getGestureColor());
if (mStealEvents) {
event = MotionEvent.obtain(event.getDownTime(), System.currentTimeMillis(),
MotionEvent.ACTION_UP, x, y, event.getPressure(), event.getSize(),
event.getMetaState(), event.getXPrecision(), event.getYPrecision(),
event.getDeviceId(), event.getEdgeFlags());
}
}
}
if (mStealEvents) {
dispatchEventToModel(event);
}
}
public void onGestureEnded(GestureOverlayView overlay, MotionEvent event) {
if (mIsGesturing) {
overlay.clear(true);
final ArrayList<OnGesturePerformedListener> listeners = mPerformedListeners;
final int count = listeners.size();
for (int i = 0; i < count; i++) {
listeners.get(i).onGesturePerformed(overlay, overlay.getCurrentGesture());
}
} else {
dispatchEventToModel(event);
overlay.clear(false);
}
}
public void addOnGestureActionListener(OnGesturePerformedListener listener) {
mPerformedListeners.add(listener);
}
public void removeOnGestureActionListener(OnGesturePerformedListener listener) {
mPerformedListeners.remove(listener);
}
public boolean isGesturing() {
return mIsGesturing;
}
public static interface OnGesturePerformedListener {
public void onGesturePerformed(GestureOverlayView overlay, Gesture gesture);
}
}
|
