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
172
173
174
175
176
177
178
179
180
181
182
183
|
/*
* Copyright (C) 2010 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 com.android.browser;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.webkit.WebView;
import java.util.Map;
/**
* Manage WebView scroll events
*/
public class ScrollWebView extends WebView implements Runnable {
private ScrollListener mScrollListener;
private boolean mIsCancelled;
private boolean mBackgroundRemoved = false;
private boolean mUserInitiated = false;
private TitleBarBase mTitleBar;
private boolean mDrawCached = false;
private Bitmap mBitmap;
private Paint mCachePaint = new Paint();
/**
* @param context
* @param attrs
* @param defStyle
* @param javascriptInterfaces
*/
public ScrollWebView(Context context, AttributeSet attrs, int defStyle,
Map<String, Object> javascriptInterfaces, boolean privateBrowsing) {
super(context, attrs, defStyle, javascriptInterfaces, privateBrowsing);
}
/**
* @param context
* @param attrs
* @param defStyle
*/
public ScrollWebView(
Context context, AttributeSet attrs, int defStyle, boolean privateBrowsing) {
super(context, attrs, defStyle, privateBrowsing);
}
/**
* @param context
* @param attrs
*/
public ScrollWebView(Context context, AttributeSet attrs) {
super(context, attrs);
}
/**
* @param context
*/
public ScrollWebView(Context context) {
super(context);
}
@Override
protected int getTitleHeight() {
return (mTitleBar != null) ? mTitleBar.getEmbeddedHeight() : 0;
}
// scroll runnable implementation
public void run() {
if (!mIsCancelled && (mScrollListener != null)) {
mScrollListener.onScroll(getVisibleTitleHeight(), mUserInitiated);
}
}
void hideEmbeddedTitleBar() {
scrollBy(0, getVisibleTitleHeight());
}
@Override
public void setEmbeddedTitleBar(final View title) {
super.setEmbeddedTitleBar(title);
mTitleBar = (TitleBarBase) title;
if (title != null && mScrollListener != null) {
// allow the scroll listener to initialize its state
post(this);
}
}
public boolean hasTitleBar() {
return (mTitleBar != null);
}
@Override
public boolean onTouchEvent(MotionEvent evt) {
if (MotionEvent.ACTION_DOWN == evt.getActionMasked()) {
mUserInitiated = true;
} else if (MotionEvent.ACTION_UP == evt.getActionMasked()
|| (MotionEvent.ACTION_CANCEL == evt.getActionMasked())) {
mUserInitiated = false;
}
return super.onTouchEvent(evt);
}
@Override
public void stopScroll() {
mIsCancelled = true;
super.stopScroll();
}
@Override
protected void onScrollChanged(int l, final int t, int ol, int ot) {
super.onScrollChanged(l, t, ol, ot);
if (!mIsCancelled) {
post(this);
} else {
mIsCancelled = false;
}
}
void setScrollListener(ScrollListener l) {
mScrollListener = l;
}
@Override
public void invalidate() {
if (!mDrawCached) {
super.invalidate();
}
}
// callback for scroll events
interface ScrollListener {
public void onScroll(int visibleTitleHeight, boolean userInitiated);
}
void setDrawCached(boolean cached) {
if (cached == mDrawCached) return;
if (cached) {
buildDrawingCache();
mBitmap = getDrawingCache(false);
mDrawCached = (mBitmap != null);
} else {
mDrawCached = false;
mBitmap = null;
destroyDrawingCache();
}
}
@Override
protected void onDraw(android.graphics.Canvas c) {
if (mDrawCached) {
c.drawBitmap(mBitmap, getScrollX(), getScrollY(), mCachePaint);
} else {
super.onDraw(c);
if (!mBackgroundRemoved && getRootView().getBackground() != null) {
mBackgroundRemoved = true;
post(new Runnable() {
public void run() {
getRootView().setBackgroundDrawable(null);
}
});
}
}
}
}
|
