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/*
* Copyright (C) 2013 Google Inc.
* Licensed to 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.mail.browse;
import android.content.Context;
import android.os.Handler;
import android.os.Looper;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.webkit.WebView;
import com.android.mail.utils.Clock;
import com.android.mail.utils.LogTag;
import com.android.mail.utils.LogUtils;
import com.android.mail.utils.Throttle;
/**
* A WebView designed to live within a {@link MessageScrollView}.
*/
public class MessageWebView extends WebView implements MessageScrollView.Touchable {
private static final String LOG_TAG = LogTag.getLogTag();
private static Handler sMainThreadHandler;
private boolean mTouched;
private static final int MIN_RESIZE_INTERVAL = 200;
private static final int MAX_RESIZE_INTERVAL = 300;
private final Clock mClock = Clock.INSTANCE;
private final Throttle mThrottle = new Throttle("MessageWebView",
new Runnable() {
@Override public void run() {
performSizeChangeDelayed();
}
}, getMainThreadHandler(),
MIN_RESIZE_INTERVAL, MAX_RESIZE_INTERVAL);
private int mRealWidth;
private int mRealHeight;
private boolean mIgnoreNext;
private long mLastSizeChangeTime = -1;
public MessageWebView(Context c) {
this(c, null);
}
public MessageWebView(Context c, AttributeSet attrs) {
super(c, attrs);
}
@Override
public boolean wasTouched() {
return mTouched;
}
@Override
public void clearTouched() {
mTouched = false;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
mTouched = true;
final boolean handled = super.onTouchEvent(event);
LogUtils.d(MessageScrollView.LOG_TAG,"OUT WebView.onTouch, returning handled=%s ev=%s",
handled, event);
return handled;
}
@Override
protected void onSizeChanged(int w, int h, int ow, int oh) {
mRealWidth = w;
mRealHeight = h;
final long now = mClock.getTime();
boolean recentlySized = (now - mLastSizeChangeTime < MIN_RESIZE_INTERVAL);
// It's known that the previous resize event may cause a resize event immediately. If
// this happens sufficiently close to the last resize event, drop it on the floor.
if (mIgnoreNext) {
mIgnoreNext = false;
if (recentlySized) {
LogUtils.w(LOG_TAG, "Suppressing size change in MessageWebView");
return;
}
}
if (recentlySized) {
mThrottle.onEvent();
} else {
// It's been a sufficiently long time - just perform the resize as normal. This should
// be the normal code path.
performSizeChange(ow, oh);
}
}
private void performSizeChange(int ow, int oh) {
super.onSizeChanged(mRealWidth, mRealHeight, ow, oh);
mLastSizeChangeTime = mClock.getTime();
}
private void performSizeChangeDelayed() {
mIgnoreNext = true;
performSizeChange(getWidth(), getHeight());
}
/**
* @return a {@link Handler} tied to the main thread.
*/
public static Handler getMainThreadHandler() {
if (sMainThreadHandler == null) {
// No need to synchronize -- it's okay to create an extra Handler, which will be used
// only once and then thrown away.
sMainThreadHandler = new Handler(Looper.getMainLooper());
}
return sMainThreadHandler;
}
}
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