Merge "Prevent infinite resizes in webview"

This commit is contained in:
Ben Komalo 2011-08-11 17:58:20 -07:00 committed by Android (Google) Code Review
commit 7c98d35990
3 changed files with 106 additions and 6 deletions

View File

@ -218,7 +218,7 @@
android:layout_weight="1"
android:layout_marginLeft="14dip"
android:layout_marginRight="14dip"
android:background="#ffffffff"
android:background="@android:color/white"
android:visibility="gone"
/>

View File

@ -150,17 +150,14 @@
<!-- end of tab area -->
<!--
content area - only one of them is visible at a time.
TODO Decide what to do with the scrollview+webview issue, and remove the scrollviews
below if we go with the outer scrollview.
-->
<WebView
<com.android.email.view.RigidWebView
android:id="@+id/message_content"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="16dip"
android:layout_marginRight="16dip"
android:background="#ffffff"
android:background="@android:color/white"
android:visibility="gone"
/>
<!--

View File

@ -0,0 +1,103 @@
/*
* Copyright (C) 2011 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.email.view;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.webkit.WebView;
import com.android.email.Clock;
import com.android.email.Email;
import com.android.email.Throttle;
import com.android.emailcommon.Logging;
import com.android.emailcommon.utility.Utility;
/**
* A custom WebView that is robust to rapid resize events in sequence.
*
* This is useful for a WebView which needs to have a layout of {@code WRAP_CONTENT}, since any
* contents with percent-based height will force the WebView to infinitely expand (or shrink).
*/
public class RigidWebView extends WebView {
public RigidWebView(Context context) {
super(context);
}
public RigidWebView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public RigidWebView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
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(getClass().getName(),
new Runnable() {
@Override public void run() {
performSizeChangeDelayed();
}
}, Utility.getMainThreadHandler(),
MIN_RESIZE_INTERVAL, MAX_RESIZE_INTERVAL);
private int mRealWidth;
private int mRealHeight;
private boolean mIgnoreNext;
private long mLastSizeChangeTime = -1;
@Override
protected void onSizeChanged(int w, int h, int ow, int oh) {
mRealWidth = w;
mRealHeight = h;
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) {
if (Email.DEBUG) {
Log.w(Logging.LOG_TAG, "Supressing size change in RigidWebView");
}
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());
}
}