/*
* Copyright 2000-2014 Vaadin Ltd.
*
* 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.vaadin.client;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Node;
import com.google.gwt.user.client.ui.RootPanel;
/**
* Alternative MeasuredSize storage for IE8. Storing any information in a DOM
* element in IE8 seems to make the browser think the element has changed in a
* way that requires a reflow. To work around that, the MeasureData is instead
* stored in Map for IE8.
*
* This implementation is injected for IE8 by a replace-with definition in the
* GWT module.
*
* @author Vaadin Ltd
* @since 7.0.0
*/
public class LayoutManagerIE8 extends LayoutManager {
private Map<Element, MeasuredSize> measuredSizes = new HashMap<Element, MeasuredSize>();
// this method is needed to test for memory leaks (see
// LayoutMemoryUsageIE8ExtensionConnector) but can be private
private int getMeasuredSizesMapSize() {
return measuredSizes.size();
}
@Override
protected void setMeasuredSize(Element element, MeasuredSize measuredSize) {
if (measuredSize != null) {
measuredSizes.put(element, measuredSize);
} else {
measuredSizes.remove(element);
}
}
@Override
protected MeasuredSize getMeasuredSize(Element element,
MeasuredSize defaultSize) {
MeasuredSize measured = measuredSizes.get(element);
if (measured != null) {
return measured;
} else {
return defaultSize;
}
}
@Override
protected void cleanMeasuredSizes() {
Profiler.enter("LayoutManager.cleanMeasuredSizes");
// #12688: IE8 was leaking memory when adding&removing components.
// Uses IE specific logic to figure if an element has been removed from
// DOM or not. For removed elements the measured size is discarded.
Node rootNode = Document.get().getBody();
Iterator<Element> i = measuredSizes.keySet().iterator();
while (i.hasNext()) {
Element e = i.next();
if (!rootNode.isOrHasChild(e)) {
i.remove();
}
}
Profiler.leave("LayoutManager.cleanMeasuredSizes");
}
@Override
protected void performBrowserLayoutHacks() {
Profiler.enter("LayoutManagerIE8.performBrowserLayoutHacks");
/*
* Fixes IE8 issues where IE8 sometimes forgets to update the size of
* the containing element. To force a reflow by modifying the magical
* zoom property.
*/
Util.forceIE8Redraw(RootPanel.get().getElement());
Profiler.leave("LayoutManagerIE8.performBrowserLayoutHacks");
}
}