/*
* Copyright (c) 2011, the Dart project authors.
*
* Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html
*
* 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.google.dart.tools.ui.internal.viewsupport;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerFilter;
/**
* filter with a live cycle
*/
public abstract class DartViewerFilter extends ViewerFilter {
private int fCount = 0;
/*
* Overrides method from ViewerFilter
*/
@Override
public Object[] filter(Viewer viewer, Object parent, Object[] elements) {
try {
filteringStart();
return super.filter(viewer, parent, elements);
} finally {
filteringEnd();
}
}
public final void filteringEnd() {
fCount--;
if (fCount == 0) {
freeFilter();
}
}
public final void filteringStart() {
if (fCount == 0) {
initFilter();
}
fCount++;
}
protected abstract void freeFilter();
/**
* To be overridden by implement
*/
protected abstract void initFilter();
}