/*
* Copyright 2015 Red Hat, Inc. and/or its affiliates.
*
* 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 org.uberfire.ext.wires.core.grids.client.widget.layer.impl;
import java.util.Comparator;
import java.util.Iterator;
import java.util.SortedSet;
import java.util.TreeSet;
import com.google.gwt.animation.client.AnimationScheduler;
import com.google.gwt.user.client.Command;
import org.uberfire.commons.validation.PortablePreconditions;
public class GridLayerRedrawManager {
private static final GridLayerRedrawManager instance = new GridLayerRedrawManager();
private final Comparator<PrioritizedCommand> COMPARATOR = new Comparator<PrioritizedCommand>() {
@Override
public int compare(final PrioritizedCommand o1,
final PrioritizedCommand o2) {
return o1.getPriority() - o2.getPriority();
}
};
SortedSet<PrioritizedCommand> commands = new TreeSet<PrioritizedCommand>(COMPARATOR);
private AnimationScheduler.AnimationCallback callback;
private GridLayerRedrawManager() {
callback = new AnimationScheduler.AnimationCallback() {
@Override
public void execute(double time) {
final SortedSet<PrioritizedCommand> clone = commands;
commands = new TreeSet<PrioritizedCommand>(COMPARATOR);
if (!clone.isEmpty()) {
final Iterator<PrioritizedCommand> itr = clone.iterator();
while (itr.hasNext()) {
final PrioritizedCommand command = itr.next();
command.execute();
}
}
}
};
}
public static final GridLayerRedrawManager get() {
return instance;
}
public void schedule(final PrioritizedCommand command) {
PortablePreconditions.checkNotNull("command",
command);
if (!commands.contains(command)) {
commands.add(command);
kick();
}
}
private void kick() {
if (commands.size() > 0) {
AnimationScheduler.get().requestAnimationFrame(callback);
}
}
public static abstract class PrioritizedCommand implements Command {
private int priority = 0;
public PrioritizedCommand(final int priority) {
this.priority = priority;
}
public int getPriority() {
return priority;
}
}
}