001/*
002 * #%L
003 * GwtMaterial
004 * %%
005 * Copyright (C) 2015 - 2017 GwtMaterialDesign
006 * %%
007 * Licensed under the Apache License, Version 2.0 (the "License");
008 * you may not use this file except in compliance with the License.
009 * You may obtain a copy of the License at
010 * 
011 *      http://www.apache.org/licenses/LICENSE-2.0
012 * 
013 * Unless required by applicable law or agreed to in writing, software
014 * distributed under the License is distributed on an "AS IS" BASIS,
015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016 * See the License for the specific language governing permissions and
017 * limitations under the License.
018 * #L%
019 */
020package gwt.material.design.client.base;
021
022import com.google.gwt.user.client.Timer;
023
024/**
025 * A <code>Timer</code> that is canceled if a new request is made.
026 *
027 * @author Ben Dol
028 */
029public abstract class InterruptibleTask {
030
031    private Timer timer;
032
033    /**
034     * Creates a new delayed task.
035     */
036    public InterruptibleTask() {
037        timer = new Timer() {
038            public void run() {
039                onExecute();
040            }
041        };
042    }
043
044    /**
045     * Cancels the task.
046     */
047    public void cancel() {
048        timer.cancel();
049    }
050
051    /**
052     * Cancels any running timers and starts a new one.
053     *
054     * @param delay the delay in ms
055     */
056    public void delay(int delay) {
057        timer.cancel();
058        if (delay > 0) {
059            timer.schedule(delay);
060        } else {
061            timer.run();
062        }
063    }
064
065    /**
066     * Called when the task should execute.
067     */
068    public abstract void onExecute();
069}