Обнаружение, когда пользователь закончил изменять размер оболочки SWT

Я использую String-идентификатор, чтобы проверить, какие задачи считаются принадлежащими одному «дросселю».

Это код, он также включает в себя обычные возможности планирования, но вы можете проверить основные части там.

package org.uilib.util;

import com.google.common.collect.Maps;

import java.util.Map;
import java.util.concurrent.DelayQueue;
import java.util.concurrent.Delayed;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public final class SmartExecutor implements Throttle, Executor {

    //~ Static fields/initializers -------------------------------------------------------------------------------------

    private static final Logger L = LoggerFactory.getLogger(SmartExecutor.class);

    //~ Instance fields ------------------------------------------------------------------------------------------------

    private final ExecutorService executor                      = Executors.newCachedThreadPool();
    private final DelayQueue<DelayedRunnable> taskQueue         = new DelayQueue<DelayedRunnable>();
    private final Map<String, ThrottledRunnable> throttledTasks = Maps.newHashMap();

    //~ Constructors ---------------------------------------------------------------------------------------------------

    /* schedule a Runnable to be executed a fixed period of time after it was scheduled
     * if a new Runnable with the same throttleName is scheduled before this one was called, it will overwrite this */
    public SmartExecutor() {
        this.executor.execute(new Scheduler());
    }

    //~ Methods --------------------------------------------------------------------------------------------------------

    /* execute a Runnable once */
    @Override
    public void execute(final Runnable runnable) {
        this.executor.execute(runnable);
    }

    /* schedule a Runnable to be executed after a fixed period of time */
    public void schedule(final long delay, final TimeUnit timeUnit, final Runnable runnable) {
        this.taskQueue.put(new DelayedRunnable(runnable, delay, timeUnit));
    }

    /* schedule a Runnable to be executed using a fixed delay between the end of a run and the start of the next one */
    public void scheduleAtFixedRate(final long period, final TimeUnit timeUnit, final Runnable runnable) {
        this.taskQueue.put(new RepeatingRunnable(runnable, period, timeUnit));
    }

    /* shut the the executor down */
    public void shutdown() {
        this.executor.shutdownNow();
    }

    @Override
    public void throttle(final String throttleName, final long delay, final TimeUnit timeUnit, final Runnable runnable) {

        final ThrottledRunnable thrRunnable = new ThrottledRunnable(runnable, throttleName, delay, timeUnit);
        this.throttledTasks.put(throttleName, thrRunnable);
        this.taskQueue.put(thrRunnable);
    }

    //~ Inner Classes --------------------------------------------------------------------------------------------------

    private static class DelayedRunnable implements Delayed, Runnable {

        protected final Runnable runnable;
        private final long endOfDelay;

        public DelayedRunnable(final Runnable runnable, final long delay, final TimeUnit delayUnit) {
            this.runnable       = runnable;
            this.endOfDelay     = delayUnit.toMillis(delay) + System.currentTimeMillis();
        }

        @Override
        public int compareTo(final Delayed other) {

            final Long delay1 = this.getDelay(TimeUnit.MILLISECONDS);
            final Long delay2 = other.getDelay(TimeUnit.MILLISECONDS);

            return delay1.compareTo(delay2);
        }

        @Override
        public long getDelay(final TimeUnit unit) {
            return unit.convert(this.endOfDelay - System.currentTimeMillis(), TimeUnit.MILLISECONDS);
        }

        @Override
        public void run() {
            this.runnable.run();
        }
    }

    private static final class RepeatingRunnable extends DelayedRunnable {

        private final long periodInMillis;

        public RepeatingRunnable(final Runnable runnable, final long period, final TimeUnit delayUnit) {
            super(runnable, period, delayUnit);

            this.periodInMillis = delayUnit.convert(period, TimeUnit.MILLISECONDS);
        }

        public RepeatingRunnable reschedule() {
            return new RepeatingRunnable(this.runnable, this.periodInMillis, TimeUnit.MILLISECONDS);
        }
    }

    private final class Scheduler implements Runnable {
        @Override
        public void run() {
            while (true) {
                try {

                    /* wait for the next runnable to become available */
                    final DelayedRunnable task = SmartExecutor.this.taskQueue.take();

                    if (task instanceof RepeatingRunnable) {
                        /* tell executor to run the action and reschedule it afterwards */
                        SmartExecutor.this.executor.execute(
                            new Runnable() {
                                    @Override
                                    public void run() {
                                        task.run();
                                        SmartExecutor.this.taskQueue.put(((RepeatingRunnable) task).reschedule());
                                    }
                                });
                    } else if (task instanceof ThrottledRunnable) {

                        final ThrottledRunnable thrTask = (ThrottledRunnable) task;

                        /* run only if this is the latest task in given throttle, otherwise skip execution */
                        if (SmartExecutor.this.throttledTasks.get(thrTask.getThrottleName()) == thrTask) {
                            SmartExecutor.this.executor.execute(task);
                        }
                    } else {
                        /* tell the executor to just run the action */
                        SmartExecutor.this.executor.execute(task);
                    }
                } catch (final InterruptedException e) {
                    SmartExecutor.L.debug("scheduler interrupted (shutting down)");
                    return;
                }
            }
        }
    }

    private static final class ThrottledRunnable extends DelayedRunnable {

        private final String throttleName;

        public ThrottledRunnable(final Runnable runnable, final String throttleName, final long period,
                                 final TimeUnit delayUnit) {
            super(runnable, period, delayUnit);

            this.throttleName = throttleName;
        }

        public String getThrottleName() {
            return this.throttleName;
        }
    }
}