com.google.gwt.user.client.DeferredCommand Maven / Gradle / Ivy
/*
* Copyright 2007 Google Inc.
*
* 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.google.gwt.user.client;
/**
* This class allows you to execute code after all currently pending event
* handlers have completed, using the {@link #addCommand(Command)} or
* {@link #addCommand(IncrementalCommand)} methods. This is useful when you need
* to execute code outside of the context of the current stack.
*
* @deprecated Replaced by
* {@link com.google.gwt.core.client.Scheduler#scheduleDeferred
* Scheduler.scheduleDeferred()} because the static nature of this
* API prevents effective mocking for JRE-only tests.
*/
@Deprecated
public class DeferredCommand {
private static final CommandExecutor commandExecutor = new CommandExecutor();
/**
* Enqueues a {@link Command} to be fired after all current events have been
* handled.
*
* @param cmd the command to be fired. If cmd is null, a "pause" will be
* inserted into the queue. Any events added after the pause will
* wait for an additional cycle through the system event loop before
* executing. Pauses are cumulative.
*
* @deprecated As of release 1.4, replaced by {@link #addCommand(Command)}
*/
@Deprecated
public static void add(Command cmd) {
commandExecutor.submit(cmd);
}
/**
* Enqueues a {@link Command} to be fired after all current events have been
* handled.
*
* Note that the {@link Command} should not perform any blocking operations.
*
* @param cmd the command to be fired
* @throws NullPointerException if cmd is null
*/
public static void addCommand(Command cmd) {
if (cmd == null) {
throw new NullPointerException("cmd cannot be null");
}
commandExecutor.submit(cmd);
}
/**
* Enqueues an {@link IncrementalCommand} to be fired after all current events
* have been handled.
*
* Note that the {@link IncrementalCommand} should not perform any blocking
* operations.
*
* @param cmd the command to be fired
* @throws NullPointerException if cmd is null
*/
public static void addCommand(IncrementalCommand cmd) {
if (cmd == null) {
throw new NullPointerException("cmd cannot be null");
}
commandExecutor.submit(cmd);
}
/**
* Adds a "pause" to the queue of {@link DeferredCommand}s. Any
* {@link DeferredCommand}s or pauses that are added after this pause will
* wait for an additional cycle through the system event loop before
* executing.
*
* @deprecated with no replacement because the presence of this method causes
* arbitrary scheduling decisions
*/
@Deprecated
public static void addPause() {
commandExecutor.submit((Command) null);
}
}