javafx.scene.input.FutureCommand Maven / Gradle / Ivy
/*
* Copyright (c) 2020 JFXCore. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 or later,
* as published by the Free Software Foundation. This particular file is
* designated as subject to the "Classpath" exception as provided in the
* LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package javafx.scene.input;
import javafx.application.Platform;
import javafx.beans.value.ObservableValue;
import java.util.concurrent.CancellationException;
import java.util.concurrent.CompletableFuture;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
/**
* A command implementation that uses {@link CompletableFuture} to encapsulate its operation.
*/
public class FutureCommand extends CommandBase {
private final Function> futureSupplier;
private final Consumer exceptionHandler;
private CancelCommand cancelCommand;
private CompletableFuture runningFuture;
/**
* Initializes a new instance of the {@link FutureCommand} class.
*
* @param futureSupplier supplier that returns a {@link CompletableFuture} encapsulating a parameterless operation
*/
public FutureCommand(Supplier> futureSupplier) {
if (futureSupplier == null) {
throw new IllegalArgumentException("futureSupplier");
}
this.futureSupplier = param -> futureSupplier.get();
this.exceptionHandler = null;
}
/**
* Initializes a new instance of the {@link FutureCommand} class.
*
* @param futureSupplier supplier that returns a {@link CompletableFuture} encapsulating a parameterized operation
*/
public FutureCommand(Function> futureSupplier) {
if (futureSupplier == null) {
throw new IllegalArgumentException("futureSupplier");
}
this.futureSupplier = futureSupplier;
this.exceptionHandler = null;
}
/**
* Initializes a new instance of the {@link FutureCommand} class.
*
* @param futureSupplier supplier that returns a {@link CompletableFuture} encapsulating a parameterless operation
* @param exceptionHandler handler for exceptions thrown by the operation; if none is provided, exceptions will be thrown on the calling thread
*/
public FutureCommand(Supplier> futureSupplier, Consumer exceptionHandler) {
if (futureSupplier == null) {
throw new IllegalArgumentException("futureSupplier");
}
this.futureSupplier = param -> futureSupplier.get();
this.exceptionHandler = exceptionHandler;
}
/**
* Initializes a new instance of the {@link FutureCommand} class.
*
* @param futureSupplier supplier that returns a {@link CompletableFuture} encapsulating a parameterized operation
* @param exceptionHandler handler for exceptions thrown by the operation; if none is provided, exceptions will be thrown on the calling thread
*/
public FutureCommand(Function> futureSupplier, Consumer exceptionHandler) {
if (futureSupplier == null) {
throw new IllegalArgumentException("futureSupplier");
}
this.futureSupplier = futureSupplier;
this.exceptionHandler = exceptionHandler;
}
/**
* Initializes a new instance of the {@link FutureCommand} class.
*
* @param futureSupplier supplier that returns a {@link CompletableFuture} encapsulating a parameterless operation
* @param condition a value that controls the executability of the command
*/
public FutureCommand(Supplier> futureSupplier, ObservableValue condition) {
super(condition);
if (futureSupplier == null) {
throw new IllegalArgumentException("futureSupplier");
}
this.futureSupplier = param -> futureSupplier.get();
this.exceptionHandler = null;
}
/**
* Initializes a new instance of the {@link FutureCommand} class.
*
* @param futureSupplier supplier that returns a {@link CompletableFuture} encapsulating a parameterized operation
* @param condition a value that controls the executability of the command
*/
public FutureCommand(Function> futureSupplier, ObservableValue condition) {
super(condition);
if (futureSupplier == null) {
throw new IllegalArgumentException("futureSupplier");
}
this.futureSupplier = futureSupplier;
this.exceptionHandler = null;
}
/**
* Initializes a new instance of the {@link FutureCommand} class.
*
* @param futureSupplier supplier that returns a {@link CompletableFuture} encapsulating a parameterless operation
* @param condition a value that controls the executability of the command
* @param exceptionHandler handler for exceptions thrown by the operation; if none is provided, exceptions will be thrown on the calling thread
*/
public FutureCommand(Supplier> futureSupplier, ObservableValue condition, Consumer exceptionHandler) {
super(condition);
if (futureSupplier == null) {
throw new IllegalArgumentException("futureSupplier");
}
this.futureSupplier = param -> futureSupplier.get();
this.exceptionHandler = exceptionHandler;
}
/**
* Initializes a new instance of the {@link FutureCommand} class.
*
* @param futureSupplier supplier that returns a {@link CompletableFuture} encapsulating a parameterized operation
* @param condition a value that controls the executability of the command
* @param exceptionHandler handler for exceptions thrown by the operation; if none is provided, exceptions will be thrown on the calling thread
*/
public FutureCommand(Function> futureSupplier, ObservableValue condition, Consumer exceptionHandler) {
super(condition);
if (futureSupplier == null) {
throw new IllegalArgumentException("futureSupplier");
}
this.futureSupplier = futureSupplier;
this.exceptionHandler = exceptionHandler;
}
/**
* Gets a command that can be used to cancel the currently running operation.
* Invoking the command calls {@link CompletableFuture#cancel(boolean)} on the current operation.
*/
public Command getCancelCommand() {
if (cancelCommand == null) {
cancelCommand = new CancelCommand();
}
return cancelCommand;
}
@Override
public void execute(T parameter) {
startExecution();
try {
runningFuture = futureSupplier.apply(parameter);
runningFuture.whenComplete((res, ex) -> Platform.runLater(() -> {
endExecution();
runningFuture = null;
handleException(ex);
}));
} catch (Throwable ex){
endExecution();
runningFuture = null;
handleException(ex);
}
}
@Override
protected void endExecution() {
if (cancelCommand != null) {
cancelCommand.endExecution();
}
super.endExecution();
}
private void handleException(Throwable ex) {
if (ex == null || ex instanceof CancellationException) {
return;
}
if (exceptionHandler != null) {
exceptionHandler.accept(ex);
} else {
throw new RuntimeException("Unhandled exception in command execution.", ex);
}
}
private final class CancelCommand extends CommandBase {
CancelCommand() {
super(FutureCommand.this.executingProperty());
}
@Override
public void execute(Void parameter) {
startExecution();
runningFuture.cancel(false);
}
@Override
public void endExecution() {
super.endExecution();
}
}
}