/*
 * #%L
 * SciJava Common shared library for SciJava software.
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 * Wisconsin-Madison, Broad Institute of MIT and Harvard, Max Planck
 * Institute of Molecular Cell Biology and Genetics, University of
 * Konstanz, and KNIME GmbH.
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 *    this list of conditions and the following disclaimer.
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package org.scijava.command;

import org.scijava.Cancelable;
import org.scijava.Context;
import org.scijava.Contextual;
import org.scijava.module.AbstractModule;
import org.scijava.module.Module;
import org.scijava.plugin.Parameter;

/**
 * A command which implements {@link Module} directly (rather than using the
 * {@link CommandModule} adapter class). This is useful for commands which want
 * to inspect and manipulate their own inputs and outputs programmatically.
 * 
 * @author Curtis Rueden
 */
public abstract class ModuleCommand extends AbstractModule implements
	Cancelable, Command, Contextual
{

	@Parameter
	private Context context;

	@Parameter
	private CommandService commandService;

	private CommandInfo info;

	/** Reason for cancelation, or null if not canceled. */
	private String cancelReason;

	// -- Module methods --

	@Override
	public CommandInfo getInfo() {
		if (info == null) {
			// NB: Obtain metadata lazily.
			info = commandService.getCommand(getClass());
		}
		return info;
	}

	// -- Contextual methods --

	@Override
	public Context getContext() {
		return context;
	}

	@Override
	public void setContext(final Context context) {
		context.inject(this);
	}

	// -- Cancelable methods --

	@Override
	public boolean isCanceled() {
		return cancelReason != null;
	}

	@Override
	public void cancel(final String reason) {
		cancelReason = reason == null ? "" : reason;
	}

	@Override
	public String getCancelReason() {
		return cancelReason;
	}

}
