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/*
 * #%L
 * SciJava Common shared library for SciJava software.
 * %%
 * Copyright (C) 2009 - 2017 Board of Regents of the University of
 * 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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package org.scijava.ui.dnd;

import java.util.List;

import org.scijava.ui.dnd.event.DragEnterEvent;
import org.scijava.ui.dnd.event.DropEvent;

/**
 * Interface for drag-and-drop data.
 * 
 * @author Curtis Rueden
 */
public interface DragAndDropData {

	/**
	 * Gets whether the data can be provided as an object with the given MIME
	 * type.
	 */
	boolean isSupported(MIMEType mimeType);

	/**
	 * Gets whether the data can be provided as an object of the given Java class.
	 */
	default boolean isSupported(final Class type) {
		return getMIMEType(type) != null;
	}

	/**
	 * Gets the data with respect to the given MIME type.
	 * 
	 * @return The data object for the given MIME type. May return null if the
	 *         data is requested too early in the drag-and-drop process, such as
	 *         during a {@link DragEnterEvent} rather than a {@link DropEvent}.
	 * @throws IllegalArgumentException if the MIME type is not supported.
	 */
	Object getData(MIMEType mimeType);

	/** Gets the data as an object of the given Java class. */
	default  T getData(final Class type) {
		final MIMEType mimeType = getMIMEType(type);
		if (mimeType == null) return null;
		@SuppressWarnings("unchecked")
		final T data = (T) getData(mimeType);
		return data;
	}

	/** Gets the best supported MIME type matching the given Java class. */
	default MIMEType getMIMEType(final Class type) {
		for (final MIMEType mimeType : getMIMETypes()) {
			if (mimeType.isCompatible(type)) return mimeType;
		}
		return null;
	}

	/** Gets the list of supported MIME types. */
	List getMIMETypes();

}