/*
 * #%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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 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
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 *    and/or other materials provided with the distribution.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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package org.scijava.ui.dnd;

import java.io.File;
import java.io.IOException;

import org.scijava.Priority;
import org.scijava.display.Display;
import org.scijava.display.DisplayService;
import org.scijava.io.IOService;
import org.scijava.log.LogService;
import org.scijava.plugin.Parameter;
import org.scijava.plugin.Plugin;

/**
 * Drag-and-drop handler for files.
 * 
 * @author Curtis Rueden
 * @author Barry DeZonia
 */
@Plugin(type = DragAndDropHandler.class, priority = Priority.LOW)
public class FileDragAndDropHandler extends
	AbstractDragAndDropHandler<File>
{

	@Parameter(required = false)
	private IOService ioService;

	@Parameter(required = false)
	private DisplayService displayService;

	@Parameter(required = false)
	private LogService log;

	// -- DragAndDropHandler methods --

	@Override
	public boolean supports(final File file) {
		if (ioService == null || displayService == null) return false;
		if (!super.supports(file)) return false;

		// verify that the file can be opened somehow
		return ioService.getOpener(file.getAbsolutePath()) != null;
	}

	@Override
	public boolean drop(final File file, final Display<?> display) {
		if (ioService == null || displayService == null) return false;
		check(file, display);
		if (file == null) return true; // trivial case

		// load the data
		final String filename = file.getAbsolutePath();
		final Object data;
		try {
			data = ioService.open(filename);
		}
		catch (final IOException exc) {
			if (log != null) log.error("Error opening file: " + filename, exc);
			return false;
		}

		// display the result
		displayService.createDisplay(data);
		return true;
	}

	// -- Typed methods --

	@Override
	public Class<File> getType() {
		return File.class;
	}

}
