lu.uni.geko.commands.AbstractFileHandler.java Source code

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Here is the source code for lu.uni.geko.commands.AbstractFileHandler.java

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/*******************************************************************************
 * Copyright (c) 2012 University of Luxembourg and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Max E. Kramer - initial API and implementation
 ******************************************************************************/
package lu.uni.geko.commands;

import java.util.ArrayList;
import java.util.List;

import lu.uni.geko.util.bridges.EMFBridge;
import lu.uni.geko.util.bridges.EclipseBridge;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.resources.IFile;
import org.eclipse.emf.common.util.URI;
import org.eclipse.jface.viewers.StructuredSelection;

/**
 * An abstract handler for commands that discriminate selected files based on their type and create a {@link java.lang.Runnable}
 * for the selected files.
 *
 * @author Max E. Kramer
 */
public abstract class AbstractFileHandler extends AbstractHandler {
    /**
     * Returns the number of distinct file types that are used to handle a command.
     *
     * @return number of distinct file types
     */
    protected abstract int getTypeCount();

    /**
     * Returns a type number between 0 (including) and the result of getTypeCount() (excluding) if this file should be selectable
     * and -1 otherwise.
     *
     * @param iFile
     *           a selected file
     * @return the type number for the given file
     */
    protected abstract int getTypeNoIfSelectable(IFile iFile);

    /**
     * Returns a list of runnables that handler the current selection of files based on their file types.
     *
     * @param uris
     *           a list containing a list of URIs for each file type
     * @return a list of runnables handling the selected file URIs of different type
     */
    protected abstract List<Runnable> getRunnables(List<List<URI>> uris);

    @Override
    public Object execute(final ExecutionEvent event) throws ExecutionException {
        List<List<URI>> selectedFileURIs = getSelectedFileURIs(event);
        for (Runnable runnable : getRunnables(selectedFileURIs)) {
            new Thread(runnable).start();
        }
        return null;
    }

    /**
     * Returns a list containing lists of URIs that contain the selected files that correspond to each file type.
     *
     * @param event
     *           the execution event
     * @return a list containing a list of URIs for each file type
     */
    public List<List<URI>> getSelectedFileURIs(final ExecutionEvent event) {
        StructuredSelection structuredSelection = EclipseBridge.getCurrentStructuredSelection(event);
        List<List<URI>> selectedFileURIs = new ArrayList<List<URI>>();
        for (int type = 0; type < getTypeCount(); type++) {
            selectedFileURIs.add(new ArrayList<URI>());
        }
        for (Object selectedElement : structuredSelection.toArray()) {
            if (selectedElement instanceof IFile) {
                IFile selectedFile = ((IFile) selectedElement);
                int type = getTypeNoIfSelectable(selectedFile);
                if (type >= 0 && type < getTypeCount()) {
                    if (selectedFile.exists()) {
                        URI selectedURI = EMFBridge.getEMFUriForIResource(selectedFile);
                        selectedFileURIs.get(type).add(selectedURI);
                    }
                }
            }
        }
        return selectedFileURIs;
    }
}