com.sap.dirigible.ide.repository.ui.command.DeleteHandler.java Source code

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Here is the source code for com.sap.dirigible.ide.repository.ui.command.DeleteHandler.java

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/*******************************************************************************
 * Copyright (c) 2014 SAP AG or an SAP affiliate company. All rights reserved.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License. 
 *******************************************************************************/

package com.sap.dirigible.ide.repository.ui.command;

import java.io.IOException;
import java.util.Comparator;
import java.util.SortedSet;
import java.util.TreeSet;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.ui.handlers.HandlerUtil;

import com.sap.dirigible.repository.api.IEntity;

public class DeleteHandler extends AbstractHandler {

    // TODO: Must determine when this command is enabled or not.

    private static final String CONFIRM_DELETE = Messages.DeleteHandler_CONFIRM_DELETE;
    private static final String ARE_YOU_SURE_YOU_WANT_TO_DELETE_SELECTED_ITEMS_D = Messages.DeleteHandler_ARE_YOU_SURE_YOU_WANT_TO_DELETE_SELECTED_ITEMS_D;
    private static final String EMPTY_STRING = ""; //$NON-NLS-1$
    private static final String ARE_YOU_SURE_YOU_WANT_TO_DELETE_SELECTED_ITEM = Messages.DeleteHandler_ARE_YOU_SURE_YOU_WANT_TO_DELETE_SELECTED_ITEM;
    private static final String SOME_OR_ALL_OF_THE_FILES_COULD_NOT_BE_DELETED = Messages.DeleteHandler_SOME_OR_ALL_OF_THE_FILES_COULD_NOT_BE_DELETED;
    private static final String DELETE_ERROR = Messages.DeleteHandler_DELETE_ERROR;

    public Object execute(ExecutionEvent event) throws ExecutionException {
        ISelection selection = HandlerUtil.getCurrentSelection(event);
        if (selection instanceof IStructuredSelection) {
            execute((IStructuredSelection) selection);
            RefreshHandler.refreshActivePart(event);
        }
        return null;
    }

    public void execute(IStructuredSelection selection) {
        Comparator<IEntity> comparator = new ResourceComparator();
        SortedSet<IEntity> resources = new TreeSet<IEntity>(comparator);
        for (Object element : selection.toArray()) {
            if (element instanceof IEntity) {
                resources.add((IEntity) element);
            }
        }
        execute(resources);
    }

    /*
     * We require that all resources are sorted in such a way that we first
     * delete the leaf-most elements and then handle elements closer to the
     * root.
     */
    private void execute(SortedSet<IEntity> resources) {
        if (resources.size() == 0) {
            return;
        }
        if (!confirmDelete(resources.size())) {
            return;
        }
        Throwable throwable = null;
        for (IEntity resource : resources) {
            try {
                resource.delete();
            } catch (IOException ex) {
                if (throwable == null) {
                    throwable = ex;
                }
            }
        }
        if (throwable != null) {
            MessageDialog.openWarning(null, DELETE_ERROR, SOME_OR_ALL_OF_THE_FILES_COULD_NOT_BE_DELETED);
        }
    }

    private static boolean confirmDelete(int count) {
        String message = EMPTY_STRING;
        if (count == 1) {
            message = ARE_YOU_SURE_YOU_WANT_TO_DELETE_SELECTED_ITEM;
        } else {
            message = String.format(ARE_YOU_SURE_YOU_WANT_TO_DELETE_SELECTED_ITEMS_D, count);
        }
        return MessageDialog.openConfirm(null, CONFIRM_DELETE, message);
    }

    private class ResourceComparator implements Comparator<IEntity> {

        @Override
        public int compare(IEntity o1, IEntity o2) {
            String path1 = o1.getPath().toString();
            String path2 = o2.getPath().toString();
            return path2.compareTo(path1);
        }

    }

}