com.mercatis.lighthouse3.ui.environment.dnd.BaseDropAdapterAssistant.java Source code

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Here is the source code for com.mercatis.lighthouse3.ui.environment.dnd.BaseDropAdapterAssistant.java

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/*
 * Copyright 2011 mercatis Technologies AG
 * 
 * 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.mercatis.lighthouse3.ui.environment.dnd;

import org.eclipse.core.runtime.IAdapterManager;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.util.LocalSelectionTransfer;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.swt.dnd.DropTargetEvent;
import org.eclipse.swt.dnd.TransferData;
import org.eclipse.ui.navigator.CommonDropAdapter;
import org.eclipse.ui.navigator.CommonDropAdapterAssistant;
import com.mercatis.lighthouse3.ui.common.CommonUIActivator;
import com.mercatis.lighthouse3.ui.environment.model.adapters.DropTargetAdapter;

public class BaseDropAdapterAssistant extends CommonDropAdapterAssistant {

    private IAdapterManager adapterManager = Platform.getAdapterManager();

    private Object[] elements;

    private int operation;

    @SuppressWarnings({ "unchecked", "rawtypes" })
    @Override
    public IStatus handleDrop(CommonDropAdapter dropAdapter, DropTargetEvent dropTargetEvent, Object target) {
        DropTargetAdapter adapter = (DropTargetAdapter) adapterManager.getAdapter(target, DropTargetAdapter.class);
        if (adapter == null)
            return new Status(IStatus.ERROR, CommonUIActivator.PLUGIN_ID, "Drop Target ("
                    + target.getClass().getName() + ") is not adaptable to " + DropTargetAdapter.class.getName());

        if (!adapter.handleDrop(operation, target, elements, getShell()))
            return new Status(IStatus.ERROR, CommonUIActivator.PLUGIN_ID,
                    "Drop Target (" + target.getClass().getName() + ") is failed to handle the drop.");

        elements = null;
        return Status.OK_STATUS;
    }

    @SuppressWarnings({ "unchecked", "rawtypes" })
    @Override
    public IStatus validateDrop(Object target, int operation, TransferData transferType) {
        this.elements = null;
        this.operation = operation;

        ISelection selection = LocalSelectionTransfer.getTransfer().getSelection();
        if (selection == null || !(selection instanceof IStructuredSelection))
            return new Status(IStatus.ERROR, CommonUIActivator.PLUGIN_ID,
                    "Selection either null or no structured selection.");

        IStructuredSelection sselection = (IStructuredSelection) selection;
        Object[] elements = sselection.toArray();
        for (Object element : elements) {
            if (target == element)
                return new Status(IStatus.ERROR, CommonUIActivator.PLUGIN_ID,
                        "You cannot drop yourself on yourself, dickhead!.");
        }

        DropTargetAdapter adapter = (DropTargetAdapter) adapterManager.getAdapter(target, DropTargetAdapter.class);
        if (adapter == null)
            return new Status(IStatus.ERROR, CommonUIActivator.PLUGIN_ID, "Drop Target ("
                    + target.getClass().getName() + ") is not adaptable to " + DropTargetAdapter.class.getName());

        if (!adapter.validateDrop(operation, target, elements))
            return new Status(IStatus.ERROR, CommonUIActivator.PLUGIN_ID,
                    "Drop Target (" + target.getClass().getName() + ") does not accept " + elements.toString());

        this.elements = elements;
        return Status.OK_STATUS;
    }

}