org.eclipse.mylyn.internal.sandbox.ui.editors.TaskEditorDropTarget.java Source code

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Here is the source code for org.eclipse.mylyn.internal.sandbox.ui.editors.TaskEditorDropTarget.java

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/*******************************************************************************
 * Copyright (c) 2004, 2008 Jingwen Ou 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:
 *     Jingwen Ou - initial API and implementation
 *******************************************************************************/

package org.eclipse.mylyn.internal.sandbox.ui.editors;

import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.ui.JavaUI;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.ITextSelection;
import org.eclipse.jface.text.TextSelection;
import org.eclipse.jface.text.source.SourceViewer;
import org.eclipse.mylyn.commons.core.StatusHandler;
import org.eclipse.mylyn.internal.sandbox.ui.hyperlinks.ResourceHyperlinkExtensions;
import org.eclipse.mylyn.internal.tasks.ui.TasksUiPlugin;
import org.eclipse.swt.custom.StyledTextDropTargetEffect;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.DropTarget;
import org.eclipse.swt.dnd.DropTargetEvent;
import org.eclipse.swt.dnd.TextTransfer;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.ui.part.ResourceTransfer;

/**
 * Specifies a move operation is allowed, but when the actual operation is performed, covert it to a copy operation
 * 
 * @author Jingwen Ou
 */
public class TaskEditorDropTarget extends StyledTextDropTargetEffect {

    public static final String DEFAULT_PREFIX = "file";

    public static void addDropTargetSupport(SourceViewer editor) {
        new TaskEditorDropTarget(editor);
    }

    private final SourceViewer editor;

    private TaskEditorDropTarget(SourceViewer editor) {
        super(editor.getTextWidget());
        this.editor = editor;

        DropTarget target = new DropTarget(editor.getControl(), DND.DROP_COPY);
        // TODO: may also add TaskTransfer?
        // TODO: this concern may also go to IResourceHyperlinkExtension by adding something like IResourceHyperlinkExtension.getTransfers()?
        target.setTransfer(new Transfer[] { JavaUI.getJavaElementClipboardTransfer(),
                ResourceTransfer.getInstance(), TextTransfer.getInstance() });
        target.addDropListener(this);
    }

    @Override
    public void dragEnter(DropTargetEvent event) {
        super.dragEnter(event);
        event.detail = DND.DROP_COPY;
    }

    @Override
    public void drop(DropTargetEvent event) {
        StringBuilder shouldDropText = new StringBuilder();
        // this concern may also go to IResourceHyperlinkExtension by adding something like IResourceHyperlinkExtension.drop(DropTargetEvent)?
        if (TextTransfer.getInstance().isSupportedType(event.currentDataType) && (event.data instanceof String)) {
            shouldDropText.append((String) event.data);
        } else if (JavaUI.getJavaElementClipboardTransfer().isSupportedType(event.currentDataType)
                && (event.data instanceof IJavaElement[])) {

            IJavaElement[] elements = (IJavaElement[]) event.data;

            for (IJavaElement element : elements) {
                shouldDropText.append(ResourceHyperlinkExtensions.getGeneratedPrefix("java")
                        + element.getElementName() + addCommaIfNeeded(elements, element));
            }

        } else if (ResourceTransfer.getInstance().isSupportedType(event.currentDataType)
                && (event.data instanceof IResource[])) {
            IResource[] elements = (IResource[]) event.data;
            for (IResource element : elements) {
                String fullName = element.getName();
                int sep_pos = fullName.lastIndexOf(".");

                if (sep_pos != -1) {
                    String fileName = fullName.substring(0, sep_pos);
                    String fileType = fullName.substring(sep_pos + 1);

                    // decide file type by file extension
                    String generatedPrefix = ResourceHyperlinkExtensions.getGeneratedPrefix(fileType.toLowerCase());

                    if (generatedPrefix != null) {
                        shouldDropText
                                .append(generatedPrefix + " " + fileName + addCommaIfNeeded(elements, element));
                    } else {
                        // cannot decide the file type, then use default
                        shouldDropText.append(ResourceHyperlinkExtensions.getDefaultPrefix() + " "
                                + element.getFullPath().toString().substring(1)
                                + addCommaIfNeeded(elements, element));
                    }
                }

            }
        }

        if (shouldDropText.length() > 0) {
            dropTextToCurrentPosition(shouldDropText.toString());
        }
    }

    private String addCommaIfNeeded(Object[] elements, Object element) {
        return ((elements.length > 1 && element != elements[elements.length - 1]) ? ", " : "");
    }

    private void dropTextToCurrentPosition(String shouldDropText) {
        try {
            ITextSelection textSelection = ((ITextSelection) editor.getSelection());
            IDocument currentDocument = editor.getDocument();
            currentDocument.replace(textSelection.getOffset(), 0, shouldDropText);

            // move cursor to the end
            editor.getTextWidget().setFocus();
            editor.setSelection(new TextSelection(textSelection.getOffset() + shouldDropText.length(), 0));
        } catch (BadLocationException e) {
            StatusHandler.log(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, "Could not drop text", e));
        }
    }
}