de.walware.ecommons.ui.util.DNDUtil.java Source code

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Here is the source code for de.walware.ecommons.ui.util.DNDUtil.java

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/*=============================================================================#
 # Copyright (c) 2005-2015 Stephan Wahlbrink (WalWare.de) 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:
 #     Stephan Wahlbrink - initial API and implementation
 #=============================================================================*/

package de.walware.ecommons.ui.util;

import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.swt.SWTError;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.dnd.Clipboard;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.DropTarget;
import org.eclipse.swt.dnd.DropTargetAdapter;
import org.eclipse.swt.dnd.DropTargetEvent;
import org.eclipse.swt.dnd.DropTargetListener;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.widgets.Control;

import de.walware.ecommons.ui.internal.Messages;

public class DNDUtil {

    public static abstract class SimpleTextDropAdapter extends DropTargetAdapter {

        protected abstract StyledText getTextWidget();

        @Override
        public void dragEnter(final DropTargetEvent e) {
            if (e.detail == DND.DROP_DEFAULT && (e.operations & DND.DROP_COPY) != 0) {
                e.detail = DND.DROP_COPY;
            }
        }

        @Override
        public void dragOperationChanged(final DropTargetEvent e) {
            if (e.detail == DND.DROP_DEFAULT && (e.operations & DND.DROP_COPY) != 0) {
                e.detail = DND.DROP_COPY;
            }
        }

        @Override
        public void dragOver(final DropTargetEvent event) {
            event.feedback = DND.FEEDBACK_SCROLL | DND.FEEDBACK_SELECT;
        }

        @Override
        public void drop(final DropTargetEvent e) {
            getTextWidget().insert((String) e.data);
        }
    }

    public static boolean setContent(final Clipboard clipboard, final Object[] datas, final Transfer[] tranfers) {
        while (true) {
            try {
                clipboard.setContents(datas, tranfers);
                return true;
            } catch (final SWTError e) {
                if (e.code != DND.ERROR_CANNOT_SET_CLIPBOARD) {
                    throw e;
                }

                if (!MessageDialog.openQuestion(UIAccess.getActiveWorkbenchShell(true),
                        Messages.CopyToClipboard_error_title, Messages.CopyToClipboard_error_message)) {
                    return false;
                }
            }
        }
    }

    /**
     * for common options (DEFAULT, MOVE, COPY).
     * 
     * @param viewer
     * @param listener
     * @param transferTypes
     */
    public static void addDropSupport(final Control control, final DropTargetListener listener,
            final Transfer[] transferTypes) {
        addDropSupport(control, new DropTargetListener[] { listener },
                DND.DROP_DEFAULT | DND.DROP_MOVE | DND.DROP_COPY, transferTypes);
    }

    public static void addDropSupport(final Control control, final DropTargetListener[] listeners,
            final int operations, final Transfer[] transferTypes) {
        final DropTarget dropTarget = new DropTarget(control, operations);
        dropTarget.setTransfer(transferTypes);
        for (final DropTargetListener listener : listeners) {
            dropTarget.addDropListener(listener);
        }
    }

    private DNDUtil() {
    }

}