Make a dropped data type depend on a target item in table : SWT Drag Drop « SWT « Java Tutorial






Make a dropped data type depend on a target item in table
/*******************************************************************************
 * Copyright (c) 2000, 2005 IBM Corporation 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
//package org.eclipse.swt.snippets;
/*
 * Make a dropped data type depend on a target item in table
 * 
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 */
import java.io.File;

import org.eclipse.swt.SWT;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.DragSource;
import org.eclipse.swt.dnd.DragSourceAdapter;
import org.eclipse.swt.dnd.DragSourceEvent;
import org.eclipse.swt.dnd.DropTarget;
import org.eclipse.swt.dnd.DropTargetAdapter;
import org.eclipse.swt.dnd.DropTargetEvent;
import org.eclipse.swt.dnd.FileTransfer;
import org.eclipse.swt.dnd.TextTransfer;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableItem;

public class DropTypeOnTable {

  public static void main(String[] args) {
    Display display = new Display();
    Shell shell = new Shell(display);
    shell.setLayout(new FillLayout());
    Label label1 = new Label(shell, SWT.BORDER);
    label1.setText("Drag Source");
    final Table table = new Table(shell, SWT.BORDER);
    for (int i = 0; i < 4; i++) {
      TableItem item = new TableItem(table, SWT.NONE);
      if (i % 2 == 0)
        item.setText("Drop a file");
      if (i % 2 == 1)
        item.setText("Drop text");
    }
    DragSource dragSource = new DragSource(label1, DND.DROP_COPY);
    dragSource
        .setTransfer(new Transfer[] { TextTransfer.getInstance(), FileTransfer.getInstance() });
    dragSource.addDragListener(new DragSourceAdapter() {
      public void dragSetData(DragSourceEvent event) {
        if (FileTransfer.getInstance().isSupportedType(event.dataType)) {
          File file = new File("temp");
          event.data = new String[] { file.getAbsolutePath() };
        }
        if (TextTransfer.getInstance().isSupportedType(event.dataType)) {
          event.data = "once upon a time";
        }
      }
    });
    DropTarget dropTarget = new DropTarget(table, DND.DROP_COPY | DND.DROP_DEFAULT);
    dropTarget
        .setTransfer(new Transfer[] { TextTransfer.getInstance(), FileTransfer.getInstance() });
    dropTarget.addDropListener(new DropTargetAdapter() {
      FileTransfer fileTransfer = FileTransfer.getInstance();

      TextTransfer textTransfer = TextTransfer.getInstance();

      public void dragEnter(DropTargetEvent event) {
        if (event.detail == DND.DROP_DEFAULT)
          event.detail = DND.DROP_COPY;
      }

      public void dragOperationChanged(DropTargetEvent event) {
        if (event.detail == DND.DROP_DEFAULT)
          event.detail = DND.DROP_COPY;
      }

      public void dragOver(DropTargetEvent event) {
        event.detail = DND.DROP_NONE;
        TableItem item = (TableItem) event.item;
        if (item == null)
          return;
        int itemIndex = table.indexOf(item);
        if (itemIndex % 2 == 0) {
          int index = 0;
          while (index < event.dataTypes.length) {
            if (fileTransfer.isSupportedType(event.dataTypes[index]))
              break;
            index++;
          }
          if (index < event.dataTypes.length) {
            event.currentDataType = event.dataTypes[index];
            event.detail = DND.DROP_COPY;
            return;
          }
        } else {
          int index = 0;
          while (index < event.dataTypes.length) {
            if (textTransfer.isSupportedType(event.dataTypes[index]))
              break;
            index++;
          }
          if (index < event.dataTypes.length) {
            event.currentDataType = event.dataTypes[index];
            event.detail = DND.DROP_COPY;
            return;
          }
        }
      }

      public void drop(DropTargetEvent event) {
        TableItem item = (TableItem) event.item;
        if (item == null) {
          event.detail = DND.DROP_NONE;
          return;
        }
        if (fileTransfer.isSupportedType(event.currentDataType)) {
          String[] files = (String[]) event.data;
          if (files != null && files.length > 0) {
            item.setText(files[0]);
          }
        }
        if (textTransfer.isSupportedType(event.currentDataType)) {
          String text = (String) event.data;
          if (text != null) {
            item.setText(text);
          }
        }
      }

    });
    shell.setSize(300, 150);
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}








17.114.SWT Drag Drop
17.114.1.Dragging and Dropping
17.114.2.Drag selected text in Text to LabelDrag selected text in Text to Label
17.114.3.Drag and Drop inside TableDrag and Drop inside Table
17.114.4.Drag and Drop example snippet: determine data types available (win32 only)Drag and Drop example snippet: determine data types available (win32 only)
17.114.5.Drag and Drop: define a default operation (in this example, Copy)Drag and Drop: define a default operation (in this example, Copy)
17.114.6.Drag and Drop: define my own data transfer typeDrag and Drop: define my own data transfer type
17.114.7.Drag leaf items in a treeDrag leaf items in a tree
17.114.8.Drag text between two labelsDrag text between two labels
17.114.9.Drag and Drop: determine native data types available (motif only)
17.114.10.Make a dropped data type depend on a target item in tableMake a dropped data type depend on a target item in table