/*
* Copyright 2010-2015 Institut Pasteur.
*
* This file is part of Icy.
*
* Icy is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Icy is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Icy. If not, see <http://www.gnu.org/licenses/>.
*/
package icy.system;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.dnd.DnDConstants;
import java.awt.dnd.DropTarget;
import java.awt.dnd.DropTargetDragEvent;
import java.awt.dnd.DropTargetDropEvent;
import java.awt.dnd.DropTargetEvent;
import java.awt.dnd.DropTargetListener;
import java.awt.event.HierarchyEvent;
import java.awt.event.HierarchyListener;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.PrintStream;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
import java.util.TooManyListenersException;
import javax.swing.BorderFactory;
import javax.swing.JComponent;
import javax.swing.border.Border;
/**
* This class makes it easy to drag and drop files from the operating
* system to a Java program. Any <tt>Component</tt> can be
* dropped onto, but only <tt>JComponent</tt>s will indicate
* the drop event with a changed
* <p/>
* To use this class, construct a new <tt>FileDrop</tt> by passing it the target component and a
* <tt>Listener</tt> to receive notification when file(s) have been dropped. Here is an example:
* <p/>
* <code><pre>
* JPanel myPanel = new JPanel();
* new FileDrop( myPanel, new FileDrop.Listener()
* { public void filesDropped( File[] files )
* {
* // handle file drop
* ...
* } // end filesDropped
* }); // end FileDrop.Listener
* </pre></code>
* <p/>
* You can specify the border that will appear when files are being dragged by calling the
* constructor with a <tt>Border</tt>. Only <tt>JComponent</tt>s will show any indication with a
* <p/>
* You can turn on some debugging features by passing a <tt>PrintStream</tt> object (such as
* <tt>System.out</tt>) into the full constructor. A <tt>null</tt> value will result in no extra
* debugging information being output.
* <p/>
* <p>
* I'm releasing this code into the Public Domain. Enjoy.
* </p>
* <p>
* <em>Original author: Robert Harder, rharder@usa.net</em>
* </p>
* <p>
* 2007-09-12 Nathan Blomquist -- Linux (KDE/Gnome) support added.<br>
* 2012-04-12 Stephane Dallogneville -- cleanup, modified for ICY
* </p>
*
* @author Robert Harder
* @author rharder@users.sf.net
* @author Stephane Dallongeville
* @version 1.0.2
*/
public class FileDrop
{
public static class TransferableObject implements Transferable
{
/**
* The MIME type for {@link #DATA_FLAVOR} is
* <tt>application/x-net.iharder.TransferableObject</tt>.
*
* @since 1.1
*/
public final static String MIME_TYPE = "application/x-net.iharder.TransferableObject";
/**
* The default {@link DataFlavor} for {@link TransferableObject} has
* the representation class <tt>net.iharder.TransferableObject.class</tt> and the MIME
* type <tt>application/x-net.iharder.TransferableObject</tt>.
*
* @since 1.1
*/
public final static DataFlavor DATA_FLAVOR = new DataFlavor(TransferableObject.class, MIME_TYPE);
private Fetcher fetcher;
private Object data;
private DataFlavor customFlavor;
/**
* Creates a new {@link TransferableObject} that wraps <var>data</var>.
* Along with the {@link #DATA_FLAVOR} associated with this class,
* this creates a custom data flavor with a representation class
* determined from <code>data.getClass()</code> and the MIME type
* <tt>application/x-net.iharder.TransferableObject</tt>.
*
* @param data
* The data to transfer
* @since 1.1
*/
public TransferableObject(Object data)
{
this.data = data;
this.customFlavor = new DataFlavor(data.getClass(), MIME_TYPE);
} // end constructor
/**
* Creates a new {@link TransferableObject} that will return the
* object that is returned by <var>fetcher</var>.
* No custom data flavor is set other than the default {@link #DATA_FLAVOR}.
*
* @see Fetcher
* @param fetcher
* The {@link Fetcher} that will return the data object
* @since 1.1
*/
public TransferableObject(Fetcher fetcher)
{
this.fetcher = fetcher;
} // end constructor
/**
* Creates a new {@link TransferableObject} that will return the
* object that is returned by <var>fetcher</var>.
* Along with the {@link #DATA_FLAVOR} associated with this class,
* this creates a custom data flavor with a representation class <var>dataClass</var>
* and the MIME type <tt>application/x-net.iharder.TransferableObject</tt>.
*
* @see Fetcher
* @param dataClass
* The {@link Class} to use in the custom data flavor
* @param fetcher
* The {@link Fetcher} that will return the data object
* @since 1.1
*/
public TransferableObject(Class dataClass, Fetcher fetcher)
{
this.fetcher = fetcher;
this.customFlavor = new DataFlavor(dataClass, MIME_TYPE);
} // end constructor
/**
* Returns the custom {@link DataFlavor} associated
* with the encapsulated object or <tt>null</tt> if the {@link Fetcher} constructor was used
* without passing a {@link Class}.
*
* @return The custom data flavor for the encapsulated object
* @since 1.1
*/
public DataFlavor getCustomDataFlavor()
{
return customFlavor;
} // end getCustomDataFlavor
/* ******** T R A N S F E R A B L E M E T H O D S ******** */
/**
* Returns a two- or three-element array containing first
* the custom data flavor, if one was created in the constructors,
* second the default {@link #DATA_FLAVOR} associated with {@link TransferableObject}, and
* third the {@link DataFlavor#stringFlavor}.
*
* @return An array of supported data flavors
* @since 1.1
*/
@Override
public DataFlavor[] getTransferDataFlavors()
{
if (customFlavor != null)
return new DataFlavor[] {customFlavor, DATA_FLAVOR, DataFlavor.stringFlavor}; // end
// flavors
return new DataFlavor[] {DATA_FLAVOR, DataFlavor.stringFlavor}; // end flavors array
} // end getTransferDataFlavors
/**
* Returns the data encapsulated in this {@link TransferableObject}.
* If the {@link Fetcher} constructor was used, then this is when
* the {@link Fetcher#getObject getObject()} method will be called.
* If the requested data flavor is not supported, then the {@link Fetcher#getObject
* getObject()} method will not be called.
*
* @param flavor
* The data flavor for the data to return
* @return The dropped data
* @since 1.1
*/
@Override
public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException, IOException
{
// Native object
if (flavor.equals(DATA_FLAVOR))
return fetcher == null ? data : fetcher.getObject();
// String
if (flavor.equals(DataFlavor.stringFlavor))
return fetcher == null ? data.toString() : fetcher.getObject().toString();
// We can't do anything else
throw new UnsupportedFlavorException(flavor);
} // end getTransferData
/**
* Returns <tt>true</tt> if <var>flavor</var> is one of the supported
* flavors. Flavors are supported using the <code>equals(...)</code> method.
*
* @param flavor
* The data flavor to check
* @return Whether or not the flavor is supported
* @since 1.1
*/
@Override
public boolean isDataFlavorSupported(DataFlavor flavor)
{
// Native object
if (flavor.equals(DATA_FLAVOR))
return true;
// String
if (flavor.equals(DataFlavor.stringFlavor))
return true;
// We can't do anything else
return false;
} // end isDataFlavorSupported
/* ******** I N N E R - I N T E R F A C E - F E T C H E R ******** */
/**
* Instead of passing your data directly to the {@link TransferableObject} constructor, you
* may want to know exactly when your data was received
* in case you need to remove it from its source (or do anyting else to it).
* When the {@link #getTransferData getTransferData(...)} method is called
* on the {@link TransferableObject}, the {@link Fetcher}'s {@link #getObject getObject()}
* method will be called.
*
* @author Robert Harder
* @version 1.1
* @since 1.1
*/
public static interface Fetcher
{
/**
* Return the object being encapsulated in the {@link TransferableObject}.
*
* @return The dropped object
* @since 1.1
*/
public abstract Object getObject();
} // end inner interface Fetcher
} // end class TransferableObject
transient Border normalBorder;
transient DropTargetListener dropListener;
// Default border color
private static Color defaultBorderColor = new Color(0f, 0f, 1f, 0.25f);
/**
* Constructor with a default border and debugging optionally turned on.
* With Debugging turned on, more status messages will be displayed to <tt>out</tt>. A common
* way to use this constructor is with <tt>System.out</tt> or <tt>System.err</tt>. A
* <tt>null</tt> value for
* the parameter <tt>out</tt> will result in no debugging output.
*
* @param c
* Component on which files will be dropped.
* @param listener
* Listens for <tt>filesDropped</tt>.
* @since 1.0
*/
public FileDrop(final Component c, final FileDropListener listener)
{
this(c, BorderFactory.createMatteBorder(2, 2, 2, 2, defaultBorderColor), false, listener);
} // end constructor
/**
* Constructor with a default border, debugging optionally turned on
* and the option to recursively set drop targets.
* If your component is a <tt>Container</tt>, then each of its children
* components will also listen for drops, though only the parent will change borders.
* With Debugging turned on, more status messages will be displayed to <tt>out</tt>. A common
* way to use this constructor is with <tt>System.out</tt> or <tt>System.err</tt>. A
* <tt>null</tt> value for
* the parameter <tt>out</tt> will result in no debugging output.
*
* @param c
* Component on which files will be dropped.
* @param recursive
* Recursively set children as drop targets.
* @param listener
* Listens for <tt>filesDropped</tt>.
* @since 1.0
*/
public FileDrop(final Component c, final boolean recursive, final FileDropListener listener)
{
this(c, BorderFactory.createMatteBorder(2, 2, 2, 2, defaultBorderColor), recursive, listener);
} // end constructor
/**
* Constructor with a specified border
*
* @param c
* Component on which files will be dropped.
* @param dragBorder
* Border to use on <tt>JComponent</tt> when dragging occurs.
* @param listener
* Listens for <tt>filesDropped</tt>.
* @since 1.0
*/
public FileDrop(final Component c, final Border dragBorder, final FileDropListener listener)
{
this(c, dragBorder, false, listener);
} // end constructor
/**
* Constructor with a specified border and the option to recursively set drop targets.
* If your component is a <tt>Container</tt>, then each of its children
* components will also listen for drops, though only the parent will change borders.
*
* @param c
* Component on which files will be dropped.
* @param dragBorder
* Border to use on <tt>JComponent</tt> when dragging occurs.
* @param recursive
* Recursively set children as drop targets.
* @param listener
* Listens for <tt>filesDropped</tt>.
* @since 1.0
*/
public FileDrop(final Component c, final Border dragBorder, final boolean recursive, final FileDropListener listener)
{
this(c, dragBorder, recursive, listener, null);
} // end constructor
/**
* Constructor with a specified border and the option to recursively set drop targets.
* If your component is a <tt>Container</tt>, then each of its children
* components will also listen for drops, though only the parent will change borders.
*
* @param c
* Component on which files will be dropped.
* @param dragBorder
* Border to use on <tt>JComponent</tt> when dragging occurs.
* @param recursive
* Recursively set children as drop targets.
* @param listener
* Listens for <tt>filesDropped</tt>.
* @since 1.0
*/
public FileDrop(final Component c, final Border dragBorder, final boolean recursive,
final FileDropExtListener listener)
{
this(c, dragBorder, recursive, null, listener);
}
/**
* Full constructor with a specified border and debugging optionally turned on.
* With Debugging turned on, more status messages will be displayed to <tt>out</tt>. A common
* way to use this constructor is with <tt>System.out</tt> or <tt>System.err</tt>. A
* <tt>null</tt> value for
* the parameter <tt>out</tt> will result in no debugging output.
*
* @param out
* PrintStream to record debugging info or null for no debugging.
* @param c
* Component on which files will be dropped.
* @param dragBorder
* Border to use on <tt>JComponent</tt> when dragging occurs.
* @param recursive
* Recursively set children as drop targets.
* @param listener
* Listens for <tt>filesDropped</tt>.
* @since 1.0
*/
FileDrop(final Component c, final Border dragBorder, final boolean recursive, final FileDropListener listener,
final FileDropExtListener listenerExt)
{
// Make a drop listener
dropListener = new DropTargetListener()
{
@Override
public void dragEnter(DropTargetDragEvent evt)
{
// Is this an acceptable drag event?
if (isDragOk(evt))
{
// If it's a Swing component, set its border
if (c instanceof JComponent)
{
JComponent jc = (JComponent) c;
normalBorder = jc.getBorder();
jc.setBorder(dragBorder);
}
// Acknowledge that it's okay to enter
// evt.acceptDrag( DnDConstants.ACTION_COPY_OR_MOVE );
evt.acceptDrag(DnDConstants.ACTION_COPY);
}
else
// Reject the drag event
evt.rejectDrag();
}
@Override
public void dragOver(DropTargetDragEvent evt)
{ // This is called continually as long as the mouse is
// over the drag target.
} // end dragOver
@Override
public void drop(DropTargetDropEvent evt)
{
try
{ // Get whatever was dropped
Transferable tr = evt.getTransferable();
// Is it a file list?
if (tr.isDataFlavorSupported(DataFlavor.javaFileListFlavor))
{
// Say we'll take it.
// evt.acceptDrop ( DnDConstants.ACTION_COPY_OR_MOVE );
evt.acceptDrop(DnDConstants.ACTION_COPY);
// Get a useful list
List<File> fileList = (List<File>) tr.getTransferData(DataFlavor.javaFileListFlavor);
// Iterator<File> iterator = fileList.iterator();
// Convert list to array
File[] filesTemp = new File[fileList.size()];
fileList.toArray(filesTemp);
final File[] files = filesTemp;
// Alert listener to drop.
if (listener != null)
listener.filesDropped(files);
if (listenerExt != null)
listenerExt.filesDropped(evt, files);
// Mark that drop is completed.
evt.getDropTargetContext().dropComplete(true);
}
else
// this section will check for a reader flavor.
{
// Thanks, Nathan!
// BEGIN 2007-09-12 Nathan Blomquist -- Linux (KDE/Gnome) support added.
DataFlavor[] flavors = tr.getTransferDataFlavors();
boolean handled = false;
for (int zz = 0; zz < flavors.length; zz++)
{
if (flavors[zz].isRepresentationClassReader())
{
// Say we'll take it.
// evt.acceptDrop (
// DnDConstants.ACTION_COPY_OR_MOVE );
evt.acceptDrop(DnDConstants.ACTION_COPY);
Reader reader = flavors[zz].getReaderForText(tr);
BufferedReader br = new BufferedReader(reader);
if (listener != null)
listener.filesDropped(createFileArray(br));
if (listenerExt != null)
listenerExt.filesDropped(evt, createFileArray(br));
// Mark that drop is completed.
evt.getDropTargetContext().dropComplete(true);
handled = true;
break;
}
}
if (!handled)
evt.rejectDrop();
// END 2007-09-12 Nathan Blomquist -- Linux (KDE/Gnome) support added.
}
}
catch (IOException io)
{
System.err.println("FileDrop: IOException - abort:");
io.printStackTrace();
evt.rejectDrop();
}
catch (UnsupportedFlavorException ufe)
{
System.err.println("FileDrop: UnsupportedFlavorException - abort:");
ufe.printStackTrace();
evt.rejectDrop();
}
finally
{
// If it's a Swing component, reset its border
if (c instanceof JComponent)
{
JComponent jc = (JComponent) c;
jc.setBorder(normalBorder);
}
}
}
@Override
public void dragExit(DropTargetEvent evt)
{
// If it's a Swing component, reset its border
if (c instanceof JComponent)
{
JComponent jc = (JComponent) c;
jc.setBorder(normalBorder);
}
}
@Override
public void dropActionChanged(DropTargetDragEvent evt)
{
// Is this an acceptable drag event?
if (isDragOk(evt))
// evt.acceptDrag( DnDConstants.ACTION_COPY_OR_MOVE );
evt.acceptDrag(DnDConstants.ACTION_COPY);
else
evt.rejectDrag();
}
};
// Make the component (and possibly children) drop targets
makeDropTarget(c, recursive);
}
// BEGIN 2007-09-12 Nathan Blomquist -- Linux (KDE/Gnome) support added.
private static String ZERO_CHAR_STRING = "" + (char) 0;
static File[] createFileArray(BufferedReader bReader)
{
try
{
List<File> list = new ArrayList<File>();
String line = null;
while ((line = bReader.readLine()) != null)
{
try
{
// kde seems to append a 0 char to the end of the reader
if (ZERO_CHAR_STRING.equals(line))
continue;
File file = new File(new java.net.URI(line));
list.add(file);
}
catch (Exception ex)
{
System.err.println("Error with " + line + ": " + ex.getMessage());
}
}
return list.toArray(new File[list.size()]);
}
catch (IOException ex)
{
System.err.println("FileDrop: IOException");
}
return new File[0];
}
// END 2007-09-12 Nathan Blomquist -- Linux (KDE/Gnome) support added.
private void makeDropTarget(final Component c, boolean recursive)
{
// Make drop target
final DropTarget dt = new DropTarget();
try
{
dt.addDropTargetListener(dropListener);
} // end try
catch (TooManyListenersException e)
{
e.printStackTrace();
System.err
.println("FileDrop: Drop will not work due to previous error. Do you have another listener attached?");
} // end catch
// Listen for hierarchy changes and remove the drop target when the parent gets cleared out.
c.addHierarchyListener(new HierarchyListener()
{
@Override
public void hierarchyChanged(HierarchyEvent evt)
{
Component parent = c.getParent();
if (parent == null)
c.setDropTarget(null);
else
new DropTarget(c, dropListener);
}
});
if (c.getParent() != null)
new DropTarget(c, dropListener);
if (recursive && (c instanceof Container))
{
// Get the container
Container cont = (Container) c;
// Get it's components
Component[] comps = cont.getComponents();
// Set it's components as listeners also
for (int i = 0; i < comps.length; i++)
makeDropTarget(comps[i], recursive);
}
}
/** Determine if the dragged data is a file list. */
boolean isDragOk(final DropTargetDragEvent evt)
{
boolean ok = false;
// Get data flavors being dragged
DataFlavor[] flavors = evt.getCurrentDataFlavors();
// See if any of the flavors are a file list
int i = 0;
while (!ok && i < flavors.length)
{
// BEGIN 2007-09-12 Nathan Blomquist -- Linux (KDE/Gnome) support added.
// Is the flavor a file list?
final DataFlavor curFlavor = flavors[i];
if (curFlavor.equals(DataFlavor.javaFileListFlavor) || curFlavor.isRepresentationClassReader())
ok = true;
// END 2007-09-12 Nathan Blomquist -- Linux (KDE/Gnome) support added.
i++;
}
return ok;
}
/**
* Removes the drag-and-drop hooks from the component and optionally
* from the all children. You should call this if you add and remove
* components after you've set up the drag-and-drop.
* This will recursively unregister all components contained within
* <var>c</var> if <var>c</var> is a {@link Container}.
*
* @param c
* The component to unregister as a drop target
* @since 1.0
*/
public static boolean remove(Component c)
{
return remove(null, c, true);
}
/**
* Removes the drag-and-drop hooks from the component and optionally
* from the all children. You should call this if you add and remove
* components after you've set up the drag-and-drop.
*
* @param out
* Optional {@link PrintStream} for logging drag and drop messages
* @param c
* The component to unregister
* @param recursive
* Recursively unregister components within a container
* @since 1.0
*/
public static boolean remove(PrintStream out, Component c, boolean recursive)
{
// Make sure we support
c.setDropTarget(null);
if (recursive && (c instanceof Container))
{
Component[] comps = ((Container) c).getComponents();
for (int i = 0; i < comps.length; i++)
remove(out, comps[i], recursive);
return true;
}
return false;
}
/* ******** I N N E R - I N T E R F A C E L I S T E N E R ******** */
/**
* Implement this inner interface to listen for when files are dropped. For example
* your class declaration may begin like this: <code><pre>
* public class MyClass implements FileDrop.Listener
* ...
* public void filesDropped( File[] files )
* {
* ...
* } // end filesDropped
* ...
* </pre></code>
*
* @since 1.1
*/
public static interface FileDropListener
{
/**
* This method is called when files have been successfully dropped.
*
* @param files
* An array of <tt>File</tt>s that were dropped.
* @since 1.0
*/
public abstract void filesDropped(File[] files);
}
/**
* Implement this inner interface to listen for when files are dropped. For example
* your class declaration may begin like this: <code><pre>
* public class MyClass implements FileDrop.Listener
* ...
* public void filesDropped( File[] files )
* {
* ...
* } // end filesDropped
* ...
* </pre></code>
*
* @since 1.1
*/
public static interface FileDropExtListener
{
/**
* This method is called when files have been successfully dropped.
*
* @param evt
* The DropTargetDropEvent which initiated the drop operation.
* @param files
* An array of <tt>File</tt>s that were dropped.
* @since 2.0
*/
public abstract void filesDropped(DropTargetDropEvent evt, File[] files);
}
} // end class FileDrop