net.iharder.dnd.FileDrop Class Reference

List of all members.

Detailed Description

This class makes it easy to drag and drop files from the operating system to a Java program.

Any java.awt.Component can be dropped onto, but only javax.swing.JComponents will indicate the drop event with a changed border. To use this class, construct a new FileDrop by passing it the target component and a Listener to receive notification when file(s) have been dropped. Here is an example: JPanel myPanel = new JPanel(); new FileDrop( myPanel, new FileDrop.Listener() { public void filesDropped( java.io.File[] files ) { // handle file drop ... } // end filesDropped }); // end FileDrop.Listener You can specify the border that will appear when files are being dragged by calling the constructor with a javax.swing.border.Border. Only JComponents will show any indication with a border. You can turn on some debugging features by passing a PrintStream object (such as System.out) into the full constructor. A null value will result in no extra debugging information being output.

I'm releasing this code into the Public Domain. Enjoy.

Original author: Robert Harder, rharder@usa.net

Author:
Robert Harder

rharder@usa.net

Version:
1.0


Public Member Functions

 FileDrop (final java.awt.Component c, final boolean recursive, final Listener listener)
 Constructor with a default border and the option to recursively set drop targets.
 FileDrop (final java.awt.Component c, final javax.swing.border.Border dragBorder, final boolean recursive, final Listener listener)
 Constructor with a specified border and the option to recursively set drop targets.
 FileDrop (final java.awt.Component c, final javax.swing.border.Border dragBorder, final Listener listener)
 Constructor with a specified border.
 FileDrop (final java.awt.Component c, final Listener listener)
 Constructs a FileDrop with a default light-blue border and, if c is a java.awt.Container, recursively sets all elements contained within as drop targets, though only the top level container will change borders.
 FileDrop (final java.io.PrintStream out, final java.awt.Component c, final boolean recursive, final Listener listener)
 Constructor with a default border, debugging optionally turned on and the option to recursively set drop targets.
 FileDrop (final java.io.PrintStream out, final java.awt.Component c, final javax.swing.border.Border dragBorder, final boolean recursive, final Listener listener)
 Full constructor with a specified border and debugging optionally turned on.
 FileDrop (final java.io.PrintStream out, final java.awt.Component c, final javax.swing.border.Border dragBorder, final Listener listener)
 Constructor with a specified border and debugging optionally turned on.
 FileDrop (final java.io.PrintStream out, final java.awt.Component c, final Listener listener)
 Constructor with a default border and debugging optionally turned on.

Static Public Member Functions

static void main (String[] args)
 Runs a sample program that shows dropped files.
static boolean remove (java.awt.Component c)
 Removes the drag-and-drop hooks from the component and optionally from the all children.
static boolean remove (java.io.PrintStream out, java.awt.Component c, boolean recursive)
 Removes the drag-and-drop hooks from the component and optionally from the all children.

Private Member Functions

boolean isDragOk (final java.io.PrintStream out, final java.awt.dnd.DropTargetDragEvent evt)
 Determine if the dragged data is a file list.
void makeDropTarget (final java.io.PrintStream out, final java.awt.Component c, boolean recursive)

Static Private Member Functions

static void log (java.io.PrintStream out, String message)
 Outputs message to out if it's not null.
static boolean supportsDnD ()

Private Attributes

transient javax.swing.border.Border normalBorder
transient java.awt.dnd.DropTargetListener dropListener

Static Private Attributes

static Boolean supportsDnD
 Discover if the running JVM is modern enough to have drag and drop.
static java.awt.Color defaultBorderColor = new java.awt.Color(0f, 0f, 1f, 0.25f)

Classes

interface  Listener
 Implement this inner interface to listen for when files are dropped. More...


Constructor & Destructor Documentation

net.iharder.dnd.FileDrop.FileDrop ( final java.awt.Component  c,
final boolean  recursive,
final Listener  listener 
)

Constructor with a default border and the option to recursively set drop targets.

If your component is a java.awt.Container, then each of its children components will also listen for drops, though only the parent will change borders.

Parameters:
c Component on which files will be dropped.
recursive Recursively set children as drop targets.
listener Listens for filesDropped.
Since:
1.0

net.iharder.dnd.FileDrop.FileDrop ( final java.awt.Component  c,
final javax.swing.border.Border  dragBorder,
final boolean  recursive,
final Listener  listener 
)

Constructor with a specified border and the option to recursively set drop targets.

If your component is a java.awt.Container, then each of its children components will also listen for drops, though only the parent will change borders.

Parameters:
c Component on which files will be dropped.
dragBorder Border to use on JComponent when dragging occurs.
recursive Recursively set children as drop targets.
listener Listens for filesDropped.
Since:
1.0

net.iharder.dnd.FileDrop.FileDrop ( final java.awt.Component  c,
final javax.swing.border.Border  dragBorder,
final Listener  listener 
)

Constructor with a specified border.

Parameters:
c Component on which files will be dropped.
dragBorder Border to use on JComponent when dragging occurs.
listener Listens for filesDropped.
Since:
1.0

net.iharder.dnd.FileDrop.FileDrop ( final java.awt.Component  c,
final Listener  listener 
)

Constructs a FileDrop with a default light-blue border and, if c is a java.awt.Container, recursively sets all elements contained within as drop targets, though only the top level container will change borders.

Parameters:
c Component on which files will be dropped.
listener Listens for filesDropped.
Since:
1.0

net.iharder.dnd.FileDrop.FileDrop ( final java.io.PrintStream  out,
final java.awt.Component  c,
final boolean  recursive,
final Listener  listener 
)

Constructor with a default border, debugging optionally turned on and the option to recursively set drop targets.

If your component is a java.awt.Container, 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 out. A common way to use this constructor is with System.out or System.err. A null value for the parameter out will result in no debugging output.

Parameters:
out PrintStream to record debugging info or null for no debugging.
out 
c Component on which files will be dropped.
recursive Recursively set children as drop targets.
listener Listens for filesDropped.
Since:
1.0

net.iharder.dnd.FileDrop.FileDrop ( final java.io.PrintStream  out,
final java.awt.Component  c,
final javax.swing.border.Border  dragBorder,
final boolean  recursive,
final Listener  listener 
)

Full constructor with a specified border and debugging optionally turned on.

With Debugging turned on, more status messages will be displayed to out. A common way to use this constructor is with System.out or System.err. A null value for the parameter out will result in no debugging output.

Parameters:
out PrintStream to record debugging info or null for no debugging.
c Component on which files will be dropped.
dragBorder Border to use on JComponent when dragging occurs.
recursive Recursively set children as drop targets.
listener Listens for filesDropped.
Since:
1.0

net.iharder.dnd.FileDrop.FileDrop ( final java.io.PrintStream  out,
final java.awt.Component  c,
final javax.swing.border.Border  dragBorder,
final Listener  listener 
)

Constructor with a specified border and debugging optionally turned on.

With Debugging turned on, more status messages will be displayed to out. A common way to use this constructor is with System.out or System.err. A null value for the parameter out will result in no debugging output.

Parameters:
out PrintStream to record debugging info or null for no debugging.
c Component on which files will be dropped.
dragBorder Border to use on JComponent when dragging occurs.
listener Listens for filesDropped.
Since:
1.0

net.iharder.dnd.FileDrop.FileDrop ( final java.io.PrintStream  out,
final java.awt.Component  c,
final Listener  listener 
)

Constructor with a default border and debugging optionally turned on.

With Debugging turned on, more status messages will be displayed to out. A common way to use this constructor is with System.out or System.err. A null value for the parameter out will result in no debugging output.

Parameters:
out PrintStream to record debugging info or null for no debugging.
out 
c Component on which files will be dropped.
listener Listens for filesDropped.
Since:
1.0


Member Function Documentation

static void net.iharder.dnd.FileDrop.main ( String[]  args  )  [static]

Runs a sample program that shows dropped files.

static boolean net.iharder.dnd.FileDrop.remove ( java.awt.Component  c  )  [static]

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 c if c is a java.awt.Container.

Parameters:
c The component to unregister as a drop target
Since:
1.0

static boolean net.iharder.dnd.FileDrop.remove ( java.io.PrintStream  out,
java.awt.Component  c,
boolean  recursive 
) [static]

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.

Parameters:
out Optional java.io.PrintStream for logging drag and drop messages
c The component to unregister
recursive Recursively unregister components within a container
Since:
1.0

static void net.iharder.dnd.FileDrop.log ( java.io.PrintStream  out,
String  message 
) [static, private]

Outputs message to out if it's not null.

boolean net.iharder.dnd.FileDrop.isDragOk ( final java.io.PrintStream  out,
final java.awt.dnd.DropTargetDragEvent  evt 
) [private]

Determine if the dragged data is a file list.


Member Data Documentation

Boolean net.iharder.dnd.FileDrop.supportsDnD [static, private]

Discover if the running JVM is modern enough to have drag and drop.


The documentation for this class was generated from the following file:
Generated on Wed Aug 8 17:02:59 2007 for CALO by  doxygen 1.5.2