Transferable
to and from Swing components. The Transferable is used to
represent data that is exchanged via a cut, copy, or paste
to/from a clipboard. It is also used in drag-and-drop operations
to represent a drag from a component, and a drop to a component.
Swing provides functionality that automatically supports cut, copy,
and paste keyboard bindings that use the functionality provided by
an implementation of this class. Swing also provides functionality
that automatically supports drag and drop that uses the functionality
provided by an implementation of this class. The Swing developer can
concentrate on specifying the semantics of a transfer primarily by setting
the transferHandler property on a Swing component.
This class is implemented to provide a default behavior of transferring
a component property simply by specifying the name of the property in
the constructor. For example, to transfer the foreground color from
one component to another either via the clipboard or a drag and drop operation
a TransferHandler can be constructed with the string "foreground". The
built in support will use the color returned by getForeground as the source
of the transfer, and setForeground for the target of a transfer.
Please see How to Use Drag and Drop and Data Transfer, a section in The Java Tutorial, for more information.
int representing a "copy" transfer action.
This value is used when data is copied to a clipboard
or copied elsewhere in a drag and drop operation.int representing a source action capability of either
"copy" or "move".int representing a "move" transfer action.
This value is used when data is moved to a clipboard (i.e. a cut)
or moved elsewhere in a drag and drop operation.int representing no transfer action.
The equals method implements an equivalence relation
on non-null object references:
x, x.equals(x) should return
true.
x and y, x.equals(y)
should return true if and only if
y.equals(x) returns true.
x, y, and z, if
x.equals(y) returns true and
y.equals(z) returns true, then
x.equals(z) should return true.
x and y, multiple invocations of
x.equals(y) consistently return true
or consistently return false, provided no
information used in equals comparisons on the
objects is modified.
x,
x.equals(null) should return false.
The equals method for class Object implements
the most discriminating possible equivalence relation on objects;
that is, for any non-null reference values x and
y, this method returns true if and only
if x and y refer to the same object
(x == y has the value true).
Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.
javax.swing.plaf.basic
package if the dragEnabled property is set on the component.
This can be called by custom UI
implementations to use the Swing drag support. This method can also be called
by a Swing extension written as a subclass of JComponent
to take advantage of the Swing drag support.
The transfer will not necessarily have been completed at the
return of this call (i.e. the call does not block waiting for the drop).
The transfer will take place through the Swing implementation of the
java.awt.dnd mechanism, requiring no further effort
from the developer. The exportDone method will be called
when the transfer has completed.
The transfer will take place using the java.awt.datatransfer
mechanism, requiring no further effort from the developer. Any data
transfer will be complete and the exportDone
method will be called with the action that occurred, before this method
returns. Should the clipboard be unavailable when attempting to place
data on it, the IllegalStateException thrown by
will
be propogated through this method. However,
exportDone will first be called with an action
of NONE for consistency.
Action that behaves like a 'copy' operation.
That is, this will invoke exportToClipboard with
a COPY argument on the TransferHandler
associated with the JComponent that is the source of
the ActionEvent.Action that behaves like a 'cut' operation.
That is, this will invoke exportToClipboard with
a MOVE argument on the TransferHandler
associated with the JComponent that is the source of
the ActionEvent.Action that behaves like a 'paste' operation.
That is, this will invoke importData on the
TransferHandler
associated with the JComponent that is the source of
the ActionEvent.COPY
only should be advertised in that case.Icon interface should
not alter the graphics clip or alpha level.
The icon implementation need not be rectangular or paint all of the
bounding rectangle and logic that calls the icons paint method should
not assume the all bits are painted. null is a valid return value
for this method and indicates there is no visual representation provided.
In that case, the calling logic is free to represent the
transferable however it wants.
The default Swing logic will not do an alpha blended drag animation if
the return is null.
java.util.Hashtable.
The general contract of hashCode is:
hashCode method on each of
the two objects must produce the same integer result.
As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the JavaTM programming language.)
Transferable represents
the data to be imported into the component.wait methods.
The awakened thread will not be able to proceed until the current thread relinquishes the lock on this object. The awakened thread will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened thread enjoys no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:
synchronized statement
that synchronizes on the object.
Class, by executing a
synchronized static method of that class.
Only one thread at a time can own an object's monitor.
wait methods.
The awakened threads will not be able to proceed until the current thread relinquishes the lock on this object. The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
toString method returns a string that
"textually represents" this object. The result should
be a concise but informative representation that is easy for a
person to read.
It is recommended that all subclasses override this method.
The toString method for class Object
returns a string consisting of the name of the class of which the
object is an instance, the at-sign character `@', and
the unsigned hexadecimal representation of the hash code of the
object. In other words, this method returns a string equal to the
value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
The current thread must own this object's monitor. The thread
releases ownership of this monitor and waits until another thread
notifies threads waiting on this object's monitor to wake up
either through a call to the notify method or the
notifyAll method. The thread then waits until it can
re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait();
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.The current thread must own this object's monitor.
This method causes the current thread (call it T) to place itself in the wait set for this object and then to relinquish any and all synchronization claims on this object. Thread T becomes disabled for thread scheduling purposes and lies dormant until one of four things happens:
A thread can also wake up without being notified, interrupted, or timing out, a so-called spurious wakeup. While this will rarely occur in practice, applications must guard against it by testing for the condition that should have caused the thread to be awakened, and continuing to wait if the condition is not satisfied. In other words, waits should always occur in loops, like this one:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout);
... // Perform action appropriate to condition
}
(For more information on this topic, see Section 3.2.3 in Doug Lea's
"Concurrent Programming in Java (Second Edition)" (Addison-Wesley,
2000), or Item 50 in Joshua Bloch's "Effective Java Programming
Language Guide" (Addison-Wesley, 2001).
If the current thread is interrupted by another thread while it is waiting, then an InterruptedException is thrown. This exception is not thrown until the lock status of this object has been restored as described above.
Note that the wait method, as it places the current thread into the wait set for this object, unlocks only this object; any other objects on which the current thread may be synchronized remain locked while the thread waits.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
This method is similar to the wait method of one
argument, but it allows finer control over the amount of time to
wait for a notification before giving up. The amount of real time,
measured in nanoseconds, is given by:
1000000*timeout+nanos
In all other respects, this method does the same thing as the method of one argument. In particular, wait(0, 0) means the same thing as wait(0).
The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:
notify method
or the notifyAll method.
timeout
milliseconds plus nanos nanoseconds arguments, has
elapsed.
The thread then waits until it can re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout, nanos);
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.