| com.jgoodies.binding.value.AbstractValueModel
 com.jgoodies.binding.value.DelayedReadValueModel
| DelayedReadValueModel | | final public class DelayedReadValueModel extends AbstractValueModel (Code) | | A ValueModel that deferres updates and read-access for a specified delay.
Useful to coalesce frequent changes. For example if a heavy computation
shall be performed only for a "stable" selection after a series of
quick selection changes.
Wraps a given subject ValueModel and observes subject value changes
and forwards them to listeners of this model after a delay. If the subject
value changes, a Swing Timer is used to delay the change notification.
A previously started timer - if any - will be stopped before.
Reading this model's value returns:
a) the subject value if there's no pending update, or
b) this model's old value that will be updated after the delay.
If a value is set to this model, it immediately updates the subject value.
TODO: Describe how and when listeners get notified about the delayed change.
TODO: Write about the recommended delay time - above the double-click time
and somewhere below a second, e.g. 100ms to 200ms.
TODO: Write about a slightly different commit handling. The current
implementation defers the commit until the value is stable for the
specified delay; it's a DelayUntilStableForXXXmsValueModel. Another
feature is to delay for a specified time but ensure that some commits
and change notifications happen. The latter is a CoalescingWriteValueModel.
TODO: Summarize the differences between the DelayedReadValueModel, the
DelayedWriteValueModel, and the DelayedPropertyChangeHandler.
author:
Karsten Lentzsch
version:
$Revision: 1.8 $
See Also: javax.swing.Timer
since:
1.1 |
| Constructor Summary | |
| public | DelayedReadValueModel(ValueModel subject, int delay)
Constructs a DelayedReadValueModel for the given subject ValueModel
and the specified Timer delay in milliseconds with coalescing disabled. | | public | DelayedReadValueModel(ValueModel subject, int delay, boolean coalesce)
Constructs a DelayedReadValueModel for the given subject ValueModel
and the specified Timer delay in milliseconds using the given
coalesce mode. |
| Method Summary | |
| public int | getDelay()
Returns the delay, in milliseconds, that is used to defer value change
notifications. | | public Object | getValue()
Returns the subject's value or in case of a pending commit,
the pending new value. | | public boolean | isCoalesce()
Returns if this model coalesces all pending changes or not. | | public void | setCoalesce(boolean b)
Sets if this model shall coalesce all pending changes or not. | | public void | setDelay(int delay)
Sets the delay, in milliseconds, that is used to defer value change
notifications. | | public void | setValue(Object newValue)
Sets the given new value immediately as the subject's new value.
Note that change notifications from the subject are deferred
by this model. | | public void | stop()
Stops a running timer - if any. |
| DelayedReadValueModel | | public DelayedReadValueModel(ValueModel subject, int delay)(Code) | | Constructs a DelayedReadValueModel for the given subject ValueModel
and the specified Timer delay in milliseconds with coalescing disabled.
Parameters:
subject - the underlying (or wrapped) ValueModel
Parameters:
delay - the milliseconds to wait before a changeshall be committed
throws:
IllegalArgumentException - if the delay is negative |
| DelayedReadValueModel | | public DelayedReadValueModel(ValueModel subject, int delay, boolean coalesce)(Code) | | Constructs a DelayedReadValueModel for the given subject ValueModel
and the specified Timer delay in milliseconds using the given
coalesce mode.
Parameters:
subject - the underlying (or wrapped) ValueModel
Parameters:
delay - the milliseconds to wait before a changeshall be committed
Parameters:
coalesce - true to coalesce all pending changes,false to fire changes with the delay when an updatehas been received
throws:
IllegalArgumentException - if the delay is negative
See Also: DelayedReadValueModel.setCoalesce(boolean) |
| getDelay | | public int getDelay()(Code) | | Returns the delay, in milliseconds, that is used to defer value change
notifications.
the delay, in milliseconds, that is used to defervalue change notifications
See Also: DelayedReadValueModel.setDelay |
| getValue | | public Object getValue()(Code) | | Returns the subject's value or in case of a pending commit,
the pending new value.
the subject's current or future value. |
| isCoalesce | | public boolean isCoalesce()(Code) | | Returns if this model coalesces all pending changes or not.
true if all pending changes will be coalesced,false if pending changes are fired with a delaywhen an update has been received.
See Also: DelayedReadValueModel.setCoalesce(boolean) |
| setCoalesce | | public void setCoalesce(boolean b)(Code) | | Sets if this model shall coalesce all pending changes or not.
In this case, a change event will be fired first,
if no updates have been received for this model's delay.
If coalesce is false, a change event will be fired
with this model's delay when an update has been received.
The default value is false.
Note that this value is not the #coalesce value
of this model's internal Swing timer.
Parameters:
b - true to coalesce,false to fire separate changes |
| setDelay | | public void setDelay(int delay)(Code) | | Sets the delay, in milliseconds, that is used to defer value change
notifications.
Parameters:
delay - the delay, in milliseconds, that is used to defervalue change notifications
See Also: DelayedReadValueModel.getDelay |
| setValue | | public void setValue(Object newValue)(Code) | | Sets the given new value immediately as the subject's new value.
Note that change notifications from the subject are deferred
by this model. Therefore listeners registered with this model
will be notified after this model's delay.
Parameters:
newValue - the value to set |
| stop | | public void stop()(Code) | | Stops a running timer - if any. The last pending change
won't be performed by the ValueUpdateListener.
since:
1.2 |
| Fields inherited from com.jgoodies.binding.value.AbstractValueModel | final public static String PROPERTYNAME_VALUE(Code)(Java Doc)
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