org.das2.system.ChangesSupport

Support class for encapsulating implementation of pendingChanges and mutator locks. PendingChanges are a way of notifying the bean and other clients using the bean that changes are coming to the bean. mutatorLock() is a way for a client to get exclusive, read-only access to a bean. This also sets the valueAdjusting property. See http://das2.org/wiki/index.php/Pending_changes (Wiki was lost, but may be recoverable.)

PROP_PENDINGCHANGES

PROP_VALUEADJUSTING

changePerformed

the change is complete, and as far as the client is concerned, the canvas is valid.

Parameters

Returns:

getChangesPending

return a map listing the pending changes. This is a thread-safe read-only copy.

Returns:

isPendingChanges

true if someone has registered a pending change.

Returns:

isValueAdjusting

true when the bean state is rapidly changing.

Returns:

mutatorLock

one client will have write access to the bean, and when unlock is called, a "valueAdjusting" property change event is fired. In the future, this will return null if the lock is already out, but for now, clients should check the valueIsAdjusting property.

Returns:

pendingChanges

return a list of all the pending changes. These are returned in a Map that goes from pending change to change manager.

Parameters

Returns:

performingChange

performingChange tells that the change is about to be performed. This is a place holder in case we use a mutator lock, but currently does nothing. If the change has not been registered, it will be registered implicitly. This will increment the internal count of how many times the change ought to occur.

Parameters

Returns:

registerPendingChange

the client knows a change will be coming, and the canvas' clients should know that its current state will change soon. Example pending changes would be:

• layout because tick labels are changing
• data is loading

Parameters

Returns: