Package com.vaadin.signals.impl
Interface UsageTracker.Usage
- Enclosing class:
- UsageTracker
public static interface UsageTracker.Usage
Tracks the state of some used value.
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Method Summary
Modifier and TypeMethodDescriptionboolean
Checks whether the used value has subsequently been changed.onNextChange
(TransientListener listener) Registers a listener that will be invoked the next time there's a change to the used value.
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Method Details
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hasChanges
boolean hasChanges()Checks whether the used value has subsequently been changed.- Returns:
true
if the value has been changed,false
if there is no change
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onNextChange
Registers a listener that will be invoked the next time there's a change to the used value. If this usage already has changes, then the listener is invoked immediately.- Parameters:
listener
- the listener to use, notnull
- Returns:
- a callback for removing the listener, not
null
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