Package org.eclipse.jface.util
Class PropertyChangeEvent
- java.lang.Object
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- java.util.EventObject
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- org.eclipse.jface.util.PropertyChangeEvent
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- All Implemented Interfaces:
Serializable
public class PropertyChangeEvent extends EventObject
An event object describing a change to a named property.This concrete class was designed to be instantiated, but may also be subclassed if required.
The JFace frameworks contain classes that report property change events for internal state changes that may be of interest to external parties. A special listener interface (
IPropertyChangeListener
) is defined for this purpose, and a typical class allow listeners to be registered via anaddPropertyChangeListener
method.- See Also:
IPropertyChangeListener
, Serialized Form
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Field Summary
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Fields inherited from class java.util.EventObject
source
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Constructor Summary
Constructors Constructor Description PropertyChangeEvent(Object source, String property, Object oldValue, Object newValue)
Creates a new property change event.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description Object
getNewValue()
Returns the new value of the property.Object
getOldValue()
Returns the old value of the property.String
getProperty()
Returns the name of the property that changed.-
Methods inherited from class java.util.EventObject
getSource, toString
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Constructor Detail
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PropertyChangeEvent
public PropertyChangeEvent(Object source, String property, Object oldValue, Object newValue)
Creates a new property change event.- Parameters:
source
- the object whose property has changedproperty
- the property that has changed (must not benull
)oldValue
- the old value of the property, ornull
if nonenewValue
- the new value of the property, ornull
if none
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Method Detail
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getNewValue
public Object getNewValue()
Returns the new value of the property.- Returns:
- the new value, or
null
if not known or not relevant (for instance if the property was removed).
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getOldValue
public Object getOldValue()
Returns the old value of the property.- Returns:
- the old value, or
null
if not known or not relevant (for instance if the property was just added and there was no old value).
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getProperty
public String getProperty()
Returns the name of the property that changed.Warning: there is no guarantee that the property name returned is a constant string. Callers must compare property names using equals, not ==.
- Returns:
- the name of the property that changed
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