public class NullChange extends Change
NullChange
is a NullChange
.
Note: this class is not intended to be extended by clients.
Constructor and Description |
---|
NullChange()
Creates a new
NullChange with a default name. |
NullChange(String name)
Creates a new
NullChange with the given name. |
Modifier and Type | Method and Description |
---|---|
Object |
getModifiedElement()
Returns the element modified by this
Change . |
String |
getName()
Returns the human readable name of this change.
|
void |
initializeValidationData(IProgressMonitor pm)
Hook method to initialize some internal state to provide an adequate answer
for the
isValid method. |
RefactoringStatus |
isValid(IProgressMonitor pm)
Verifies that this change object is still valid and can be executed by calling
perform . |
Change |
perform(IProgressMonitor pm)
Performs this change.
|
dispose, getAdapter, getAffectedObjects, getDescriptor, getParent, isEnabled, setEnabled, setEnabledShallow
public NullChange()
NullChange
with a default name.public NullChange(String name)
NullChange
with the given name.name
- the human readable name of this changepublic String getName()
null
.public void initializeValidationData(IProgressMonitor pm)
isValid
method. This method gets called after a change
or a whole change tree has been created.
Typically this method is implemented in one of the following ways:
dispose
.isValid
is called.
For example, a change object that manipulates the content of an IFile
could either listen to resource changes and detect that the file got changed or
it could remember some content stamp and compare it with the actual content stamp
when isValid
is called.
initializeValidationData
in class Change
pm
- a progress monitorpublic RefactoringStatus isValid(IProgressMonitor pm) throws CoreException
perform
. If a refactoring status with a severity of RefactoringStatus.FATAL
is returned then the change has to be treated as invalid
and can no longer be executed. Performing such a change produces an unspecified
result and will very likely throw an exception.
This method is also called by the UndoManager
to decide if
an undo or redo change is still valid and therefore can be executed.
isValid
in class Change
pm
- a progress monitor.CoreException
- if an error occurred during validation check. The change
is to be treated as invalid if an exception occurspublic Change perform(IProgressMonitor pm) throws CoreException
IProgressMonitor.isCanceled()
since canceling a change tree in the
middle of its execution leaves the workspace in a half changed state.perform
in class Change
pm
- a progress monitornull
if no
undo is providedCoreException
- if an error occurred during change executionpublic Object getModifiedElement()
Change
. The method may return
null
if the change isn't related to an element.getModifiedElement
in class Change
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