Eclipse JDT
Release 3.0

org.eclipse.ltk.core.refactoring
Class TextFileChange

java.lang.Object
  extended byorg.eclipse.ltk.core.refactoring.Change
      extended byorg.eclipse.ltk.core.refactoring.TextChange
          extended byorg.eclipse.ltk.core.refactoring.TextFileChange
All Implemented Interfaces:
org.eclipse.core.runtime.IAdaptable

public class TextFileChange
extends TextChange

A special TextChange that operates on a IFile.

The class should be subclassed by clients which need to perform special operation when acquiring or releasing a document.

Since:
3.0

Field Summary
static int FORCE_SAVE
          Flag (value 2) indicating that the file is to be saved after the change has been applied.
static int KEEP_SAVE_STATE
          Flag (value 1) indicating that the file's save state has to be kept.
static int LEAVE_DIRTY
          Flag (value 4) indicating that the file will not be saved after the change has been applied.
 
Constructor Summary
TextFileChange(String name, org.eclipse.core.resources.IFile file)
          Creates a new TextFileChange for the given file.
 
Method Summary
protected  org.eclipse.jface.text.IDocument acquireDocument(org.eclipse.core.runtime.IProgressMonitor pm)
          Acquires a reference to the document to be changed by this text change. A document acquired by this call MUST be released via a call to TextChange.releaseDocument(IDocument, IProgressMonitor).

The method releaseDocument must be call as many times as aquireDocument has been called.

protected  void commit(org.eclipse.jface.text.IDocument document, org.eclipse.core.runtime.IProgressMonitor pm)
          Commits the document acquired via a call to aquireDocument. It is up to the implementors of this method to decide what committing a document means. Typically, the content of the document is written back to the file system.
protected  Change createUndoChange(org.eclipse.text.edits.UndoEdit edit)
          Hook to create an undo change for the given undo edit. This hook gets called while performing the change to construct the corresponding undo change object.
protected  Change createUndoChange(org.eclipse.text.edits.UndoEdit edit, ContentStamp stampToRestore)
          Hook to create an undo change for the given undo edit and content stamp.
 void dispose()
          Disposes this change. Subclasses that override this method typically unregister listeners which got registered during the call to initializeValidationState.

Subclasses may override this method.

 org.eclipse.core.resources.IFile getFile()
          Returns the IFile this change is working on.
 Object getModifiedElement()
          Returns the element modified by this Change. The method may return null if the change isn't related to an element.
 int getSaveMode()
          Returns the save state set via setSaveMode(int).
 void initializeValidationData(org.eclipse.core.runtime.IProgressMonitor pm)
          Hook method to initialize some internal state to provide an adequate answer for the 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:

  • the change hooks up a listener on some delta notification mechanism and marks itself as invalid if it receives a certain delta. Is this the case the implementor must take care of unhooking the listener in dispose.
  • the change remembers some information allowing to decide if a change object is still valid when 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.

 RefactoringStatus isValid(org.eclipse.core.runtime.IProgressMonitor pm)
          Verifies that this change object is still valid and can be executed by calling 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.

protected  void releaseDocument(org.eclipse.jface.text.IDocument document, org.eclipse.core.runtime.IProgressMonitor pm)
          Releases the document acquired via a call to aquireDocument.
 void setSaveMode(int saveMode)
          Sets the save state.
 
Methods inherited from class org.eclipse.ltk.core.refactoring.TextChange
addTextEditChangeGroup, addTextEditGroup, getCurrentContent, getCurrentContent, getCurrentDocument, getEdit, getKeepPreviewEdits, getName, getPreviewContent, getPreviewContent, getPreviewDocument, getPreviewEdit, getPreviewEdits, getTextEditChangeGroups, getTextType, perform, setEdit, setEnabled, setKeepPreviewEdits, setTextType
 
Methods inherited from class org.eclipse.ltk.core.refactoring.Change
getAdapter, getParent, isEnabled
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

KEEP_SAVE_STATE

public static final int KEEP_SAVE_STATE
Flag (value 1) indicating that the file's save state has to be kept. This means an unsaved file is still unsaved after performing the change and a saved one will be saved.

See Also:
Constant Field Values

FORCE_SAVE

public static final int FORCE_SAVE
Flag (value 2) indicating that the file is to be saved after the change has been applied.

See Also:
Constant Field Values

LEAVE_DIRTY

public static final int LEAVE_DIRTY
Flag (value 4) indicating that the file will not be saved after the change has been applied.

See Also:
Constant Field Values
Constructor Detail

TextFileChange

public TextFileChange(String name,
                      org.eclipse.core.resources.IFile file)
Creates a new TextFileChange for the given file.

Parameters:
name - the change's name mainly used to render the change in the UI
file - the file this text change operates on
Method Detail

setSaveMode

public void setSaveMode(int saveMode)
Sets the save state. Must be one of KEEP_SAVE_STATE, FORCE_SAVE or LEAVE_DIRTY.

Parameters:
saveMode - indicating how save is handled when the document gets committed

getSaveMode

public int getSaveMode()
Returns the save state set via setSaveMode(int).

Returns:
the save state

getFile

public org.eclipse.core.resources.IFile getFile()
Returns the IFile this change is working on.

Returns:
the file this change is working on

createUndoChange

protected Change createUndoChange(org.eclipse.text.edits.UndoEdit edit,
                                  ContentStamp stampToRestore)
Hook to create an undo change for the given undo edit and content stamp. This hook gets called while performing the change to construct the corresponding undo change object.

Parameters:
edit - the UndoEdit to create an undo change for
stampToRestore - the content stamp to restore when the undo edit is executed.
Returns:
the undo change or null if no undo change can be created. Returning null results in the fact that the whole change tree can't be undone. So returning null is only recommended if an exception occurred during creating the undo change.

getModifiedElement

public Object getModifiedElement()
Returns the element modified by this Change. The method may return null if the change isn't related to an element.

Specified by:
getModifiedElement in class Change
Returns:
the element modified by this change

initializeValidationData

public void initializeValidationData(org.eclipse.core.runtime.IProgressMonitor pm)
Hook method to initialize some internal state to provide an adequate answer for the 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:

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.

Specified by:
initializeValidationData in class Change
Parameters:
pm - a progress monitor

isValid

public RefactoringStatus isValid(org.eclipse.core.runtime.IProgressMonitor pm)
                          throws org.eclipse.core.runtime.CoreException
Verifies that this change object is still valid and can be executed by calling 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.

Specified by:
isValid in class Change
Parameters:
pm - a progress monitor.
Returns:
a refactoring status describing the outcome of the validation check
Throws:
org.eclipse.core.runtime.CoreException - if an error occurred during validation check. The change is to be treated as invalid if an exception occurs

dispose

public void dispose()
Disposes this change. Subclasses that override this method typically unregister listeners which got registered during the call to initializeValidationState.

Subclasses may override this method.

Overrides:
dispose in class Change

acquireDocument

protected org.eclipse.jface.text.IDocument acquireDocument(org.eclipse.core.runtime.IProgressMonitor pm)
                                                    throws org.eclipse.core.runtime.CoreException
Acquires a reference to the document to be changed by this text change. A document acquired by this call MUST be released via a call to TextChange.releaseDocument(IDocument, IProgressMonitor).

The method releaseDocument must be call as many times as aquireDocument has been called.

Specified by:
acquireDocument in class TextChange
Parameters:
pm - a progress monitor
Returns:
a reference to the document to be changed
Throws:
org.eclipse.core.runtime.CoreException - if the document can't be acquired

commit

protected void commit(org.eclipse.jface.text.IDocument document,
                      org.eclipse.core.runtime.IProgressMonitor pm)
               throws org.eclipse.core.runtime.CoreException
Commits the document acquired via a call to aquireDocument. It is up to the implementors of this method to decide what committing a document means. Typically, the content of the document is written back to the file system.

Specified by:
commit in class TextChange
Parameters:
document - the document to commit
pm - a progress monitor
Throws:
org.eclipse.core.runtime.CoreException - if the document can't be committed

releaseDocument

protected void releaseDocument(org.eclipse.jface.text.IDocument document,
                               org.eclipse.core.runtime.IProgressMonitor pm)
                        throws org.eclipse.core.runtime.CoreException
Releases the document acquired via a call to aquireDocument.

Specified by:
releaseDocument in class TextChange
Parameters:
document - the document to release
pm - a progress monitor
Throws:
org.eclipse.core.runtime.CoreException - if the document can't be released

createUndoChange

protected final Change createUndoChange(org.eclipse.text.edits.UndoEdit edit)
Hook to create an undo change for the given undo edit. This hook gets called while performing the change to construct the corresponding undo change object.

Specified by:
createUndoChange in class TextChange
Parameters:
edit - the UndoEdit to create an undo change for
Returns:
the undo change or null if no undo change can be created. Returning null results in the fact that the whole change tree can't be undone. So returning null is only recommended if an exception occurred during creating the undo change.

Eclipse JDT
Release 3.0

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