Package org.eclipse.ltk.core.refactoring

Class TextFileChange

  • All Implemented Interfaces:
    IAdaptable
    public class TextFileChange
extends TextChange
    A special TextChange that operates on a IFile.

    As of 3.1 the content stamp managed by a text file change maps to the modification stamp of its underlying IFile. Undoing a text file change will roll back the modification stamp of a resource to its original value using the new API IResource.revertModificationStamp(long)

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

    Since:
    3.0

    • 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,
                      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 IFile getFile()
        Returns the IFile this change is working on.
        Returns:
        the file this change is working on

      • createUndoChange

        protected Change createUndoChange​(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()
        Description copied from class: Change
        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

      • getAffectedObjects

        public Object[] getAffectedObjects()
        Description copied from class: Change
        Returns the elements affected by this change or null if the affected elements cannot be determined. Returns an empty array if the change doesn't modify any elements.

        This default implementation returns null to indicate that the affected elements are unknown. Subclasses should reimplement this method if they can compute the set of affected elements.

        Overrides:
        getAffectedObjects in class Change
        Returns:
        the elements affected by this change or null if the affected elements cannot be determined

      • initializeValidationData

        public void initializeValidationData​(IProgressMonitor monitor)
        Description copied from class: Change
        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.

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

      • isValid

        public RefactoringStatus isValid​(IProgressMonitor monitor)
                          throws CoreException
        Description copied from class: Change
        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:
        monitor - a progress monitor.
        Returns:
        a refactoring status describing the outcome of the validation check
        Throws:
        CoreException - if an error occurred during validation check. The change is to be treated as invalid if an exception occurs

      • dispose

        public void dispose()
        Description copied from class: Change
        Disposes this change. Subclasses that override this method typically unregister listeners which got registered during the call to initializeValidationData.

        Subclasses may override this method.

        Overrides:
        dispose in class Change

      • commit

        protected void commit​(IDocument document,
                      IProgressMonitor pm)
               throws 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.

        The implementation of this method only commits the underlying buffer if needsSaving() and isDocumentModified() returns true.

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

      • createUndoChange

        protected final Change createUndoChange​(UndoEdit edit)
        Description copied from class: TextChange
        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 the creation of the undo change.

      • performEdits

        protected UndoEdit performEdits​(IDocument document)
                         throws BadLocationException,
                                MalformedTreeException
        Description copied from class: TextChange
        Executes the text edits on the given document. Subclasses that override this method should call super.performEdits(document).
        Overrides:
        performEdits in class TextChange
        Parameters:
        document - the document
        Returns:
        an object representing the undo of the executed edits
        Throws:
        BadLocationException - is thrown if one of the edits in the tree can't be executed. The state of the document is undefined if this exception is thrown.
        MalformedTreeException - is thrown if the edit tree isn't in a valid state. This exception is thrown before any edit is executed. So the document is still in its original state.

      • isDocumentAcquired

        protected boolean isDocumentAcquired()
        Is the document currently acquired?
        Returns:
        true if the document is currently acquired, false otherwise
        Since:
        3.2

      • isDocumentModified

        protected boolean isDocumentModified()
        Has the document been modified since it has been first acquired by the change?
        Returns:
        Returns true if the document has been modified since it got acquired by the change. false is returned if the document has not been acquired yet, or has been released already.
        Since:
        3.3

      • needsSaving

        protected boolean needsSaving()
        Does the text file change need saving?

        The implementation of this method returns true if the FORCE_SAVE flag is enabled, or the underlying file is not dirty and KEEP_SAVE_STATE is enabled.

        Returns:
        true if it needs saving according to its dirty state and the save mode flags, false otherwise
        Since:
        3.3