DocumentEvent, in this case an edit
- * instruction, that is affilitated with a Position on a
- * document. The offset of the document event is not stored statically, but
- * taken from the affiliated Position, which gets updated
- * when other edits occurr.
- */
- static class Edit extends DocumentEvent {
-
- /**
- * Factory for edits which manages the creation, installation and
- * destruction of position categories, position updaters etc. on a
- * certain document. Once a factory has been obtained, Edit
- * objects can be obtained from it which will be linked to the document
- * by positions of one position category.
- *
- * Clients are required to call release once the
- * Edits are not used any more, so the positions can be
- * discarded.
- *
EditFactory with an unambiguous
- * position category name.
- *
- * @param document
- * the document that is being edited.
- */
- public EditFactory(IDocument document) {
- fCategory = CATEGORY + fgCount++;
- fDocument = document;
- }
-
- /**
- * Creates a new edition on the document of this factory.
- *
- * @param offset
- * the offset of the edition at the point when is
- * created.
- * @param length
- * the length of the edition (not updated via the
- * position update mechanism)
- * @param text
- * the text to be replaced on the document
- * @return an Edit reflecting the edition on the
- * document
- */
- public Edit createEdit(int offset, int length, String text)
- throws BadLocationException {
-
- if (!fDocument.containsPositionCategory(fCategory)) {
- fDocument.addPositionCategory(fCategory);
- fUpdater = new DefaultPositionUpdater(fCategory);
- fDocument.addPositionUpdater(fUpdater);
- }
-
- Position position = new Position(offset);
- try {
- fDocument.addPosition(fCategory, position);
- } catch (BadPositionCategoryException e) {
- Assert.isTrue(false);
- }
- return new Edit(fDocument, length, text, position);
- }
-
- /**
- * Releases the position category on the document and uninstalls the
- * position updater. Edits managed by this factory
- * are not updated after this call.
- */
- public void release() {
- if (fDocument != null
- && fDocument.containsPositionCategory(fCategory)) {
- fDocument.removePositionUpdater(fUpdater);
- try {
- fDocument.removePositionCategory(fCategory);
- } catch (BadPositionCategoryException e) {
- Assert.isTrue(false);
- }
- fDocument = null;
- fUpdater = null;
- }
- }
- }
-
- /** The position in the document where this edit be executed. */
- private Position fPosition;
-
- /**
- * Creates a new edition on document, taking its offset
- * from position.
- *
- * @param document
- * the document being edited
- * @param length
- * the length of the edition
- * @param text
- * the replacement text of the edition
- * @param position
- * the position keeping the edition's offset
- */
- protected Edit(IDocument document, int length, String text,
- Position position) {
- super(document, 0, length, text);
- fPosition = position;
- }
-
- /*
- * @see org.eclipse.jface.text.DocumentEvent#getOffset()
- */
- public int getOffset() {
- return fPosition.getOffset();
- }
-
- /**
- * Executes the edition on document. The offset is taken from the
- * position.
- *
- * @throws BadLocationException
- * if the execution of the document fails.
- */
- public void perform() throws BadLocationException {
- getDocument().replace(getOffset(), getLength(), getText());
- }
-
- }
-
- public void run() {
- if (!isEnabled())
- return;
-
- ITextEditor editor = getTextEditor();
- if (editor == null || !ensureEditable(editor))
- return;
-
- ITextSelection selection = getCurrentSelection();
- if (!isValidSelection(selection))
- return;
-
- if (!validateEditorInputState())
- return;
-
- IDocumentProvider docProvider = editor.getDocumentProvider();
- IEditorInput input = editor.getEditorInput();
- if (docProvider == null || input == null)
- return;
-
- IDocument document = docProvider.getDocument(input);
- if (document == null)
- return;
-
- IDocumentExtension3 docExtension;
- if (document instanceof IDocumentExtension3)
- docExtension = (IDocumentExtension3) document;
- else
- return;
-
- IRewriteTarget target = (IRewriteTarget) editor
- .getAdapter(IRewriteTarget.class);
- if (target != null) {
- target.beginCompoundChange();
- }
-
- Edit.EditFactory factory = new Edit.EditFactory(document);
-
- try {
- runInternal(selection, docExtension, factory);
-
- } catch (BadLocationException e) {
- // can happen on concurrent modification, deletion etc. of the
- // document
- // -> don't complain, just bail out
- } catch (BadPartitioningException e) {
- // should not happen
- Assert.isTrue(false, "bad partitioning"); //$NON-NLS-1$
- } finally {
- factory.release();
-
- if (target != null) {
- target.endCompoundChange();
- }
- }
- }
-
- /**
- * Calls perform on all Edits in
- * edits.
- *
- * @param edits
- * a list of Edits
- * @throws BadLocationException
- * if an Edit threw such an exception.
- */
- protected void executeEdits(List edits) throws BadLocationException {
- for (Iterator it = edits.iterator(); it.hasNext();) {
- Edit edit = (Edit) it.next();
- edit.perform();
- }
- }
-
- /**
- * Ensures that the editor is modifyable. If the editor is an instance of
- * ITextEditorExtension2, its
- * validateEditorInputState method is called, otherwise, the
- * result of isEditable is returned.
- *
- * @param editor
- * the editor to be checked
- * @return true if the editor is editable, false
- * otherwise
- */
- protected boolean ensureEditable(ITextEditor editor) {
- Assert.isNotNull(editor);
-
- if (editor instanceof ITextEditorExtension2) {
- ITextEditorExtension2 ext = (ITextEditorExtension2) editor;
- return ext.validateEditorInputState();
- }
-
- return editor.isEditable();
- }
-
- /*
- * @see org.eclipse.ui.texteditor.IUpdate#update()
- */
- public void update() {
- super.update();
-
- if (isEnabled()) {
- if (!canModifyEditor() || !isValidSelection(getCurrentSelection()))
- setEnabled(false);
- }
- }
-
- /**
- * Returns the editor's selection, or null if no selection
- * can be obtained or the editor is null.
- *
- * @return the selection of the action's editor, or null
- */
- protected ITextSelection getCurrentSelection() {
- ITextEditor editor = getTextEditor();
- if (editor != null) {
- ISelectionProvider provider = editor.getSelectionProvider();
- if (provider != null) {
- ISelection selection = provider.getSelection();
- if (selection instanceof ITextSelection)
- return (ITextSelection) selection;
- }
- }
- return null;
- }
-
- /**
- * Runs the real command once all the editor, document, and selection checks
- * have succeeded.
- *
- * @param selection
- * the current selection we are being called for
- * @param docExtension
- * the document extension where we get the partitioning from
- * @param factory
- * the edit factory we can use to create Edits
- * @throws BadLocationException
- * if an edition fails
- * @throws BadPartitioningException
- * if a partitioning call fails
- */
- protected abstract void runInternal(ITextSelection selection,
- IDocumentExtension3 docExtension, Edit.EditFactory factory)
- throws BadLocationException, BadPartitioningException;
-
- /**
- * Checks whether selection is valid.
- *
- * @param selection
- * the selection to check
- * @return true if the selection is valid, false
- * otherwise
- */
- protected abstract boolean isValidSelection(ITextSelection selection);
-
- /**
- * Returns the text to be inserted at the selection start.
- *
- * @return the text to be inserted at the selection start
- */
- protected String getCommentStart() {
- // for now: no space story
- return "/*"; //$NON-NLS-1$
- }
-
- /**
- * Returns the text to be inserted at the selection end.
- *
- * @return the text to be inserted at the selection end
- */
- protected String getCommentEnd() {
- // for now: no space story
- return "*/"; //$NON-NLS-1$
- }
-
-}