How to use org.eclipse.jface.text.source.projection

/**
 * Installs this projection support on its viewer.
 */
public void install() {
  fViewer.setProjectionSummary(createProjectionSummary());
  fProjectionListener= new ProjectionListener();
  fViewer.addProjectionListener(fProjectionListener);
}

private void internalInvalidateTextPresentation(int offset, int length) {
  if (fCommandQueue != null) {
    fCommandQueue.add(new ProjectionCommand(offset, length));
  } else {
    invalidateTextPresentation(offset, length);
  }
}

/**
 * Disables the projection mode.
 */
public final void disableProjection() {
  if (isProjectionMode()) {
    removeProjectionAnnotationModel(getVisualAnnotationModel());
    fProjectionAnnotationModel.removeAllAnnotations();
    fFindReplaceDocumentAdapter= null;
    fireProjectionDisabled();
  }
}

private void internalUpdateSummaries(IProgressMonitor monitor) {
  IAnnotationModel visualAnnotationModel= fProjectionViewer.getVisualAnnotationModel();
  if (visualAnnotationModel == null)
    return;
  removeSummaries(monitor, visualAnnotationModel);
  if (isCanceled(monitor))
    return;
  createSummaries(monitor, visualAnnotationModel);
}

@Override
protected void mouseClicked(int line) {
  clearCurrentAnnotation();
  if (fMouseDownLine != line)
    return;
  ProjectionAnnotation annotation= findAnnotation(line, true);
  if (annotation != null) {
    ProjectionAnnotationModel model= (ProjectionAnnotationModel) getModel();
    model.toggleExpansionState(annotation);
  }
}

@Override
protected void mouseDoubleClicked(int rulerLine) {
  if (findAnnotation(rulerLine, true) != null)
    return;
  ProjectionAnnotation annotation= findAnnotation(rulerLine, false);
  if (annotation != null) {
    ProjectionAnnotationModel model= (ProjectionAnnotationModel)getModel();
    model.toggleExpansionState(annotation);
  }
}

  private void processModelChanged(IAnnotationModel model, AnnotationModelEvent event) {
    if (model == fProjectionAnnotationModel) {
      if (fProjectionSummary != null)
        fProjectionSummary.updateSummaries();
      processCatchupRequest(event);
    } else if (model == getAnnotationModel() && fProjectionSummary != null)
      fProjectionSummary.updateSummaries();
  }
}

/**
 * Replace the visible document with the given document. Maintains the
 * scroll offset and the selection.
 *
 * @param slave the visible document
 */
private void replaceVisibleDocument(IDocument slave) {
  if (fReplaceVisibleDocumentExecutionTrigger != null) {
    ReplaceVisibleDocumentExecutor executor= new ReplaceVisibleDocumentExecutor(slave);
    executor.install(fReplaceVisibleDocumentExecutionTrigger);
  } else
    executeReplaceVisibleDocument(slave);
}

/**
 * Forces an updated of the annotation summary.
 */
public void updateSummaries() {
  synchronized (fLock) {
    if (fConfiguredAnnotationTypes != null) {
      if (fSummarizer == null)
        fSummarizer= new Summarizer();
      fSummarizer.reset();
    }
  }
}

/**
 * Returns the drawing strategy to be used by the support's annotation painter.
 *
 * @return the drawing strategy to be used by the support's annotation painter
 * @since 3.1
 */
private AnnotationPainter.IDrawingStrategy getDrawingStrategy() {
  if (fDrawingStrategy == null)
    fDrawingStrategy= new ProjectionDrawingStrategy();
  return fDrawingStrategy;
}

private boolean clearCurrentAnnotation() {
  if (fCurrentAnnotation != null) {
    fCurrentAnnotation.setRangeIndication(false);
    fCurrentAnnotation= null;
    return true;
  }
  return false;
}

/**
 * Expands all annotations that overlap with the given range and are collapsed.
 *
 * @param offset the range offset
 * @param length the range length
 * @return <code>true</code> if any annotation has been expanded, <code>false</code> otherwise
 */
public boolean expandAll(int offset, int length) {
  return expandAll(offset, length, true);
}

/**
 * Disables the projection mode.
 */
public final void disableProjection() {
  if (isProjectionMode()) {
    removeProjectionAnnotationModel(getVisualAnnotationModel());
    fProjectionAnnotationModel.removeAllAnnotations();
    fFindReplaceDocumentAdapter= null;
    fireProjectionDisabled();
  }
}

/**
 * Installs this projection support on its viewer.
 */
public void install() {
  fViewer.setProjectionSummary(createProjectionSummary());
  fProjectionListener= new ProjectionListener();
  fViewer.addProjectionListener(fProjectionListener);
}

private void internalUpdateSummaries(IProgressMonitor monitor) {
  IAnnotationModel visualAnnotationModel= fProjectionViewer.getVisualAnnotationModel();
  if (visualAnnotationModel == null)
    return;
  removeSummaries(monitor, visualAnnotationModel);
  if (isCanceled(monitor))
    return;
  createSummaries(monitor, visualAnnotationModel);
}

@Override
protected void mouseClicked(int line) {
  clearCurrentAnnotation();
  if (fMouseDownLine != line)
    return;
  ProjectionAnnotation annotation= findAnnotation(line, true);
  if (annotation != null) {
    ProjectionAnnotationModel model= (ProjectionAnnotationModel) getModel();
    model.toggleExpansionState(annotation);
  }
}

private void internalInvalidateTextPresentation(int offset, int length) {
  if (fCommandQueue != null) {
    fCommandQueue.add(new ProjectionCommand(offset, length));
  } else {
    invalidateTextPresentation(offset, length);
  }
}

@Override
protected void mouseDoubleClicked(int rulerLine) {
  if (findAnnotation(rulerLine, true) != null)
    return;
  ProjectionAnnotation annotation= findAnnotation(rulerLine, false);
  if (annotation != null) {
    ProjectionAnnotationModel model= (ProjectionAnnotationModel)getModel();
    model.toggleExpansionState(annotation);
  }
}

  private void processModelChanged(IAnnotationModel model, AnnotationModelEvent event) {
    if (model == fProjectionAnnotationModel) {
      if (fProjectionSummary != null)
        fProjectionSummary.updateSummaries();
      processCatchupRequest(event);
    } else if (model == getAnnotationModel() && fProjectionSummary != null)
      fProjectionSummary.updateSummaries();
  }
}

/**
 * Replace the visible document with the given document. Maintains the
 * scroll offset and the selection.
 *
 * @param slave the visible document
 */
private void replaceVisibleDocument(IDocument slave) {
  if (fReplaceVisibleDocumentExecutionTrigger != null) {
    ReplaceVisibleDocumentExecutor executor= new ReplaceVisibleDocumentExecutor(slave);
    executor.install(fReplaceVisibleDocumentExecutionTrigger);
  } else
    executeReplaceVisibleDocument(slave);
}