How to use

modelRange2WidgetRange

method

in

org.eclipse.jface.text.TextViewer

/**
 * Returns whether the marked region of this viewer is empty.
 *
 * @return <code>true</code> if the marked region of this viewer is empty, otherwise <code>false</code>
 * @since 2.0
 */
private boolean isMarkedRegionEmpty() {
  return
    fTextWidget == null ||
    fMarkPosition == null ||
    fMarkPosition.isDeleted() ||
    modelRange2WidgetRange(fMarkPosition) == null;
}

/**
 * Returns whether the marked region of this viewer is empty.
 *
 * @return <code>true</code> if the marked region of this viewer is empty, otherwise <code>false</code>
 * @since 2.0
 */
private boolean isMarkedRegionEmpty() {
  return
    fTextWidget == null ||
    fMarkPosition == null ||
    fMarkPosition.isDeleted() ||
    modelRange2WidgetRange(fMarkPosition) == null;
}

/**
 * Same as {@link #modelRange2WidgetRange(IRegion)} just for a {@link org.eclipse.jface.text.Position}.
 *
 * @param modelPosition the position describing a range in the viewer's document
 * @return a region describing a range in the viewer's widget
 * @since 2.1
 */
protected IRegion modelRange2WidgetRange(Position modelPosition) {
  return modelRange2WidgetRange(new Region(modelPosition.getOffset(), modelPosition.getLength()));
}

/**
 * Same as {@link #modelRange2WidgetRange(IRegion)} just for a {@link org.eclipse.jface.text.Position}.
 *
 * @param modelPosition the position describing a range in the viewer's document
 * @return a region describing a range in the viewer's widget
 * @since 2.1
 */
protected IRegion modelRange2WidgetRange(Position modelPosition) {
  return modelRange2WidgetRange(new Region(modelPosition.getOffset(), modelPosition.getLength()));
}

IRegion region= modelRange2WidgetRange(presentation.getCoverage());
if (region == null)
  return;

IRegion region= modelRange2WidgetRange(presentation.getCoverage());
if (region == null)
  return;

/**
 * Translates a style range given relative to the viewer's document into style
 * ranges relative to the viewer's widget or <code>null</code>.
 *
 * @param range the style range in the coordinates of the viewer's document
 * @return the style range in the coordinates of the viewer's widget or <code>null</code>
 * @since 2.1
 */
protected StyleRange modelStyleRange2WidgetStyleRange(StyleRange range) {
  IRegion region= modelRange2WidgetRange(new Region(range.start, range.length));
  if (region != null) {
    StyleRange result= (StyleRange) range.clone();
    result.start= region.getOffset();
    result.length= region.getLength();
    return result;
  }
  return null;
}

/**
 * Translates a style range given relative to the viewer's document into style
 * ranges relative to the viewer's widget or <code>null</code>.
 *
 * @param range the style range in the coordinates of the viewer's document
 * @return the style range in the coordinates of the viewer's widget or <code>null</code>
 * @since 2.1
 */
protected StyleRange modelStyleRange2WidgetStyleRange(StyleRange range) {
  IRegion region= modelRange2WidgetRange(new Region(range.start, range.length));
  if (region != null) {
    StyleRange result= (StyleRange) range.clone();
    result.start= region.getOffset();
    result.length= region.getLength();
    return result;
  }
  return null;
}

  return null;
IRegion region= ((TextViewer)fInput.fViewer).modelRange2WidgetRange(new Region(pos.offset, pos.length));
if (region == null)
  return null;

  return null;
IRegion region= ((TextViewer)fInput.fViewer).modelRange2WidgetRange(new Region(pos.offset, pos.length));
if (region == null)
  return null;

  return null;
IRegion region= ((TextViewer)fInput.fViewer).modelRange2WidgetRange(new Region(pos.offset, pos.length));
if (region == null)
  return null;

private IRegion modelRange2WidgetRange(IRegion region) {
  if (fEditorViewer instanceof ITextViewerExtension5) {
    ITextViewerExtension5 extension = (ITextViewerExtension5) fEditorViewer;
    return extension.modelRange2WidgetRange(region);
  }
  if (fEditorViewer instanceof TextViewer) {
    return ((TextViewer) fEditorViewer).modelRange2WidgetRange(region);
  }
  IRegion visibleRegion = fEditorViewer.getVisibleRegion();
  int start = region.getOffset() - visibleRegion.getOffset();
  int end = start + region.getLength();
  if (end > visibleRegion.getLength())
    end = visibleRegion.getLength();
  return new Region(start, end - start);
}

/**
 * Invalidates the given range of the text presentation.
 *
 * @param offset the offset of the range to be invalidated
 * @param length the length of the range to be invalidated
 * @since 2.1
 */
@Override
public final void invalidateTextPresentation(int offset, int length) {
  if (fVisibleDocument != null) {
    IRegion widgetRange= modelRange2WidgetRange(new Region(offset, length));
    if (widgetRange != null) {
      fWidgetCommand.event= null;
      fWidgetCommand.start= widgetRange.getOffset();
      fWidgetCommand.length= widgetRange.getLength();
      try {
        fWidgetCommand.text= fVisibleDocument.get(widgetRange.getOffset(), widgetRange.getLength());
        updateTextListeners(fWidgetCommand);
      } catch (BadLocationException x) {
        // can not happen because of previous checking
      }
    }
  }
}

/**
 * Invalidates the given range of the text presentation.
 *
 * @param offset the offset of the range to be invalidated
 * @param length the length of the range to be invalidated
 * @since 2.1
 */
@Override
public final void invalidateTextPresentation(int offset, int length) {
  if (fVisibleDocument != null) {
    IRegion widgetRange= modelRange2WidgetRange(new Region(offset, length));
    if (widgetRange != null) {
      fWidgetCommand.event= null;
      fWidgetCommand.start= widgetRange.getOffset();
      fWidgetCommand.length= widgetRange.getLength();
      try {
        fWidgetCommand.text= fVisibleDocument.get(widgetRange.getOffset(), widgetRange.getLength());
        updateTextListeners(fWidgetCommand);
      } catch (BadLocationException x) {
        // can not happen because of previous checking
      }
    }
  }
}

/**
 * Paints the highlighting of this range.
 */
private void paint() {
  IRegion widgetRegion= modelRange2WidgetRange(fPosition);
  int offset= widgetRegion.getOffset();
  int length= widgetRegion.getLength();
  int count= fTextWidget.getCharCount();
  if (offset + length >= count) {
    length= count - offset; // clip
    Point upperLeft= fTextWidget.getLocationAtOffset(offset);
    Point lowerRight= fTextWidget.getLocationAtOffset(offset + length);
    int width= fTextWidget.getClientArea().width;
    int height= fTextWidget.getLineHeight(offset + length) + lowerRight.y - upperLeft.y;
    fTextWidget.redraw(upperLeft.x, upperLeft.y, width, height, false);
  }
  fTextWidget.redrawRange(offset, length, true);
}

/**
 * Paints the highlighting of this range.
 */
private void paint() {
  IRegion widgetRegion= modelRange2WidgetRange(fPosition);
  int offset= widgetRegion.getOffset();
  int length= widgetRegion.getLength();
  int count= fTextWidget.getCharCount();
  if (offset + length >= count) {
    length= count - offset; // clip
    Point upperLeft= fTextWidget.getLocationAtOffset(offset);
    Point lowerRight= fTextWidget.getLocationAtOffset(offset + length);
    int width= fTextWidget.getClientArea().width;
    int height= fTextWidget.getLineHeight(offset + length) + lowerRight.y - upperLeft.y;
    fTextWidget.redraw(upperLeft.x, upperLeft.y, width, height, false);
  }
  fTextWidget.redrawRange(offset, length, true);
}

/**
 * Copies/cuts the marked region.
 *
 * @param delete <code>true</code> if the region should be deleted rather than copied.
 * @since 2.0
 */
protected void copyMarkedRegion(boolean delete) {
  if (fTextWidget == null)
    return;
  if (fMarkPosition == null || fMarkPosition.isDeleted() || modelRange2WidgetRange(fMarkPosition) == null)
    return;
  int widgetMarkOffset= modelOffset2WidgetOffset(fMarkPosition.offset);
  Point selection= fTextWidget.getSelection();
  if (selection.x <= widgetMarkOffset)
    fTextWidget.setSelection(selection.x, widgetMarkOffset);
  else
    fTextWidget.setSelection(widgetMarkOffset, selection.x);
  if (delete) {
    wrapCompoundChange(new Runnable() {
      @Override
      public void run() {
        fTextWidget.cut();
      }
    });
  } else {
    fTextWidget.copy();
    fTextWidget.setSelection(selection.x); // restore old cursor position
  }
}

/**
 * Copies/cuts the marked region.
 *
 * @param delete <code>true</code> if the region should be deleted rather than copied.
 * @since 2.0
 */
protected void copyMarkedRegion(boolean delete) {
  if (fTextWidget == null)
    return;
  if (fMarkPosition == null || fMarkPosition.isDeleted() || modelRange2WidgetRange(fMarkPosition) == null)
    return;
  int widgetMarkOffset= modelOffset2WidgetOffset(fMarkPosition.offset);
  Point selection= fTextWidget.getSelection();
  if (selection.x <= widgetMarkOffset)
    fTextWidget.setSelection(selection.x, widgetMarkOffset);
  else
    fTextWidget.setSelection(widgetMarkOffset, selection.x);
  if (delete) {
    wrapCompoundChange(() -> fTextWidget.cut());
  } else {
    fTextWidget.copy();
    fTextWidget.setSelection(selection.x); // restore old cursor position
  }
}

/**
 * Similar to {@link #modelRange2WidgetRange(IRegion)}, but more forgiving:
 * if <code>modelRange</code> describes a region entirely hidden in the
 * image, then this method returns the zero-length region at the offset of
 * the folded region.
 *
 * @param modelRange the model range
 * @return the corresponding widget range, or <code>null</code>
 * @since 3.1
 */
protected IRegion modelRange2ClosestWidgetRange(IRegion modelRange) {
  if (!(fInformationMapping instanceof IDocumentInformationMappingExtension2))
    return modelRange2WidgetRange(modelRange);
  try {
    if (modelRange.getLength() < 0) {
      Region reversed= new Region(modelRange.getOffset() + modelRange.getLength(), -modelRange.getLength());
      IRegion result= ((IDocumentInformationMappingExtension2) fInformationMapping).toClosestImageRegion(reversed);
      if (result != null)
        return new Region(result.getOffset() + result.getLength(), -result.getLength());
    }
    return ((IDocumentInformationMappingExtension2) fInformationMapping).toClosestImageRegion(modelRange);
  } catch (BadLocationException x) {
  }
  return null;
}

/**
 * Similar to {@link #modelRange2WidgetRange(IRegion)}, but more forgiving:
 * if <code>modelRange</code> describes a region entirely hidden in the
 * image, then this method returns the zero-length region at the offset of
 * the folded region.
 *
 * @param modelRange the model range
 * @return the corresponding widget range, or <code>null</code>
 * @since 3.1
 */
protected IRegion modelRange2ClosestWidgetRange(IRegion modelRange) {
  if (!(fInformationMapping instanceof IDocumentInformationMappingExtension2))
    return modelRange2WidgetRange(modelRange);
  try {
    if (modelRange.getLength() < 0) {
      Region reversed= new Region(modelRange.getOffset() + modelRange.getLength(), -modelRange.getLength());
      IRegion result= ((IDocumentInformationMappingExtension2) fInformationMapping).toClosestImageRegion(reversed);
      if (result != null)
        return new Region(result.getOffset() + result.getLength(), -result.getLength());
    }
    return ((IDocumentInformationMappingExtension2) fInformationMapping).toClosestImageRegion(modelRange);
  } catch (BadLocationException x) {
  }
  return null;
}