How can I use org.eclipse.jface.text.PaintManager in subclass of TextEditor?

Question

How can I attach a PaintManager to my TextEditor? For example, draw the background of cursor line with org.eclipse.jface.text.CursorLinePainter.

Answer 1

Your editor's TextViewer or SourceViewer provides the paint manager. You can access it using the ITextViewerExtension2 interface of the viewer.

For example this code is from SourceViewerDecorationSupport:

private void showCursorLine() {
    if (fCursorLinePainter == null) {
        if (fSourceViewer instanceof ITextViewerExtension2) {
            fCursorLinePainter = new CursorLinePainter(fSourceViewer);
            fCursorLinePainter.setHighlightColor(getColor(fCursorLinePainterColorKey));

            ITextViewerExtension2 extension = (ITextViewerExtension2) fSourceViewer;
            extension.addPainter(fCursorLinePainter);
        }
    }
}