question: @ Override protected boolean _mouseEnteredDrawable ( Drawable drawable ) { Diagram diag = tab . getDiagram ( ) ; if ( diag != null && diag . getStateForDrawable ( drawable ) != null ) { return true ; } return false ; }
target:  Returns true if and only if the given drawable instance is associated by the most recently used diagram with a DiagramDataProvider state, id est a position in the text area.