/// Emits a signal about the selection blocking. Emits a signal to change the selection.
/// If the block is true, the signal clear selection, otherwise if restore selection flag allows,
/// the internal operation features are to be selected
/// Emits a signal about the selection blocking. Emits a signal to change the selection.
/// If the block is true, the signal clear selection, otherwise if restore selection flag allows,
/// the internal operation features are to be selected