⌂ Affecting items only on the left or right of a line break (BarLines, KeySignatures, Clefs, etc.)

If you want to affect the behaviour (color, rotation, translate, etc.) of an item at a line break only on the left or the right side (like BarLines, KeySignatures, Clefs, TimeSignatures, etc.), use the definitions and functions as defined here. Several other definitions are possible by using this examples.