isRoll
True for a roll: EpubLayout.ROLL, or a pre-paginated book whose flow is scrolled-continuous, which EPUB Reading Systems 3.4 asks to read the same way (#506).
True for a roll: EpubLayout.ROLL, or a pre-paginated book whose flow is scrolled-continuous, which EPUB Reading Systems 3.4 asks to read the same way (#506).