An input display device, a method of controlling the same, a program, and a printing apparatus that enable an intuitive change in page layout order without reducing the display area of a preview screen in a preview display of an image to be printed are provided. To accomplish this, when pages of held original data are aggregated and displayed at one time as a preview of multiple pages, if a predetermined rotation operation has been detected, the input display device changes the layout order of the displayed pages according to a combination of the orientation of the input display device and the predetermined rotation operation, and reflects the changed page layout order on the held original data.