Display Area Movement Control for Edge Scrolling

The patent applies different movement characteristics to different regions of the display area. When the display area is within the freely-movable region, it can move freely in all directions. When it approaches the edge of the freely-movable region, movement in the direction toward the edge is restricted while movement in other directions remains allowed. This local differentiation of movement properties resolves the contradiction by providing both freedom of movement and predictable behavior at boundaries.

The patent implements dynamic movement restrictions that adapt based on the display area's position. The restriction in the direction toward the edge of the freely-movable region is not absolute but depends on the positional relationship between the display area and the boundary. This dynamic approach allows the display area to move predictably when near edges while still permitting access to content outside the freely-movable region under certain conditions, thus resolving the contradiction between predictability and scrolling range.