Rulers

Rulers appear on the top and the left of the Dia canvas. They show, in centimeters, how large your canvas is.

On each ruler exists an arrow. The arrow moves on the ruler in coordination with where the mouse pointer is. For example, if the user moves the mouse up, the vertical ruler's arrow will move up, indicating the change. These arrows become useful when an object needs to line up exactly at a certain measurement point.

Rulers, unlike gridlines, cannot be removed.