Patent ID: 7623128

Claim:
A method of creating and editing interactive constraint-based alignment objects in a computer-implemented graphics system, comprising: (a) creating a first drawing entity and one or more second drawing entities in the graphics system, wherein the first and second drawing entities are linked together as an alignment object, and the first drawing entity includes a persistent tangency rule related to one or more of the second drawing entities, wherein the persistent tangency rule comprises (1) the first drawing entity being a fixed entity not dependent on tangency to any of the second drawing entities to define the fixed entity's geometry, (2) the first drawing entity being a floating entity dependent on tangency to one of the second drawing entities before or after the floating entity to define the floating entity's geometry, and (3) the first drawing entity being a free entity dependent on tangency to two of the second drawing entities before and after the free entity to define the free entity's geometry; (b) editing the one or more of the second drawing entities, without editing the first drawing entity, in the graphics system, after the first and second drawing entities have been created, wherein the persistent tangency rule results in the first drawing entity's geometry being affected in response to the one or more second drawing entities being edited, such that the first drawing entity with the persistent tangency rule is dependent on the one or more second drawing entities being edited to define the first drawing entity's geometry; and (c) displaying the first and second drawing entities on the graphics system.