1. A method implemented in a processor-based computing system, comprising: rendering at least a portion of a diagram to a display device coupled to the computing system, the diagram comprising a plurality of elements; identifying a user gesture based on input received via at least one user input device coupled to the computing system; selecting, subsequent to said identifying, a subset of elements from among a plurality of different elements of the diagram based on the identified user gesture; selecting, automatically, a layout constraint from among a plurality of layout constraints based on a path or a shape of the identified user gesture, each layout constraint controlling a manner in which elements of a diagram are arranged when rendered to a display device; applying the selected layout constraint to the selected subset of elements; and rendering at least a portion of the diagram to the display device after application of the selected layout constraint to the selected subset of elements.