Incremental run-time layout composition

Performing incremental runtime composition. A method includes a computing system receiving a user input gesture modifying a diagram displayed on a diagram surface. The diagram includes a first element, a second element, and a plurality of elements connected to the second element laid out in a particular layout pattern with respect to the second element. The method further includes interpreting the user input gesture to be a gesture creating a graph by connecting the first element to the second element of the diagram. The method further includes performing an auto layout of the diagram by automatically, and without user intervention, repositioning the second element with respect to the first element but without substantially repositioning the plurality of elements with respect to the second element by moving the second element and the plurality of elements as an atomic unit.