Animated user interface control elements

A method for providing an animated transition effect between a first display state associated with a first control state of a control element rendered on a graphical user interface of a computer system, and a second display state associated with a second control state of said control element is provided. The method renders the control element in said first state and then receives at the graphic user interface, a user input event to invoke the second control state of the control element. The method evaluates a graph associated with the control element, the graph having entries each corresponding to a state of the control element, each entry comprising an event, an associated transition and a destination state, to identify a graph entry specifying a transition invoked by the input event from a current displayed first state to the destination state, being the second control state. An entry is identified corresponding to the second control state as the current state of the control element and a description of an animation associated with the specified transition is retrieved. The animation is then rendered.