1. A method for receiving input from a graphical user interface, the method comprising: displaying, by a computing device, a graphical user interface on a display device, the graphical user interface comprising a document area and a control ribbon, the document area containing at least a portion of a document that a user is currently editing, the control ribbon containing a first horizontal control gallery, the first horizontal control gallery containing a plurality of class controls, each class control in the plurality of class controls associated with a different class in a plurality of classes, each class control in the plurality of class controls containing a class icon graphically describing the class associated with the class control, each class in the plurality of classes being a subset of commands in an overall set of commands; selecting one of the plurality of class controls displayed in the first horizontal control gallery; in response to selecting one of the plurality of class controls in the first horizontal control gallery, displaying a preview of a default slide transition effect (STE) associated with the one of the plurality of class controls; while the first horizontal control gallery is displayed, receiving, at the computing device, a class selection input from the user, the class selection input indicating a selected class control in the plurality of class controls, the selected class control associated with a selected class in the plurality of classes; after receiving the class selection input, displaying, by the computing device, a second vertical control gallery in the graphical user interface, the second vertical control gallery being separate from and not graphically connected to the first horizontal control gallery, the second vertical control gallery containing a plurality of variation controls, each variation control in the plurality of variation controls associated with a different command in the selected class, each variation control in the plurality of variation controls containing a variation icon graphically describing the command associated with the variation control; selecting one of the plurality of variation controls displayed in the second vertical control gallery; in response to selecting one of the plurality of variation controls in the second vertical control gallery, displaying a preview of a default slide transition effect (STE) associated with the one of the plurality of variation controls; while the second vertical control gallery is displayed, receiving, at the computing device, a variation selection input from the user, the variation selection input indicating a selected variation control in the plurality of variation controls; and in response to receiving the variation selection input, modifying, by the computing device, the document by executing the command associated with the selected variation control.
11. The method of claim 1 further comprising: in response to receiving the class selection input, modifying, by the computing device, the document by executing a default command in the selected class.