= Graphical user interface
A <graphical user interface> lets a user inspect and manipulate a program through visual controls such as windows, buttons, menus and text fields. A <GUI widget> combines a displayed representation with interaction behavior. Input <software events>[events] select a control or action, while application <state> determines what is drawn next.
For example, pressing a button can initiate a calculation and later display its result. The <Event handler> should not have to embed every computational detail; separating the underlying model from its view makes other <application programming interfaces>[interfaces] and tests possible. Qt Widgets provides visual elements, layout management and event handling as separate cooperating mechanisms.<Qt Widgets documentation>[Widgets, Layouts and Model/View Classes]{ref} A visible control is therefore an interaction interface, not an <authorization> boundary or proof that the requested action succeeded.
Back to article page
