Interactive GUIs 10 26 2011 Opening Discussion Minute essay comments Scope in programs What languages are used to write apps GUI for text adventure Simple spreadsheet Blog layout Simple game Quiz GUI Can a GUI only have one MainFrame Menus The frame has a MenuBar Contents of a MenuBar should be Menus Menus can hold the following MenuItem Menu CheckMenuItem RadioMenuItem Separator Example GUI We want to have a simple GUI that has a few components for us to play with Interactive GUIs Last time we learned how to build a GUI with components Our GUI wasn t interactive though Buttons and MenuItems are easy because we give them an Action Simple read model of console apps is insufficient Need a way to deal with input from many sources Publisher Reactor The basic model employed by scala swing is Publishers and Reactors A Reactor can listenTo events from a Publisher Events are in scala swing event To stop listening set yourself to be deafTo The Publisher can be the component or an object in the component Partial Functions Scala has a construct called a partial function It is a function that only works on some inputs The brief syntax for them is like a match with no match So it has curly braces with cases in them case 1 doOption1 case 2 doOption2 Events reactions When a Reactor is listening to a Publisher it needs to define reactions You can add PartialFunctions into the reactions of the Reactor They should respond to the events you are interested in reactions case e ActionEvent case e SelectionChanged Making the GUI Interactive Let s use this new knowledge to make it so that our GUI interacts with the user Minute Essay Questions Remember to turn in Assignment 2 by tonight
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