Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Interactive GUIs10-26-2011Opening DiscussionMinute 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?MenusThe frame has a MenuBar.Contents of a MenuBar should be Menus.Menus can hold the following:MenuItemMenuCheckMenuItemRadioMenuItemSeparatorExample GUIWe want to have a simple GUI that has a few components for us to play with.Interactive GUIsLast 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/ReactorThe 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 FunctionsScala 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/reactionsWhen 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 InteractiveLet's use this new knowledge to make it so that our GUI interacts with the user.Minute EssayQuestions?Remember to turn in Assignment #2 by
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