Lecture 15 Graphical User Interfaces (GUI’s)

Objectives Provide a general set of concepts for GUI’s Layout manager GUI components GUI Design Guidelines

Topics Events and Listeners Containers – Allows us to organize the components efficiently and appropriately Components – Buttons, fields etc.. Layout Managers – Specifies how components are arranged in a container Special Features – How to make the best UI AWT and Swing – Swing provides alternative components that are more useful than AWT counterparts – We will focus on Swing here

Containers A special component that can hold other components Containers and layout managers decide how components are organized and displayed The Applet class of the java.applet package contains AWT components Frame is a container – Frame is a free standing window that can be positioned anywhere on the screen Panels – Can be added to an existing container – Useful for organizing groups of components within a lager container Frames and Panels are defined by the swing classes JFrame and JPanel. Frame demo

Components Labels and Image Icons – Label defined by JLabel class Provide info to user or decorate GUI – Lable consists of text, images or both – Label cannot be selected and does not react to user actions – An image used in label defined as ImageIcon object See Label Demo

Buttons Several types of buttons – Push Button - initiate an action – Check Box - can be turned on/off – Radio Buttons Set of mutually exclusive options Set of buttons grouped together See Demo

Combo Boxes Allows user to select one of several options A combo box is defined by JComboBox class See Demo