GUI

• JAVA Is popular because of the abilities to easily make GUis
• AWT: Abstract Windowing Toolkit
  • The early Java way to create GUIs
  • Very east and mostly intuitive
  • AWT stuff is in java.awt.
• Swing
  • Newer GUI toolkit
  • Built on top of AWT, and lots of similar functionality to AWT
  • Swing stuff is in javax.swing.
  • Swing components start with a J to distinguish from AWT counterparts
• This class will talk mostly about Swing - older existing programs will use AWT though

JLabel, JButton, and FlowLayout

• a JLabel is just a bit of text that is dsiplayed
• User doesn't modify a label directly
• Jbutton is a button that can be clicked on
• When designing an interface, decide how you want the components displayed
• Several different layout managers, available for common ways
• FlowLayout adds a component immediately to the right of the previous component until theres no more room, then the component is placed on the next row
• Theses components acan be added to a layout in a frame or jPanel with the add method

Event Handling

• Java uses an event handling scheme for dealing with users interacting with the components
• When a user clicks a button, an event is triggered
• If you don't listen for th event, and write some code to do something with it, your button is still useless
• There are several different types of event listeners
• When a user clicks a mouse button, a MouseEvent is triggered, and you can handle it by implementing a MouseListener interface
• There are also keyboard listeners, window listeners, etc.
• After implementing the MouseListener interface, you have to register the listener with a component, so it knows it should be listening for events
• Since listeners are very ...

Adding a Mouse Listener

• MouseListener is an interface with 5 methods that need to be implemented
• mouseClicked
• mouseEntered
• mouseExited
• mouseRelease
• Recall,m an interface is similar to an abstract class with all abstract functions
  • Thereforre all functions need to be implemented
• Inside the AndresFrame definition, create an inter clas that implments the MousteListener interface

Making GUIS Look Like They're Supposed To

• What if I ahve a certain layout of my GUI compeonetns I need to implement?

Other Layout Managers

• FlowLayout:
  • components flow from left to right
  • Things move whne the window is resized
• GridLayout:
  • Must specify how many rows an columns of components you want
  • Each grid space is the same ize, so some components can come out looking out of proportion
• BorderLayout:
  • Most commonly used, most useful
  • Anchored to the top, right, bottom, left, or middle of the area
• BoxLayout:
  • Aligns components horizontally or vertically

BoxLayout and Box

• BoxLayout is aonother layout manager that is often useful
  • Places components in a straight line that won't wrap like FlowLayout
  • Box is not a layout manager - it is a component
    • It can be placed anywhere any component cant by a layout manager
    • Box is sort of like a JPanel with BoxLauouy as its default manager

Changing JLabels