GUIs

and

Event-driven programming

The mother of all demos

State of the Art?

http://www.oblong.com/

GUI

• Graphical User Interface
• An interface that is visual/graphical
• Has evolved to become more readily discovered (this is often called "intuitive")

GUI events

• Most modern GUIs rely on the concepts of events
  • Mouse movement
  • Mouse click
  • Keyboard type
  • Gesture in the air
  • etc.

Events and programming

• How to model events in programming?

Event-driven programming

• The system waits for events
• An event is triggered
  • by the system
  • or user interaction with physical devices
• This triggers an action in the program
  • Often through what's called a callback function
• When the event is processed, go back to waiting

This is called the "event loop"

GUI toolkits

• Native (platform specific)
  • MFC or .Net on Windows
  • Cocoa on OS X
• Cross-platform
  • Qt
  • WxWidgets
• Bullet Three

Do you need a toolkit?

• Are other systems enough?
  • e.g. Processing, etc.
• Does it make sense to make the interface with something else and then send the data?
  • e.g. an OSC interface with TouchOSC or GoOSC?
• or do you need a rich, efficient toolkit?

The interface is a lie

Interface vs. functionality

• You can never be certain how events will propagate in the software