Callbacks and Async Event-Based Programming

Core Concepts

• What are asynchronous events
• How to respond to them with callbacks
• How to apply in Java and Android

What are asynchronous events

Synchronous vs. Asynchronous

Synchronous

• Work executes sequentially, including time-consuming tasks.
• Attention must stay focused at the task at hand.
• Less efficient overall.

Asynchronous

• Work can be performed in parallel.
• Attention can be freed up to perform other tasks.
• More efficient overall.

Same Paradigm

• We have similar paradigms in mobile devices.

  • A mouse click on a button can occur at any point in the future.

  • A request to fetch data from a web site will be issued but might not respond immediately.