Performance Tips and Tricks in Flutter

These are my slides for the session at droidcon 2022 kenya. This session was about how optimise the on-device performance of your flutter application.

Transcript

1. Performance tips and tricks in fl utter Get that optimal performance Samuel Baraka Senior Flutter Developer Kwikbasket @sababuvercetti
2. About me Mobile Applications Developer Flutter Former Drummer I use Redmi Love taking photos (with my Redmi)
3. What is performance This is basically a measure of how a fl utter app behaves under a variety of load conditions
4. Why performance matters Great performance matters in fl utter applications because we want our Users to have the best experience as much as possible.
5. Flutter Apps - Outside the box, fl utter apps perform well. - But in your development, you may fall for practices which will impact the Performance of your fl utter application
6. How to avoid that …
7. Minimize the use of expensive operations
8. Opacity Clipping Grids and Lists
9. Avoid stateful widgets
10. Prefer Stateless Widgets Stateful widgets are more resource intensive .
11. What if you must use a stateful widget
12. Why stateful When you want to change the appearance of the widget in response to user events.
13. Avoid setState high up in the widget tree
14. Avoid widget methods Widget methods trigger, change in state will trigger the entire wrapping widget to be rebuilt, unlike using a widget(Stateless or Stateful)
15. Cache widgets If a subtree does not change, cache it - assign a widget to a fi nal state variable and re-use it in the build method.
16. Use Constant Widgets This also prevents the trigger to rebuild on state change
17. Avoid changing the depth of any created widget subtrees This will trigger a rebuild
18. Opacity and Clipping Use opacity only when it is necessary Clipping is really expensive
19. Thoughtful grids and lists usage
20. QA
21. Thanks