Advanced Android Touches

on YouTube ↗20m

" summary

Traces how Android routes MotionEvent objects through dispatchTouchEvent and onInterceptTouchEvent down to onTouchEvent, shows why getRawX/Y and action masks matter, and recommends GestureDetector and ViewConfiguration constants instead of reimplementing basics. Presents a working GitHub demo with logs and a real build: a custom translucent bottom bar over a RecyclerView that forwards scroll gestures (a hacky but functional dispatch) so clicks pass through while scrolls are captured.

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" chapters (17)

1. 0:00Start
2. 1:19How do those Android APIs really work?
3. 2:40Motivations for you
4. 3:03What happens when a user touches a screen?
5. 4:12View on a screen
6. 4:49boolean onTouchEvent()
7. 5:56Custom 'click' listener
8. 8:37Swipe down to dismiss
9. 9:47Why have we been extending the View class?
10. 10:13boolean dispatchTouchEvent()
11. 10:34boolean onInterceptTouchEvent()
12. 11:48How MotionEvents are propagated
13. 15:19GestureDetector
14. 15:36ViewConfiguration.java
15. 16:02Multitouch
16. 16:36In Summary
17. 17:00Other great talks

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