kylefang/react-native
1
0
Fork 0
mirror of https://github.com/zhigang1992/react-native.git synced 2026-06-19 21:29:36 +08:00
Code Issues Packages Projects Releases Wiki Activity

Correct scrollEventThrottle docs

Browse Source 
Summary:The docs indicated that a higher number was more accurate, however based on the implementation:

```
  /**
   * TODO: this logic looks wrong, and it may be because it is. Currently, if _scrollEventThrottle
   * is set to zero (the default), the "didScroll" event is only sent once per scroll, instead of repeatedly
   * while scrolling as expected. However, if you "fix" that bug, ScrollView will generate repeated
   * warnings, and behave strangely (ListView works fine however), so don't fix it unless you fix that too!
   */
  if (_allowNextScrollNoMatterWhat ||
      (_scrollEventThrottle > 0 && _scrollEventThrottle < (now - _lastScrollDispatchTime)))
```
https://github.com/facebook/react-native/blob/master/React/Views/RCTScrollView.m#L564

It appears that only 0 is a special case here, and perhaps a known issue ;)
Closes https://github.com/facebook/react-native/pull/3729

Differential Revision: D3074801

Pulled By: mkonicek

fb-gh-sync-id: f63b00755f7565165cc628085efa5ed96badcfe1
shipit-source-id: f63b00755f7565165cc628085efa5ed96badcfe1
This commit is contained in:
Nick Hudkins
2016-03-20 09:51:21 -07:00
committed by Facebook Github Bot 3
parent ac2571d5ec
commit a3ba25ed90
1 changed files with 6 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
Libraries/Components/ScrollView/ScrollView.js
View File

@@ -231,11 +231,14 @@ var ScrollView = React.createClass({
scrollEnabled: PropTypes.bool,
/**
* This controls how often the scroll event will be fired while scrolling
* (in events per seconds). A higher number yields better accuracy for code
* (as a time interval in ms). A lower number yields better accuracy for code
* that is tracking the scroll position, but can lead to scroll performance
* problems due to the volume of information being send over the bridge.
* The default value is zero, which means the scroll event will be sent
* only once each time the view is scrolled.
* You will not notice a difference between values set between 1-16 as the
* JS run loop is synced to the screen refresh rate. If you do not need precise
* scroll position tracking, set this value higher to limit the information
* being sent across the bridge. The default value is zero, which results in
* the scroll event being sent only once each time the view is scrolled.
* @platform ios
*/
scrollEventThrottle: PropTypes.number,