Summary:
public
React Native currently exposes the iOS layer shadow properties more-or-less directly, however there are a number of problems with this:
1) Performance when using these properties is poor by default. That's because iOS calculates the shadow by getting the exact pixel mask of the view, including any tranlucent content, and all of its subviews, which is very CPU and GPU-intensive.
2) The iOS shadow properties do not match the syntax or semantics of the CSS box-shadow standard, and are unlikely to be possible to implement on Android.
3) We don't expose the `layer.shadowPath` property, which is crucial to getting good performance out of layer shadows.
This diff solves problem number 1) by implementing a default `shadowPath` that matches the view border for views with an opaque background. This improves the performance of shadows by optimizing for the common usage case. I've also reinstated background color propagation for views which have shadow props - this should help ensure that this best-case scenario occurs more often.
For views with an explicit transparent background, the shadow will continue to work as it did before ( `shadowPath` will be left unset, and the shadow will be derived exactly from the pixels of the view and its subviews). This is the worst-case path for performance, however, so you should avoid it unless absolutely necessary. **Support for this may be disabled by default in future, or dropped altogether.**
For translucent images, it is suggested that you bake the shadow into the image itself, or use another mechanism to pre-generate the shadow. For text shadows, you should use the textShadow properties, which work cross-platform and have much better performance.
Problem number 2) will be solved in a future diff, possibly by renaming the iOS shadowXXX properties to boxShadowXXX, and changing the syntax and semantics to match the CSS standards.
Problem number 3) is now mostly moot, since we generate the shadowPath automatically. In future, we may provide an iOS-specific prop to set the path explicitly if there's a demand for more precise control of the shadow.
Reviewed By: weicool
Differential Revision: D2827581
fb-gh-sync-id: 853aa018e1d61d5f88304c6fc1b78f9d7e739804
Summary:
Problem: https://github.com/facebook/react-native/issues/4708
Solution: Added a ColorPropType that validates the color used by the dev
Notes:
1) I'm working a Win8.1 machine and couldn't build the react-native using the github repo. As soon as I figure that out, I'll probably figure how to run the tests and how to add some for this feature.
2) It's my first pull request. Be gentle :)
Closes https://github.com/facebook/react-native/pull/4866
Reviewed By: bestander, svcscm
Differential Revision: D2783672
Pulled By: nicklockwood
fb-gh-sync-id: ca22aa3c0999188075681b5d20fff0631496e238
Summary:
For some reason we're now spamming the logs everytime we render an Image because overflow is not defined in the whitelist. overflow: 'hidden' is needed for network images with cover mode.
The way we currently define those is not optimal where we try to factor as many things as possible into distinct propTypes. However for Text we're not even using this but we are getting all the ones from View (which many do not apply) and remove some that aren't needed.
It may be useful to cleanup this in the future but in the short term, it's better to remove this warning that doesn't have much value anyway.
Nick Lockwood
StefanT
zjlovezj
Christopher Chedeau
Peter Zich
Spencer Ahrens
Basil Hosmer
Felix Kling