6114f863c3
Summary: Abstract class `ReactBaseTextShadowNode` was decoupled from `ReactTextShadowNode` to separate two goals/roles: * `ReactBaseTextShadowNode` represents spanned `<Text>` nodes, which can bear text attributes (both `RCTText` and `RCTVirtualText`); * `ReactTextShadowNode` represents anchor `<Text>` view in Yoga terms, which can bear layout attributes (`RCTText` and `RCTTextInput`). `ReactVirtualTextShadowNode` now inherits `ReactBaseTextShadowNode`. The same architectural changes was applited to view managers. Why? * This is just a better architecture which represents the nature of this objects. * Bunch of "negative" logic which turn off excessive features for some suclasses was removed. * Memory efficiency. * Now we can improve `<TextInput>` component using right inheritance. Yay! Reviewed By: achen1 Differential Revision: D5715830 fbshipit-source-id: ecc0764a03b5b7586fe77ad31f149cd840f4da41
Nodes
Nodes is an experimental, alternate version of
UIImplementation for ReactNative on Android. It has two main advantages over the existing UIImplementation:
- Support for
overflow:visibleon Android. - More efficient generation of view hierarchies.
The intention is to ultimately replace the existing UIImplementation on
Android with Nodes (after all the issues are ironed out).
How to test
In a subclass of ReactNativeHost, add this:
@Override
protected UIImplementationProvider getUIImplementationProvider() {
return new FlatUIImplementationProvider();
}
How it Works
The existing
UIImplementation maps all non-layout tags to Views (resulting in an almost 1:1 mapping of tags
to Views, with the exception of some optimizations for layout only tags that
don't draw content). Nodes, on the other hand, maps react tags to a set of
DrawCommands. In other words, an <image> tag will often be mapped to a
Drawable instead of an ImageView and a <text> tag will be mapped to a
Layout instead of a TextView. This helps flatten the resulting View
hierarchy.
There are situations where DrawCommands are promoted to Views:
- Existing Android components that are wrapped by React Native (for example,
ViewPager,ScrollView, etc). - When using a
Viewis more optimal (for example,opacity, to avoid unnecessary invalidations). - To facilitate the implementation of certain features (accessibility, transforms, etc).
This means that existing custom ViewManagers should continue to work as they
did with the existing UIImplementation.
Limitations and Known Issues
LayoutAnimations are not yet supportedzIndexis not yet supported