Summary:
public
Blending semitransparent pixels against their background is fairly a fairly expensive operation on mobile GPUs. To reduce blending, React Native has a system called "background color propagation", where the background color of parent views is automatically inherited by child views unless explicitly overridden. This means that translucent pixels can be blended directly against a known background color, avoiding the need to do this dynamically on the GPU.
In practice, this is only useful for views that do their own drawing, which is basically just `<Image/>` and `<Text/>` components, and for image components it only really matters when the image has an alpha component.
The automatic background propagation is a bit of a hack, and often does the wrong thing - for example if a view overflows its bounds, or if it overlaps a sibling, the background color will often be incorrect and need to be manually disabled. Because the only place that it provides a significant performance benefit is for text, this diff disables the behavior for everything except `<Text/>` nodes. It might still be useful for `<Image/>` nodes too, but looking through the examples in UIExplorer, the number of places where it does the wrong thing for images outnumbers the cases where it provides significant reduction in blending.
Note that this diff does not prevent you from eliminating blending on image components by manually setting an opaque background color, nor does it stop you from disabling color propagation on text components by manually setting a transparent background.
Reviewed By: javache
Differential Revision: D2811031
fb-gh-sync-id: 2eb08918c9031c582a3dd2d40e04b27a663dac82
Summary: public
Added lightweight genarics annotations to make the code more readable and help the compiler catch bugs.
Fixed some type bugs and improved bridge validation in a few places.
Reviewed By: javache
Differential Revision: D2600189
fb-gh-sync-id: f81e22f2cdc107bf8d0b15deec6d5b83aacc5b56
Summary:
Previously the text highlight overlay did not take padding into account in its positioning, so it would be misaligned for padded text. This fixes that.
Summary:
This diff implements highlighting of tapped text subranges for the iOS `<Text>` component, styled to match how iOS webkit views highlight links (translucent grey overlay with rounded corners).
Highlighting is enabled by default for any `<Text>` component which has an onPress handler. To disable the highlight, add `suppressHighlighting={true}` to the component props.
Summary:
@public
This fixes an issue with the containerBackgroundColor property of `<Text>` nodes, where containerBackgroundColor was being overridden by the backgroundColor. I also fixed up the example so that it demonstrates the feature more clearly.
Test Plan:
* Check UIExplorer text example
* Run Catalyst snapshot tests and check MAdMan, Groups
Summary:
Fixes#979.
Previously, a Text whose width is determined automatically (as opposed to set by a container) would position the text incorrectly after an update to the text *if* the text's width did not change (i.e., when changing only digits in a font with tabular numbers).
Every time RCTShadowText's RCTMeasure runs, it sets the text container's size to be the maximum allowed size for the text. When RCTText's drawRect is called later, it relied on layoutSubviews having been called to set the text container's size back to the proper width. But if RCTMeasure returned the same dimensions as last time, then RCTText's frame wasn't reset and so layoutSubviews was never re-called. With this change, we set the textContainer's size each time we draw the text.
We could also fix this by using a different NSTextContainer instance in RCTMeasure. Not sure what the pros and cons of that are.
Closes https://github.com/facebook/react-native/pull/989
Github Author: Ben Alpert <balpert@fb.com>
Test Plan: Imported from GitHub, without a `Test Plan:` line.
Summary:
For a very simple view I was observing that the text background was black and had to manually be set to transparent. This ensures that text nodes have a transparent background by default.
Closes https://github.com/facebook/react-native/pull/256
Github Author: James Ide <ide@jameside.com>
Test Plan:
This example component no longer renders what looks like a black block, and instead displays legible text.
var Example = React.createClass({
render: function() {
return (
<View style={styles.container}>
<Text>hello</Text>
</View>
);
},
});
var styles = StyleSheet.create({
container: {
flex: 1,
},
};
Nick Lockwood
Alex Akers
Georgiy Kassabli
Ben Alpert
James Ide
guru inamdar
Tadeu Zagallo
Christopher Chedeau
Spencer Ahrens
