Summary: `<Image resizeMode="repeat" />` for Android, matching the iOS implementation (#7968). (Non-goal: changing the component's API for finer-grained control / feature parity with CSS - this would be nice in the future) As requested in e.g. #14158. Given https://github.com/facebook/fresco/issues/1575, and lacking the context to follow the specific recommendations in https://github.com/facebook/fresco/issues/1575#issuecomment-267004303, I've opted for a minimal change within RN itself. It's likely that performance can be improved by offloading this work to Fresco in some clever way; but I'm assuming that the present naive approach is still an improvement over a userland implementation with `onLayout` and multiple `<Image>` instances. - Picking up on a TODO note in the existing code, I implemented `MultiPostprocessor` to allow arbitrary chaining of Fresco-compatible postprocessors inside `ReactImageView`. - Rather than extensively refactor `ImageResizeMode`, `ReactImageManager` and `ReactImageView`, I mostly preserved the existing API that maps `resizeMode` values to [`ScaleType`](http://frescolib.org/javadoc/reference/com/facebook/drawee/drawable/ScalingUtils.ScaleType.html) instances, and simply added a second mapping, to [`TileMode`](https://developer.android.com/reference/android/graphics/Shader.TileMode.html). - To match the iOS rendering exactly for oversized images, I found that scaling with a custom `ScaleType` was required - a kind of combination of `CENTER_INSIDE` and `FIT_START` which Fresco doesn't provide - so I implemented that as `ScaleTypeStartInside`. (This is, frankly, questionable as the default behaviour on iOS to begin with - but I am aiming for parity here) - `resizeMode="repeat"` is therefore unpacked by the view manager to the effect of: ```js view.setScaleType(ScaleTypeStartInside.INSTANCE); view.setTileMode(Shader.TileMode.REPEAT); ``` And the added postprocessing in the view (in case of a non-`CLAMP` tile mode) consists of waiting for layout, allocating a destination bitmap and painting the source bitmap with the requested tile mode and scale type. Note that as in https://github.com/facebook/react-native/pull/17398#issue-285235247, I have neither updated nor tested the "Flat" UI implementation - everything compiles but I've taken [this comment](https://github.com/facebook/react-native/issues/12770#issuecomment-294052694) to mean there's no point in trying to wade through it on my own right now; I'm happy to tackle it if given some pointers. Also, I'm happy to address any code style issues or other feedback; I'm new to this codebase and a very infrequent Android/Java coder. Tested by enabling the relevant case in RNTester on Android. | iOS | Android | |-|-| | <img src=https://user-images.githubusercontent.com/2246565/34461897-4e12008e-ee2f-11e7-8581-1dc0cc8f2779.png width=300>| <img src=https://user-images.githubusercontent.com/2246565/34461894-40b2c8ec-ee2f-11e7-8a8f-96704f3c8caa.png width=300> | Docs update: https://github.com/facebook/react-native-website/pull/106 [ANDROID] [FEATURE] [Image] - Implement resizeMode=repeat Closes https://github.com/facebook/react-native/pull/17404 Reviewed By: achen1 Differential Revision: D7070329 Pulled By: mdvacca fbshipit-source-id: 6a72fcbdcc7c7c2daf293dc1d8b6728f54ad0249
RNTester
The RNTester showcases React Native views and modules.
Running this app
Before running the app, make sure you ran:
git clone https://github.com/facebook/react-native.git
cd react-native
npm install
Running on iOS
Mac OS and Xcode are required.
- Open
RNTester/RNTester.xcodeproj
in Xcode - Hit the Run button
See Running on device if you want to use a physical device.
Running on Android
You'll need to have all the prerequisites (SDK, NDK) for Building React Native installed.
Start an Android emulator (Genymotion is recommended).
cd react-native
./gradlew :RNTester:android:app:installDebug
./scripts/packager.sh
Note: Building for the first time can take a while.
Open the RNTester app in your emulator.
See Running on Device in case you want to use a physical device.
Running with Buck
Follow the same setup as running with gradle.
Install Buck from here.
Run the following commands from the react-native folder:
./gradlew :ReactAndroid:packageReactNdkLibsForBuck
buck fetch rntester
buck install -r rntester
./scripts/packager.sh
Note: The native libs are still built using gradle. Full build with buck is coming soon(tm).
Built from source
Building the app on both iOS and Android means building the React Native framework from source. This way you're running the latest native and JS code the way you see it in your clone of the github repo.
This is different from apps created using react-native init
which have a dependency on a specific version of React Native JS and native code, declared in a package.json
file (and build.gradle
for Android apps).