Dimensions window support for Split View and Slide Over on iPad

[Freddy03h]

Is this a bug report?

Yes

Have you read the Contributing Guidelines?

Yes

Environment

Environment:
OS: macOS Sierra 10.12.6
Node: 7.2.1
Yarn: 0.24.6
npm: 3.10.10
Watchman: 4.7.0
Xcode: Xcode 9.0 Build version 9A235
Android Studio: 2.3 AI-162.4069837

Packages: (wanted => installed)
react: 16.0.0-alpha.12 => 16.0.0-alpha.12
react-native: 0.48.4 => 0.48.4

Steps to Reproduce

On on iPad, with the app on "Split View" or "Slide Over".

console.log(Dimensions.get('screen')) // {fontScale: 1, width: 768, height: 1024, scale: 2}
console.log(Dimensions.get('window')) // {fontScale: 1, width: 768, height: 1024, scale: 2}

(example of console log on iPad Pro 9.7 inch)

Expected Behavior

On iOS Dimensions.get('screen') and Dimensions.get('window') always return the same data. It assuming that the app is always in fullscreen. But on iPad the screen can be share with an other app (Split View), and since iOS, can "float" in a little window over an other app (Slide Over).

Dimensions.get('window') shouldn't always return Dimensions.get('screen') width and height but the real size of the window.

Actual Behavior

Dimensions.get('window') always return Dimensions.get('screen'), even on "Split View" or "Slide Over"

Slide Over example

console.log(Dimensions.get('window')) // {fontScale: 1, width: 768, height: 1024, scale: 2}

Split View example 1

console.log(Dimensions.get('window')) // {fontScale: 1, width: 768, height: 1024, scale: 2}

Split View example 2

console.log(Dimensions.get('window')) // {fontScale: 1, width: 768, height: 1024, scale: 2}

Reproducible Demo

It can be easily tested on iPad by adding console.log(Dimensions.get('window')) anywhere in an existing app or in a fresh create-react-native-app.
And using Split View and Slide Over features of iOS on iPad.

Snack Expo is here : https://snack.expo.io/ryIHToaiW but it need to be tested on an iPad Device or Simulator.

[Freddy03h]

I find a way to send correct width and height for the window.
In RCTDeviceInfo.m I change RCTExportedDimensions :

static NSDictionary *RCTExportedDimensions(RCTBridge *bridge)
{
  RCTAssertMainQueue();

  // Don't use RCTScreenSize since it the interface orientation doesn't apply to it
  CGRect screenSize = [[UIScreen mainScreen] bounds];
  NSDictionary *dimsScreen = @{
                         @"width": @(screenSize.size.width),
                         @"height": @(screenSize.size.height),
                         @"scale": @(RCTScreenScale()),
                         @"fontScale": @(bridge.accessibilityManager.multiplier)
                         };
  CGRect windowSize = [RCTKeyWindow() bounds];
  NSDictionary *dimsWindow = @{
                         @"width": @(windowSize.size.width),
                         @"height": @(windowSize.size.height),
                         @"scale": @(RCTScreenScale()),
                         @"fontScale": @(bridge.accessibilityManager.multiplier)
                         };

  return @{
           @"window": dimsWindow,
           @"screen": dimsScreen
           };
}

It send the correct value but it didn't trigger a change event on Dimensions when resizing the app window in a Split-View mode.

Currently, two fonctions in Obj-C can trigger this event : didReceiveNewContentSizeMultiplier and interfaceOrientationDidChange. I think we need to create a new observer for the event, but I'm not an iOS dev, and I don't understand all the code in this file. Also, I don't get why it use NotificationCenter stuffs or why they use the status bar orientation to get the orientation change of all the screen…

edit: ok apparently NotificationCenter is just a EventEmmiter, nothing related to Notifications for end-user (I thought that it was a very tricky code ^^')

[variantf]

Waiting for this feature!!! Thanks a lot

[Freddy03h]

No one target the iPad ? :(

[jamsch]

I'm having the same issue. Using a FlatList set to horizontal where every item has it's width set to the current dimensions. As a result, the items are now too wide because the window dimensions aren't correct.

One of my components listens for dimension changes and the view is updated to reflect those changes. while it works fine when not in split screen.

import { Dimensions } from 'react-native';
...
componentDidMount() {
  Dimensions.addEventListener('change', this._handleScreenDimensionsChange);
}
_handleScreenDimensionsChange = (dimensions: DimensionsChangeEvent) => {
  this.props.dispatch(dimensionsChange(dimensions.window));
};

image

[neiker]

Absolutely!

I solved this measuring the root component onLayout and sending the size to the store.

[mrtnzlml]

This is still a valid issue (latest RN release ^0.55.4). We have to use very nasty workarounds to make it really work (inspired by comments in this issue) and it's considered one of the biggest pains in our codebase.

[Freddy03h]

The issue is still valid !

[hackrmomo]

PR Pending!!! Any updates on the admin side? When is thing being pulled into master?

[manoj2166]

Hi,
you can use "onLayout" function on the root view of the component to calculate its dimensions. I have used and working fine here is sample code:

....//inner codes

onLayoutScreen = (e) => {
let width = e.nativeEvent.layout.width;
if(width != this.state.layoutWidth) {
this.setState({
layoutWidth: width
})
}

}

[rdonnelly]

I've had a PR open for a few months now and am not sure how to proceed. So far, I'm not getting any traction on getting it merged. If anyone has an idea, please feel free to chime in.

For me, this issue is still valid.

[Gustash]

This issue is still on the latest version of RN. We shouldn't have to apply workarounds for this. Split screen has been a feature of iOS since version 9. This seems like something that needs fixing urgently

[Freddy03h]

For information, it's fixed in 0.59.5, thank's all!

[m4ttheweric]

I am still seeing that when I run Dimensions.get('window') while the app is in multitasking mode (either floating over an app, or splitting the screen), the Dimensions reported seem to be for the entire device width, not the current width of the window that app is running in.

Using expo latest version in the expo app.

[rdonnelly]

@m4ttheweric This is working fine for me:

On a fresh Expo (36.0.0) project, my App.js looks like this:

import React from 'react';
import { StyleSheet, Text, View } from 'react-native';
import { Dimensions } from 'react-native';

export default function App() {
  const windowWidth = Math.round(Dimensions.get('window').width);
  const windowHeight = Math.round(Dimensions.get('window').height);

  const screenWidth = Math.round(Dimensions.get('screen').width);
  const screenHeight = Math.round(Dimensions.get('screen').height);

  return (
    <View style={styles.container}>
      <Text>Open up App.js to start working on your app!</Text>
      <Text>WINDOW Width: {windowWidth}</Text>
      <Text>WINDOW Height: {windowHeight}</Text>
      <Text>SCREEN Width: {screenWidth}</Text>
      <Text>SCREEN Height: {screenHeight}</Text>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#fff',
    alignItems: 'center',
    justifyContent: 'center',
  },
});

Mind you, you need to refresh after you enter multitasking. A better example would use an event listener for screen/window size changes.