iOS/iPadOS 13 support “true” external displays
I saw some chatter regarding iPads supporting true external display output – i.e. connect an iPad Pro to an external monitor to render a proper 16:9 output, rather than the simple mirror image of today. It doesn’t seem widely known, but iOS is already capable of this. *Sorta*.
If you want to see for yourself, download the **Trulia** app. Open the app and start AirPlay mirroring to your Apple TV. You’ll notice that the TV output is not mirrored from your iPad (or iPhone) but instead a 1920×1080 interface being properly rendered in 16:9! The auto layout framework even takes care of the user interface layout as intended.
To be clear: I’m referring to the iOS device outputting a unique 1920×1080 interface, with the buttons and layout correctly scaled by AutoLayout, to an external display. This is NOT mirroring the 4:3 iPad display or an iPhone portrait orientation. This is a true 16:9 interface that the app is correctly scaling to.
To further confirm, take a screenshot – you’ll get **two** screenshots. One your device screen, and the other this 1920×1080 external display interface. As many of you know, this is the same behavior as taking a screenshot while using CarPlay.
[Trulia iPad display](https://i.imgur.com/dW11X42.jpg)
[Trulia’s AirPlay external display](https://i.imgur.com/QcV8XgU.jpg)
This is a bug in the Trulia app today, as it’s impossible to force proper mirroring and there’s no way to control the 1920×1080 external display even with the new mouse support. I believe they are tapping into the CarPlay external display rendering by accident.
But there you have it, a working example (for now) of how external displays can be supported in a future iOS/iPadOS. We’ve learned that autolayout will handle scaling the iOS apps we have today to 16×9 @1x interfaces. If we make some noise about this with WWDC coming up, perhaps we can get Apple to take note and roll out proper support in the future, at least for iPads with USB-C output and mouse control.