The best moment of this year’s WWDC exhibition was the direct demonstration of the macOS function, Universal Control. The idea is simple enough: it allows you to use the Mac keyboard and trackpad to directly control the iPad, and even makes it easier to drag and drop content between these devices.
What made the demo so impressive was how easy and seamless everything looked. Apple’s classic move required no setup at all. The segment happened so fast that it even seemed (wrong, as it turns out) that the Mac was able to physically find the iPad in space so it knew where to place the mouse pointer.
After Zaprudering the video and asking a few questions to Apple, I now better understand what̵
Here is what happens in this demonstration.
First, you need to get the iPad and Mac relatively close together. Universal Control is built from the same continuity and transmission features that have long been part of iOS and macOS. When the devices are close enough, their Bluetooth modules inform each other. Of course, all devices here must be in the same iCloud account for this to work.
Then start Universal Control by dragging the mouse pointer all the way to the left or right edge of your Mac screen, then slightly beyond this edge. When you do, the Mac will assume that you are trying to move the mouse to another device, in this case the iPad.
So there is no UWB location detection, just a good old guess. One note is that if you have a lot of compatible devices, Monterey assumes you’re dragging to the last iPad or Mac you interacted with.
At this point, a Wi-Fi Direct connection is made and the iPad will show a small sidebar with a few bumps. This is something of an indicator that the iPad is aware that you are trying to drag a mouse into it. Keep dragging and pulse, the boom is released in a round mouse pointer. When the mouse is on the iPad screen, it and your Mac keyboard control the iPad. Move it back to the Mac and you control the Mac.
But a little clever funding is built into this strange tape. There are a few arrows in it, a hint that you can drag this boom up or down before it breaks into the iPad itself. This way you arrange the iPad screen with your Mac so that dragging the mouse between the screens doesn’t cause a strange jump.
You go through the same process to set up a second device with Universal Control – it reaches a maximum of three. If all this automatic setup sounds like a hassle, you can simply go into system preferences and set a device as your favorite Universal Control friend gadget.
However you set it up, you can drag and drop content between devices, and it will use either Wi-Fi Direct or USB to transfer files. Of course, if you’re dragging files into your iPad, make sure you have an open app (like Files) that can accept it.
This is almost long and short. There are still some details about hashing, Apple tells me, and it’s not available in the developer’s first review. If you place your dock at the left or right end of the screen, for example, it’s not clear if this whole setting will work.
The fascinating thing about this system for me – as I discuss in the video above – is that this is really only possible due to a long series of software improvements that have been built into the iPad over the years, including:
- Continuity, transmission and AirDrop. Universal Control is not technically AirDrop, but it is the same basic idea. All of these are the main ways in which Apple devices communicate directly with each other instead of through the cloud.
- Multitasking. I don’t mean the split screen, but the drag-and-drop support that came with the iPad’s enhanced windows options.
- Keyboard and mouse support. This is an obvious premise, but it wasn’t always obvious that Apple would put mouse support on the iPad.
- Sidecar. Sidecar is the tool that allows you to use the iPad as a second monitor on a Mac. I don’t think Universal Control uses the same bits of software as Sidecar, but I think there were probably latency lessons out there that would be useful here.
I sensed that there would be a similar history of evolution on the part of the Mac this story. I thought all the iPad and iOS technology on the Mac with the last few releases played a role. Catalyst apps have become proprietary iPad apps for the M1 Mac. Control center, shortcuts, and focus mode are things for iOS that are also on the Mac.
Good idea, but wrong. Apple tells me that the basics on the Mac side are as simple as they seem, based on Continuity and Handoff.
I hope Universal Control works as well in the real world as in this staged demonstration – and I know that’s not certain. But what I like about the feature is how it’s just a clever recombination of existing technologies that Apple has already built for other purposes.
Inside the Apple ecosystem, you expect that the trade you make just for using Apple devices gets synergistic integrations like this. In fact, they have been rarer than I would have guessed in the last few years. But as the Mac and iPad begin to trade more and more features with each other, I expect to see more of them ahead.