Desktop windowing on Android Tablets

Posted by Francesco Romano – Developer Relations Engineer on Android, and Fahd Imtiaz – Product Manager, Android Developer

To empower tablet users to get more done, we’re enhancing freeform windowing, allowing them to run multiple apps simultaneously and resize windows for optimal multitasking. Today, we’re excited to share that desktop windowing on Android tablets is available in developer preview.

For app developers, the concept of Android apps running in freeform windows has already existed with solutions like Samsung DeX and ChromeOS. Updating your apps to support adaptive layouts, more robust multitasking, and adaptive inputs will ensure your apps work well on large screens across the Android ecosystem.

Let’s explore how to optimize your apps for desktop windowing and deliver the optimal experience to users.

What is desktop windowing?

Desktop windowing allows users to run multiple apps simultaneously and resize app windows, offering a more flexible and desktop-like experience. This, along with a refreshed System UI and new APIs, allows users to be even more productive and creates a more seamless, desktop-like experience on tablets.

In Figure 1, you can see the anatomy of the screen with desktop windowing enabled. Things to make note of:

• Users can run multiple apps side-by-side, simultaneously
• Taskbar is fixed and shows the running apps, users can pin apps for quick access
• New header bar with window controls at the top of each window which apps can customize

How can users invoke desktop windowing?

By default, apps open in full screen on Android tablets. To run the apps as a desktop window on Pixel Tablet, press and hold the window handle at the top in the middle of the screen and drag it within the UI, as seen in Figure 2.

Once you are in the desktop space, all future apps will be launched as desktop windows as well.

You can also invoke desktop windowing from the menu that shows up below the window handle when you tap/click on it or use the keyboard shortcut meta key (Windows, Command, or Search) + Ctrl + Down.

You can exit desktop windowing and display an app as full screen by closing all active windows or by grabbing the window handle at the top of the window and dragging the app to the top of the screen. You can also use the meta + H keyboard shortcut to run apps as full screen again.

To return to the desktop, move a full screen app to the desktop space by using the methods mentioned above, or simply tap on the desktop space tile in the Recents screen.

What does this mean for app developers?

Desktop windowing on Android tablets creates new opportunities for your apps, particularly around productivity and multitasking. The possibility to resize and reposition multiple app windows allows users to easily compare documents, reference information while composing emails, and multitask efficiently.

By optimizing for desktop windowing, you can deliver unique user experiences to match the growing demand for tablet-based productivity. At the same time, you’ll enhance the overall user experience on tablets, making your apps more versatile and adaptable to different scenarios.

If your app already meets the Tier 2 (Large Screens optimized) quality bar in the Large screen app quality guidelines, then there is minimal additional optimization required! If your app has not been optimized for large screens yet, updating it according to the Large screen app quality guidelines becomes even more crucial in the context of desktop windowing. Let’s see why:

• Freeform resizing enables users to resize apps to their preference for maximized productivity. Considering this, developers should note:
• Apps with locked orientation are freely resizable. That means, even if an activity is locked to portrait orientation, users can still resize the app to landscape orientation window. In a future update, apps declared as non-resizable will have their UI scaled while keeping the same aspect ratio.
• Adaptive layouts: By adapting your UI, apps have an opportunity to effortlessly handle a wide range of window sizes, from compact to expanded screen layouts. In desktop windowing, apps can be resized down to a minimum size of 386dp x 352dp, so make sure to leverage window size classes to adjust your app’s layout, content, and interactions to adapt to different window dimensions.
• State management: With freeform resizing, configuration changes happen each time the window resizes, so your app should either handle these configuration changes gracefully or make sure you are preserving the app state when the OS initiates the re-creation of the app. As a reminder, users can change the screen density while your app is running, so it’s best to ensure that your app can handle screen density configuration changes as well.



Figure 3. Apps with locked orientation are freely resizable.

• Desktop windowing takes productivity on tablets to the next level with multiple apps running simultaneously. Similar to split screen, Desktop windowing encourages users to have multiple windows open. Considering this, developers should note: 
• Multitasking support: For enhanced productivity, users can have two or more apps open simultaneously, and they expect to easily share content between apps, so add support for drag and drop gestures. Also, ensure your app continues to function correctly even when not in focus, and if your app uses exclusive resources like camera or microphone, the app needs to handle resource loss gracefully when other apps acquire the resource. 
• Multi-instance support: Users can run multiple instances of your app side-by-side; for example, a document editor application may allow users to start new documents while still being able to reference the already open documents. Apps can set this new Multi-instance property to declare that System UI should be shown for this app to allow it to be launched as multiple instances. Also note that in desktop windowing, new tasks open in a new window, so double-check the user journey if your app starts multiple tasks.



Figure 4. Start another instance of Chrome by dragging a tab out of the app window.

Note: Images are examples and subject to change

• With desktop windowing, input methods beyond touch and insets handling become even more important for a seamless user experience. 
• More input methods (keyboard, mouse): Users are more likely to use your app with a variety of input methods like external keyboards, mice, and trackpads. Check that users can interact smoothly with your app using keyboard and mouse peripherals or through the emulator. Developers can add support for app shortcuts and publish them using the keyboard shortcuts API, which allows users to easily view the supported app shortcuts through a standardized surface on Android devices.
• Insets handling: All apps when running in desktop windowing have a header bar, even in immersive mode. Ensure your app’s content isn’t obscured by this. The new header bar is reported as a caption bar in Compose (androidx.compose.foundation:foundation-layout.WindowInsets.Companion.captionBar) and in Views (android.view.WindowInsets.Type.CAPTION_BAR), which is part of the system bars. API 35 also introduced a new appearance type, to make the header bar transparent, to allow apps to draw custom content inside.