The folks over at XDA-Developers have managed to get their hands on an early build of Android Q, which was said to include the latest platform security patches for February 2019 along with the current internal master of the Google ASOP. However, the most intriguing feature of this early Android Q build is the inclusion of a system-wide dark theme.
The new dark theme can be accessed by navigating to Display settings and enabling "Set Dark Mode". As you can see in the screenshots above, you can either set Dark mode to be enabled at all times, or have it come on automatically depending on the time of day. When it is enabled, however, the darkened appearance is seen in Settings, Launcher, Launcher settings and the Files app accordion to XDA-Developers.
There is also a setting that can force dark mode to be enabled even for apps that don't currently have native support for the feature. That could make some interesting visual anomalies until developers can adapt to these changes.
Google has repeatedly come under fire for lapses in security and user privacy -- primarily due to apps available in the Google Play Store. Android Q will include provisions to restrict location permission so that they are only accessible while an app is in use. This offers more granular control over what's currently possible with Android Pie, which either toggles location permissions on or off. In addition, it appears that Android will enable a location-based feature that has long been offered in Apple's iOS:
You can see when an app is actively using location permissions by pulling down the status bar and tapping on the top-right hand location icon that appears. If you do, a dialog pops up telling you which apps are accessing your device’s location.
There are other features that were unearthed including a "desktop mode" that appears to be similar in concept to Samsung DeX or Continuum on Microsoft's abandoned Windows 10 Mobile platform. There are also new accessibility features, new screen lock options, and new ways to filter by file type with the built-in Files app.
The first Android Pie Developer Preview landing in early March 2018, so perhaps Google will stick to the same release schedule with Android Q.