The ability to take screenshots on Android mobile devices was introduced back in 2011 with the release of Android 4.0 Ice Cream Sandwich (ICS). Those who were using Samsung handsets that ran Android 2.3 Gingerbread with the Touchwiz user interface on top were also fortunate to have been able to use the function then. Fast forward to the era of Android 7.0 Nougat, and we see no significant improvement in how users can take screen grabs of their phones and tablets. The feature has remained stagnant at least in stock Android for the past five years in that users can only capture the full screen of a device by default with no other options. Other skins developed by original equipment manufacturers already allow users to scroll the screenshot feature.
But that is likely to change soon as some Reddit users were able to find some interesting code in the Android Nougat 7.1 Android Open Source Project that indicates the existence of a commit called "partial screenshot". This means it will not be long before Android users will be able to decide the size and position of their screenshot. A Reddit user going by the handle Maxr1998 managed to activate the feature on the Nexus 4 by altering code in line 53 of TakeScreenshotService to takeScreenshotPartial() while running the NitrogenOS ROM. Maxr1998 demonstrated in the video below how this is done.
The partial screenshot feature is especially helpful when you want to hide a certain portion of your phone's display that you do not want to share with others for privacy reasons. In the video, a focus area is selected without the need to resort to an external photo editing app to crop the screenshot. At the moment, the function seems to be restricted from the public yet. To activate the feature for yourself, you will need to flash an entire ROM first. But the inclusion of the feature in the Android 7.0 Nougat AOSP indicates Google has been testing the function for quite some time now, and could soon introduce the partial screenshot functionality to Android devices already out in the market. The Google Pixel phones and Nexus devices will be the first to get this feature as soon as Google decides to include it in an actual build of Android Nougat.