Device detection mini-app

The best way to learn about detecting and responding to devices and their varying attributes (screens, orientations, and so on) is to make a simple app:

1. Create a new Empty Activity project and call it Device Detection. Leave all the other settings as their defaults.
2. Open the activity_main.xml file in the design tab and delete the default Hello world! TextView.
3. Drag a Button onto the top of the screen and set its onClick property to detectDevice. We will code this method in a minute.
4. Drag two TextView widgets onto the layout, one below the other, and set their id properties to txtOrientation and txtResolution.
5. Check you have a layout that looks something like this next screenshot:

   Note

   I have stretched my widgets (mainly horizontally) and increased the textSize attributes to 24sp to make them clearer on the screen, but this is not required for the app to work correctly.

   Figure 24.3– Layout check

6. Click the Infer Constraints...