Users can interact with their Smart Android devices using hardware keypads and buttons or by touching the screen.
Touching the screen puts the device into touch mode. The user can then interact with it by touching the on-screen virtual buttons, images, etc.
The device remains in touch mode across activities until the user exits touch mode.
Touching a hardware button causes the device to exit touch mode.
You can check if the device is in touch mode by calling the View class’s isInTouchMode() method.
A view or widget is usually highlighted or displays a flashing cursor when it’s in focus. This indicates that it’s ready to accept input from the user.
Focus is necessary for devices using trackballs, styluses, external keyboards and hardware buttons so that the user can see which view is ready to receive input.
Focus is not necessary when the device is in touch mode.