Mobile Programming (Android) — User Interface

View

> all user interface elements in an Android app are built using View and ViewGroup objects.

> View is an object that draws something on the screen that the user can interact with.

> ex, Button, EditText, TextView, ImageView

ViewGroup

> ViewGroup is an object that holds other View (and might be also consist of another ViewGroup) object in order to define the layout of the interface.

> ex, LinearLayout, ConstraintLayout

LinearLayout

> Layout that organises its children into a single horizontal or vertical row.

> It creates a scrollbar if the length of the window exceeds the length of the screen.

RelativeLayout

> Enables us to specify the location of child objects relative to each other (child A to the left of child B) or to the parent (aligned to the top of the parent).

WebView

> Displays web pages

ListView

> Displays a scrolling single column list

GridView

> Displays a scrolling grid of columns and rows