Android User Interface and Layouts

A comprehensive set of vocabulary flashcards covering Android User Interface components, layout types, and interactive input controls based on the lecture notes.

User Interface

The “face” of a program or application consisting of everything a program user can see and/or interact with.

View Object

An object that draws something on the screen that the user can interact with.

ViewGroup Object

An object that holds other View and/or ViewGroup objects for defining the layout of the interface.

App Bar (Action Bar)

Provides visual structure and interactive elements for app identity, indicating user location, accessing important actions, and supporting navigation.

Dialog

A small window that prompts the user to make a decision or enter additional information without filling the entire screen.

Notifications

Messages displayed outside of the application’s normal interface, appearing first as an icon in the notification area at the top of the screen.

Toasts

Small pop-ups that provide simple feedback about an operation without interrupting the current activity.

Layout

The “framework” of an interface that defines the visual structure and arranges contents in a pleasing or orderly manner.

Declared UI elements in XML

A method of designing UI layouts using an XML vocabulary consisting of a series of nested elements similar to HTML.

Instantiation of Elements at Runtime

A method where the application creates View and ViewGroup objects with properties that can be manipulated during execution.

Linear Layout

A layout that aligns all children in a single direction, either vertically or horizontally.

android:orientation

An attribute in a Linear Layout that allows you to specify the direction of the layout.

android:layout_weight

An attribute in a Linear Layout that enables you to indicate the amount of space an element should occupy on the screen.

Relative Layout

A layout that displays child views in positions relative to sibling elements or the parent area.

android:layout_alignParentTop

A property that makes the top edge of a view match the top edge of the parent.

android:layout_alignLeft

A property that makes the left edge of a view match the left edge of a given anchor view ID.

android:layout_centerVertical

A property that centers a child vertically within its parent.

android:layout_below

A property that positions the top edge of a view below the view specified with a resource ID.

android:layout_toRightOf

A property that positions the left edge of a view to the right of a given anchor view ID.

List View

A layout that displays items in a vertically scrolling list, dependent on the swipe function.

Grid View

A layout that displays items in a two-dimensional scrollable grid, similar to the Home menu of Android devices.

Input Controls

Interactive components of the app’s user interface that let a user enter data such as characters, numbers, and email addresses.

Button class

Used to create a text button in the user interface.

ImageButton class

Used to create an icon button in the user interface.

android:drawableLeft

An attribute used with the Button class to create a button with both an icon (placed at the leftmost side) and text.

Text Fields

Components that enable a user to enter text, which can be single-line or multi-line.

Checkboxes

Controls that allow users to choose one or more options from a set number of choices, typically listed vertically.

Radio Buttons

Controls that allow the user to select only one option from a set of mutually exclusive choices.

Toggle Buttons

Controls that allow users to change a setting between two states, such as On/Off or Enabled/Disabled.

Switch

A type of toggle button for Android 4.0+ that provides a slider for setting changes.

Spinners

A component providing a quick way to choose a value from a set, displaying a drop-down menu when touched.

Pickers

Dialog-based controls used for time and date selection to ensure valid and correctly formatted input.