Android User Interface Design

Podcast

Play an AI-generated podcast conversation about this lesson

Download our mobile app to listen on the go

Get App

Questions and Answers

What two orientations are there for a screen?

Diagonal
Portrait (correct)
Vertical
Landscape (correct)

What is the definition of screen size and how is it generally categorized?

Screen size is the actual physical size of the screen, measured as the screen's diagonal. Screen sizes are generally categorized into four generalized sizes: small, normal, large, and extra large.

Screen density is the quantity of pixels within a physical area of the screen usually referred to as dots per inch.

True (A)

What is a Density-independent pixel (dp)? Describe its purpose and how it is scaled at runtime.

A density-independent pixel is a virtual pixel unit used to define UI layout, to express layout dimensions or position in a density-independent way. The dp is equivalent to one physical pixel on a 160 dpi screen. At runtime, the system transparently handles any scaling of the dp units, as necessary, based on the actual density of the screen in use. Signup and view all the answers

Match the following screen sizes with their corresponding dp sizes.

xlarge = at least 960dp x 720dp large = at least 640dp x 480dp normal = at least 470dp x 320dp small = at least 426dp x 320dp Signup and view all the answers

What is the formula for converting dp units to screen pixels?

px = dp * (dpi / 160) Signup and view all the answers

Explain the purpose of dp units in defining the UI of an application.

Dp units are used to define the application's UI to ensure proper UI display on screens with different densities. Signup and view all the answers

What is the hierarchy used to define the user interface layout in Android?

The user interface layout is defined using a hierarchy of Views and ViewGroups. Signup and view all the answers

A single user interface can only have one root element.

True (A) Signup and view all the answers

Describe the purpose of the View object in Android.

A View is a basic building block of UI (User Interface) in Android. It is a small rectangular box that responds to user inputs, such as EditText, Button, CheckBox, etc. Signup and view all the answers

What is the purpose of ViewGroup in the context of Android UI?

ViewGroup is a subclass of the View class that provides functionality for organizing other Views in a layout. It serves as an invisible container to hold other views and defines the layout properties. Signup and view all the answers

Provide a list of commonly used ViewGroup subclasses in Android applications.

FrameLayout, WebView, ListView, GridView, LinearLayout, RelativeLayout, TableLayout. Signup and view all the answers

The term Layout refers to the android.view.View class.

False (B) Signup and view all the answers

What differentiates a View from a ViewGroup in the context of Android UI?

View is a simple rectangle box that responds to the user's actions while ViewGroup is the invisible container. It holds Views and ViewGroups. Views are UI elements, while ViewGroups are containers for other Views and ViewGroups. Signup and view all the answers

Explain the role of Android Layout in Android applications.

Android Layout defines the user interface, which holds the UI controls or widgets that will appear on an Android application or activity screen. Signup and view all the answers

Android layouts are exclusively built using View objects.

False (B) Signup and view all the answers

What method is used to declare UI elements in XML for Android layouts and what are its benefits?

You can declare UI elements in XML using Android's straightforward XML vocabulary, which corresponds to View classes and subclasses. Declaring the UI in XML allows developers to separate the app's presentation from its code that controls its behavior, making it easier to provide different layouts for different screen sizes and orientations. Signup and view all the answers

Name two methods used for building an Android application's UI. Which of these should be preferred for the initial layout?

The Android framework allows you to use either or both methods to build your app's UI. These methods are declaring layouts in XML and creating views programmatically. Declaring layouts in XML should be preferred for the initial layout as it provides a simpler and more efficient way to structure the UI. Signup and view all the answers

What is the primary purpose of the Layout Editor in Android Studio?

The Layout Editor helps developers build layouts quickly by dragging UI elements into a visual design editor instead of writing layout XML by hand. Signup and view all the answers

Explain how the use of the Layout Editor can benefit a developer's workflow.

The Layout Editor allows developers to preview their layouts on different devices, versions, and screen sizes. The editor also allows for dynamic resizing and editing of the layout elements, ensuring scalability and responsiveness of the UI across various screen configurations. Signup and view all the answers

Where are layout resources stored in Android applications?

Layout resources are stored as XML files in the /res/layout resource directory for the application. Signup and view all the answers

Which of the following layouts is the most common layout used in Android applications?

LinearLayout (A) Signup and view all the answers

Describe how LinearLayout arranges its children in a layout.

LinearLayout arranges controls (its children) in a single column or row. Controls can be aligned in one of the following directions. Horizontally, it will only be one row high (the height of the tallest child, plus padding). Vertically, it will only have one child per row, no matter how wide they are. Signup and view all the answers

Explain the purpose of the android:orientation attribute in a LinearLayout.

The android:orientation attribute defines whether children within the LinearLayout are arranged horizontally or vertically. It allows developers to specify the flow of UI elements within the layout. Signup and view all the answers

What is the purpose of the android:layout_width and android:layout_height attributes in a LinearLayout?

The android:layout_width and android:layout_height attributes are used to specify the width and height of the layout. These attributes can be set to various values such as fill_parent, wrap_content, match_parent, or specific dp values. Signup and view all the answers

Explain the purpose of the `android:layout_alignParentRight` attribute in a RelativeLayout.

The android:layout_alignParentRight attribute aligns the control to the right of the parent (e.g., layout) in a RelativeLayout. Signup and view all the answers

What is the main purpose of the `android:layout_toLeftOf` attribute in a RelativeLayout?

It is used to align a control to the left of another control with a unique identity within a RelativeLayout. Signup and view all the answers

Explain the purpose and function of the `android:layout_marginLeft attribute within a RelativeLayout.

<code>android:layout_marginLeft</code> is used to set a margin for the left side of the control, effectively placing the element a specific margin distance away from the left edge of the parent layout. Signup and view all the answers

Describe the functionality of TableLayout in Android application development.

TableLayout arranges its controls (its children) in rows and columns, similar to an HTML table. Each row has zero or more cells defined by any other view. Cells can contain various View objects, such as ImageView or TextView objects. Signup and view all the answers

Describe the purpose of the FrameLayout in Android UI.

FrameLayout creates a blank space on the screen that can be filled with a single object. Usually, it is used to hold a single child view because it can be difficult to organize child views in a scalable way to different screen sizes without the children overlapping each other. The FrameLayout is mainly used for tabbed views and image switchers. Signup and view all the answers

You can modify the location of a child view in a FrameLayout.

False (B) Signup and view all the answers

Describe the concept of TabLayout in Android UI?

TabLayout in Android UI is a layout that provides a way to display and navigate between different content panels or screens using a tabbed interface. It typically consists of two main elements: a tab indicator and a view or activity to hold content associated with each tab. Signup and view all the answers

What is the purpose of ConstraintLayout and what are its key advantages?

ConstraintLayout allows developers to create large and complex layouts using a flat view hierarchy. It allows you to position and size widgets in a flexible way and works efficiently on Android screens, especially with the Layout Editor. It helps reduce nesting of views and improves performance. Signup and view all the answers

ConstraintLayout is similar to RelativeLayout in its functionality.

True (A) Signup and view all the answers

Explain the process of loading an XML layout in an Android application using Java Code.

The process of loading an XML layout resource in an Android application involves using the <code>setContentView()</code> method within the <code>onCreate()</code> method of your Activity class. This method takes the resource ID of the layout file, which is generated by Android's build process, as an argument. By calling <code>setContentView()</code>, you tell the Android system to inflate the layout resource, meaning to create the corresponding View objects and their hierarchy, and display them on the screen. Signup and view all the answers

What is the purpose of `setContentView()` method in Android development?

The <code>setContentView()</code> method in Android is used to set the layout of the user interface (UI) of an activity. It takes an integer resource ID as its parameter, which represents the layout resource file that defines the UI design. When this method is called, the Android system inflates the specified layout file, creating the necessary View objects and their hierarchy, and displays them on the screen. Signup and view all the answers

Explain the difference between padding and margin in the context of Android views.

Padding refers to the space inside the border of a view, between the border and the view's content. Margin refers to the space outside the border of a view, between the border and the other elements next to the view. Signup and view all the answers

Describe how properties of Android views can be set.

Properties of Android views can be set in two primary ways: by using attributes in XML layout files and by manipulating them programmatically using Java code. Signup and view all the answers

Explain the concept of setting focus on a view in Android UI.

Setting focus on a view in Android UI involves directing the user's input to that specific view. This is typically achieved using the <code>requestFocus()</code> method, which allows the view to receive the user's actions, such as text input, button clicks, or other interactions. Signup and view all the answers

Describe the purpose of using listeners in Android UI.

Listeners in Android UI are used to monitor and respond to events that occur on UI elements, such as button clicks, text input changes, or touch gestures. By implementing listeners, developers can write code that will be executed when specific events happen, allowing for dynamic and interactive UI behavior. Signup and view all the answers

How can view visibility be controlled in Android?

View visibility in Android can be controlled using the <code>setVisibility()</code> method. This method takes an integer value as its argument, indicating the desired visibility state of the view. The possible values for visibility are <code>VISIBLE</code>, <code>INVISIBLE</code>, and <code>GONE</code>. VISIBLE makes the view visible and interactive. INVISIBLE makes the view invisible but still occupies its space in the layout. GONE makes the view invisible and removes it from the layout, freeing up space for other elements. Signup and view all the answers

Flashcards

Screen Orientation

The screen's orientation as viewed by the user (landscape or portrait).

Screen Resolution

The total number of pixels on a screen.