Today you will create your first interactive Android application in Java. You will use the Activity class - the major building block of your applications user interface - that defines a single thing the user can do. You will also encounter various widgets to make the UI more interactive, and utilize resources to implement a scalable and maintainable application.

What you'll learn

• How to create interactive applications using Java
• How the Activity Lifecycle works
• How to link XML and Java code
• How to create Toast and Logcat messages
• How to use various Android widgets such as a Switch, a Button and a ProgressBar
• How to externalize and use resources
• How to localize an application
• How to provide alternative resources
• How to work with styles & themes
• How to work with icons & images

Create an info-log message in onCreate of your activity. Run the application and find the log.

When is each method in the activity lifecycle called? Utilize the Log class to find out what happens when:

• The application is started
• The home button is pressed
• Receiving an SMS
• Receiving a phone call
• Pressing the back button
• Closing the application with the task manager
• Rotating the device

Utilize an OnClickListener to make a Button display a Toast when it is clicked.

Utilize the onClick attribute in XML to make a Button display a Toast when it is clicked.

Create an app as shown in the image below. When the Button is pressed the text from the EditText should be displayed in the TextView. Hint: Use setText() and getText().

Create an app with two buttons and a ProgressBar. One button should increment the ProgressBar and one should decrement it. HINT: Use setProgress().

Create a login screen with an email and password field, as well as a login button. The Button should create a welcoming Toast if the login information was:

Email: user@email.com

Password: ILOVEAND

Create a new String resource in the values folder with the value "AND IS AWESOME". Create two TextViews in your layout and use this String resource in both of them. Then give the TextViews a background color, that you define in colors.xml.

Create an Activity that changes the text of a TextView when a Button is pressed. All strings should be retrieved from the values folder.

Make an ImageView change between two images using a Switch.

Create an app with a few TextViews that supports two languages.

Create an Activity that uses two different layouts depending on whether it is in landscape or portrait mode.

Create a new launcher icon for an application using Android Studio's build-in Asset Studio.

Create a new style for an app which contains TextViews. The style should define the size, color, font and style of the text, as well as making it all CAPS.

Create a theme with new colors for the app- and status bar. Apply it to the main Activity.

Create a calculator, that can add numbers together. It can be as simple as two EditText fields and a Button, or as complex as the image below - your choice.

Use everything you have learned so far to design and develop your own score keeper!