mutwakilmo / hellocompat

HelloCompat

Android fundamentals 03.3: Support libraries

App overview

In this practical you'll create an app called HelloCompat with one TextView that displays "Hello World" on the screen, and one Button that changes the color of the text. There are 20 possible colors, defined as resources in the color.xml file, and each button click randomly picks one of those colors. The methods to get a color value from the app's resources have changed with different versions for the Android framework. This example uses the ContextCompat class in the Android Support Library, which allows you to use a method that works for all versions.

What you'll learn

• How to verify that the Android Support Library is available in your Android Studio installation.
• How to indicate support library classes in your app.
• How to tell the difference between the values for compileSdkVersion, targetSdkVersion, and minSdkVersion.
• How to recognize deprecated or unavailable APIs in your code.
• More about the Android support libraries.

What you'll do

• Create a new app with one TextView and one Button.
• Verify that the Android Support Repository (containing the Android Support Library) is available in your Android Studio installation.
• Explore the build.gradle files for your app project.
• Manage class or method calls that are unavailable for the version of Android your app supports.
• Use a compatibility class from the support library to provide backward-compatibility for your app.