To Lecture Notes

TextDisplay Example

Goal

• Create a TextDisplay project that displays text on the screen.

Directions

1. Open Android Studio.
2. Select "Create New Project."
3. In the Select a Project Template Dialog:
   Select Phone and Tablet >> Empty Activity >> Click Next Button.
4. In the Configure Your Project Dialog:
   
   • Enter TextDisplay as the Application name
   • Enter it372.smiths.textdisplay as the package name (replace smiths with your last name and initial of first name).
   • Enter the Save location where you want to store your project.
   • Select Java as the Language.
   • For the minimum SDK, select APR 16: Android 4.1 (JellyBean).
   • Click the Finish button.
5. A window with caption Building Examples Gradle Project shows the Gradle files that are created.
6. Check these project files that have been created:
         activity_main.xml   MainActivity.java
7. Select Main Menu Tools >> AVD Manager
8. In the Your Virtual Devices Dialog:
   Create Virtual Device
9. In the Select Hardware Dialog:
   Select Phone >> Galaxy Nexus.
   Click Next.
10. In the System Image Dialog, select Lollipop >> Click Download >>
        Click Next to verify the configuration
11. In the Android Virtual Device Dialog, click Finish.
12. Change the text attribute of the TextView tag:
    

    android:text="Hello, my name is Stan."
    

    for the LinearLayout tag.
13. Compile and run the project:
    Select Run in the main menu of Android Studio >> Run App.
    The Emulator Window appears for testing the app.
14. Change the title of the application by modifying the strings.xml files located in the folder
    

    app/res/values
    

15. Now replace the ConstraintLayout in the XML file with a LinearLayout like we did in class.
    Replace
    

    <androidx.constraintlayout.widget.ConstraintLayout
    

    with
    

    <LinearLayout
    

    and replace
    

    </androidx.constraintlayout.widget.ConstraintLayout>
    

    with

    </LinearLayout>
    

    Delete Line 3 where the namespace app is defined, and delete lines 14 through 17 which are not needed in the LinearLayout.
16. Add the attribute setting
    

    android:gravity="center"
    

    to the LinearLayout tag. This centers the text horizontally and vertically within the TextView widget.
17. Add source code headers with name, project number, and submit date. Here are the resulting layout files:
    activity_main.xml   MainActivity.java.