Practical-06

Mobile Application

Practical List

Create an android program that will display the use of a menu that will change the color of the background screen after selecting a menu option.

Steps

1. Create a new Android project in Android Studio.
2. Open the activity_main.xml layout file.
3. Add a TextView element to the layout with the following attributes:
   • android:id="@+id/textView"
   • android:layout_width="match_parent"
   • android:layout_height="match_parent"
   • android:gravity="center"
   • android:text="Background Color Changer"
   • android:textSize="24sp"
4. Open the MainActivity.java file.
5. Inside the onCreate method, add the following code to set the content view to the activity_main.xml layout:

   setContentView(R.layout.activity_main);
6. Create a new method called showColorMenu to display the color menu options:

   private void showColorMenu() {
       PopupMenu popupMenu = new PopupMenu(this, findViewById(R.id.textView));
       popupMenu.getMenuInflater().inflate(R.menu.color_menu, popupMenu.getMenu());
       popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
           @Override
           public boolean onMenuItemClick(MenuItem item) {
               int color = 0;
               switch (item.getItemId()) {
                   case R.id.menu_red:
                       color = Color.RED;
                       break;
                   case R.id.menu_green:
                       color = Color.GREEN;
                       break;
                   case R.id.menu_blue:
                       color = Color.BLUE;
                       break;
               }
               findViewById(R.id.textView).setBackgroundColor(color);
               return true;
           }
       });
       popupMenu.show();
   }
7. Create a new XML file called color_menu.xml in the res/menu directory.
8. Open the color_menu.xml file and add the following code to define the color menu options:

   <menu xmlns:android="http://schemas.android.com/apk/res/android">
       <item
           android:id="@+id/menu_red"
           android:title="Red" />
       <item
           android:id="@+id/menu_green"
           android:title="Green" />
       <item
           android:id="@+id/menu_blue"
           android:title="Blue" />
   </menu>
9. Open the activity_main.xml layout file.
10. Add a button element below the TextView with the following attributes:
    • android:id="@+id/button"
    • android:layout_width="wrap_content"
    • android:layout_height="wrap_content"
    • android:text="Change Color"
11. Open the MainActivity.java file.
12. Inside the onCreate method, add the following code to set a click listener for the button:

    Button button = findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            showColorMenu();
        }
    });
13. Run the application on an Android device or emulator.
14. Click the "Change Color" button to display the color menu.
15. Select a color option from the menu to change the background color of the text view.

Congratulations! You have successfully created an Android program that displays the use of a menu to change the color of the background screen.