How would you extend a TextView using a specific method?

You can extend TextView by creating your own class that inherits from TextView and overriding the necessary methods, such as onDraw() or onMeasure(). For example:

public class CustomTextView extends androidx.appcompat.widget.AppCompatTextView {

    public CustomTextView(Context context) {
        super(context);
        init();
    }

    public CustomTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public CustomTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {
        // Additional initialization logic if needed
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        // Add custom drawing logic, for example, a border or underline
        Paint paint = new Paint();
        paint.setColor(Color.RED);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(2);
        canvas.drawRect(0, 0, getWidth(), getHeight(), paint);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        // Add custom size measurement logic
        int width = getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec);
        int height = getDefaultSize(getSuggestedMinimumHeight(), heightMeasureSpec);
        setMeasuredDimension(width, height);
        // You can modify the measured dimensions if needed
    }
}

In this example, the CustomTextView class inherits from AppCompatTextView. The onDraw() method is overridden to add a red border around the text, and onMeasure() remains unchanged but demonstrates the possibility of overriding to customize size measurements.

To use a custom TextView in XML layout, specify the full class name:

<com.your_package_name.CustomTextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Hello, Custom TextView!" />

Replace com.your_package_name with the path to your package.