[Java/Android] VerticalTextView

layout.xml

<com.example.app.VerticalTextView
    android:id="@+id/textview_days"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Thursday"
    android:layout_centerVertical="true"
    android:layout_alignParentStart="true" />

VerticalTextView.java

import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.view.Gravity;
import android.widget.TextView;
 
public class VerticalTextView extends TextView {
    final boolean topDown;

    public VerticalTextView(Context context, AttributeSet attrs){
        super(context, attrs);
        final int gravity = getGravity();
        if(Gravity.isVertical(gravity) && (gravity&Gravity.VERTICAL_GRAVITY_MASK) == Gravity.BOTTOM) {
            setGravity((gravity&Gravity.HORIZONTAL_GRAVITY_MASK) | Gravity.TOP);
            topDown = false;
        }else
            topDown = true;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
        super.onMeasure(heightMeasureSpec, widthMeasureSpec);
        setMeasuredDimension(getMeasuredHeight(), getMeasuredWidth());
    }

    @Override
    protected boolean setFrame(int l, int t, int r, int b){
        return super.setFrame(l, t, l+(b-t), t+(r-l));
    }

    @Override
    public void draw(Canvas canvas){
        if(topDown){
            canvas.translate(getHeight(), 0);
            canvas.rotate(90);
        }else {
            canvas.translate(0, getWidth());
            canvas.rotate(-90);
        }
        canvas.clipRect(0, 0, getWidth(), getHeight(), android.graphics.Region.Op.REPLACE);
        super.draw(canvas);
    }
}