BottomLinedTextView.java

package me.mesmo.app.presentation.views;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.support.annotation.ColorInt;
import android.support.annotation.Nullable;
import android.support.v7.widget.AppCompatTextView;
import android.text.Layout;
import android.util.AttributeSet;

import me.mesmo.app.R;
import me.mesmo.app.presentation.utils.ScreenUtils;


public class BottomLinedTextView extends AppCompatTextView {

    private Paint paint = new Paint();

    private float lineHeight;
    private float lineHorizontalPadding;

    public BottomLinedTextView(Context context) {
        super(context);
        init(context, null, 0);
    }

    public BottomLinedTextView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs, 0);
    }

    public BottomLinedTextView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs, defStyleAttr);
    }

    private void init(Context context, AttributeSet attrs, int defStyleAttr) {
        if (attrs != null) {
            TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.BottomLinedTextView, defStyleAttr, 0);
            try {
                float lineHeight = ta.getDimension(R.styleable.BottomLinedTextView_lineHeight, ScreenUtils.dp2Px(context, 1));
                setLineHeight(lineHeight);

                float lineHorizontalPadding = ta.getDimension(R.styleable.BottomLinedTextView_lineHorizontalPadding, 0f);
                setLineHorizontalPadding(lineHorizontalPadding);

                int lineColor = ta.getColor(R.styleable.BottomLinedTextView_lineColor, getCurrentTextColor());
                setLineColor(lineColor);

            } finally {
                ta.recycle();
            }
        }
    }

    @SuppressWarnings("SuspiciousNameCombination")
    public void setLineHeight(float lineHeight) {
        this.lineHeight = lineHeight;
        paint.setStrokeWidth(lineHeight);
        invalidate();
    }

    public void setLineHorizontalPadding(float lineHorizontalPadding) {
        this.lineHorizontalPadding = lineHorizontalPadding;
        invalidate();
    }

    public void setLineColor(@ColorInt int lineColor) {
        paint.setColor(lineColor);
        invalidate();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        Layout layout = getLayout();

        float lastLineWidth = layout.getLineWidth(layout.getLineCount() - 1);

        float startX = (getWidth() - lastLineWidth) / 2 + lineHorizontalPadding;
        float stopX = getWidth() - startX;
        float y = getHeight() - lineHeight;

        canvas.drawLine(startX, y, stopX, y, paint);
    }
}