Dashed Underlined TextView

colors.xml

<resources>
    <!-- TODO: Update this! -->
    <color name="dashColor">#3F51B5</color>
</resources>

DashedUnderlinedTextView.java

/*
* @author Dipendra Sunar
*/
public class DashedUnderlinedTextView extends AppCompatTextView {

    private Rect mRect;
    private Paint mPaint;
    private float mStrokeWidth;
    private int mUnderlinePadding;

    public DashedUnderlinedTextView(Context context) {
        this(context, null, 0);
    }

    public DashedUnderlinedTextView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

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

        /// turning off hardware acceleration
        // can be removed/commented out if no dashed underline needed.
        setLayerType(View.LAYER_TYPE_SOFTWARE, null);
    }

    private void init(Context context, AttributeSet attributeSet, int defStyle) {

        float density = context.getResources().getDisplayMetrics().density;

        TypedArray typedArray = context.obtainStyledAttributes(attributeSet, R.styleable.DashedUnderlinedTextView, defStyle, 0);
        int underlineColor = typedArray.getColor(R.styleable.DashedUnderlinedTextView_underlineColor, ContextCompat.getColor(context, R.color.dashColor));
        mStrokeWidth = typedArray.getDimension(R.styleable.DashedUnderlinedTextView_underlineWidth, density * 2);
        mUnderlinePadding = typedArray.getInteger(R.styleable.DashedUnderlinedTextView_underlinePadding, 2);

        typedArray.recycle();

        mRect = new Rect();
        mPaint = new Paint();
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setColor(underlineColor);
        mPaint.setStrokeWidth(mStrokeWidth);

        // Comment below line if no dashed underline needed.
        mPaint.setPathEffect(new DashPathEffect(new float[]{5,5},0));
    }

    @SuppressWarnings("unused")
    public int getUnderLineColor() {
        return mPaint.getColor();
    }

    @SuppressWarnings("unused")
    public void setUnderLineColor(int mColor) {
        mPaint.setColor(mColor);
        invalidate();
    }

    @SuppressWarnings("unused")
    public float getUnderlineWidth() {
        return mStrokeWidth;
    }

    @SuppressWarnings("unused")
    public void setUnderlineWidth(float mStrokeWidth) {
        this.mStrokeWidth = mStrokeWidth;
        invalidate();
    }

    @Override
    protected void onDraw(Canvas canvas) {

        int count = getLineCount();

        final Layout layout = getLayout();
        float x_start, x_stop, x_diff;
        int firstCharInLine, lastCharInLine;

        for (int i = 0; i < count; i++) {
            int baseline = getLineBounds(i, mRect) + mUnderlinePadding;
            firstCharInLine = layout.getLineStart(i);
            lastCharInLine = layout.getLineEnd(i);

            x_start = layout.getPrimaryHorizontal(firstCharInLine);
            x_diff = layout.getPrimaryHorizontal(firstCharInLine + 1) - x_start;
            x_stop = layout.getPrimaryHorizontal(lastCharInLine - 1) + x_diff;

            canvas.drawLine(x_start, baseline + mStrokeWidth, x_stop, baseline + mStrokeWidth, mPaint);
        }

        super.onDraw(canvas);
    }
}

layout.xml

<DashedUnderlinedTextView 
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:text="Date of Service"
    app:underlineColor="@color/dashColor"
    app:underlineWidth="2dp"
    app:underlinePadding="4"/>

styles.xml

<resources>
<declare-styleable name="DashedUnderlinedTextView">
        <attr name="underlineWidth" format="dimension" />
        <attr name="underlineColor" format="color" />
        <attr name="underlinePadding" format="integer"/>
    </declare-styleable>
  </resources>