Android TextView 字体-顶部对齐

在工作中，遇到这样一种需求，TextView 中有字体大小不一致的文字，要求顶部对齐。如下图

public class TopAlignSpan extends SuperscriptSpan {

    /** 字体大小 */
    private float fontSizePx;

    //shift value, 0 to 1.0
    protected float shiftPercentage = 0;

    //doesn't shift
    public TopAlignSpan(float fontSizePx) {
        this(fontSizePx, 0);
    }

    //sets the shift percentage
    public TopAlignSpan(float fontSizePx, float shiftPercentage) {
        if (shiftPercentage > 0.0 && shiftPercentage < 1.0) {
            this.shiftPercentage = shiftPercentage;
        }
        this.fontSizePx = fontSizePx;
    }

    @Override
    public void updateDrawState(TextPaint tp) {
        //original ascent
        float ascent = tp.ascent();

        //scale down the font
        tp.setTextSize(fontSizePx);

        //get the new font ascent
        float newAscent = tp.getFontMetrics().ascent;

        //move baseline to top of old font, then move down size of new font
        //adjust for errors with shift percentage
     //   tp.baselineShift += (ascent - ascent * shiftPercentage)
    //            - (newAscent - newAscent * shiftPercentage);
    //计算基线偏移量
  tp.baselineShift += (ascent - newAscent) * (1 - shiftPercentage);
    }

    @Override
    public void updateMeasureState(TextPaint tp) {
        updateDrawState(tp);
    }
}