TextView+ImageSpan同一行文字圖片居中

項目開發中遇到了這樣一個需求，標籤（圖片）和文字，標籤顯示在標題的開頭，天然而然想到了用TextView+ImageSpan的方式來弄，開始沒有思路，網上搜索一下基本上都有說到，可是都沒有解決一個問題，就是居中。怎麼設置都設置不了！後來找到一篇文章裏面介紹了ImageSpan的getSize()方法設置了展現位置！下面給出自定義修改的ImageSpan，至於怎麼用ImageSpan就很少說了

 

/**
 * 垂直居中的ImageSpan
 *
 * @author KenChung
 */
public class VerticalImageSpan extends ImageSpan {

    public VerticalImageSpan(Drawable drawable) {
        super(drawable);
    }

    public int getSize(Paint paint, CharSequence text, int start, int end,
                       Paint.FontMetricsInt fontMetricsInt) {
        Drawable drawable = getDrawable();
        Rect rect = drawable.getBounds();
        if (fontMetricsInt != null) {
            Paint.FontMetricsInt fmPaint = paint.getFontMetricsInt();
            int fontHeight = fmPaint.bottom - fmPaint.top;
            int drHeight = rect.bottom - rect.top;

            int top = drHeight / 2 - fontHeight / 4;
            int bottom = drHeight / 2 + fontHeight / 4;

            fontMetricsInt.ascent = -bottom;
            fontMetricsInt.top = -bottom;
            fontMetricsInt.bottom = top;
            fontMetricsInt.descent = top;
        }
        return rect.right;
    }

    @Override
    public void draw(Canvas canvas, CharSequence text, int start, int end,
                     float x, int top, int y, int bottom, Paint paint) {
        Drawable drawable = getDrawable();
        canvas.save();
        int transY = 0;
        transY = ((bottom - top) - drawable.getBounds().bottom) / 2 + top;
        canvas.translate(x, transY);
        drawable.draw(canvas);
        canvas.restore();
    }
}