QMUIAlignMiddleImageSpan.java 文件源码

@Override
    public void draw(Canvas canvas, CharSequence text, int start, int end,
                     float x, int top, int y, int bottom, Paint paint) {
        if (mVerticalAlignment == ALIGN_MIDDLE) {
            Drawable d = getDrawable();
            canvas.save();

//            // 注意如果这样实现会有问题：TextView 有 lineSpacing 时，这里 bottom 偏大，导致偏下
//            int transY = bottom - d.getBounds().bottom; // 底对齐
//            transY -= (paint.getFontMetricsInt().bottom - paint.getFontMetricsInt().top) / 2 - d.getBounds().bottom / 2; // 居中对齐
//            canvas.translate(x, transY);
//            d.draw(canvas);
//            canvas.restore();

            Paint.FontMetricsInt fontMetricsInt = paint.getFontMetricsInt();
            int fontTop = y + fontMetricsInt.top;
            int fontMetricsHeight = fontMetricsInt.bottom - fontMetricsInt.top;
            int iconHeight = d.getBounds().bottom - d.getBounds().top;
            int iconTop = fontTop + (fontMetricsHeight - iconHeight) / 2;
            canvas.translate(x, iconTop);
            d.draw(canvas);
            canvas.restore();
        } else {
            super.draw(canvas, text, start, end, x, top, y, bottom, paint);
        }
    }