Auto Scale TextView Text to Fit within Bounds

Question

I\'m looking for an optimal way to resize wrapping text in a TextView so that it will fit within its getHeight and getWidth bounds. I\'m not simply looking for

Answer 1

Here's yet another solution, just for kicks. It's probably not very efficient, but it does cope with both height and width of the text, and with marked-up text.

@Override
protected void onMeasure(final int widthMeasureSpec, final int heightMeasureSpec)
{
    if ((MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED)
            && (MeasureSpec.getMode(heightMeasureSpec) != MeasureSpec.UNSPECIFIED)) {

        final float desiredWidth = MeasureSpec.getSize(widthMeasureSpec);
        final float desiredHeight = MeasureSpec.getSize(heightMeasureSpec);

        float textSize = getTextSize();
        float lastScale = Float.NEGATIVE_INFINITY;
        while (textSize > MINIMUM_AUTO_TEXT_SIZE_PX) {
            // Measure how big the textview would like to be with the current text size.
            super.onMeasure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);

            // Calculate how much we'd need to scale it to fit the desired size, and
            // apply that scaling to the text size as an estimate of what we need.
            final float widthScale = desiredWidth / getMeasuredWidth();
            final float heightScale = desiredHeight / getMeasuredHeight();
            final float scale = Math.min(widthScale, heightScale);

            // If we don't need to shrink the text, or we don't seem to be converging, we're done.
            if ((scale >= 1f) || (scale <= lastScale)) {
                break;
            }

            // Shrink the text size and keep trying.
            textSize = Math.max((float) Math.floor(scale * textSize), MINIMUM_AUTO_TEXT_SIZE_PX);
            setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize);
            lastScale = scale;
        }
    }
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}