GridUtils.m

+ (CGFloat)getUITextElementBelowBaselineHeight:(ASPUITextElement)element traitCollection:(UITraitCollection *)contextTraitCollection {

    // 1. Get the style guide typography style we're using for this UI element
    ASPUITextStyle elementTextStyle = [self mapUIElementToStyle:element elementVariation:ASPUITextElementVariationDefault];
    UIFont *font = [ASPFontUtil getUIFont:elementTextStyle traitCollection:contextTraitCollection];
    // 2. Get line height multiple for typography - this is important because line height affects descender and ascender calculations
    CGFloat lineHeightMultiple = [self getUILineHeightMultiple:elementTextStyle font:font traitCollection:contextTraitCollection];
    
    // 3. If we're using a non-default line height, calculate an adjusment
    CGFloat lineHeightAdjustment = 0.0;
    if (lineHeightMultiple != 1) {
        lineHeightAdjustment = (font.lineHeight - (font.lineHeight * lineHeightMultiple))/2;
    }

    // 4. We're ready to do our font metric math - we want the height below the baseline, which is lineHeight minus ascender (adjusted to match the actual line height we use)
    return ((font.lineHeight - font.ascender) - lineHeightAdjustment);
}




+(CGFloat)roundToSubPixelPrecision:(CGFloat)value deviceScale:(CGFloat)deviceScale  {
    if (deviceScale > 0) {
        return (round(value*deviceScale))/deviceScale;
    }
    ASP_Log(@"Worry about nil/zero device scale");
    return value;
}