leftContents The contents for the left button. Declarationvar leftContents: TCControlContents? { get set } DiscussionMay be nil. See AlsoInspecting the descriptorcompositeLabeldownContentsdownLabelhighlightDurationinputIsMutuallyExclusiveisDigitalisRadialleftLabeloffsetrightContentsrightLabelsizeupContentsupLabelzIndex