TextSelection.collapsed constructor
- required int offset,
 - TextAffinity affinity = TextAffinity.downstream,
 
Creates a collapsed selection at the given offset.
A collapsed selection starts and ends at the same offset, which means it contains zero characters but instead serves as an insertion point in the text.
Implementation
const TextSelection.collapsed({required int offset, this.affinity = TextAffinity.downstream})
  : baseOffset = offset,
    extentOffset = offset,
    isDirectional = false,
    super.collapsed(offset);