SetSelectionRange

Forms, interaction, Unicode

Description

Sets the anchor and caret of the active form-field edit selection in the requested index unit

The two positions are clamped independently, so an anchor greater than the caret creates a reversed selection while the normalized SelectionStart and SelectionLength properties remain ordered

Code-point and grapheme-cluster units always resolve to valid Unicode boundaries and cannot divide a surrogate pair, combining sequence or joined emoji cluster

Declaration

function SetSelectionRange(AnchorIndex, CaretIndex: Integer;
  IndexUnit: TPDFlibFormSelectionUnit): Integer;

Parameters

AnchorIndex	Fixed edge of the directed selection in `IndexUnit`, clamped to the editable value
CaretIndex	Moving edge of the directed selection in `IndexUnit`, clamped to the editable value
IndexUnit	`fsuUTF16CodeUnit`, `fsuUnicodeCodePoint` or `fsuGraphemeCluster`

Return value

Returns 1 when an edit is active and the selection is stored, otherwise 0

Performance

Code-point and grapheme boundary tables are built lazily for the current edit value, reused by later selection operations and invalidated by SetEditValue

Example

if Session.BeginEdit(FieldIndex) = 1 then
begin
  Session.SetEditValue('A' + WideChar($D83D) + WideChar($DE00) + 'B');
  Session.SetSelectionRange(1, 2, fsuUnicodeCodePoint);
end;