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taCenter

taCenter = 2

Example​

function IsCentredAlignment(Alignment: TAlignment): Boolean;
begin
  Result := Alignment = taCenter;
end;

Usage​

taCenter selects centred TAlignment rendering but falls through Velox fixed-width export without centring or width enforcement.

Additional Technical Info​

taCenter is the third member of Delphi's TAlignment enumeration. A control or other consumer that implements the standard meaning positions text horizontally in the centre of its available area.

The constant expresses an alignment choice; it does not itself measure, pad, truncate or render text. The consuming class decides how—and whether—to implement centring.

Velox script exposure

Velox registers TAlignment = (taLeftJustify, taRightJustify, taCenter) as a hidden scripting type and exposes its members as constants. The current reduced TField script import does not expose native TField.Alignment, so scripts cannot use this constant to change a dataset field's alignment through that documented surface. It remains valid in compatible TAlignment expressions and any exposed signature that accepts the type.

The example classifies a value only. It is source-reviewed and is not executed by the documentation workflow.

Critical fixed-width export quirk

Velox's non-delimited flat-file writer has explicit branches for taLeftJustify and taRightJustify, but no taCenter branch and no fallback. If a native dataset field is centred:

  • a value shorter than DisplayWidth is written without left or right padding;
  • a value longer than DisplayWidth is written without truncation; and
  • the resulting record can be shorter or longer than the configured fixed-width layout.

This is not centred padding. It is a fall-through that bypasses width enforcement and can shift every following field. Treat a centred native field in a fixed-width output definition as a configuration defect unless downstream layout explicitly permits variable width.

Delimited output bypasses the alignment case entirely, so this quirk applies only when FieldDelimited is false. Trimming and string quoting still occur before the case, even though no width processing follows for this member.

Core behavior and boundaries

  • The ordinal is 2 even though this page appears first among the ta* pages under alphabetical navigation.
  • UI consumers can account for font metrics, control padding and bidirectional layout; the enum alone does not define those policies.
  • TField.Alignment is primarily display metadata. Velox additionally reuses it as fixed-width serialization metadata, with the incomplete behavior above.
  • The constant is resolved at script compile time, has no shared state and is safe to compare concurrently.

External references

Created 2026-07-15