Mega Code Archive
Automatically expanding TEdit
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Title: Automatically-expanding TEdit
Question: A TEdit descendent that automatically fits itself to the text it contains (like editing filenames in the Windows Explorer).
Answer:
[This was written by Rick Rogers]
Here's a component which does the trick. Hopefully you'll learn from it:
unit ExpandingEdit;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls;
type
TExpandingEdit = class(TEdit)
private
FCanvas: TControlCanvas;
protected
procedure Change; override;
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
end;
procedure Register;
implementation
constructor TExpandingEdit.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FCanvas := TControlCanvas.Create;
FCanvas.Control := Self;
end;
destructor TExpandingEdit.Destroy;
begin
FCanvas.Free;
inherited Destroy;
end;
procedure TExpandingEdit.Change;
const
EditMargin = 8;
var
W: Integer;
begin
inherited Change;
if not HandleAllocated then Exit;
FCanvas.Font := Font;
W := FCanvas.TextWidth(Text) + (2 * EditMargin);
if (Width end;
procedure Register;
begin
RegisterComponents('Samples', [TExpandingEdit]);
end;
end.
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