change width SysIPAddress32 - delphi

Question

I'm trying implement IP edit. This my code:
unit Main;
interface
uses
System.SysUtils, System.Classes,
Winapi.Windows, Winapi.Messages, Winapi.CommCtrl,
Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.StdCtrls, Vcl.ComCtrls;
type
TIpEdit = class(TWinControl)
strict protected
procedure CreateParams(var Params: TCreateParams); override;
procedure WMGetDlgCode(var Message: TWMGetDlgCode); message WM_GETDLGCODE;
procedure WMSetFont(var Message: TWMSetFont); message WM_SETFONT;
end;
TMainForm = class(TForm)
Btn1: TButton;
procedure FormCreate(Sender: TObject);
procedure Btn1Click(Sender: TObject);
private
FIpEdit: TIpEdit;
public
{ Public declarations }
end;
var
MainForm: TMainForm;
implementation
{$R *.dfm}
{ TIPEdit }
procedure TIPEdit.CreateParams(var Params: TCreateParams);
begin
InitCommonControl(ICC_INTERNET_CLASSES);
inherited CreateParams(Params);
CreateSubClass(Params, WC_IPADDRESS);
Params.Style := Params.Style or WS_TABSTOP or WS_CHILD;
end;
procedure TIPEdit.WMGetDlgCode(var Message: TWMGetDlgCode);
begin
inherited;
Message.Result := Message.Result or DLGC_WANTARROWS;
end;
procedure TIPEdit.WMSetFont(var Message: TWMSetFont);
var
LF: LOGFONT;
begin
if GetObject(Message.Font, SizeOf(LF), #LF) <> 0 then
begin
Message.Font := CreateFontIndirect(LF);
inherited;
end;
end;
{ TMainForm }
procedure TMainForm.Btn1Click(Sender: TObject);
begin
FIpEdit.Width := FIpEdit.Width + 100;
end;
procedure TMainForm.FormCreate(Sender: TObject);
begin
FIpEdit := TIpEdit.Create(Self);
FIpEdit.Parent := Self;
FIpEdit.SetBounds(10, 10, 120, 21);
end;
end.
Before Btn1.Click
After Btn1.Click
As a result: Control change own width but not change width internal edits.
I try fix by two ways
Use RecreateWnd. This works, but IMHO its ugly solution.
Fix internal edits width manualy. This works, but it is difficult to
implement, due to the internal work of the control
Maybe I missed something and there is a simpler solution?
Edit:
I tested the RecreateWnd, but it can not be used when using DevExpress layout control. It seems that layout control uses the direct call of the API bypassing the SetBounds method. In this case RecreateWnd can not be using.
The final conclusion is:
RecreateWnd is simple solution with some ristrictions
RepeatUntil answer more difficult, but always working

Answer 1

The control does not provide a mechanism to update its layout after it has been created. Yes you could hack at the internal edit controls, but that is dangerous. You'd be relying on undocumented implementation detail that is subject to change.
In summary, I would say that recreating the window is the best solution available.

Answer 2

You can use TPanel with child TEdit controls to create your own IP Edit, That will give you more control of their property.
This how its look at run time:
I wrote this time ago, its not completed work but may give an idea of what i mean.
unit IPEdit;
interface
uses
System.SysUtils, System.Classes, Vcl.Controls, Vcl.StdCtrls, Vcl.ExtCtrls, Vcl.Forms,
Vcl.Graphics, System.UITypes;
type
TExitType = (etNone, etNext);
type
TIPEdit = class(TCustomPanel)
private
FPart1 : TEdit;
FPart2 : TEdit;
FPart3 : TEdit;
FPart4 : TEdit;
FSplitter1 : TPanel;
FSplitter2 : TPanel;
FSplitter3 : TPanel;
FRiseErr : Boolean;
FErrMsg : string;
FExitType : TExitType;
FBevelInner : TPanelBevel;
FLeadingzero: Boolean;
procedure SetExitType(Value : TExitType);
procedure SetBevelInner(Value: TPanelBevel);
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
protected
procedure EditOnKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
procedure EditOnChange(Sender: TObject);
procedure OnPanelResize(Sender: TObject);
procedure EditOnExit(Sender: TObject);
published
property ShowError: Boolean read FRiseErr write FRiseErr default False;
property Leadingzero: Boolean read FLeadingzero write FLeadingzero default False;
property ErrorText: string read FErrMsg write FErrMsg;
property ExitType: TExitType read FExitType write SetExitType default etNext;
property BevelInner: TPanelBevel read FBevelInner write SetBevelInner default bvNone;
end;
implementation
const
Msg_Err_Value_Exceeded = 'Value cannot be greater than 255';
SplitterWidth = 5;
{ TIPEdit }
constructor TIPEdit.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
if AOwner is TWinControl then
Parent := TWinControl(AOwner);
{ Main Panle Style }
ParentBackground := False;
BevelKind := bkFlat;
BevelOuter := bvNone;
Color := clWindow;
Height := 25;
Width := 165;
Caption := '';
/////////////////////////////
{ Set Handlers}
OnResize := OnPanelResize;
{ Create child controls }
FPart1 := TEdit.Create(Self);
FPart1.Name := 'IPEditPart1';
FPart1.Visible := False;
FSplitter1 := TPanel.Create(Self);
FSplitter1.Name := 'IPSplitter1';
FSplitter1.Visible:= False;
FPart2 := TEdit.Create(Self);
FPart2.Name := 'IPEditPart2';
FPart2.Visible := False;
FSplitter2 := TPanel.Create(Self);
FSplitter2.Name := 'IPSplitter2';
FSplitter2.Visible:= False;
FPart3 := TEdit.Create(Self);
FPart3.Name := 'IPEditPart3';
FPart3.Visible := False;
FSplitter3 := TPanel.Create(Self);
FSplitter3.Name := 'IPSplitter3';
FSplitter3.Visible:= False;
FPart4 := TEdit.Create(Self);
FPart4.Name := 'IPEditPart4';
FPart4.Visible := False;
FPart1.Align := alLeft;
FSplitter1.Align := alLeft;
FPart2.Align := alLeft;
FSplitter2.Align := alLeft;
FPart3.Align := alLeft;
FSplitter3.Align := alLeft;
FPart4.Align := alLeft;
/////////////////////////////
{ Set Child Style }
// This order is very important //
FPart1.Parent := TWinControl(Self);
FSplitter1.Parent := TWinControl(Self);
FPart2.Parent := TWinControl(Self);
FSplitter2.Parent := TWinControl(Self);
FPart3.Parent := TWinControl(Self);
FSplitter3.Parent := TWinControl(Self);
FPart4.Parent := TWinControl(Self);
FPart1.Visible := True;
FSplitter1.Visible := True;
FPart2.Visible := True;
FSplitter2.Visible := True;
FPart3.Visible := True;
FSplitter3.Visible := True;
FPart4.Visible := True;
//////////////////////////////////
FPart1.Alignment := taCenter;
FPart2.Alignment := taCenter;
FPart3.Alignment := taCenter;
FPart4.Alignment := taCenter;
FPart1.Margins.Left := 0;
FPart2.Margins.Left := 0;
FPart3.Margins.Left := 0;
FPart4.Margins.Left := 0;
FSplitter1.Margins.Left := 0;
FSplitter2.Margins.Left := 0;
FSplitter3.Margins.Left := 0;
FPart1.Margins.Right := 0;
FPart2.Margins.Right := 0;
FPart3.Margins.Right := 0;
FPart4.Margins.Right := 0;
FSplitter1.Margins.Right := 0;
FSplitter2.Margins.Right := 0;
FSplitter3.Margins.Right := 0;
FPart1.AlignWithMargins := True;
FSplitter1.AlignWithMargins := True;
FPart2.AlignWithMargins := True;
FSplitter2.AlignWithMargins := True;
FPart3.AlignWithMargins := True;
FSplitter3.AlignWithMargins := True;
FPart4.AlignWithMargins := True;
FPart1.AutoSize := False;
FPart2.AutoSize := False;
FPart3.AutoSize := False;
FPart4.AutoSize := False;
FPart1.BorderStyle := bsNone;
FPart2.BorderStyle := bsNone;
FPart3.BorderStyle := bsNone;
FPart4.BorderStyle := bsNone;
FPart1.NumbersOnly := True;
FPart2.NumbersOnly := True;
FPart3.NumbersOnly := True;
FPart4.NumbersOnly := True;
FPart1.MaxLength := 3;
FPart2.MaxLength := 3;
FPart3.MaxLength := 3;
FPart4.MaxLength := 3;
FPart1.Width := 36;
FPart2.Width := 36;
FPart3.Width := 36;
FPart4.Width := 36;
FSplitter1.Alignment := taCenter;
FSplitter2.Alignment := taCenter;
FSplitter3.Alignment := taCenter;
FSplitter1.Caption := '.';
FSplitter2.Caption := '.';
FSplitter3.Caption := '.';
FSplitter1.BevelOuter := bvNone;
FSplitter2.BevelOuter := bvNone;
FSplitter3.BevelOuter := bvNone;
FSplitter1.Color := clWindow;
FSplitter2.Color := clWindow;
FSplitter3.Color := clWindow;
FSplitter1.ParentBackground := False;
FSplitter2.ParentBackground := False;
FSplitter3.ParentBackground := False;
FSplitter1.TabStop := False;
FSplitter2.TabStop := False;
FSplitter3.TabStop := False;
FSplitter1.Width := SplitterWidth;
FSplitter2.Width := SplitterWidth;
FSplitter3.Width := SplitterWidth;
FSplitter1.Font.Style := FSplitter1.Font.Style + [fsBold];
FSplitter2.Font.Style := FSplitter2.Font.Style + [fsBold];
FSplitter3.Font.Style := FSplitter3.Font.Style + [fsBold];
//////////////////////////////
{Set Child handlers}
FPart1.OnChange := EditOnChange;
FPart2.OnChange := EditOnChange;
FPart3.OnChange := EditOnChange;
FPart4.OnChange := EditOnChange;
FPart1.OnKeyDown := EditOnKeyDown;
FPart2.OnKeyDown := EditOnKeyDown;
FPart3.OnKeyDown := EditOnKeyDown;
FPart4.OnKeyDown := EditOnKeyDown;
FPart1.OnExit := EditOnExit;
FPart2.OnExit := EditOnExit;
FPart3.OnExit := EditOnExit;
FPart4.OnExit := EditOnExit;
{Set Child control tab order for the handlers work}
FPart1.TabOrder := 0;
FPart2.TabOrder := 1;
FPart3.TabOrder := 2;
FPart4.TabOrder := 3;
FPart1.Text := '1';
FPart2.Text := '2';
FPart3.Text := '3';
FPart4.Text := '4';
FExitType := etNext;
FErrMsg := Msg_Err_Value_Exceeded;
end;
destructor TIPEdit.Destroy;
begin
FPart1.Free;
FPart2.Free;
FPart3.Free;
FPart4.Free;
FSplitter1.Free;
FSplitter2.Free;
FSplitter3.Free;
inherited;
end;
procedure TIPEdit.EditOnChange(Sender: TObject);
var
iValue : Integer;
bValGrater : Boolean;
I: Integer;
begin
if NOT (Sender is TEdit) then Exit;
bValGrater := False;
if TryStrToInt(TEdit(Sender).Text, iValue) then begin
if (iValue > 255) then begin
iValue := 255;
bValGrater := True;
TEdit(Sender).Text := iValue.ToString;
if (FRiseErr and bValGrater) then
raise Exception.Create(FErrMsg);
end;
end;
if Length(TEdit(Sender).Text) = 3 then begin
case FExitType of
etNone: ;
etNext: FindNextControl(TEdit(Sender), True, False, False).SetFocus;
end;
end;
end;
procedure TIPEdit.EditOnKeyDown(Sender: TObject; var Key: Word;
Shift: TShiftState);
const
vkReturn = $0D;
begin
if not (Sender is TEdit) then Exit;
if Key = vkReturn then
FindNextControl(TEdit(Sender), True, False, False).SetFocus;
end;
procedure TIPEdit.OnPanelResize(Sender: TObject);
const
EditCount = 4;
SplitterCount = 3;
var
EditWidth : Integer;
FSplitterWidth : Integer;
EditMargin : Integer;
begin
EditWidth := Trunc(((Width) / EditCount) - (SplitterCount * (SplitterWidth)));
FPart1.Width := EditWidth;
FPart2.Width := EditWidth;
FPart3.Width := EditWidth;
FPart4.Width := EditWidth;
FSplitterWidth := Trunc(( (Width) - ( EditWidth * EditCount) ) / SplitterCount);
FSplitter1.Width := FSplitterWidth;
FSplitter2.Width := FSplitterWidth;
FSplitter3.Width := FSplitterWidth;
{Center edits text vertically == this is a temporary workaround}
FPart1.Margins.Top := 0;
FPart2.Margins.Top := 0;
FPart3.Margins.Top := 0;
FPart4.Margins.Top := 0;
EditMargin := Round( ((Height / 5)));
FPart1.Margins.Top := EditMargin;
FPart2.Margins.Top := EditMargin;
FPart3.Margins.Top := EditMargin;
FPart4.Margins.Top := EditMargin;
FSplitter1.Margins.Top := EditMargin + SplitterWidth; { the +lblWidth to make it lower than the edits}
FSplitter2.Margins.Top := EditMargin + SplitterWidth;
FSplitter3.Margins.Top := EditMargin + SplitterWidth;
end;
procedure TIPEdit.SetBevelInner(Value: TPanelBevel);
begin
TPanel(Self).BevelInner := Value;
end;
procedure TIPEdit.SetExitType(Value: TExitType);
begin
FExitType := Value;
end;
procedure TIPEdit.EditOnExit(Sender: TObject);
var
I: Integer;
begin
if not (Sender IS TEdit) then Exit;
if FLeadingzero then begin
if Length(TEdit(Sender).Text) >= 1 then
for I := Length(TEdit(Sender).Text) to 2 do begin
TEdit(Sender).Text := '0' + TEdit(Sender).Text;
end;
end;
end;
end.