unit PxFormStorage;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  JvComponent, JvFormPlacement, JvAppStorage;

type
  TPxFormStorage = class(TJvFormStorage)
  private
    { Déclarations privées }
    FSaveFormCloseQuery: TCloseQueryEvent;
    FSaveFormShow: TNotifyEvent;
    FSaveFormCreate: TNotifyEvent;
    procedure SetPxEvents;
    procedure FormCreate(Sender: TObject);
  protected
    { Déclarations protégées }
    procedure Notification(AComponent: TComponent; Operation: TOperation);
      override;

  protected
    procedure Loaded; override;
  public
    { Déclarations publiques }
    constructor Create(AOwner: TComponent); override;
  published
    { Déclarations publiées }
  end;

procedure Register;

implementation
{TPxFormStorage}

procedure TPxFormStorage.Notification(AComponent: TComponent; Operation: TOperation);
begin
  inherited Notification(AComponent, Operation);
  if not (csDestroying in ComponentState) and (Operation = opRemove) and
    (AppStorage <> nil) then
    if AppStorage = AComponent then
      AppStorage := nil;
end;

constructor TPxFormStorage.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  if Owner is TCustomForm then
    with Form do
    begin
      FSaveFormCloseQuery := OnCloseQuery;
      FSaveFormShow := OnShow;
    end
end;

procedure TPxFormStorage.FormCreate(Sender: TObject);
begin
  if Assigned(FSaveFormCreate) then
    FSaveFormCreate(Sender);
  if IsActive then
  try
    RestoreFormPlacement;
  except
    Application.HandleException(Self);
  end;
  if Form.Left > screen.Width then
    Form.Left := screen.Width - Form.Width;
  if Form.Top > screen.Height then
    Form.Top := screen.Height - Form.Height;
end;

procedure TPxFormStorage.SetPxEvents;
begin
  if Owner is TCustomForm then
    with Form do
    begin
      FSaveFormCreate := OnCreate;
      OnCreate := FormCreate;
      OnCloseQuery := FSaveFormCloseQuery; //Cancel redirection FormCloseQuery;
      OnShow := FSaveFormShow; //Cancel JvFormStorage redirection to Form.OnShow
    end;
end;

procedure TPxFormStorage.Loaded;
var
  Loading: boolean;
  procedure LinkAppStorageFrom(AOwner: TComponent);
  var
    i: integer;
  begin
    if AOwner = Application then
      AOwner := Application.MainForm;
    if Assigned(AOwner) then
      with AOwner do
      begin
        for i := 0 to ComponentCount - 1 do
          if (Components[i] is TJvFormStorage) and
            Assigned(TJvFormStorage(Components[i]).AppStorage) then
          begin
            AppStorage := TJvFormStorage(Components[i]).AppStorage;
            if AppStoragePath = '' then
              AppStoragePath := AOwner.Name;
            AppStoragePath := TJvFormStorage(Components[i]).AppStoragePath + AppStoragePath;
            Break;
          end;
        if not Assigned(AppStorage) and (AOwner <> Application.MainForm) then
          LinkAppStorageFrom(AOwner.Owner); //Owner..n
      end;
  end;
begin
  Loading := csLoading in ComponentState;
  inherited Loaded;
  if Loading and not (csDesigning in ComponentState) then
  begin
    SetPxEvents;
    if not Assigned(AppStorage) then
      LinkAppStorageFrom(FORM.Owner);
  end;
end;

procedure Register;
begin
  RegisterComponents('Paradoxos', [TPxFormStorage]);
end;

end.