December 1997

Starting your application minimized

I want you to try something before your users do. First, create a Windows shortcut to an application you've written with C++ Builder. Then, right-click on the shortcut, choose Properties from the speed menu, and select the Shortcut tab in the resulting dialog box. In the Run dropdown box, select either Minimized or Maximized, as shown in Figure A.

Figure A: Set the Run property to Minimized.

Now run your application using the shortcut. Did your application's main window appear minimized or maximized? No? Then read on. In this article, we'll explain why your application didn't appear in the proper state and how you can easily work around this problem.

The bug and the hidden window

Borland included the following obstacle in the VCL on purpose: Every VCL-based application is a hidden window. The VCL makes Windows, the operating system, think this hidden window--rather than your main form--is your application's main window.When a user minimizes your application, this hidden window is minimized and the VCL hides your main form. Your main form is never actually minimized. Borland has tried to ease your pain by including methods and events in the TApplication class such as Minimize() and OnMinimize. We'll use another event from Tapplication--OnRestore--in our code. Let's see how to use our workaround.

Working around

www.cobb.com/cpb

as part of the file dec97.zip; click the Source Code hyperlink.) To begin, create a new project with a single form named MinMaxForm. Add an OnCreate event named FormCreate() to the form, as shown in Listing A. FormCreate() will do nearly all the work.

Listing A: TMinMaxForm

//------------------------------------
#include <vcl\vcl.h>
#pragma hdrstop

#include "Main.h"
//------------------------------------
#pragma resource "*.dfm"

TMinMaxForm *MinMaxForm;
//------------------------------------
__fastcall
TMinMaxForm::TMinMaxForm(TComponent*
   Owner) : TForm(Owner)
   {
   Application->OnRestore = OnRestore;
   }
//------------------------------------
void __fastcall
TMinMaxForm::FormCreate(TObject
   *Sender)
   {
   int cmdShow = System::CmdShow;

   if (cmdShow == SW_SHOWDEFAULT ||
      cmdShow == SW_HIDE)
      {
      STARTUPINFO startupInfo;
      GetStartupInfo(&startupInfo);

      if (startupInfo.dwFlags &
         STARTF_USESHOWWINDOW)
         cmdShow =
            startupInfo.wShowWindow;
      }

   if (cmdShow == SW_MINIMIZE ||
      cmdShow == SW_SHOWMINIMIZED ||
      cmdShow == SW_SHOWMINNOACTIVE)
      {
      ::ShowWindow(
         Application->Handle,
            SW_HIDE);
      ::ShowWindow(
         Application->Handle,
            SW_MINIMIZE);
      Application->ShowMainForm =
         false;
      }
   else if (cmdShow == SW_MAXIMIZE ||
      cmdShow == SW_SHOWMAXIMIZED)
      WindowState = wsMaximized;
}
//------------------------------------
void __fastcall
   TMinMaxForm::OnRestore(TObject
      *Sender)
      {
      Visible = true;
      }
//------------------------------------