ControlPanel

• Download source files - 46 Kb
• Download executable - 7 Kb

Introduction

The ControlPanel is a small application showing you how the Windows Control Panel application works.

The normal procedure is that when the application is launched it looks for .cpl files in the windows system directory. The cpl files are simple dll's which exports the CPlApplet() function. Control Panel now loads each cpl file one by one and gets the address of its CPlApplet() function. For each file it calls the CPlApplet() function by passing it different messages such as CPL_INIT, CPL_INQUIRE etc. You can get help about different messages in the MSDN. When control panel calls CPlApplet() function with CPL_INQUIRE message, the cpl file returns a CPLINFO structure which holds information about that perticular applet such as its name, icon, info tip etc. When a control panel applet is double clicked control panel calls CPlApplet() function with CPL_DBLCLK message to let the applet perform its work.

History

17 Nov 2002: Changed code. Now one can simply use the

class CControlItems
{
public:
	CControlItems();
	~CControlItems();

	void ReadFiles ( HWND hWnd );
	
	virtual void ProgressText ( char* pText );
	virtual void AddCplDialog( char* pName, int i, int k );

	// Return TRUE if one found,
	BOOL CheckIndex ( int iCpl, int iDialog );
	BOOL FindIndexByName ( const char* pName, int iCpl, int iDialog );

	HICON GetIconByIndex ( int iCpl, int iDialog );

	const char* GetToolTipByIndex ( int iCpl, int iDialog );
	const char* GetToolTipByName ( char* pName );

	BOOL StartByIndex ( HWND hWnd, int iCpl, int iDialog );
	BOOL StartByName ( HWND hWnd, char* pName );

	CCtrlPnlInfo* cpl_info;
};

By adding this class to a simple dialog which has a CListBox called m_list and a button which calls the ReadFiles

void CCPService::OnButtonReload() 
{
	m_list.ResetContent();

	ReadFiles( GetSafeHwnd() );

	m_list.UpdateWindow();
}

void CCPService::ProgressText ( char* pText )
{
	CWnd* pButton = GetDlgItem ( IDC_BUTTON_RELOAD );
	if ( pButton )
	{
		pButton->SetWindowText ( pText );
	}
}

void CCPService::AddCplDialog( char* pName, int i, int k )
{
	// Simple way to remember the index in an integer
	int iData = i << 16 | k;

	int iNewItem = m_list.AddString((LPCTSTR) pName);
	m_list.SetItemData( iNewItem,iData);

	m_list.UpdateWindow();
}

void CCPService::OnSelchangeList1() 
{
	int index = m_list.GetCurSel();
	if(index > -1)
	{
		int iData = m_list.GetItemData( index );

		// Split integer to the index values
		int i = iData >> 16;
		int k = iData & 0xffff;

		HICON hI = GetIconByIndex	( i, k );
		const char* pT = GetToolTipByIndex( i, k );

		if ( pT )
		{
			CWnd* pW = GetDlgItem ( IDC_TOOLTIP );
			if ( pW )
			{
				pW->SetWindowText ( pT );
			}
		}

		if ( hI )
		{
			m_icon.SetIcon ( hI );
		}	
	}
}