MFC ActiveX Digital Clock

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Introduction

The main idea of this project is creation of a digital segment indicator. In the first version I had developed one segment indicator. After this I grouped some segment indicators and colon indicator and made the DigitalClock class. The next step was creation of an Active X control, based on DigitalClock class.

The base class is CDigit. This class draws segments of a digit with given brush, pen and width. The common function of this class is drawDigit(HDC dc, const int iDigit). This function gives the device context for painting and the number.

// draw digit, form 0 - 9

void CDigit::drawDigit( HDC dc, const int iDigit ) 
{ 
switch( iDigit )
{
case 0:

drawSegment(dc, UET, true ); 
drawSegment( dc, RUET, true ); 
drawSegment( dc, RDET, true ); 
drawSegment( dc, DET, true ); 
drawSegment( dc, LDET, true ); 
drawSegment( dc, LUET, true );
drawSegment( dc, MET, false );

break;
case 1:

drawSegment( dc, UET, false ); drawSegment( dc, RUET, true ); 
drawSegment( dc, RDET, true ); drawSegment( dc, DET, false ); 
drawSegment( dc, LDET, false ); drawSegment( dc, LUET, false );
drawSegment( dc, MET, false );

break;
.........In same manner draw segments for other digits...............

The digit enumeration:

enum DEType
{

UET = 0,
RUET = 1,
RDET = 2,
DET = 3,
LDET = 4,
LUET = 5,
MET = 6

};

The function drawSegment is used for painting of one segment:

// draw segment with selected color and pen
void CDigit::drawSegment( HDC dc, const DEType segType, 
                                const bool bState ) const 
{ 

HBRUSH oldBrush = (HBRUSH) SelectObject( dc, 
         (bState) ? m_activeBrush : m_inactiveBrush );
HPEN oldPen = (HPEN) SelectObject( dc, (bState) ? m_hActPen : m_hInactPen );
Polygon( dc, m_ptDG[ segType ], 6 );
SelectObject( dc, oldPen );
SelectObject( dc, oldBrush );

}

drawSegment selects the correspond brush and pen and calls Poligon API function, which draws a segment.

In this project, I had some difficulties with persisting of control's properties. After some experiments I did following:

void CDigitalClockCtrl::DoPropExchange(CPropExchange* pPX)
{
ExchangeVersion(pPX, MAKELONG(_wVerMinor, _wVerMajor));
COleControl::DoPropExchange(pPX);

// TODO: Call PX_ functions for each persistent custom property.
long lSOffset = GetLSOffset();
long lSWidth = GetLSWidth();
long lXOffset = GetLXOffset();
long lYOffset = GetLYOffset();
OLE_COLOR clrActive = GetClrActive();
OLE_COLOR clrBkgnd = GetClrBkgnd(); 
OLE_COLOR clrInactive = GetClrInactive();

PX_Long( pPX, _T("lSOffset"), lSOffset );
PX_Long( pPX, _T("lSWidth"), lSWidth );
PX_Long( pPX, _T("lXOffset"), lXOffset );
PX_Long( pPX, _T("lYOffset"), lYOffset );

PX_Color( pPX, _T("clrActive"), clrActive );
PX_Color( pPX, _T("clrBkgnd"), clrBkgnd );
PX_Color( pPX, _T("clrInactive"), clrInactive );

SetLSOffset( lSOffset );
SetLSWidth( lSWidth );
SetLXOffset( lXOffset );
SetLYOffset( lYOffset );
SetClrActive( clrActive );
SetClrBkgnd( clrBkgnd ); 
SetClrInactive( clrInactive );

}

First I get control's properties by invoking control's Getxxx functions, after that call macros and call Setxxx functions to set new properties' values.

Using the component

1. Register component by using: regsvr32 <path\to installed\axtivex>
2. Add component to projects
3. The component icon will appear on controls toolbar
4. Using drag-and-drop operation, put the component into dialogs.
5. Set appropriate settings