INTERFACE OBJECTS

GRAPHICS DEVICE INTERFACE OBJECTS

1. Run AppWizard to generate the third project.

2. Use ClassWizard to override the OnPrepareDC function in the thirdView class.

void thirdView :: OnPrepareDC (CDC* pDC, CPrintInfo* pInfo)

{

pDC -> SetMapMode (MM_ANISOTROPHIC);

pDC -> SetWindowExt (1440, 1440);

pDC -> SetViewPortExt (

pDC -> GetDeviceCaps (LOGPIXELSX),

pDC -> GetDeviceCaps (LOGPIXELSY));

}

3. Add a private ShowFont helper function to the view class. (thirdView.h)

private:

void ShowFont (CDC* pDC, int& nPos, int nPoints);

then add the function in thirdView.cpp

void thirdView :: ShowFont (CDC* pDC, int& nPos, int nPoints)

{

TEXTMETRIC tm;

CFont fontText;

CString strText;

CSize sizeText;

fontText.CreateFont (nPoints * 20, 0,0,0,400,FALSE,FALSE,0,

ANSI_CHARSET, OUT_DEFAULT_PRECIS,

CLIP_DEFAULT_PRECIS, DEFAULT_QUALITY, DEFAULT_PITCH | FF_SWISS, “Arial”);

CFont* pOldFont = (CFont* ) pDC -> SelectObject (&fontText);

pDC -> GetTextMetrics (&tm);

TRACE (“points = %d, tmHeight = %d, tmExternalLeading = %d”,”tmExternalLeading = %d\n”, nPoints, tm.tmHeight, tm.tmInternalLeading, tm.tmExternalLeading);

strText.Format(“This is %d – point Arial”,nPoints);

sizeText = pDC -> GetTextExtent (strText);

TRACE(“string width = %d, string height = %d\n”, sizeText.cx, sizeText.cy);

pDC -> TextOut (0,nPos, strText);

pDC -> SelectObject (pOldFont);

nPos -= tm.tmHeight + tm.tmExternalLeading;

}

4. Edit the OnDraw function in thirdView.cpp

void thirdView :: OnDraw (CDC* pDC)

{

int nPosition = 0;

for ( int i = 6; i <= 24; i +=2)

{

ShowFont (pDC, nPosition, i);

}

TRACE (“LOGPIXEL = %d, LOGPIXEL = %d\n”,

pDC -> GetDeviceCaps (LOGPIXELSX),

pDC -> GetDeviceCaps (LOGPIXELSY));

TRACE (“HORZSIZE = %d, VERTSIZE = %d\n”,

pDC -> GetDeviceCaps (HORZSIZE),

pDC -> GetDeviceCaps (VERTSIZE));

TRACE (“HORZRES = %d, VERTRES = %d\n’,

pDC -> GetDeviceCaps ( HORZRES),

pDC -> GetDeviceCaps (VERTRES));

}

5. Build and run the program.