appclasses.cpp

一个内存受限系统内存分配的源代码。

#include "appclasses.h"
#include "AEEStdLib.h"


Writer::Writer():  m_pIDisplay(0)
{
    int charHeight, pnAscent, pnDescent;
	IApplet *a = GETAPPINSTANCE();
	IShell* pIShell = ((AEEApplet*)a)->m_pIShell;
    ISHELL_CreateInstance(pIShell, AEECLSID_DISPLAY, (void **)&m_pIDisplay);

    ISHELL_GetDeviceInfo(pIShell,&m_di);

    charHeight = IDISPLAY_GetFontMetrics ((IDisplay*)m_pIDisplay, AEE_FONT_NORMAL,
      &pnAscent, &pnDescent);

    m_cMaxLine = (m_di.cyScreen / charHeight) - 3;
    m_cLineNum = 1;
    IDISPLAY_EraseRgn((IDisplay*)m_pIDisplay, 0, 0, m_di.cxScreen, m_di.cyScreen);

}

Writer::~Writer()
{
    IDISPLAY_Release(m_pIDisplay);
}


void Writer::WriteLine(const char *pszStr)
{
    char ellipsis[4];
    STRCPY(ellipsis, "...");

	if (m_cLineNum > m_cMaxLine)
		return;


	if (m_cLineNum == m_cMaxLine)
	{
		DisplayOutput(m_cLineNum++, ellipsis);
	    return;
	}

    m_cLineNum += DisplayOutput(m_cLineNum, pszStr);
    IDISPLAY_UpdateEx((IDisplay*)m_pIDisplay, TRUE);
	return;

} 


void Writer::WriteLine(int i)
{
	char ch[12];
	SPRINTF(ch, "%ld", i);
	WriteLine(ch);
	
} 

int Writer::DisplayOutput(int nline, const char *pszStr)
{
   AECHAR * szBuf;     // a buffer that supports 200 char string
   AECHAR * psz = NULL;
   int charHeight = 0;      // Stores the char height in pixels for given font
   int pnAscent = 0;        // Stores the ascent in number of pixels
   int pnDescent = 0;       // Stores the descent in number of pixels
   int pixelWidth;
   AEEFont font = AEE_FONT_NORMAL;
   int pnFits = 0, dy;
   int totalCh = 0;
   int numLinesPrinted = 0;

   if (m_pIDisplay == NULL)
	   return 0;

   if ((szBuf = (AECHAR *) MALLOC(TEXT_BUFFER_SIZE)) == NULL)
	   return 0;


   charHeight = IDISPLAY_GetFontMetrics ((IDisplay*)m_pIDisplay, AEE_FONT_NORMAL,
      &pnAscent, &pnDescent);

   STR_TO_WSTR ((char *)pszStr, szBuf, TEXT_BUFFER_SIZE);


   if (nline < 0) {
      dy = m_di.cyScreen*2/5;
   }
   else{
      dy = nline * charHeight + 5;
   }


   psz = szBuf;
      

   totalCh = STRLEN ((char *)pszStr);


   while ((totalCh > 0) && (*psz != NULL))
   { 

      pixelWidth = IDISPLAY_MeasureTextEx((IDisplay*)m_pIDisplay,
                      font, 
                      (AECHAR *) psz,  // Start of the buffer to display,
                      -1,
                      m_di.cxScreen - 5, // maxWidth
                      &pnFits);         // Number of chars that will fit a line

      // If pnFits is zero there is something wrong in the input to above function. 
      // Normally this scenario should not occur. But, have the check anyway.
      if (pnFits == 0)
	  {
		 FREE(szBuf);
         return 0;
	  }

      IDISPLAY_DrawText((IDisplay*)m_pIDisplay, AEE_FONT_NORMAL, psz, pnFits, 5 /*start dx*/, 
         dy, 0 /* use default rectangle coordinates */, 0);

      psz += pnFits;      // move pointer to the next segment to be displayed
      totalCh -= pnFits;  // reduce the total number of characters to still display
      dy += charHeight;   // Place next line charHeight pixels below the 
                          // previous line.
	  ++numLinesPrinted;

      IDISPLAY_Update((IDisplay*)m_pIDisplay); //, TRUE);
      if (totalCh < pnFits)
         pnFits = totalCh;  // if total number is less than pnFits, adjust pnFits
   }

   FREE(szBuf);

   return numLinesPrinted;   
}