disp.c

JPEG基本系统的解码器

#include <windows.h>          
////////////////////////////////////////////////////////////////
#define SCROLL_RATIO    50
//---------------------------------------------------------------------
void FitNewSize (HWND hWnd);
void SizeProc (HWND hWnd);
void ScrollProc (HWND hWnd, int message, WORD wPos, WORD wScrollType);
void DisProc(HWND hWnd,HGLOBAL hbi);
//---------------------------------------------------------------------
extern int imgheight,imgwidth;
extern BOOL HSCROLL,VSCROLL;
//---------------------------------------------------------------------
void FitNewSize (HWND hWnd)
{
	RECT DeskRect,rect;
	int  NewX,NewY,NewWidth,NewHeight;
	int  HBorder,VBorder;
	POINT pt;
	int  cxWindow,cyWindow,cxRange,cyRange;

	GetWindowRect(GetDesktopWindow(), &DeskRect);
	
	HBorder=GetSystemMetrics (SM_CXBORDER)/2;
	VBorder=GetSystemMetrics (SM_CYBORDER)/2+GetSystemMetrics (SM_CYMENU)+GetSystemMetrics (SM_CYCAPTION);
	
	if((imgwidth+HBorder)<(DeskRect.right-DeskRect.left))
		{
		NewWidth=imgwidth+HBorder;
		NewX=( (DeskRect.right-DeskRect.left) - (imgwidth+HBorder) ) /2;
		HSCROLL=FALSE;
		}
	else
		{
		NewX=(DeskRect.right-DeskRect.left)/10;
		NewWidth=NewX*8;
		HSCROLL=TRUE;
		}
		
	if((imgheight+VBorder)<(DeskRect.bottom-DeskRect.top))
		{
		NewHeight=imgheight+VBorder;
		NewY=( (DeskRect.bottom-DeskRect.top) - (imgheight+VBorder) ) /2;
		VSCROLL=FALSE;
		}
	else
		{
		NewY=(DeskRect.bottom-DeskRect.top)/10;
		NewHeight=NewY*8;
		VSCROLL=TRUE;
		}
	
	if(HSCROLL)
		{
		NewHeight+= GetSystemMetrics (SM_CYHSCROLL);
		NewY-=GetSystemMetrics (SM_CYHSCROLL)/2;
		}

	if(VSCROLL)
		{
		NewWidth+= GetSystemMetrics (SM_CXVSCROLL);
		NewX-=GetSystemMetrics (SM_CXVSCROLL)/2;
		}
	
	SendMessage(GetDesktopWindow(),WM_PAINT,0,0);
	
	GetWindowRect(hWnd,(LPRECT)&DeskRect);
	pt.x=DeskRect.left-1;
	pt.y=DeskRect.top-1;
	MoveWindow(hWnd,NewX,NewY,NewWidth,NewHeight,TRUE);
	SendMessage(WindowFromPoint(pt),WM_PAINT,0,0);

	GetClientRect(hWnd,(LPRECT)&rect);
	   	
   	cxWindow = rect.right - rect.left;
   	cyWindow = rect.bottom - rect.top;

  	cxRange =  imgwidth - cxWindow - 1;
  	cyRange =  imgheight - cyWindow - 1;
  	
	if(HSCROLL)
		{
		SetScrollRange (hWnd, SB_HORZ, 0, cxRange, FALSE);
		SetScrollPos(hWnd,SB_HORZ,0,TRUE);
		}
	else
		SetScrollRange (hWnd, SB_HORZ, 0, 0, FALSE);

	if(VSCROLL)
		{
		SetScrollRange (hWnd, SB_VERT, 0, cyRange, FALSE);
		SetScrollPos(hWnd,SB_VERT,0,TRUE);
		}
	else
		SetScrollRange (hWnd, SB_VERT, 0, 0, FALSE);
}
////////////////////////////////////////////////////////////////////////
/*
void SizeProc(HWND hWnd)
{
	RECT ClientRect;
	BOOL scrolled=FALSE;
	
	GetClientRect (hWnd, (LPRECT)&ClientRect);
	
	if(imgwidth<=(ClientRect.right-ClientRect.left))
		SetScrollRange (hWnd, SB_HORZ, 0, 0, TRUE);		
	else
		{
		SetScrollRange (hWnd, SB_HORZ, 0, 100, TRUE);
		scrolled=TRUE;
		}
		
	if(imgheight<=(ClientRect.bottom-ClientRect.top))
		SetScrollRange (hWnd, SB_VERT, 0, 0, TRUE);			
	else
		{
		SetScrollRange (hWnd, SB_VERT, 0, 100, TRUE);
		scrolled=TRUE;
		}
	if(scrolled)
		{
		InvalidateRect(hWnd,NULL,FALSE);
		UpdateWindow(hWnd);
		}
}
*/
///////////////////////////////////////////////////////////////////////////
void ScrollProc (HWND hWnd, int message, WORD wPos, WORD wScrollType)
{
	int  xBar;
   	int  nMin;
   	int  nMax;
   	int  dx;
   	int  nOneUnit;
   	int  cxClient;
   	int  nHorzOrVert;
   	RECT rect;
    
   	GetClientRect (hWnd, &rect);

   	if (message == WM_HSCROLL)
    	{
      	nHorzOrVert = SB_HORZ;
      	cxClient    = rect.right - rect.left;
      	}
   	else
    	{
      	nHorzOrVert = SB_VERT;
      	cxClient    = rect.bottom - rect.top;
      	}

   	nOneUnit = cxClient / SCROLL_RATIO;
   	if (!nOneUnit)
    	nOneUnit = 1;

   	xBar = GetScrollPos (hWnd, nHorzOrVert);
   	GetScrollRange (hWnd, nHorzOrVert, &nMin, &nMax);   	

   	switch (wScrollType)
    	{
      	case SB_LINEDOWN:             // One line right.
        	dx = nOneUnit;
         	break;

      	case SB_LINEUP:               // One line left.
         	dx = -nOneUnit;
         	break;

      	case SB_PAGEDOWN:             // One page right.
        	dx = cxClient/4;
         	break;

      	case SB_PAGEUP:               // One page left.
        	dx = -cxClient/4;
         	break;

      	case SB_THUMBPOSITION:        // Absolute position.     
         	dx = wPos - xBar;
         	break;

      	default:                      // No change.
        	dx = 0;
         	break;
      	}

	if (dx)
    	{
      	xBar += dx;

      	if (xBar < nMin)
        	{
         	dx  -= xBar-nMin;
         	xBar = nMin;
         	}

      	if (xBar > nMax)
        	{
         	dx  -= xBar - nMax;
         	xBar = nMax;
         	}

      	if (dx)
        	{
         	SetScrollPos (hWnd, nHorzOrVert, xBar, TRUE);

         	if (nHorzOrVert == SB_HORZ)
            	ScrollWindow (hWnd, -dx, 0, NULL, NULL);
         	else
            	ScrollWindow (hWnd, 0, -dx , NULL, NULL);
            
         	UpdateWindow (hWnd);
         	}
      	}
}
//---------------------------------------------------------------------
void DisProc(HWND hWnd,HGLOBAL hbi)
{
	HDC         hDC;
   	PAINTSTRUCT ps;
   	int         xScroll, yScroll;
   	int         dx,dy;
   	RECT        rectClient, rc;
    LPSTR       lpDIBHdr, lpDIBBits;   	

   	if (!hbi)
    	return;

  	hDC      = BeginPaint (hWnd, &ps);
   
   	xScroll  = GetScrollPos  (hWnd, SB_HORZ);
   	yScroll  = GetScrollPos  (hWnd, SB_VERT);

   	GetClientRect (hWnd, &rectClient);

   	rc.left   = xScroll;
   	rc.top    = yScroll;
   	rc.right  = xScroll + rectClient.right - rectClient.left;
   	rc.bottom = yScroll + rectClient.bottom - rectClient.top;
   	
    if (rc.right > imgwidth)
      	{
	    dx = imgwidth - rc.right;
       	rc.right += dx;
       	rectClient.right+=dx;
       	}

   	if (rc.bottom > imgheight)
      	{
       	dy = imgheight - rc.bottom;
      	rc.bottom += dy;
       	rectClient.bottom+=dy;
      	}

	lpDIBHdr  = GlobalLock (hbi);
    lpDIBBits = lpDIBHdr+sizeof(BITMAPINFOHEADER);
	
	SetStretchBltMode (hDC, COLORONCOLOR);
 
    SetDIBitsToDevice (hDC,
    				   rectClient.left,
    				   rectClient.top,
    				   rectClient.right-rectClient.left,
    				   rectClient.bottom-rectClient.top,
    				   rc.left,
    				   imgheight-rc.bottom,
    				   0,
    				   imgheight,
                       (char far *)lpDIBBits,
                       (LPBITMAPINFO) lpDIBHdr,
                       DIB_RGB_COLORS);
	GlobalUnlock (hbi);
   	EndPaint (hWnd, &ps);
/*
	HDC         hDC;
   	PAINTSTRUCT ps;
   	int         xScroll, yScroll;
   	RECT        rectClient, rc;
    LPSTR       lpDIBHdr, lpDIBBits;
    int         rectw,recth;

   	if (!hbi)
    	return;
    	
	xScroll=yScroll=0;
	GetClientRect (hWnd, &rectClient);
	rectw=rectClient.right-rectClient.left;
	recth=rectClient.bottom-rectClient.top;

  	hDC      = BeginPaint (hWnd, &ps);
   
   	if(HSCROLL)
   		{
   		xScroll  = GetScrollPos  (hWnd, SB_HORZ);
   		}
   		
   	if(VSCROLL)
   		{
   		yScroll  = GetScrollPos  (hWnd, SB_VERT);
   		}

   	rc.right  =  rc.left+rectw;
   	rc.bottom =  rc.top+recth;

	lpDIBHdr  = GlobalLock (hbi);
    lpDIBBits = lpDIBHdr+sizeof(BITMAPINFOHEADER);
	
	SetStretchBltMode (hDC, COLORONCOLOR);
 
    SetDIBitsToDevice (hDC,
    				   rectClient.left,
    				   rectClient.top,
    				   rectClient.right-rectClient.left,
    				   rectClient.bottom-rectClient.top,
    				   rc.left,
    				   imgheight-rc.bottom,
    				   0,
    				   imgheight,
                       (char far *)lpDIBBits,
                       (LPBITMAPINFO) lpDIBHdr,
                       DIB_RGB_COLORS);
	GlobalUnlock (hbi);
   	EndPaint (hWnd, &ps);
*/   	
}