L_ContainerSetOffset

#include "LtCon.h"

L_LTCON_API L_INT L_ContainerSetOffset(pContainer, nXOffset, nYOffset, nZOffset)

pCONTAINERHANDLE pContainer;	pointer to a container handle
L_INT nXOffset;	x-coordinates offset
L_INT nYOffset;	y-coordinates offset
L_INT nZOffset;	z-coordinates offset

Sets the container coordinates offset values.

Parameter	Description
pContainer	Pointer to a container handle.
nXOffset	The X offset of the external representation.
nYOffset	The Y offset of the external representation.
nZOffset	The Z offset of the external representation.

Returns

SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

The user should set the offset every time the window that owns the container is scrolled. When assigning an external representation to the container, every point (Xa, Ya) in the external representation is transformed by the container to the point (Xc, Yc) by using the following steps:

1. Add offsets:

   Xb = Xa + nXOffset

2. Multiply by scalars:

   Xc = (Xb * nXScalarNum) / nXScalarDen 
   Yc = (Yb * nYScalarNum) / nYScalarDen

The default offset values are nXOffset=0, nYOffset=0, and nZOffset=0.

Required DLLs and Libraries

LTCON

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application

Example

/* This will show to modify the container coordinates offset values to reflect the changes in the window offset */ 
L_INT ContainerSetOffsetExample(HWND             hWnd, 
pCONTAINERHANDLE pContainer, 
pBITMAPHANDLE    pBitmap, 
LPRECT           prcView, 
L_INT            cx, 
L_INT            cy, 
L_INT            nZoom, 
L_INT*           pnHScroll, 
L_INT*           pnVScroll) 
{ 
   L_INT nRet; 
   SCROLLINFO si ; 
   L_INT      nXOffset, nYOffset ; 
   if ( NULL != pBitmap && pBitmap->Flags.Allocated ) 
   { 
      si.cbSize = sizeof ( SCROLLINFO ) ; 
      si.fMask  = SIF_ALL ; 
      // vertical scroll. 
      GetScrollInfo ( hWnd, SB_VERT, &si ) ; 
      si.nMin  = 0 ; 
      si.nMax  = BITMAPHEIGHT ( pBitmap ) ; 
      si.nPage = MulDiv ( cy, 100, nZoom ) ; 
      SetScrollInfo ( hWnd, SB_VERT, &si, TRUE ) ; 
      GetScrollInfo ( hWnd, SB_VERT, &si ) ; 
      *pnVScroll = si.nPos ; 
      // horizontal scroll 
      GetScrollInfo ( hWnd, SB_HORZ, &si ) ; 
      si.nMin  = 0 ; 
      si.nMax  = BITMAPWIDTH ( pBitmap ) ; 
      si.nPage = MulDiv ( cx, 100, nZoom ) ; 
      SetScrollInfo ( hWnd, SB_HORZ, &si, TRUE ) ; 
      GetScrollInfo ( hWnd, SB_HORZ, &si ) ; 
      *pnHScroll = si.nPos ; 
   } 
   else 
   { 
      si.cbSize = sizeof ( SCROLLINFO ) ; 
      si.fMask  = SIF_RANGE ; 
      si.nMin   = 0 ; 
      si.nMax   = 0 ; 
      SetScrollInfo ( hWnd, SB_VERT, &si, TRUE ) ; 
      SetScrollInfo ( hWnd, SB_HORZ, &si, TRUE ) ; 
      *pnHScroll = 0 ; 
      *pnVScroll = 0 ; 
   } 
   // set the painting rectangel. 
   SetRect ( prcView, 0, 0, BITMAPWIDTH ( pBitmap ), BITMAPHEIGHT ( pBitmap ) ) ; 
   if ( nZoom < 100 ) 
   { 
      nXOffset = MulDiv ( *pnHScroll, 100, nZoom ) ; 
      nYOffset = MulDiv ( *pnVScroll, 100, nZoom ) ; 
   } 
   else 
   { 
      nXOffset = *pnHScroll ; 
      nYOffset = *pnVScroll ; 
   } 
   OffsetRect ( prcView, - nXOffset, - nYOffset ) ; 
   prcView->left   = MulDiv ( prcView->left,   nZoom, 100 ) ; 
   prcView->top    = MulDiv ( prcView->top,    nZoom, 100 ) ; 
   prcView->right  = MulDiv ( prcView->right,  nZoom, 100 ) ; 
   prcView->bottom = MulDiv ( prcView->bottom, nZoom, 100 ) ; 
   nRet = L_ContainerSetOffset ( pContainer, - prcView->left, - prcView->top, 0 ) ; 
   return nRet; 
}

Help Version 19.0.2017.10.27

LEADTOOLS Container and Automation C API Help

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Function References

Functions:	L_ContainerSetScalar, L_ContainerGetOffset
Topics:	Container Offsets