Article ID: 138266
Article Last Modified on 11/21/2006
APPLIES TO
- Microsoft Foundation Class Library 4.2, when used with:
- Microsoft Visual C++ 1.5 Professional Edition
- Microsoft Visual C++ 1.51
- Microsoft Visual C++ 1.52 Professional Edition
- Microsoft Visual C++ 2.0 Professional Edition
- Microsoft Visual C++ 2.1
- Microsoft Visual C++ 2.2
- Microsoft Visual C++ 4.0 Standard Edition
- Microsoft Visual C++ 4.1 Subscription
- Microsoft Visual C++ 4.2 Enterprise Edition
- Microsoft Visual C++ 4.2 Professional Edition
- Microsoft Visual C++ 5.0 Enterprise Edition
- Microsoft Visual C++ 5.0 Professional Edition
- Microsoft Visual C++ 6.0 Enterprise Edition
- Microsoft Visual C++ 6.0 Professional Edition
- Microsoft Visual C++ 6.0 Standard Edition
This article was previously published under Q138266
SUMMARY
This article shows by example how to implement scaling properly.
Printing an embedded object from an AppWizard-generated OLE container application may cause the printout of the embedded object to appear too small.
The developer of an OLE container must implement the code to scale an embedded object properly from the screen device to the printer device. If only the screen device is considered, the embedded object will appear too small on a printout.
MORE INFORMATION
Sample code
/* Compile options needed: none
*/
In the MFC Container sample, step 2 implements a container that does not consider the difference in resolution between the screen device and the printer device. If, for instance, Scribble, step 7 is embedded in Container and PRINT or PRINT PREVIEW is selected, the embedded object will appear too small.
Using Container as an example of MFC container that doesn't support scaling, the following code can be added to CContainView::OnDraw() to implement proper scaling:
void CContainerView::OnDraw(CDC* pDC)
{
CContainerDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
// draw the OLE items from the list
POSITION pos = pDoc->GetStartPosition();
while (pos != NULL)
{
// draw the item
CContainerItem* pItem = (CContainerItem*)pDoc->GetNextItem(pos);
// copy the client items rect, which will be scaled
CRect rect2(pItem->m_rect);
if(pDC->IsPrinting())
{
// get the printer's pixel resolution
int ixp=pDC->GetDeviceCaps(LOGPIXELSX);
int iyp=pDC->GetDeviceCaps(LOGPIXELSY);
// get the current window's resolution
CDC* pddc = GetDC();
int ixd=pddc->GetDeviceCaps(LOGPIXELSX);
int iyd=pddc->GetDeviceCaps(LOGPIXELSY);
// scale rect2 up by the ratio of the resolutions
int width = MulDiv(rect2.Width(),ixp, ixd);
int height = MulDiv(rect2.Height(), iyp, iyd);
rect2.left = MulDiv(rect2.left, ixp, ixd);
rect2.top = MulDiv(rect2.top, ixp, ixd);
rect2.right = rect2.left + width;
rect2.bottom = rect2.top + height;
}
pItem->Draw(pDC, rect2);
if(!pDC->IsPrinting())
{
// draw the tracker over the item
CRectTracker tracker;
SetupTracker(pItem, &tracker);
tracker.Draw(pDC);
}
}
}
Keywords: kbcontainer kbgdi kbhowto kbprint KB138266
