PRB: SetItemRects Causes Server to Change Zoom Factor

ID: Q126563

The information in this article applies to:

The Microsoft Foundation Classes (MFC), included with:
- Microsoft Visual C++ for Windows, versions 1.50, 1.51
- Microsoft Visual C++ 32-bit Edition, versions 2.0, 2.1

SYMPTOMS

Calling COleClientItem::SetItemRects() causes the server to change its zoom-factor.

RESOLUTION

In some cases, you may find it advantageous to have a container change the area provided to an in-place active object without changing the zoom factor of the object. To do this, have the container first set the object's extents by calling COleClientItem::SetExtent and then set the in-place item's window size by calling COleClientItem::SetItemRects.

STATUS

This behavior is by design.

MORE INFORMATION

COleClientItem::SetItemRects() calls IOleInPlaceObject::SetObjectRects() and passes its parameters. The following is the description of IOleInPlaceObject::SetObjectRects() in Volume 2 of the OLE2 Programmer's Reference:

The object should compare its width and height with those provided by its container (conveyed through lprcPosRect). If the comparison does not result in a match, the container is applying either scaling or zooming to the object. The object must then decide whether it should continue the in-place editing in the scale/zoom mode or deactivate."

The object's width and height are determined by the extent information passed to it via COleClientItem::SetExtent() -- which calls IOleObject::SetExtent on the in-place object). Therefore if you want the client application to change the rectangle used by an in-place active object, have it first set the extent of the object in HIMETRIC units to the size of the new rectangle and then set the rectangle.

The following sample code demonstrates this technique. It assumes that CMyClientItem is derived from COleClientItem and that rect has coordinates specified with respect to the view which contains the object. It returns true if SetItemRects was successful.

Sample Code


BOOL CMyClientItem::MySetObjectRects(CRect &rect)
{
  ASSERT_VALID(this);
  ASSERT(m_lpObject != NULL);
  ASSERT(IsInPlaceActive());

  // get the size of this new rectangle
  CSize size = rect.Size();

  // now convert this size to HIMETRIC units
  size.cx = XformHeightInPixelsToHimetric(NULL, size.cx);
  size.cy = XformWidthInPixelsToHimetric(NULL, size.cy);

  // use this size to set the extent of the object
  SetExtent(size);

  // finally set the new size for the in-place window
  return SetItemRects(rect, rect);
}

Additional query words: 1.00 1.50 2.00 2.10 2.50 2.51 3.00 3.10 scale zoom size ole

Keywords :
Version : winnt:
Platform : winnt
Issue type :