\func{void}{SetClippingRegion}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
+\func{void}{SetClippingRegion}{\param{const wxPoint\& }{pt}, \param{const wxSize\& }{sz}}
+
+\func{void}{SetClippingRegion}{\param{const wxRect\&}{ rect}}
+
\func{void}{SetClippingRegion}{\param{const wxRegion\&}{ region}}
-Sets the clipping region for the DC. The clipping region is an area
-to which drawing is restricted. Possible uses for the clipping region are for clipping text
-or for speeding up window redraws when only a known area of the screen is damaged.
+Sets the clipping region for this device context to the intersection of the
+given region described by the parameters of this method and the previously set
+clipping region. You should call
+\helpref{DestroyClippingRegion}{wxdcdestroyclippingregion} if you want to set
+the clipping region exactly to the region specified.
+
+The clipping region is an area to which drawing is restricted. Possible uses
+for the clipping region are for clipping text or for speeding up window redraws
+when only a known area of the screen is damaged.
\wxheading{See also}
#endif
RECT rect;
- GetClipBox(GetHdc(), &rect);
+ ::GetClipBox(GetHdc(), &rect);
m_clipX1 = (wxCoord) XDEV2LOG(rect.left);
m_clipY1 = (wxCoord) YDEV2LOG(rect.top);
m_clipY2 = (wxCoord) YDEV2LOG(rect.bottom);
}
-void wxDC::DoSetClippingRegion(wxCoord x, wxCoord y, wxCoord w, wxCoord h)
+// common part of DoSetClippingRegion() and DoSetClippingRegionAsRegion()
+void wxDC::SetClippingHrgn(WXHRGN hrgn)
{
+ wxCHECK_RET( hrgn, wxT("invalid clipping region") );
+
#ifdef __WXMICROWIN__
- if (!GetHDC()) return;
-#endif
+ if (!GetHdc()) return;
+#endif // __WXMICROWIN__
+
+ // note that we combine the new clipping region with the existing one: this
+ // is compatible with what the other ports do and is the documented
+ // behaviour now (starting with 2.3.3)
+#ifdef __WIN16__
+ RECT rectClip;
+ if ( !::GetClipBox(GetHdc(), &rectClip) )
+ return;
+
+ HRGN hrgnDest = ::CreateRectRgn(0, 0, 0, 0);
+ HRGN hrgnClipOld = ::CreateRectRgn(rectClip.left, rectClip.top,
+ rectClip.right, rectClip.bottom);
+
+ if ( ::CombineRgn(hrgnDest, hrgnClipOld, (HRGN)hrgn, RGN_AND) != ERROR )
+ {
+ ::SelectClipRgn(GetHdc(), hrgnDest);
+ }
+
+ ::DeleteObject(hrgnClipOld);
+ ::DeleteObject(hrgnDest);
+#else // Win32
+ if ( ::ExtSelectClipRgn(GetHdc(), (HRGN)hrgn, RGN_AND) == ERROR )
+ {
+ wxLogLastError(_T("ExtSelectClipRgn"));
+
+ return;
+ }
+#endif // Win16/32
m_clipping = TRUE;
+ UpdateClipBox();
+}
+
+void wxDC::DoSetClippingRegion(wxCoord x, wxCoord y, wxCoord w, wxCoord h)
+{
// the region coords are always the device ones, so do the translation
// manually
//
}
else
{
- if ( ::SelectClipRgn(GetHdc(), hrgn) == ERROR )
- {
- wxLogLastError(_T("SelectClipRgn"));
- }
- DeleteObject(hrgn);
+ SetClippingHrgn((WXHRGN)hrgn);
- UpdateClipBox();
+ ::DeleteObject(hrgn);
}
}
void wxDC::DoSetClippingRegionAsRegion(const wxRegion& region)
{
-#ifdef __WXMICROWIN__
- if (!GetHDC()) return;
-#endif
-
- wxCHECK_RET( GetHrgnOf(region), wxT("invalid clipping region") );
-
- m_clipping = TRUE;
-
-#ifdef __WIN16__
- SelectClipRgn(GetHdc(), GetHrgnOf(region));
-#else // Win32
- ExtSelectClipRgn(GetHdc(), GetHrgnOf(region), RGN_AND);
-#endif // Win16/32
-
- UpdateClipBox();
+ SetClippingHrgn(region.GetHRGN());
}
void wxDC::DestroyClippingRegion()
if (m_clipping && m_hDC)
{
// TODO: this should restore the previous clipping region,
- // so that OnPaint processing works correctly, and the update clipping region
- // doesn't get destroyed after the first DestroyClippingRegion.
+ // so that OnPaint processing works correctly, and the update
+ // clipping region doesn't get destroyed after the first
+ // DestroyClippingRegion.
HRGN rgn = CreateRectRgn(0, 0, 32000, 32000);
- SelectClipRgn(GetHdc(), rgn);
- DeleteObject(rgn);
+ ::SelectClipRgn(GetHdc(), rgn);
+ ::DeleteObject(rgn);
}
m_clipping = FALSE;