disallow creation of wxDC objects and made wxDC an ABC; use wxDCTemp instead of wxDC in wx code; fixed WinCE bug with deleting a DC which should be released in wxListBox::MSWOnMeasure()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@36564 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/dc.h

@@ -9,8 +9,8 @@
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-#ifndef _WX_DC_H_
+#ifndef _WX_MSW_DC_H_
-#define _WX_DC_H_
+#define _WX_MSW_DC_H_
 
 #include "wx/defs.h"
 
@@ -40,10 +40,12 @@ public:
 };
 #endif
 
+// this is an ABC: use one of the derived classes to create a DC associated
+// with a window, screen, printer and so on
 class WXDLLEXPORT wxDC : public wxDCBase
 {
 public:
-    wxDC();
+    wxDC(WXHDC hDC) { Init(); m_hDC = hDC; }
     ~wxDC();
 
     // implement base class pure virtuals
@@ -138,6 +140,26 @@ public:
 #endif
 
 protected:
+    void Init()
+    {
+        m_canvas = NULL;
+        m_bOwnsDC = false;
+        m_hDC = NULL;
+
+        m_oldBitmap = NULL;
+        m_oldPen = NULL;
+        m_oldBrush = NULL;
+        m_oldFont = NULL;
+
+#if wxUSE_PALETTE
+        m_oldPalette = NULL;
+#endif // wxUSE_PALETTE
+    }
+
+    // create an uninitialized DC: this should be only used by the derived
+    // classes
+    wxDC() { Init(); }
+
     virtual bool DoFloodFill(wxCoord x, wxCoord y, const wxColour& col,
                              int style = wxFLOOD_SURFACE);
 
@@ -186,7 +208,6 @@ protected:
     virtual void DoGetClippingBox(wxCoord *x, wxCoord *y,
                                   wxCoord *w, wxCoord *h) const;
 
-    virtual void DoGetSize(int *width, int *height) const;
     virtual void DoGetSizeMM(int* width, int* height) const;
 
     virtual void DoDrawLines(int n, wxPoint points[],
@@ -216,6 +237,17 @@ protected:
     // common part of DoSetClippingRegion() and DoSetClippingRegionAsRegion()
     void SetClippingHrgn(WXHRGN hrgn);
 
+    // implementation of DoGetSize() for wxScreen/PrinterDC: this simply
+    // returns the size of the entire device this DC is associated with
+    //
+    // notice that we intentionally put it in a separate function instead of
+    // DoGetSize() itself because we want it to remain pure virtual both
+    // because each derived class should take care to define it as needed (this
+    // implementation is not at all always appropriate) and because we want
+    // wxDC to be an ABC to prevent it from being created directly
+    void GetDeviceSize(int *width, int *height) const;
+
+
     // MSW-specific member variables
     // -----------------------------
 
@@ -259,12 +291,29 @@ protected:
 class WXDLLEXPORT wxDCTemp : public wxDC
 {
 public:
-    wxDCTemp(WXHDC hdc) { SetHDC(hdc); }
+    wxDCTemp(WXHDC hdc) : wxDC(hdc)
-    virtual ~wxDCTemp() { SetHDC((WXHDC)NULL); }
+    {
+    }
+
+    virtual ~wxDCTemp()
+    {
+        // prevent base class dtor from freeing it
+        SetHDC((WXHDC)NULL);
+    }
+
+    virtual void DoGetSize(int *w, int *h) const
+    {
+        wxFAIL_MSG( _T("no way to retrieve the size of generic DC") );
+
+        if ( w )
+            *w = 0;
+        if ( h )
+            *h = 0;
+    }
 
 private:
     DECLARE_NO_COPY_CLASS(wxDCTemp)
 };
 
-#endif
+#endif // _WX_MSW_DC_H_
-    // _WX_DC_H_
+

include/wx/msw/dcprint.h

@@ -9,8 +9,8 @@
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-#ifndef _WX_DCPRINT_H_
+#ifndef _WX_MSW_DCPRINT_H_
-#define _WX_DCPRINT_H_
+#define _WX_MSW_DCPRINT_H_
 
 #if wxUSE_PRINTING_ARCHITECTURE
 
@@ -41,6 +41,11 @@ protected:
                         wxCoord width, wxCoord height,
                         wxDC *source, wxCoord xsrc, wxCoord ysrc,
                         int rop = wxCOPY, bool useMask = false, wxCoord xsrcMask = wxDefaultCoord, wxCoord ysrcMask = wxDefaultCoord);
+    virtual void DoGetSize(int *w, int *h) const
+    {
+        GetDeviceSize(w, h);
+    }
+
 
     // init the dc
     void Init();
@@ -59,6 +64,5 @@ WXHDC WXDLLEXPORT wxGetPrinterDC(const wxPrintData& data);
 
 #endif // wxUSE_PRINTING_ARCHITECTURE
 
-#endif
+#endif // _WX_MSW_DCPRINT_H_
-    // _WX_DCPRINT_H_
 

include/wx/msw/dcscreen.h

@@ -9,29 +9,33 @@
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-#ifndef _WX_DCSCREEN_H_
+#ifndef _WX_MSW_DCSCREEN_H_
-#define _WX_DCSCREEN_H_
+#define _WX_MSW_DCSCREEN_H_
 
-#include "wx/dcclient.h"
+#include "wx/dc.h"
 
-class WXDLLEXPORT wxScreenDC : public wxWindowDC
+class WXDLLEXPORT wxScreenDC : public wxDC
 {
 public:
     // Create a DC representing the whole screen
     wxScreenDC();
 
+    // these functions are obsolete and shouldn't be used
+
     // Compatibility with X's requirements for drawing on top of all windows
-    static bool StartDrawingOnTop(wxWindow* WXUNUSED(window)) { return true; }
+    wxDEPRECATED( static bool StartDrawingOnTop(wxWindow* window) );
-    static bool StartDrawingOnTop(wxRect* WXUNUSED(rect) = NULL) { return true; }
+    wxDEPRECATED( static bool StartDrawingOnTop(wxRect* rect = NULL) );
-    static bool EndDrawingOnTop() { return true; }
+    wxDEPRECATED( static bool EndDrawingOnTop() );
 
 protected:
-    virtual void DoGetSize(int *width, int *height) const;
+    virtual void DoGetSize(int *w, int *h) const
+    {
+        GetDeviceSize(w, h);
+    }
 
 private:
     DECLARE_DYNAMIC_CLASS_NO_COPY(wxScreenDC)
 };
 
-#endif
+#endif // _WX_MSW_DCSCREEN_H_
-    // _WX_DCSCREEN_H_
 

src/msw/bmpbuttn.cpp

@@ -304,8 +304,7 @@ bool wxBitmapButton::MSWOnDraw(WXDRAWITEMSTRUCT *item)
     }
 
     // draw the bitmap
-    wxDC dst;
+    wxDCTemp dst((WXHDC)hDC);
-    dst.SetHDC((WXHDC) hDC, false);
     dst.DrawBitmap(*bitmap, x1, y1, true);
 
     // draw focus / disabled state, if auto-drawing

src/msw/dc.cpp

@@ -258,23 +258,6 @@ wxColourChanger::~wxColourChanger()
 // wxDC
 // ---------------------------------------------------------------------------
 
-// Default constructor
-wxDC::wxDC()
-{
-    m_canvas = NULL;
-
-    m_oldBitmap = 0;
-    m_oldPen = 0;
-    m_oldBrush = 0;
-    m_oldFont = 0;
-#if wxUSE_PALETTE
-    m_oldPalette = 0;
-#endif // wxUSE_PALETTE
-
-    m_bOwnsDC = false;
-    m_hDC = 0;
-}
-
 wxDC::~wxDC()
 {
     if ( m_hDC != 0 )
@@ -2285,12 +2268,14 @@ bool wxDC::DoBlit(wxCoord xdest, wxCoord ydest,
     return success;
 }
 
-void wxDC::DoGetSize(int *w, int *h) const
+void wxDC::GetDeviceSize(int *width, int *height) const
 {
     WXMICROWIN_CHECK_HDC
 
-    if ( w ) *w = ::GetDeviceCaps(GetHdc(), HORZRES);
+    if ( width )
-    if ( h ) *h = ::GetDeviceCaps(GetHdc(), VERTRES);
+        *width = ::GetDeviceCaps(GetHdc(), HORZRES);
+    if ( height )
+        *height = ::GetDeviceCaps(GetHdc(), VERTRES);
 }
 
 void wxDC::DoGetSizeMM(int *w, int *h) const

src/msw/dcscreen.cpp

@@ -25,7 +25,7 @@
 
 #include "wx/dcscreen.h"
 
-IMPLEMENT_DYNAMIC_CLASS(wxScreenDC, wxWindowDC)
+IMPLEMENT_DYNAMIC_CLASS(wxScreenDC, wxDC)
 
 // Create a DC representing the whole screen
 wxScreenDC::wxScreenDC()
@@ -37,10 +37,18 @@ wxScreenDC::wxScreenDC()
     ::SetBkMode( GetHdc(), TRANSPARENT );
 }
 
-void wxScreenDC::DoGetSize(int *width, int *height) const
+// deprecated functions
+bool wxScreenDC::StartDrawingOnTop(wxWindow* WXUNUSED(window))
 {
-    // skip wxWindowDC version because it doesn't work without a valid m_canvas
+    return true;
-    // (which we don't have)
-    wxDC::DoGetSize(width, height);
 }
 
+bool wxScreenDC::StartDrawingOnTop(wxRect* WXUNUSED(rect))
+{
+    return true;
+}
+
+bool wxScreenDC::EndDrawingOnTop()
+{
+    return true;
+}

src/msw/listbox.cpp

@@ -776,16 +776,19 @@ bool wxListBox::MSWOnMeasure(WXMEASUREITEMSTRUCT *item)
     HDC hdc = CreateIC(wxT("DISPLAY"), NULL, NULL, 0);
 #endif
 
-    wxDC dc;
+    {
-    dc.SetHDC((WXHDC)hdc);
+        wxDCTemp dc((WXHDC)hdc);
-    dc.SetFont(GetFont());
+        dc.SetFont(GetFont());
 
-    pStruct->itemHeight = dc.GetCharHeight() + 2*OWNER_DRAWN_LISTBOX_EXTRA_SPACE;
+        pStruct->itemHeight = dc.GetCharHeight() + 2*OWNER_DRAWN_LISTBOX_EXTRA_SPACE;
-    pStruct->itemWidth  = dc.GetCharWidth();
+        pStruct->itemWidth  = dc.GetCharWidth();
-
+    }
-    dc.SetHDC(0);
 
+#ifdef __WXWINCE__
+    ReleaseDC(NULL, hdc);
+#else
     DeleteDC(hdc);
+#endif
 
     return true;
 }