Made DC cacheing less obstrusive

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@10974 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/latex/wx/dc.tex

@@ -104,8 +104,8 @@ and the background colour set to WHITE.
 This sequence of operations ensures that the source's transparent area need not be black,
 and logical functions are supported.
 
-{\bf Note:} on Windows, blitting with masks can be speeded up considerably by using 
-\helpref{DC cacheing}{wxdcenablecache}. You can also influence whether MaskBlt
+{\bf Note:} on Windows, blitting with masks can be speeded up considerably by compiling
+wxWindows with the wxUSE\_DC\_CACHE option enabled. You can also influence whether MaskBlt
 or the explicit mask blitting code above is used, by using \helpref{wxSystemOptions}{wxsystemoptions} and
 setting the {\bf no-maskblt} option to 1.
 
@@ -128,6 +128,7 @@ See \helpref{wxMemoryDC}{wxmemorydc} for typical usage.
 
 \helpref{wxMemoryDC}{wxmemorydc}, \helpref{wxBitmap}{wxbitmap}, \helpref{wxMask}{wxmask}
 
+\begin{comment}
 \membersection{wxDC::CacheEnabled}\label{wxdccacheenabled}
 
 \func{static bool}{CacheEnabled}{\void}
@@ -143,6 +144,7 @@ wxUSE\_DC\_CACHEING preprocessor symbol for portability.
 \wxheading{See also}
 
 \helpref{wxDC::EnableCache}{wxdcenablecache}, \helpref{wxDC::ClearCache}
+\end{comment}
 
 \membersection{wxDC::CalcBoundingBox}\label{wxdccalcboundingbox}
 
@@ -162,6 +164,7 @@ Adds the specified point to the bounding box which can be retrieved with
 
 Clears the device context using the current background brush.
 
+\begin{comment}
 \membersection{wxDC::ClearCache}\label{wxdcclearcache}
 
 \func{static void}{ClearCache}{\void}
@@ -179,6 +182,7 @@ wxUSE\_DC\_CACHEING preprocessor symbol for portability.
 \wxheading{See also}
 
 \helpref{wxDC::EnableCache}{wxdcenablecache}, \helpref{wxDC::CacheEnabled}
+\end{comment}
 
 \membersection{wxDC::CrossHair}\label{wxdccrosshair}
 
@@ -417,6 +421,7 @@ text more precisely.
 but it is ignored by wxMSW. Thus, you should avoid using logical functions
 with this function in portable programs.
 
+\begin{comment}
 \membersection{wxDC::EnableCache}\label{wxdcenablecache}
 
 \func{static void}{EnableCache}{\param{bool}{ enableCache}}
@@ -431,6 +436,7 @@ wxUSE\_DC\_CACHEING preprocessor symbol for portability.
 \wxheading{See also}
 
 \helpref{wxDC::CacheEnabled}{wxdccacheenabled}, \helpref{wxDC::ClearCache}
+\end{comment}
 
 \membersection{wxDC::EndDoc}\label{wxdcenddoc}
 

samples/dragimag/dragimag.cpp

@@ -101,9 +101,6 @@ void MyCanvas::OnEraseBackground(wxEraseEvent& event)
             wxClientDC dc(this);
             wxGetApp().TileBitmap(rect, dc, wxGetApp().GetBackgroundBitmap());
         }
-#if wxUSE_DC_CACHEING
-        wxDC::ClearCache();
-#endif
     }
     else
         event.Skip(); // The official way of doing it
@@ -281,9 +278,6 @@ void MyCanvas::DrawShapes(wxDC& dc)
           shape->Draw(dc);
         node = node->Next();
     }
-#if wxUSE_DC_CACHEING
-    wxDC::ClearCache();
-#endif
 }
 
 void MyCanvas::EraseShape(DragShape* shape, wxDC& dc)
@@ -385,12 +379,6 @@ bool MyApp::OnInit()
     wxImage::AddHandler( new wxPNGHandler );
 #endif
 
-    // The DC cache is an efficiency measure to be used
-    // when a lot of masked blitting is done
-#if wxUSE_DC_CACHEING
-    wxDC::EnableCache(TRUE);
-#endif
-
     wxImage image;
     if (image.LoadFile("backgrnd.png", wxBITMAP_TYPE_PNG))
     {
@@ -445,9 +433,6 @@ bool MyApp::OnInit()
 
 int MyApp::OnExit()
 {
-#if wxUSE_DC_CACHEING
-    wxDC::ClearCache();
-#endif
     return 0;
 }
 

src/msw/app.cpp

@@ -1112,6 +1112,14 @@ void wxApp::OnIdle(wxIdleEvent& event)
     wxLog::FlushActive();
 #endif // wxUSE_LOG
 
+#if wxUSE_DC_CACHEING
+    // automated DC cache management: clear the cached DCs and bitmap
+    // if it's likely that the app has finished with them, that is, we
+    // get an idle event and we're not dragging anything.
+    if (!::GetKeyState(MK_LBUTTON) && !::GetKeyState(MK_MBUTTON) && ::GetKeyState(MK_RBUTTON))
+        wxDC::ClearCache();
+#endif // wxUSE_DC_CACHEING
+
     // Send OnIdle events to all windows
     if ( SendIdleEvents() )
     {

src/msw/dc.cpp

@@ -42,6 +42,7 @@
 
 #include "wx/sysopt.h"
 #include "wx/dcprint.h"
+#include "wx/module.h"
 
 #include <string.h>
 #include <math.h>
@@ -1985,6 +1986,19 @@ void wxDC::ClearCache()
     sm_dcCache.DeleteContents(FALSE);
 }
 
+// Clean up cache at app exit
+class wxDCModule : public wxModule
+{
+public:
+    virtual bool OnInit() { return TRUE; }
+    virtual void OnExit() { wxDC::ClearCache(); }
+
+private:
+    DECLARE_DYNAMIC_CLASS(wxDCModule)
+};
+
+IMPLEMENT_DYNAMIC_CLASS(wxDCModule, wxModule)
+
 #endif
     // wxUSE_DC_CACHEING