X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/a9f1207c1bbff188c5b258040560dc63276f79af..2a45803fc3877afd0ae3ce356dfe216505165882:/include/wx/private/textmeasure.h?ds=inline

diff --git a/include/wx/private/textmeasure.h b/include/wx/private/textmeasure.h
index a543214366..393946e7bf 100644
--- a/include/wx/private/textmeasure.h
+++ b/include/wx/private/textmeasure.h
@@ -23,7 +23,8 @@ class wxTextMeasureBase
 {
 public:
     // The first ctor argument must be non-NULL, i.e. each object of this class
-    // is associated with either a valid wxDC or a valid wxWindow.
+    // is associated with either a valid wxDC or a valid wxWindow. The font can
+    // be NULL to use the current DC/window font or can be specified explicitly.
     wxTextMeasureBase(const wxDC *dc, const wxFont *theFont);
     wxTextMeasureBase(const wxWindow *win, const wxFont *theFont);
 
@@ -61,30 +62,39 @@ public:
                                wxArrayInt& widths,
                                double scaleX);
 
-protected:
+
     // These functions are called by our public methods before and after each
     // call to DoGetTextExtent(). Derived classes may override them to prepare
     // for -- possibly several -- subsequent calls to DoGetTextExtent().
     //
     // As these calls must be always paired, they're never called directly but
     // only by our friend MeasuringGuard class.
+    //
+    // NB: They're public only to allow VC6 to compile this code, there doesn't
+    //     seem to be any way to give MeasuringGuard access to them (FIXME-VC6)
     virtual void BeginMeasuring() { }
     virtual void EndMeasuring() { }
 
-    friend class MeasuringGuard;
+    // This is another method which is only used by MeasuringGuard.
+    bool IsUsingDCImpl() const { return m_useDCImpl; }
 
+protected:
     // RAII wrapper for the two methods above.
     class MeasuringGuard
     {
     public:
         MeasuringGuard(wxTextMeasureBase& tm) : m_tm(tm)
         {
-            m_tm.BeginMeasuring();
+            // BeginMeasuring() should only be called if we have a native DC,
+            // so don't call it if we delegate to a DC of unknown type.
+            if ( !m_tm.IsUsingDCImpl() )
+                m_tm.BeginMeasuring();
         }
 
         ~MeasuringGuard()
         {
-            m_tm.EndMeasuring();
+            if ( !m_tm.IsUsingDCImpl() )
+                m_tm.EndMeasuring();
         }
 
     private:
@@ -121,6 +131,10 @@ protected:
                            wxCoord *descent = NULL,
                            wxCoord *externalLeading = NULL);
 
+    // Return a valid font: if one was given to us in the ctor, use this one,
+    // otherwise use the current font of the associated wxDC or wxWindow.
+    wxFont GetFont() const;
+
 
     // Exactly one of m_dc and m_win is non-NULL for any given object of this
     // class.