X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/79275a0dae9a4f29415b4bc57dbebdbb4e203957..51623cc53f350935337e57930eaaf1afe9a48c3b:/include/wx/private/textmeasure.h

diff --git a/include/wx/private/textmeasure.h b/include/wx/private/textmeasure.h
index ebd6a61214..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);
 
@@ -74,6 +75,9 @@ public:
     virtual void BeginMeasuring() { }
     virtual void EndMeasuring() { }
 
+    // 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
@@ -81,12 +85,16 @@ protected:
     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:
@@ -123,6 +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.