Fix handling of wxGA_PROGRESS in wxGauge under MSW

This was broken by the refactoring during the addition of OS X implementation
of wxAppProgressIndicator in 11a5b83e2c, restore
this functionality by explicitly calling the code initializing the progress
indicator in wxGaugeBase from wxMSW implementation.

Closes #17301.

include/wx/gauge.h

@@ -99,6 +99,13 @@ public:
 protected:
     virtual wxBorder GetDefaultBorder() const wxOVERRIDE { return wxBORDER_NONE; }
 
+    // Initialize m_appProgressIndicator if necessary, i.e. if this object has
+    // wxGA_PROGRESS style. This method is supposed to be called from the
+    // derived class Create() if it doesn't call the base class Create(), which
+    // already does it, after initializing the window style and range.
+    void InitProgressIndicatorIfNeeded();
+
+
     // the max position
     int m_rangeMax;
 

src/common/gaugecmn.cpp

@@ -104,6 +104,20 @@ wxCONSTRUCTOR_6( wxGauge, wxWindow*, Parent, wxWindowID, Id, int, Range, \
 // wxGauge creation
 // ----------------------------------------------------------------------------
 
+void wxGaugeBase::InitProgressIndicatorIfNeeded()
+{
+    m_appProgressIndicator = NULL;
+    if ( HasFlag(wxGA_PROGRESS) )
+    {
+        wxWindow* topParent = wxGetTopLevelParent(this);
+        if ( topParent != NULL )
+        {
+            m_appProgressIndicator =
+                new wxAppProgressIndicator(topParent, GetRange());
+        }
+    }
+}
+
 bool wxGaugeBase::Create(wxWindow *parent,
                          wxWindowID id,
                          int range,
@@ -122,23 +136,15 @@ bool wxGaugeBase::Create(wxWindow *parent,
     SetValidator(validator);
 #endif // wxUSE_VALIDATORS
 
-    m_appProgressIndicator = NULL;
-    if ( (style & wxGA_PROGRESS) != 0 )
-    {
-        wxWindow* topParent = wxGetTopLevelParent(this);
-        if ( topParent != NULL )
-        {
-            m_appProgressIndicator =
-                new wxAppProgressIndicator(topParent, range);
-        }
-    }
-
     SetRange(range);
     SetValue(0);
+
 #if wxGAUGE_EMULATE_INDETERMINATE_MODE
     m_nDirection = wxRIGHT;
 #endif
 
+    InitProgressIndicatorIfNeeded();
+
     return true;
 }
 

src/msw/gauge.cpp

@@ -97,6 +97,8 @@ bool wxGauge::Create(wxWindow *parent,
 
     SetRange(range);
 
+    InitProgressIndicatorIfNeeded();
+
     return true;
 }