Add support for arbitrary window labels in wxStaticBox to wxMSW

Just reparent the label window and position it accordingly and, also,
avoid painting over it in MSW-specific code.

include/wx/msw/statbox.h

@@ -27,6 +27,16 @@ public:
         Create(parent, id, label, pos, size, style, name);
     }
 
+    wxStaticBox(wxWindow* parent, wxWindowID id,
+                wxWindow* label,
+                const wxPoint& pos = wxDefaultPosition,
+                const wxSize& size = wxDefaultSize,
+                long style = 0,
+                const wxString &name = wxStaticBoxNameStr)
+    {
+        Create(parent, id, label, pos, size, style, name);
+    }
+
     bool Create(wxWindow *parent, wxWindowID id,
                 const wxString& label,
                 const wxPoint& pos = wxDefaultPosition,
@@ -34,6 +44,13 @@ public:
                 long style = 0,
                 const wxString& name = wxStaticBoxNameStr);
 
+    bool Create(wxWindow *parent, wxWindowID id,
+                wxWindow* label,
+                const wxPoint& pos = wxDefaultPosition,
+                const wxSize& size = wxDefaultSize,
+                long style = 0,
+                const wxString& name = wxStaticBoxNameStr);
+
     /// Implementation only
     virtual void GetBordersForSizer(int *borderTop, int *borderOther) const wxOVERRIDE;
 
@@ -66,5 +83,8 @@ protected:
     wxDECLARE_DYNAMIC_CLASS_NO_COPY(wxStaticBox);
 };
 
+// Indicate that we have the ctor overload taking wxWindow as label.
+#define wxHAS_WINDOW_LABEL_IN_STATIC_BOX
+
 #endif // _WX_MSW_STATBOX_H_
 

interface/wx/statbox.h

@@ -111,7 +111,7 @@ public:
         }
         @endcode
 
-        Currently this constructor is only available in wxGTK, use
+        Currently this constructor is only available in wxGTK and wxMSW, use
         @c wxHAS_WINDOW_LABEL_IN_STATIC_BOX to check whether it can be used at
         compile-time.
 

src/msw/statbox.cpp

@@ -107,6 +107,27 @@ bool wxStaticBox::Create(wxWindow *parent,
     return true;
 }
 
+bool wxStaticBox::Create(wxWindow* parent,
+                         wxWindowID id,
+                         wxWindow* labelWin,
+                         const wxPoint& pos,
+                         const wxSize& size,
+                         long style,
+                         const wxString& name)
+{
+    wxCHECK_MSG( labelWin, false, wxS("Label window can't be null") );
+
+    if ( !Create(parent, id, wxString(), pos, size, style, name) )
+        return false;
+
+    m_labelWin = labelWin;
+    m_labelWin->Reparent(this);
+
+    m_labelWin->Move(FromDIP(LABEL_HORZ_OFFSET), 0);
+
+    return true;
+}
+
 WXDWORD wxStaticBox::MSWGetStyle(long style, WXDWORD *exstyle) const
 {
     long styleWin = wxStaticBoxBase::MSWGetStyle(style, exstyle);
@@ -269,7 +290,21 @@ void wxStaticBox::MSWGetRegionWithoutSelf(WXHRGN hRgn, int w, int h)
     GetBordersForSizer(&borderTop, &border);
 
     // top
+    if ( m_labelWin )
+    {
+        // Don't exclude the entire rectangle at the top, we do need to paint
+        // the background of the gap between the label window and the box
+        // frame.
+        const wxRect labelRect = m_labelWin->GetRect();
+        const int gap = FromDIP(LABEL_HORZ_BORDER);
+
+        SubtractRectFromRgn(hrgn, 0, 0, labelRect.GetLeft() - gap, borderTop);
+        SubtractRectFromRgn(hrgn, labelRect.GetRight() + gap, 0, w, borderTop);
+    }
+    else
+    {
         SubtractRectFromRgn(hrgn, 0, 0, w, borderTop);
+    }
 
     // bottom
     SubtractRectFromRgn(hrgn, 0, h - border, w, h);
@@ -415,7 +450,7 @@ void wxStaticBox::PaintForeground(wxDC& dc, const RECT&)
     // background mode doesn't change anything: the static box def window proc
     // still draws the label in its own colours, so we need to redraw the text
     // ourselves if we have a non default fg colour
-    if ( m_hasFgCol && wxUxThemeEngine::GetIfActive() )
+    if ( m_hasFgCol && wxUxThemeEngine::GetIfActive() && !m_labelWin )
     {
         // draw over the text in default colour in our colour
         HDC hdc = GetHdcOf(*impl);
@@ -535,8 +570,31 @@ void wxStaticBox::OnPaint(wxPaintEvent& WXUNUSED(event))
     GetBordersForSizer(&borderTop, &border);
 
     // top
+    if ( m_labelWin )
+    {
+        // We also have to exclude the area taken by the label window,
+        // otherwise there would be flicker when it draws itself on top of it.
+        const wxRect labelRect = m_labelWin->GetRect();
+
+        // We also leave a small border around label window to make it appear
+        // more similarly to a plain text label.
+        const int gap = FromDIP(LABEL_HORZ_BORDER);
+
+        dc.Blit(border, 0,
+                labelRect.GetLeft() - gap - border,
+                borderTop,
+                &memdc, border, 0);
+        dc.Blit(labelRect.GetRight() + gap, 0,
+                rc.right - (labelRect.GetRight() + gap),
+                borderTop,
+                &memdc, border, 0);
+    }
+    else
+    {
         dc.Blit(border, 0, rc.right - border, borderTop,
                 &memdc, border, 0);
+    }
+
     // bottom
     dc.Blit(border, rc.bottom - border, rc.right - border, border,
             &memdc, border, rc.bottom - border);