Allow to leave another window enabled in wxWindowDisabler

Allow specifying another window to "skip", i.e. not to disable, in
wxWindowDisabler.

This is not used yet, but will be in the upcoming commit.

include/wx/utils.h

@@ -732,8 +732,8 @@ public:
     // it doesn't do anything
     explicit wxWindowDisabler(bool disable = true);
 
-    // ctor disables all windows except winToSkip
-    explicit wxWindowDisabler(wxWindow *winToSkip);
+    // ctor disables all windows except the given one(s)
+    explicit wxWindowDisabler(wxWindow *winToSkip, wxWindow *winToSkip2 = NULL);
 
     // dtor enables back all windows disabled by the ctor
     ~wxWindowDisabler();

interface/wx/utils.h

@@ -97,8 +97,12 @@ public:
         from happening you may want to use wxFRAME_TOOL_WINDOW, if applicable,
         or wxFRAME_NO_TASKBAR style when creating the window that will remain
         enabled.
+
+        The argument @a winToSkip2 may be used to specify another window to
+        leave enabled, if it is non-null. This parameter is only available
+        since wxWidgets 3.1.7.
     */
-    explicit wxWindowDisabler(wxWindow* winToSkip);
+    explicit wxWindowDisabler(wxWindow* winToSkip, wxWindow* winToSkip2 = NULL);
 
     /**
         Reenables the windows disabled by the constructor.

src/common/utilscmn.cpp

@@ -1526,12 +1526,14 @@ wxWindowDisabler::wxWindowDisabler(bool disable)
     }
 }
 
-wxWindowDisabler::wxWindowDisabler(wxWindow *winToSkip)
+wxWindowDisabler::wxWindowDisabler(wxWindow *winToSkip, wxWindow *winToSkip2)
 {
     m_disabled = true;
 
     if ( winToSkip )
         m_windowsToSkip.push_back(winToSkip);
+    if ( winToSkip2 )
+        m_windowsToSkip.push_back(winToSkip2);
 
     DoDisable();