Moved all interface headers into a 'wx' subdirectory for proper use of Doxygen path settings.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@54385 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/recguard.h

@@ -0,0 +1,100 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        recguard.h
+// Purpose:     interface of wxRecursionGuardFlag
+// Author:      wxWidgets team
+// RCS-ID:      $Id$
+// Licence:     wxWindows license
+/////////////////////////////////////////////////////////////////////////////
+
+/**
+    @class wxRecursionGuardFlag
+    @wxheader{recguard.h}
+
+    This is a completely opaque class which exists only to be used with
+    wxRecursionGuard, please see the example in that class' documentation.
+
+    @remarks
+
+    wxRecursionGuardFlag object must be declared @c static or the recursion
+    would never be detected.
+
+    @library{wxbase}
+    @category{misc}
+*/
+class wxRecursionGuardFlag
+{
+public:
+
+};
+
+
+
+/**
+    @class wxRecursionGuard
+    @wxheader{recguard.h}
+
+    wxRecursionGuard is a very simple class which can be used to prevent reentrancy
+    problems in a function. It is not thread-safe and so should be used only in
+    single-threaded programs or in combination with some thread synchronization
+    mechanisms.
+
+    wxRecursionGuard is always used together with the
+    wxRecursionGuardFlag like in this example:
+
+    @code
+    void Foo()
+    {
+        static wxRecursionGuardFlag s_flag;
+        wxRecursionGuard guard(s_flag);
+        if ( guard.IsInside() )
+        {
+            // don't allow reentrancy
+            return;
+        }
+
+        ...
+    }
+    @endcode
+
+    As you can see, wxRecursionGuard simply tests the flag value and sets it to
+    @true if it hadn't been already set.
+    IsInside() allows testing the old flag
+    value. The advantage of using this class compared to directly manipulating the
+    flag is that the flag is always reset in the wxRecursionGuard destructor and so
+    you don't risk to forget to do it even if the function returns in an unexpected
+    way (for example because an exception has been thrown).
+
+    @library{wxbase}
+    @category{misc}
+*/
+class wxRecursionGuard
+{
+public:
+    /**
+        A wxRecursionGuard object must always be initialized with a @c static
+        wxRecursionGuardFlag. The constructor saves the
+        value of the flag to be able to return the correct value from
+        IsInside().
+    */
+    wxRecursionGuard(wxRecursionGuardFlag& flag);
+
+    /**
+        The destructor resets the flag value so that the function can be entered again
+        the next time.
+
+        @note This is not virtual, so this class is not meant to be derived
+              from (besides, there is absolutely no reason to do it anyhow).
+    */
+    ~wxRecursionGuard();
+
+    /**
+        Returns @true if we're already inside the code block "protected" by this
+        wxRecursionGuard (i.e. between this line and the end of current scope).
+        Usually the function using wxRecursionGuard takes some specific actions
+        in such case (may be simply returning) to prevent reentrant calls to itself.
+
+        If this method returns @false, it is safe to continue.
+    */
+    bool IsInside() const;
+};
+