add support for persistent controls

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58529 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/persist/window.h

@@ -0,0 +1,51 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        wx/persist/window.h
+// Purpose:     interface of wxPersistentWindow<>
+// Author:      Vadim Zeitlin
+// RCS-ID:      $Id$
+// Copyright:   (c) 2009 Vadim Zeitlin <vadim@wxwidgets.org>
+// Licence:     wxWindows license
+/////////////////////////////////////////////////////////////////////////////
+
+/**
+    Base class for persistent windows.
+
+    Compared to wxPersistentObject this class does three things:
+        - Most importantly, wxPersistentWindow catches wxWindowDestroyEvent
+        generated when the window is destroyed and saves its properties
+        automatically when it happens.
+        - It implements GetName() using wxWindow::GetName() so that the derived
+        classes don't need to do it.
+        - It adds a convenient wxPersistentWindow::Get() accessor returning the
+        window object of the correct type.
+ */
+template <class T>
+class wxPersistentWindow : public wxPersistentObject
+{
+public:
+    /// The type of the associated window.
+    typedef T WindowType;
+
+    /**
+        Constructor for a persistent window object.
+
+        The constructor uses wxEvtHandler::Connect() to catch
+        wxWindowDestroyEvent generated when the window is destroyed and call
+        wxPersistenceManager::SaveAndUnregister() when this happens. This
+        ensures that the window properties are saved and that this object
+        itself is deleted when the window is.
+     */
+    wxPersistentWindow(WindowType *win);
+
+    WindowType *Get() const { return static_cast<WindowType *>(GetWindow()); }
+    /**
+        Implements the base class pure virtual method using wxWindow::GetName().
+
+        Notice that window names are usually not unique while this function
+        must return a unique (at least among the objects of this type) string.
+        Because of this you need to specify a non-default window name in its
+        constructor when creating it or explicitly call wxWindow::SetName()
+        before saving or restoring persistent properties.
+     */
+    virtual wxString GetName() const;
+};