Merge branch 'shared-client-data'

Allow sharing client data in wxGrid-related classes.

See #22369.

interface/wx/clntdata.h

@@ -21,7 +21,7 @@
     @library{wxbase}
     @category{containers}
 
-    @see wxEvtHandler, wxClientData
+    @see wxSharedClientDataContainer, wxEvtHandler, wxClientData
 */
 class wxClientDataContainer
 {
@@ -59,6 +59,56 @@ public:
 
 
 
+/**
+    @class wxSharedClientDataContainer
+
+    This class is a replacement for @ref wxClientDataContainer, and unlike
+    wxClientDataContainer the wxSharedClientDataContainer client data is
+    copiable, so it can be copied when objects containing it are cloned.
+    Like wxClientDataContainer, wxSharedClientDataContainer is a mixin
+    that provides storage and management of "client data.". The client data
+    is reference counted and managed by the container. As the client data
+    is a shared object, changing the client data used by any object changes
+    it for all other objects, too.
+
+    @note If your class has a Clone function and needs to store client data,
+          use wxSharedClientDataContainer and not wxClientDataContainer!
+
+    @library{wxbase}
+    @category{containers}
+
+    @see wxClientDataContainer, wxClientData
+    @since 3.1.7
+*/
+class wxSharedClientDataContainer
+{
+public:
+    // Provide the same functions as in wxClientDataContainer, so that objects
+    // using it and this class could be used in exactly the same way.
+
+    /**
+        Get the untyped client data.
+    */
+    void* GetClientData() const;
+
+    /**
+        Get a pointer to the client data object.
+    */
+    wxClientData* GetClientObject() const;
+
+    /**
+        Set the untyped client data.
+    */
+    void SetClientData(void* data);
+
+    /**
+        Set the client data object. Any previous object will be deleted.
+    */
+    void SetClientObject(wxClientData* data);
+};
+
+
+
 /**
     @class wxClientData
 

interface/wx/grid.h

@@ -28,7 +28,7 @@
          wxGridCellFloatRenderer, wxGridCellNumberRenderer,
          wxGridCellStringRenderer
 */
-class wxGridCellRenderer : public wxClientDataContainer, public wxRefCounter
+class wxGridCellRenderer : public wxSharedClientDataContainer, public wxRefCounter
 {
 public:
     wxGridCellRenderer();
@@ -571,7 +571,7 @@ public:
          wxGridCellFloatEditor, wxGridCellNumberEditor,
          wxGridCellTextEditor, wxGridCellDateEditor
 */
-class wxGridCellEditor : public wxClientDataContainer, public wxRefCounter
+class wxGridCellEditor : public wxSharedClientDataContainer, public wxRefCounter
 {
 public:
     /**
@@ -1217,7 +1217,7 @@ public:
     @library{wxcore}
     @category{grid}
 */
-class wxGridCellAttr : public wxClientDataContainer, public wxRefCounter
+class wxGridCellAttr : public wxSharedClientDataContainer, public wxRefCounter
 {
 public:
     /**