+// ----------------------------------------------------------------------------
+// wxGtkTreeSelectionLock: prevent selection from changing during the
+// lifetime of this object
+// ----------------------------------------------------------------------------
+
+// Implementation note: it could be expected that setting the selection
+// function in this class ctor and resetting it back to the old value in its
+// dtor would work. However currently gtk_tree_selection_get_select_function()
+// can't be passed NULL (see https://bugzilla.gnome.org/show_bug.cgi?id=626276)
+// so we can't do this. Instead, we always use the selection function (which
+// imposes extra overhead, albeit minimal one, on all selection operations) and
+// just set/reset the flag telling it whether it should allow or forbid the
+// selection.
+//
+// Also notice that currently only a single object of this class may exist at
+// any given moment. It's just simpler like this and we don't need anything
+// more for now.
+
+extern "C"
+gboolean wxdataview_selection_func(GtkTreeSelection * WXUNUSED(selection),
+ GtkTreeModel * WXUNUSED(model),
+ GtkTreePath * WXUNUSED(path),
+ gboolean WXUNUSED(path_currently_selected),
+ gpointer data)
+{
+ return data == NULL;
+}
+
+class wxGtkTreeSelectionLock
+{
+public:
+ wxGtkTreeSelectionLock(GtkTreeSelection *selection)
+ : m_selection(selection)
+ {
+ wxASSERT_MSG( !ms_instance, "this class is not reentrant currently" );
+
+ ms_instance = this;
+
+ CheckCurrentSelectionFunc(NULL);
+
+ // Pass some non-NULL pointer as "data" for the callback, it doesn't
+ // matter what it is as long as it's non-NULL.
+ gtk_tree_selection_set_select_function(selection,
+ wxdataview_selection_func,
+ this,
+ NULL);
+ }
+
+ ~wxGtkTreeSelectionLock()
+ {
+ CheckCurrentSelectionFunc(wxdataview_selection_func);
+
+ gtk_tree_selection_set_select_function(m_selection,
+ wxdataview_selection_func,
+ NULL,
+ NULL);
+
+ ms_instance = NULL;
+ }
+
+private:
+ void CheckCurrentSelectionFunc(GtkTreeSelectionFunc func)
+ {
+ // We can only use gtk_tree_selection_get_select_function() with 2.14+
+ // so check for its availability both during compile- and run-time.
+#if GTK_CHECK_VERSION(2, 14, 0)
+ if ( gtk_check_version(2, 14, 0) != NULL )
+ return;
+
+ // If this assert is triggered, it means the code elsewhere has called
+ // gtk_tree_selection_set_select_function() but currently doing this
+ // breaks this class so the code here needs to be changed.
+ wxASSERT_MSG
+ (
+ gtk_tree_selection_get_select_function(m_selection) == func,
+ "selection function has changed unexpectedly, review this code!"
+ );
+#endif // GTK+ 2.14+
+
+ wxUnusedVar(func);
+ }
+
+ static wxGtkTreeSelectionLock *ms_instance;
+
+ GtkTreeSelection * const m_selection;
+
+ wxDECLARE_NO_COPY_CLASS(wxGtkTreeSelectionLock);
+};
+
+wxGtkTreeSelectionLock *wxGtkTreeSelectionLock::ms_instance = NULL;
+
projects / wxWidgets.git / blobdiff