IconView stack extending

[Kevin Ryde <user42 zip com au>]

This is three yet more stack extending bits I've had kicking around.
There's tests in t/GtkIconView.t of all except get_item_at_pos(),
commented out for gtk dodginess.  I've never used iconview, beyond
giving it a run to see what it looked like, so I hope I haven't broken
something.

Other funcs like say get_drag_dest_item() are simple getters and don't
call out to the model.  It's tempting to give all funcs the treatment
though (in any widgets using a model or renderer), since it costs little
and you never know if the gtk implementation might change, like asking
the model for info at more places or defering size calculations.

Index: GtkIconView.xs
===================================================================
--- GtkIconView.xs      (revision 2135)
+++ GtkIconView.xs      (working copy)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004-2005 by the gtk2-perl team (see the file AUTHORS)
+ * Copyright (c) 2004-2005, 2009 by the gtk2-perl team (see the file AUTHORS)
  *
  * Licensed under the LGPL, see LICENSE file for more information.
  *
@@ -157,12 +157,15 @@
     PREINIT:
        GtkTreePath *path = NULL;
        GtkCellRenderer *cell = NULL;
-    PPCODE:
+    CODE:
+       /* Note gtk_icon_view_get_item_at_pos() can call out to perl model
+          and/or cell renderer code when figuring sizes, so avoid local
+          SP. */
        if (!gtk_icon_view_get_item_at_pos (icon_view, x, y, &path, &cell))
                XSRETURN_EMPTY;
-       EXTEND (sp, 2);
-       PUSHs (sv_2mortal (newSVGtkTreePath_own (path)));
-       PUSHs (sv_2mortal (newSVGtkCellRenderer (cell)));
+       ST(0) = sv_2mortal (newSVGtkTreePath_own (path));
+       ST(1) = sv_2mortal (newSVGtkCellRenderer (cell));
+       XSRETURN(2);
 
 
 ## gboolean gtk_icon_view_get_visible_range (GtkIconView *icon_view, GtkTreePath **start_path, GtkTreePath 
**end_path);
@@ -258,12 +261,15 @@
     PREINIT:
        GtkTreePath *path = NULL;
        GtkIconViewDropPosition pos;
-    PPCODE:
+    CODE:
+       /* Note gtk_icon_view_get_dest_item_at_pos() may call out to perl
+          model and/or cell renderer code when figuring cell sizes (in
+          gtk_icon_view_get_item_at_coords()), so avoid local SP. */
        if (!gtk_icon_view_get_dest_item_at_pos (icon_view, drag_x, drag_y, &path, &pos))
                XSRETURN_EMPTY;
-       EXTEND (sp, 2);
-       PUSHs (sv_2mortal (newSVGtkTreePath_own (path)));
-       PUSHs (sv_2mortal (newSVGtkIconViewDropPosition (pos)));
+       ST(0) = sv_2mortal (newSVGtkTreePath_own (path));
+       ST(1) = sv_2mortal (newSVGtkIconViewDropPosition (pos));
+       XSRETURN(2);
 
 GdkPixmap_noinc *gtk_icon_view_create_drag_icon (GtkIconView *icon_view, GtkTreePath *path);
 
@@ -285,8 +291,12 @@
        GtkTreePath *path = NULL;
        GtkTreeIter iter = {0, };
     PPCODE:
+       /* PUTBACK/SPAGAIN because gtk_icon_view_get_tooltip_context() calls
+          gtk_tree_model_get_iter(), which may reach a perl code model. */
+       PUTBACK;
        if (! gtk_icon_view_get_tooltip_context (icon_view, &x, &y, keyboard_tip, &model, &path, &iter))
                XSRETURN_EMPTY;
+       SPAGAIN;
        EXTEND (sp, 5);
        PUSHs (sv_2mortal (newSViv (x)));
        PUSHs (sv_2mortal (newSViv (y)));