[gnumeric] diff engine: cleanup callback dispatch.

[Morten Welinder <mortenw src gnome org>]

commit 7155f096bb41d6c00130fb5e2534b98e2a812186
Author: Morten Welinder <terra gnome org>
Date:   Sun Apr 8 16:16:21 2018 -0400

    diff engine: cleanup callback dispatch.

 src/sheet-diff.c |   68 ++---------------------------------------------------
 1 files changed, 3 insertions(+), 65 deletions(-)
---
diff --git a/src/sheet-diff.c b/src/sheet-diff.c
index ebad5b7..e1ad03b 100644
--- a/src/sheet-diff.c
+++ b/src/sheet-diff.c
@@ -35,70 +35,8 @@
 
 /* ------------------------------------------------------------------------- */
 
-static gboolean
-null_diff_start (G_GNUC_UNUSED gpointer user)
-{
-       return FALSE;
-}
-
-static void
-null_diff_end (G_GNUC_UNUSED gpointer user)
-{
-}
-
-static void
-null_sheet_start (G_GNUC_UNUSED gpointer user,
-                 G_GNUC_UNUSED Sheet const *os,
-                 G_GNUC_UNUSED Sheet const *ns)
-{
-}
-
-static void
-null_sheet_end (G_GNUC_UNUSED gpointer user)
-{
-}
-
-static void
-null_sheet_order_changed (G_GNUC_UNUSED gpointer user)
-{
-}
-
-static void
-null_sheet_attr_int_changed (G_GNUC_UNUSED gpointer user,
-                            G_GNUC_UNUSED const char *name,
-                            G_GNUC_UNUSED int o,
-                            G_GNUC_UNUSED int n)
-{
-}
-
-static void
-null_colrow_changed (G_GNUC_UNUSED gpointer user,
-                    G_GNUC_UNUSED ColRowInfo const *oc, G_GNUC_UNUSED ColRowInfo const *nc,
-                    G_GNUC_UNUSED gboolean is_cols, G_GNUC_UNUSED int i)
-{
-}
-
-static void
-null_cell_changed (G_GNUC_UNUSED gpointer user,
-                  G_GNUC_UNUSED GnmCell const *oc, GnmCell const *nc)
-{
-}
-
-static void
-null_style_changed (G_GNUC_UNUSED gpointer user,
-                   G_GNUC_UNUSED GnmRange const *r,
-                   G_GNUC_UNUSED GnmStyle const *os, G_GNUC_UNUSED GnmStyle const *ns)
-{
-}
-
-static void
-null_name_changed (G_GNUC_UNUSED gpointer user,
-                  G_GNUC_UNUSED GnmNamedExpr const *on, G_GNUC_UNUSED GnmNamedExpr const *nn)
-{
-
-}
-
-#define DISPATCH(method) (istate->actions->method ? istate->actions->method : null_ ## method)
+#define DISPATCH(method) if (istate->actions->method == NULL) { } else (istate->actions->method)
+#define DISPATCH_VAL(method,def) (istate->actions->method == NULL) ? (def) : (istate->actions->method)
 
 /* ------------------------------------------------------------------------- */
 
@@ -470,7 +408,7 @@ real_diff_workbooks (GnmDiffIState *istate,
        istate->old_wb = old_wb;
        istate->new_wb = new_wb;
 
-       if (DISPATCH(diff_start) (istate->user)) {
+       if (DISPATCH_VAL(diff_start,FALSE) (istate->user)) {
                istate->error = TRUE;
                return;
        }