perf gtk/hists: Add a double-click handler for callchains

If callchain is displayed, add "row-activated" signal handler for
handling double-click or pressing ENTER key action.
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1370337737-30812-6-git-send-email-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/ui/gtk/hists.c

@@ -187,6 +187,18 @@ static void perf_gtk__add_callchain(struct rb_root *root, GtkTreeStore *store,
 	}
 }
 
+static void on_row_activated(GtkTreeView *view, GtkTreePath *path,
+			     GtkTreeViewColumn *col __maybe_unused,
+			     gpointer user_data __maybe_unused)
+{
+	bool expanded = gtk_tree_view_row_expanded(view, path);
+
+	if (expanded)
+		gtk_tree_view_collapse_row(view, path);
+	else
+		gtk_tree_view_expand_row(view, path, FALSE);
+}
+
 static void perf_gtk__show_hists(GtkWidget *window, struct hists *hists,
 				 float min_pcnt)
 {
@@ -314,6 +326,8 @@ static void perf_gtk__show_hists(GtkWidget *window, struct hists *hists,
 		}
 	}
 
+	g_signal_connect(view, "row-activated",
+			 G_CALLBACK(on_row_activated), NULL);
 	gtk_container_add(GTK_CONTAINER(window), view);
 }