perf ui/gtk: Add GTK info_bar widget to browser window

The GtkInfoBar is a modern UI component to display messages without
bothering the main window. It'll be used for showing a warning message.

As the GtkInfoBar requires 2.18 (or newer) version of GTK+ library, add
availability check to Makefile too.

Suggested-by: Sunjin Yang <fan4326@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
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/1338265382-6872-7-git-send-email-namhyung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/ui/gtk/browser.c b/tools/perf/ui/gtk/browser.c
index ece360d..fd41e8d 100644
--- a/tools/perf/ui/gtk/browser.c
+++ b/tools/perf/ui/gtk/browser.c
@@ -122,6 +122,34 @@
 	gtk_container_add(GTK_CONTAINER(window), view);
 }
 
+#ifdef HAVE_GTK_INFO_BAR
+static GtkWidget *perf_gtk__setup_info_bar(void)
+{
+	GtkWidget *info_bar;
+	GtkWidget *label;
+	GtkWidget *content_area;
+
+	info_bar = gtk_info_bar_new();
+	gtk_widget_set_no_show_all(info_bar, TRUE);
+
+	label = gtk_label_new("");
+	gtk_widget_show(label);
+
+	content_area = gtk_info_bar_get_content_area(GTK_INFO_BAR(info_bar));
+	gtk_container_add(GTK_CONTAINER(content_area), label);
+
+	gtk_info_bar_add_button(GTK_INFO_BAR(info_bar), GTK_STOCK_OK,
+				GTK_RESPONSE_OK);
+	g_signal_connect(info_bar, "response",
+			 G_CALLBACK(gtk_widget_hide), NULL);
+
+	pgctx->info_bar = info_bar;
+	pgctx->message_label = label;
+
+	return info_bar;
+}
+#endif
+
 static GtkWidget *perf_gtk__setup_statusbar(void)
 {
 	GtkWidget *stbar;
@@ -145,6 +173,7 @@
 	struct perf_evsel *pos;
 	GtkWidget *vbox;
 	GtkWidget *notebook;
+	GtkWidget *info_bar;
 	GtkWidget *statbar;
 	GtkWidget *window;
 
@@ -189,6 +218,10 @@
 
 	gtk_box_pack_start(GTK_BOX(vbox), notebook, TRUE, TRUE, 0);
 
+	info_bar = perf_gtk__setup_info_bar();
+	if (info_bar)
+		gtk_box_pack_start(GTK_BOX(vbox), info_bar, FALSE, FALSE, 0);
+
 	statbar = perf_gtk__setup_statusbar();
 	gtk_box_pack_start(GTK_BOX(vbox), statbar, FALSE, FALSE, 0);