perf ui: Introduce struct ui_helpline

Add struct ui_helpline in order to provide flexible implementation of
helpline APIs.  And convert existing TUI implementation to use it.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1345104894-14205-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/ui/helpline.c b/tools/perf/ui/helpline.c
index 2f950c2..78ba28a 100644
--- a/tools/perf/ui/helpline.c
+++ b/tools/perf/ui/helpline.c
@@ -5,23 +5,32 @@
 #include "../debug.h"
 #include "helpline.h"
 #include "ui.h"
-#include "libslang.h"
-
-void ui_helpline__pop(void)
-{
-}
 
 char ui_helpline__current[512];
 
+static void nop_helpline__pop(void)
+{
+}
+
+static void nop_helpline__push(const char *msg __used)
+{
+}
+
+static struct ui_helpline default_helpline_fns = {
+	.pop	= nop_helpline__pop,
+	.push	= nop_helpline__push,
+};
+
+struct ui_helpline *helpline_fns = &default_helpline_fns;
+
+void ui_helpline__pop(void)
+{
+	helpline_fns->pop();
+}
+
 void ui_helpline__push(const char *msg)
 {
-	const size_t sz = sizeof(ui_helpline__current);
-
-	SLsmg_gotorc(SLtt_Screen_Rows - 1, 0);
-	SLsmg_set_color(0);
-	SLsmg_write_nstring((char *)msg, SLtt_Screen_Cols);
-	SLsmg_refresh();
-	strncpy(ui_helpline__current, msg, sz)[sz - 1] = '\0';
+	helpline_fns->push(msg);
 }
 
 void ui_helpline__vpush(const char *fmt, va_list ap)
@@ -50,30 +59,3 @@
 	ui_helpline__pop();
 	ui_helpline__push(msg);
 }
-
-void ui_helpline__init(void)
-{
-	ui_helpline__puts(" ");
-}
-
-char ui_helpline__last_msg[1024];
-
-int ui_helpline__show_help(const char *format, va_list ap)
-{
-	int ret;
-	static int backlog;
-
-	pthread_mutex_lock(&ui__lock);
-	ret = vscnprintf(ui_helpline__last_msg + backlog,
-			sizeof(ui_helpline__last_msg) - backlog, format, ap);
-	backlog += ret;
-
-	if (ui_helpline__last_msg[backlog - 1] == '\n') {
-		ui_helpline__puts(ui_helpline__last_msg);
-		SLsmg_refresh();
-		backlog = 0;
-	}
-	pthread_mutex_unlock(&ui__lock);
-
-	return ret;
-}