xref: /linux/tools/perf/ui/tui/helpline.c (revision 8ca4fc323d2e4ab9dabbdd57633af40b0c7e6af9)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <string.h>
5 #include <linux/kernel.h>
6 #include <linux/string.h>
7 
8 #include "../helpline.h"
9 #include "../ui.h"
10 #include "../libslang.h"
11 
12 char ui_helpline__last_msg[1024];
13 bool tui_helpline__set;
14 
15 static void tui_helpline__pop(void)
16 {
17 }
18 
19 static void tui_helpline__push(const char *msg)
20 {
21 	const size_t sz = sizeof(ui_helpline__current);
22 
23 	SLsmg_gotorc(SLtt_Screen_Rows - 1, 0);
24 	SLsmg_set_color(0);
25 	SLsmg_write_nstring((char *)msg, SLtt_Screen_Cols);
26 	SLsmg_refresh();
27 	strlcpy(ui_helpline__current, msg, sz);
28 }
29 
30 static int tui_helpline__show(const char *format, va_list ap)
31 {
32 	int ret;
33 	static int backlog;
34 
35 	mutex_lock(&ui__lock);
36 	ret = vscnprintf(ui_helpline__last_msg + backlog,
37 			sizeof(ui_helpline__last_msg) - backlog, format, ap);
38 	backlog += ret;
39 
40 	tui_helpline__set = true;
41 
42 	if (ui_helpline__last_msg[backlog - 1] == '\n') {
43 		ui_helpline__puts(ui_helpline__last_msg);
44 		SLsmg_refresh();
45 		backlog = 0;
46 	}
47 	mutex_unlock(&ui__lock);
48 
49 	return ret;
50 }
51 
52 struct ui_helpline tui_helpline_fns = {
53 	.pop	= tui_helpline__pop,
54 	.push	= tui_helpline__push,
55 	.show	= tui_helpline__show,
56 };
57 
58 void ui_helpline__init(void)
59 {
60 	helpline_fns = &tui_helpline_fns;
61 	ui_helpline__puts(" ");
62 }
63