perf tui: Add help window to show key associations

Suggested-by: Ingo Molnar <mingo@elte.hu>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/newt.c

@@ -167,6 +167,48 @@ static int popup_menu(int argc, char * const argv[])
 	return rc;
 }
 
+static int ui__help_window(const char *text)
+{
+	struct newtExitStruct es;
+	newtComponent tb, form = newt_form__new();
+	int rc = -1;
+	int max_len = 0, nr_lines = 0;
+	const char *t;
+
+	if (form == NULL)
+		return -1;
+
+	t = text;
+	while (1) {
+		const char *sep = strchr(t, '\n');
+		int len;
+
+		if (sep == NULL)
+			sep = strchr(t, '\0');
+		len = sep - t;
+		if (max_len < len)
+			max_len = len;
+		++nr_lines;
+		if (*sep == '\0')
+			break;
+		t = sep + 1;
+	}
+
+	tb = newtTextbox(0, 0, max_len, nr_lines, 0);
+	if (tb == NULL)
+		goto out_destroy_form;
+
+	newtTextboxSetText(tb, text);
+	newtFormAddComponent(form, tb);
+	newtCenteredWindow(max_len, nr_lines, NULL);
+	newtFormRun(form, &es);
+	newtPopWindow();
+	rc = 0;
+out_destroy_form:
+	newtFormDestroy(form);
+	return rc;
+}
+
 static bool dialog_yesno(const char *msg)
 {
 	/* newtWinChoice should really be accepting const char pointers... */
@@ -756,6 +798,10 @@ static int hist_browser__populate(struct hist_browser *self, struct hists *hists
 	newtFormAddHotKey(self->form, 'd');
 	newtFormAddHotKey(self->form, 'T');
 	newtFormAddHotKey(self->form, 't');
+	newtFormAddHotKey(self->form, '?');
+	newtFormAddHotKey(self->form, 'H');
+	newtFormAddHotKey(self->form, 'h');
+	newtFormAddHotKey(self->form, NEWT_KEY_F1);
 	newtFormAddHotKey(self->form, NEWT_KEY_RIGHT);
 	newtFormAddComponents(self->form, self->tree, NULL);
 	self->selection = newt__symbol_tree_get_current(self->tree);
@@ -842,13 +888,27 @@ int hists__browse(struct hists *self, const char *helpline, const char *input_na
 		dso = browser->selection->map ? browser->selection->map->dso : NULL;
 
 		if (es.reason == NEWT_EXIT_HOTKEY) {
+			if (es.u.key == NEWT_KEY_F1)
+				goto do_help;
+
 			switch (toupper(es.u.key)) {
 			case 'A':
 				goto do_annotate;
 			case 'D':
 				goto zoom_dso;
 			case 'T':
 				goto zoom_thread;
+			case 'H':
+			case '?':
+do_help:
+				ui__help_window("->        Zoom into DSO/Threads & Annotate current symbol\n"
+						"<-        Zoom out\n"
+						"a         Annotate current symbol\n"
+						"h/?/F1    Show this window\n"
+						"d         Zoom into current DSO\n"
+						"t         Zoom into current Thread\n"
+						"q/CTRL+C  Exit browser");
+				continue;
 			default:;
 			}
 			if (toupper(es.u.key) == 'Q' ||