patch 8.0.0683: visual bell flashes too quickly
Problem: When using a visual bell there is no delay, causing the flash to
be very short, possibly unnoticeable. Also, the flash and the
beep can lockup the UI when repeated often.
Solution: Do the delay in Vim or flush the output before the delay. Limit the
bell to once per half a second. (Ozaki Kiichi, closes #1789)
diff --git a/src/term.c b/src/term.c
index 56d698b..0dbe6d5 100644
--- a/src/term.c
+++ b/src/term.c
@@ -2514,6 +2514,75 @@
#endif
/*
+ * A conditional-flushing out_str, mainly for visualbell.
+ * Handles a delay internally, because termlib may not respect the delay or do
+ * it at the wrong time.
+ * Note: Only for terminal strings.
+ */
+ void
+out_str_cf(char_u *s)
+{
+ if (s != NULL && *s)
+ {
+ char_u *p;
+
+#ifdef FEAT_GUI
+ /* Don't use tputs() when GUI is used, ncurses crashes. */
+ if (gui.in_use)
+ {
+ out_str_nf(s);
+ return;
+ }
+#endif
+ if (out_pos > OUT_SIZE - 20)
+ out_flush();
+#ifdef HAVE_TGETENT
+ for (p = s; *s; ++s)
+ {
+ /* flush just before delay command */
+ if (*s == '$' && *(s + 1) == '<')
+ {
+ char_u save_c = *s;
+ int duration = atoi((char *)s + 2);
+
+ *s = NUL;
+ tputs((char *)p, 1, TPUTSFUNCAST out_char_nf);
+ *s = save_c;
+ out_flush();
+#ifdef ELAPSED_FUNC
+ /* Only sleep here if we can limit this happening in
+ * vim_beep(). */
+ p = vim_strchr(s, '>');
+ if (p == NULL || duration <= 0)
+ {
+ /* can't parse the time, don't sleep here */
+ p = s;
+ }
+ else
+ {
+ ++p;
+ do_sleep(duration);
+ }
+#else
+ /* Rely on the terminal library to sleep. */
+ p = s;
+#endif
+ break;
+ }
+ }
+ tputs((char *)p, 1, TPUTSFUNCAST out_char_nf);
+#else
+ while (*s)
+ out_char_nf(*s++);
+#endif
+
+ /* For testing we write one string at a time. */
+ if (p_wd)
+ out_flush();
+ }
+}
+
+/*
* out_str(s): Put a character string a byte at a time into the output buffer.
* If HAVE_TGETENT is defined use the termcap parser. (jw)
* This should only be used for writing terminal codes, not for outputting