Re: [mpg123-devel] [PATCH] term_posix: Ignore escape sequences

[Thomas O. <tho...@or...>]

Hi all,

I added something to the mpg123 trunk and current snapshot now to
handle (spurious) escape sequences. It boils down to this:

@@ -589,8 +589,34 @@
 static void term_handle_input(mpg123_handle *fr, out123_handle *ao, int do_delay)
 {
 	char val;
-	if(term_get_key(playstate==STATE_STOPPED, do_delay, &val))
+	if(term_get_key(playstate==STATE_STOPPED, do_delay ? 1 : 0, &val))
 	{
+		// Crude ignoring of 7-bit escape sequences. 8-bit ones you better really handle
+		// in the terminal and do not pass on. The idea is that pressing cursor keys
+		// that contain plain characters in the triggered escape sequences should
+		// not confuse mpg123 terminal control At the same time, the user pressing
+		// ESC on its own should not confuse mpg123 into starting a sequence.
+		// So the assumption is quick succession of the bytes for real sequences.
+		// If the sequence has been ignoret, return, as this has been handled. Come
+		// back for real control.
+		if(val == 0x1b) // ESC, get next key, if any
+		{
+			int seq_len = 1;
+			if(term_get_key(FALSE, -1, &val))
+			{
+				++seq_len;
+				if(val == 'Z') // SCI, single character to drop, if any
+					term_get_key(FALSE, -1, &val);
+				else if(val == '[') // sequence begin
+				{
+					while(term_get_key(FALSE, -1, &val) && strchr("0123456789;", val))
+						++seq_len;
+				} // else simple single-character escape
+			}
+			mdebug("dropped escape sequence of length %d", seq_len);
+			return;
+		} else
+			mdebug("got key: %02x", val);
 		term_handle_key(fr, ao, val);
 	}

It looks for ESC by itself, followed by Z and a single character,
followed by [ and a sequence, or just another single character, to
cover the relevant cases of 7-bit escape sequences. Follow-up is with 1
ms select() timeout instead of 10 ms for paused mode (or none while
playing).

Seems to work fine during local testing. Reports welcome. Now, pressing
of cursor keys or various function keys should not confuse mpg123
terminal control anymore.


Alrighty then,

Thomas