Implement de/focus event parsing

So far there is no way to set it up, I'm not sure how to go about it.

CMakeLists.txt

@@ -147,6 +147,7 @@ set (project_tests
 	30mouse
 	31position
 	32modereport
+	33focus
 	39csi)
 
 if (BUILD_TESTING)

LICENSE

@@ -1,5 +1,5 @@
 Copyright (c) 2007-2014 Paul Evans <leonerd@leonerd.org.uk>
-Copyright (c) 2014 Přemysl Eric Janouch <p@janouch.name>
+Copyright (c) 2014-2020 Přemysl Eric Janouch <p@janouch.name>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

driver-csi.c

@@ -331,6 +331,33 @@ handle_csi_m (termo_t *tk, termo_key_t *key, int cmd, long *arg, int args)
 	return TERMO_RES_NONE;
 }
 
+//
+// Handler for CSI I / CSI O focus events
+//
+
+static termo_result_t
+handle_csi_IO (termo_t *tk, termo_key_t *key, int cmd, long *arg, int args)
+{
+	(void) tk;
+	(void) arg;
+	(void) args;
+
+	switch (cmd &= 0xff)
+	{
+	case 'I':
+		key->type = TERMO_TYPE_FOCUS;
+		key->code.focused = true;
+		return TERMO_RES_KEY;
+	case 'O':
+		key->type = TERMO_TYPE_FOCUS;
+		key->code.focused = false;
+		return TERMO_RES_KEY;
+	default:
+		return TERMO_RES_NONE;
+	}
+	return TERMO_RES_NONE;
+}
+
 termo_result_t
 termo_interpret_mouse (termo_t *tk, const termo_key_t *key,
 	termo_mouse_event_t *event, int *button, int *line, int *col)
@@ -671,6 +698,9 @@ register_keys (void)
 	csi_handlers['M' - 0x20] = &handle_csi_m;
 	csi_handlers['m' - 0x20] = &handle_csi_m;
 
+	csi_handlers['I' - 0x20] = &handle_csi_IO;
+	csi_handlers['O' - 0x20] = &handle_csi_IO;
+
 	csi_handlers['R' - 0x20] = &handle_csi_R;
 
 	csi_handlers['y' - 0x20] = &handle_csi_y;

termo.c

@@ -156,6 +156,9 @@ print_key (termo_t *tk, termo_key_t *key)
 			ev, button, line, col);
 		break;
 	}
+	case TERMO_TYPE_FOCUS:
+		fprintf (stderr, "%s\n", key->code.focused ? "Focused" : "Defocused");
+		break;
 	case TERMO_TYPE_POSITION:
 	{
 		int line, col;
@@ -1572,6 +1575,8 @@ termo_strfkey_generic (termo_t *tk, char *buffer, size_t len,
 		}
 		break;
 	}
+	case TERMO_TYPE_FOCUS:
+		l = snprintf (buffer + pos, len - pos, "Focus(%d)", key->code.focused);
 	case TERMO_TYPE_POSITION:
 		l = snprintf (buffer + pos, len - pos, "Position");
 		break;
@@ -1826,6 +1831,8 @@ termo_keycmp (termo_t *tk,
 			return cmp;
 		break;
 	}
+	case TERMO_TYPE_FOCUS:
+		return key1.code.focused - key2.code.focused;
 	case TERMO_TYPE_POSITION:
 	{
 		int line1, col1, line2, col2;

termo.h

@@ -97,6 +97,7 @@ enum termo_type
 	TERMO_TYPE_MOUSE,
 	TERMO_TYPE_POSITION,
 	TERMO_TYPE_MODEREPORT,
+	TERMO_TYPE_FOCUS,
 	// add other recognised types here
 
 	TERMO_TYPE_UNKNOWN_CSI = -1
@@ -159,6 +160,7 @@ struct termo_key
 		uint32_t    codepoint; // TERMO_TYPE_KEY
 		int         number;    // TERMO_TYPE_FUNCTION
 		termo_sym_t sym;       // TERMO_TYPE_KEYSYM
+		int         focused;   // TERMO_TYPE_FOCUS
 
 		// TERMO_TYPE_MODEREPORT
 		// opaque, see termo_interpret_modereport()

tests/33focus.c

@@ -0,0 +1,28 @@
+#include "../termo.h"
+#include "taplib.h"
+
+int
+main (int argc, char *argv[])
+{
+	termo_t *tk;
+	termo_key_t key;
+
+	plan_tests (6);
+
+	tk = termo_new_abstract ("vt100", NULL, 0);
+
+	termo_push_bytes (tk, "\e[I", 3);
+	is_int (termo_getkey (tk, &key), TERMO_RES_KEY,
+		"getkey yields RES_KEY for focus in");
+	is_int (key.type, TERMO_TYPE_FOCUS, "key.type for focus in");
+	is_int (key.code.focused, 1, "focused indicator for focus in");
+
+	termo_push_bytes (tk, "\e[O", 3);
+	is_int (termo_getkey (tk, &key), TERMO_RES_KEY,
+		"getkey yields RES_KEY for focus out");
+	is_int (key.type, TERMO_TYPE_FOCUS, "key.type for focus out");
+	is_int (key.code.focused, 0, "focused indicator for focus out");
+
+	termo_destroy (tk);
+	return exit_status ();
+}