Add LIBTERMINPUT_SEPARATE_BACKTAB and LIBTERMINPUT_ESC_ON_BLOCK

Signed-off-by: Mattias Andrée <maandree@kth.se>

3 files changed, 44 insertions, 9 deletions

diff --git a/interactive-test.c b/interactive-test.c
index e38b638..57bb20c 100644
--- a/interactive-test.c
+++ b/interactive-test.c
@@ -34,6 +34,14 @@ main(void)
 		fprintf(stderr, "LIBTERMINPUT_INS_ON_CSI_AT set\n");
 		libterminput_set_flags(&ctx, LIBTERMINPUT_INS_ON_CSI_AT);
 	}
+	if (getenv("TEST_LIBTERMINPUT_SEPARATE_BACKTAB")) {
+		fprintf(stderr, "LIBTERMINPUT_SEPARATE_BACKTAB set\n");
+		libterminput_set_flags(&ctx, LIBTERMINPUT_SEPARATE_BACKTAB);
+	}
+	if (getenv("TEST_LIBTERMINPUT_ESC_ON_BLOCK")) {
+		fprintf(stderr, "LIBTERMINPUT_ESC_ON_BLOCK set\n");
+		libterminput_set_flags(&ctx, LIBTERMINPUT_ESC_ON_BLOCK);
+	}
 
 	if (tcgetattr(STDERR_FILENO, &stty)) {
 		perror("tcgetattr STDERR_FILENO");
@@ -61,6 +69,7 @@ main(void)
 			case LIBTERMINPUT_LEFT:            printf("\t%s: %s\n", "key", "left");            break;
 			case LIBTERMINPUT_BEGIN:           printf("\t%s: %s\n", "key", "begin");           break;
 			case LIBTERMINPUT_TAB:             printf("\t%s: %s\n", "key", "tab");             break;
+			case LIBTERMINPUT_BACKTAB:         printf("\t%s: %s\n", "key", "backtab");         break;
 			case LIBTERMINPUT_F1:              printf("\t%s: %s\n", "key", "f1");              break;
 			case LIBTERMINPUT_F2:              printf("\t%s: %s\n", "key", "f2");              break;
 			case LIBTERMINPUT_F3:              printf("\t%s: %s\n", "key", "f3");              break;
diff --git a/libterminput.c b/libterminput.c
index 95a4e03..7ca36de 100644
--- a/libterminput.c
+++ b/libterminput.c
@@ -63,7 +63,14 @@ again:
 			}
 		}
 	} else if (c == 033 && !*ctx->key) {
-		/* ESC at the beginning, save as a Meta/ESC */
+		/* ESC at the beginning, save as a Meta/ESC (for default behaviour) */
+		if ((ctx->flags & LIBTERMINPUT_ESC_ON_BLOCK) && ctx->stored_tail == ctx->stored_head) {
+			input->symbol[0] = (char)c;
+			input->symbol[1] = '\0';
+			input->mods = ctx->mods;
+			ctx->mods = 0;
+			return 1;
+		}
 		ctx->meta += 1;
 	} else if (c == 0) {
 		/* CTRL on Space */
@@ -430,8 +437,12 @@ parse_sequence(union libterminput_input *input, struct libterminput_state *ctx)
 			case 'U': input->keypress.key = LIBTERMINPUT_NEXT;  break;
 			case 'V': input->keypress.key = LIBTERMINPUT_PRIOR; break;
 			case 'Z':
-				input->keypress.key = LIBTERMINPUT_TAB;
-				input->keypress.mods |= LIBTERMINPUT_SHIFT;
+				if (!(ctx->flags & LIBTERMINPUT_SEPARATE_BACKTAB)) {
+					input->keypress.key = LIBTERMINPUT_TAB;
+					input->keypress.mods |= LIBTERMINPUT_SHIFT;
+				} else {
+					input->keypress.key = LIBTERMINPUT_BACKTAB;
+				}
 				break;
 			case 'a':
 				input->keypress.key = LIBTERMINPUT_UP;
@@ -847,6 +858,10 @@ again:
 			input->keypress.key = LIBTERMINPUT_ENTER;
 			input->keypress.symbol[0] = '\0';
 			break;
+		case 033:
+			input->keypress.key = LIBTERMINPUT_ESC;
+			input->keypress.symbol[0] = '\0';
+			break;
 		default:
 			input->keypress.key = LIBTERMINPUT_SYMBOL;
 			strcpy(input->keypress.symbol, ret.symbol);
diff --git a/libterminput.h b/libterminput.h
index 7e94564..8318dff 100644
--- a/libterminput.h
+++ b/libterminput.h
@@ -12,10 +12,20 @@
  * terminal support this flag if set.
  */
 enum libterminput_flags {
-	LIBTERMINPUT_DECSET_1005    = 0x0001,
-	LIBTERMINPUT_MACRO_ON_CSI_M = 0x0002,
-	LIBTERMINPUT_PAUSE_ON_CSI_P = 0x0004,
-	LIBTERMINPUT_INS_ON_CSI_AT  = 0x0008
+	LIBTERMINPUT_DECSET_1005      = 0x0001,
+	LIBTERMINPUT_MACRO_ON_CSI_M   = 0x0002,
+	LIBTERMINPUT_PAUSE_ON_CSI_P   = 0x0004,
+	LIBTERMINPUT_INS_ON_CSI_AT    = 0x0008,
+	LIBTERMINPUT_SEPARATE_BACKTAB = 0x0010,
+
+	/**
+	 * If an ESC is received without anything after it,
+	 * return ESC keypress. This is not always desirable
+	 * behaviour as the use may manually press ESC to
+	 * simulate a keypress that terminal does not support
+	 * (yes, this is a real world issue).
+	 */
+	LIBTERMINPUT_ESC_ON_BLOCK     = 0x0020
 };
 
 enum libterminput_mod {
@@ -30,8 +40,9 @@ enum libterminput_key {
 	LIBTERMINPUT_DOWN,
 	LIBTERMINPUT_RIGHT,
 	LIBTERMINPUT_LEFT,
-	LIBTERMINPUT_BEGIN, /* keypad 5 without numlock */
-	LIBTERMINPUT_TAB,   /* backtab if with shift */
+	LIBTERMINPUT_BEGIN,   /* keypad 5 without numlock */
+	LIBTERMINPUT_TAB,     /* backtab is interpreted as shift+tab by default */
+	LIBTERMINPUT_BACKTAB, /* requires LIBTERMINPUT_SEPARATE_BACKTAB */
 	LIBTERMINPUT_F1,
 	LIBTERMINPUT_F2,
 	LIBTERMINPUT_F3,