editor: react on Enter, Tab, and Up-Down arrow keys

The editor will now insert new lines and tabulations when
pressing the corresponding keys on the virtual keyboard.

The Up and Down arrows can be used to navigate through
lines.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=77496

Signed-off-by: Manuel Bachmann <manuel.bachmann@open.eurogiciel.org>

clients/editor.c

@@ -110,6 +110,47 @@ utf8_next_char(const char *p)
 	return NULL;
 }
 
+static void
+move_up(const char *p, uint32_t *cursor)
+{
+	const char *posr, *posr_i;
+	char text[16];
+
+	xkb_keysym_to_utf8(XKB_KEY_Return, text, sizeof(text));
+
+	posr = strstr(p, text);
+	while (posr) {
+		if (*cursor > (unsigned)(posr-p)) {
+			posr_i = strstr(posr+1, text);
+			if (!posr_i || !(*cursor > (unsigned)(posr_i-p))) {
+				*cursor = posr-p;
+				break;
+			}
+			posr = posr_i;
+		} else {
+			break;
+		}
+	}
+}
+
+static void
+move_down(const char *p, uint32_t *cursor)
+{
+	const char *posr;
+	char text[16];
+
+	xkb_keysym_to_utf8(XKB_KEY_Return, text, sizeof(text));
+
+	posr = strstr(p, text);
+	while (posr) {
+		if (*cursor <= (unsigned)(posr-p)) {
+			*cursor = posr-p + 1;
+			break;
+		}
+		posr = strstr(posr+1, text);
+	}
+}
+
 static void text_entry_redraw_handler(struct widget *widget, void *data);
 static void text_entry_button_handler(struct widget *widget,
 				      struct input *input, uint32_t time,
@@ -374,6 +415,23 @@ text_input_keysym(void *data,
 		return;
 	}
 
+	if (key == XKB_KEY_Up ||
+	    key == XKB_KEY_Down) {
+		if (state != WL_KEYBOARD_KEY_STATE_RELEASED)
+			return;
+
+		if (key == XKB_KEY_Up)
+			move_up(entry->text, &entry->cursor);
+		else
+			move_down(entry->text, &entry->cursor);
+
+		if (!(modifiers & entry->keysym.shift_mask))
+			entry->anchor = entry->cursor;
+		widget_schedule_redraw(entry->widget);
+
+		return;
+	}
+
 	if (key == XKB_KEY_BackSpace) {
 		const char *start, *end;
 
@@ -395,17 +453,20 @@ text_input_keysym(void *data,
 		return;
 	}
 
-	switch (key) {
-		case XKB_KEY_Tab:
-			key_label = "Tab";
-			break;
-		case XKB_KEY_KP_Enter:
-		case XKB_KEY_Return:
-			key_label = "Enter";
-			break;
-	}
+	if (key == XKB_KEY_Tab ||
+	    key == XKB_KEY_KP_Enter ||
+	    key == XKB_KEY_Return) {
+		char text[16];
+
+		if (state != WL_KEYBOARD_KEY_STATE_RELEASED)
+			return;
+
+		xkb_keysym_to_utf8(key, text, sizeof(text));
+
+		text_entry_insert_at_cursor(entry, text, 0, 0);
 
-	fprintf(stderr, "%s key was %s.\n", key_label, state_label);
+		return;
+	}
 }
 
 static void
@@ -1208,6 +1269,22 @@ key_handler(struct window *window,
 				widget_schedule_redraw(entry->widget);
 			}
 			break;
+		case XKB_KEY_Up:
+			text_entry_commit_and_reset(entry);
+
+			move_up(entry->text, &entry->cursor);
+			if (!(input_get_modifiers(input) & MOD_SHIFT_MASK))
+				entry->anchor = entry->cursor;
+			widget_schedule_redraw(entry->widget);
+			break;
+		case XKB_KEY_Down:
+			text_entry_commit_and_reset(entry);
+
+			move_down(entry->text, &entry->cursor);
+			if (!(input_get_modifiers(input) & MOD_SHIFT_MASK))
+				entry->anchor = entry->cursor;
+			widget_schedule_redraw(entry->widget);
+			break;
 		case XKB_KEY_Escape:
 			break;
 		default: