key-state.c: generalize set operations

src/common/meson.build

@@ -16,6 +16,7 @@ labwc_sources += files(
   'scaled-font-buffer.c',
   'scaled-scene-buffer.c',
   'scene-helpers.c',
+  'set.c',
   'surface-helpers.c',
   'spawn.c',
   'string-helpers.c',

src/common/set.c

@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <wlr/util/log.h>
+#include "common/set.h"
+
+bool
+lab_set_contains(struct lab_set *set, uint32_t value)
+{
+	for (int i = 0; i < set->size; ++i) {
+		if (set->values[i] == value) {
+			return true;
+		}
+	}
+	return false;
+}
+
+void
+lab_set_add(struct lab_set *set, uint32_t value)
+{
+	if (lab_set_contains(set, value)) {
+		return;
+	}
+	if (set->size >= LAB_SET_MAX_SIZE) {
+		wlr_log(WLR_ERROR, "lab_set size exceeded");
+		return;
+	}
+	set->values[set->size++] = value;
+}
+
+void
+lab_set_remove(struct lab_set *set, uint32_t value)
+{
+	bool shifting = false;
+
+	for (int i = 0; i < LAB_SET_MAX_SIZE; ++i) {
+		if (set->values[i] == value) {
+			--set->size;
+			shifting = true;
+		}
+		if (shifting) {
+			set->values[i] = i < LAB_SET_MAX_SIZE - 1
+				? set->values[i + 1] : 0;
+		}
+	}
+}