new modole system

core/src/watcher.h

@@ -0,0 +1,34 @@
+#pragma once
+
+template <class T>
+class watcher {
+public:
+    watcher(bool changed = false) {
+        _changed = changed;
+    }
+
+    watcher(T value, bool changed = false) {
+        val = value;
+        _val = value;
+        _changed = changed;
+    }
+
+    bool changed(bool clear = true) {
+        bool ch = ((val != _val) || _changed);
+        if (clear) {
+            _changed = false;
+            _val = val;
+        }
+        return ch;
+    }
+
+    void markAsChanged() {
+        _changed = true;
+    }
+
+    T val;
+
+private:
+    bool _changed;
+    T _val;
+};