forgot to commit everything...

user/FadeOnce.h

@@ -0,0 +1,44 @@
+#ifndef FLASHONCE_H
+#define FLASHONCE_H
+
+
+#include "ESP8266lib/ext/led/WS2812B.h"
+
+/** fade between two colors */
+class FadeOnce {
+
+    Color c1;
+    Color c2;
+	int fadeOut_ticks = 0;
+    int ticksLeft = 0;
+
+public:
+
+	/** ctor */
+    FadeOnce() {
+		;
+	}
+
+    void setColor(Color c1, Color c2) {
+        this->c1 = c1;
+        this->c2 = c2;
+	}
+
+    void setFadeDuration(int duration_ticks) {
+		this->fadeOut_ticks = duration_ticks;
+        this->ticksLeft = duration_ticks;
+	}
+
+	void update() {
+        if (ticksLeft > 0) {--ticksLeft;}	// fade-out
+	}
+
+	Color getCurrent() const {
+        const int percent = (ticksLeft * 100 / fadeOut_ticks);
+        return Color::mix(c1, c2, percent);
+	}
+
+};
+
+
+#endif // FLASHONCE_H