Add more demo platforms (#8903)

esphome/components/demo/demo_valve.h

@@ -0,0 +1,50 @@
+#pragma once
+
+#include "esphome/components/valve/valve.h"
+
+namespace esphome {
+namespace demo {
+
+enum class DemoValveType {
+  TYPE_1,
+  TYPE_2,
+};
+
+class DemoValve : public valve::Valve {
+ public:
+  valve::ValveTraits get_traits() override {
+    valve::ValveTraits traits;
+    if (this->type_ == DemoValveType::TYPE_2) {
+      traits.set_supports_position(true);
+      traits.set_supports_toggle(true);
+      traits.set_supports_stop(true);
+    }
+    return traits;
+  }
+
+  void set_type(DemoValveType type) { this->type_ = type; }
+
+ protected:
+  void control(const valve::ValveCall &call) override {
+    if (call.get_position().has_value()) {
+      this->publish_state(*call.get_position());
+      return;
+    } else if (call.get_toggle().has_value()) {
+      if (call.get_toggle().value()) {
+        if (this->position == valve::VALVE_OPEN) {
+          this->publish_state(valve::VALVE_CLOSED);
+        } else {
+          this->publish_state(valve::VALVE_OPEN);
+        }
+      }
+      return;
+    } else if (call.get_stop()) {
+      this->publish_state(this->position);  // Keep the current position
+      return;
+    }
+  }
+  DemoValveType type_{};
+};
+
+}  // namespace demo
+}  // namespace esphome