Add select entities and implement template select (#2067)

Co-authored-by: Otto Winter <otto@otto-winter.com>

esphome/core/application.h

@@ -35,6 +35,9 @@
 #ifdef USE_NUMBER
 #include "esphome/components/number/number.h"
 #endif
+#ifdef USE_SELECT
+#include "esphome/components/select/select.h"
+#endif
 
 namespace esphome {
 
@@ -89,6 +92,10 @@ class Application {
   void register_number(number::Number *number) { this->numbers_.push_back(number); }
 #endif
 
+#ifdef USE_SELECT
+  void register_select(select::Select *select) { this->selects_.push_back(select); }
+#endif
+
   /// Register the component in this Application instance.
   template<class C> C *register_component(C *c) {
     static_assert(std::is_base_of<Component, C>::value, "Only Component subclasses can be registered");
@@ -224,6 +231,15 @@ class Application {
     return nullptr;
   }
 #endif
+#ifdef USE_SELECT
+  const std::vector<select::Select *> &get_selects() { return this->selects_; }
+  select::Select *get_select_by_key(uint32_t key, bool include_internal = false) {
+    for (auto *obj : this->selects_)
+      if (obj->get_object_id_hash() == key && (include_internal || !obj->is_internal()))
+        return obj;
+    return nullptr;
+  }
+#endif
 
   Scheduler scheduler;
 
@@ -264,6 +280,9 @@ class Application {
 #ifdef USE_NUMBER
   std::vector<number::Number *> numbers_{};
 #endif
+#ifdef USE_SELECT
+  std::vector<select::Select *> selects_{};
+#endif
 
   std::string name_;
   std::string compilation_time_;

esphome/core/controller.cpp

@@ -59,6 +59,12 @@ void Controller::setup_controller() {
       obj->add_on_state_callback([this, obj](float state) { this->on_number_update(obj, state); });
   }
 #endif
+#ifdef USE_SELECT
+  for (auto *obj : App.get_selects()) {
+    if (!obj->is_internal())
+      obj->add_on_state_callback([this, obj](const std::string &state) { this->on_select_update(obj, state); });
+  }
+#endif
 }
 
 }  // namespace esphome

esphome/core/controller.h

@@ -28,6 +28,9 @@
 #ifdef USE_NUMBER
 #include "esphome/components/number/number.h"
 #endif
+#ifdef USE_SELECT
+#include "esphome/components/select/select.h"
+#endif
 
 namespace esphome {
 
@@ -61,6 +64,9 @@ class Controller {
 #ifdef USE_NUMBER
   virtual void on_number_update(number::Number *obj, float state){};
 #endif
+#ifdef USE_SELECT
+  virtual void on_select_update(select::Select *obj, const std::string &state){};
+#endif
 };
 
 }  // namespace esphome

esphome/core/defines.h

@@ -14,6 +14,7 @@
 #define USE_LIGHT
 #define USE_CLIMATE
 #define USE_NUMBER
+#define USE_SELECT
 #define USE_MQTT
 #define USE_POWER_SUPPLY
 #define USE_HOMEASSISTANT_TIME