Add support for matrix keypads (#4241)

Co-authored-by: Samuel Sieb <samuel@sieb.net>

esphome/components/key_provider/__init__.py

@@ -0,0 +1,6 @@
+import esphome.codegen as cg
+
+CODEOWNERS = ["@ssieb"]
+
+key_provider_ns = cg.esphome_ns.namespace("key_provider")
+KeyProvider = key_provider_ns.class_("KeyProvider")

esphome/components/key_provider/key_provider.cpp

@@ -0,0 +1,13 @@
+#include "key_provider.h"
+
+namespace esphome {
+namespace key_provider {
+
+void KeyProvider::add_on_key_callback(std::function<void(uint8_t)> &&callback) {
+  this->key_callback_.add(std::move(callback));
+}
+
+void KeyProvider::send_key_(uint8_t key) { this->key_callback_.call(key); }
+
+}  // namespace key_provider
+}  // namespace esphome

esphome/components/key_provider/key_provider.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "esphome/core/automation.h"
+#include "esphome/core/component.h"
+
+namespace esphome {
+namespace key_provider {
+
+/// interface for components that provide keypresses
+class KeyProvider {
+ public:
+  void add_on_key_callback(std::function<void(uint8_t)> &&callback);
+
+ protected:
+  void send_key_(uint8_t key);
+
+  CallbackManager<void(uint8_t)> key_callback_{};
+};
+
+}  // namespace key_provider
+}  // namespace esphome