[Base] Move Factory class to xenia-base

src/xenia/base/factory.h

@@ -0,0 +1,98 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2020 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_BASE_FACTORY_H_
+#define XENIA_BASE_FACTORY_H_
+
+#include <functional>
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace xe {
+
+template <typename T, typename... Args>
+class Factory {
+ private:
+  struct Creator {
+    std::string name;
+    std::function<bool()> is_available;
+    std::function<std::unique_ptr<T>(Args...)> instantiate;
+  };
+
+  std::vector<Creator> creators_;
+
+ public:
+  void Add(const std::string_view name, std::function<bool()> is_available,
+           std::function<std::unique_ptr<T>(Args...)> instantiate) {
+    creators_.push_back({std::string(name), is_available, instantiate});
+  }
+
+  void Add(const std::string_view name,
+           std::function<std::unique_ptr<T>(Args...)> instantiate) {
+    auto always_available = []() { return true; };
+    Add(name, always_available, instantiate);
+  }
+
+  template <typename DT>
+  void Add(const std::string_view name) {
+    Add(name, DT::IsAvailable, [](Args... args) {
+      return std::make_unique<DT>(std::forward<Args>(args)...);
+    });
+  }
+
+  std::unique_ptr<T> Create(const std::string_view name, Args... args) {
+    if (!name.empty() && name != "any") {
+      auto it = std::find_if(
+          creators_.cbegin(), creators_.cend(),
+          [&name](const auto& f) { return name.compare(f.name) == 0; });
+      if (it != creators_.cend() && (*it).is_available()) {
+        return (*it).instantiate(std::forward<Args>(args)...);
+      }
+      return nullptr;
+    } else {
+      for (const auto& creator : creators_) {
+        if (!creator.is_available()) continue;
+        auto instance = creator.instantiate(std::forward<Args>(args)...);
+        if (!instance) continue;
+        return instance;
+      }
+      return nullptr;
+    }
+  }
+
+  std::vector<std::unique_ptr<T>> CreateAll(const std::string_view name,
+                                            Args... args) {
+    std::vector<std::unique_ptr<T>> instances;
+    if (!name.empty() && name != "any") {
+      auto it = std::find_if(
+          creators_.cbegin(), creators_.cend(),
+          [&name](const auto& f) { return name.compare(f.name) == 0; });
+      if (it != creators_.cend() && (*it).is_available()) {
+        auto instance = (*it).instantiate(std::forward<Args>(args)...);
+        if (instance) {
+          instances.emplace_back(std::move(instance));
+        }
+      }
+    } else {
+      for (const auto& creator : creators_) {
+        if (!creator.is_available()) continue;
+        auto instance = creator.instantiate(std::forward<Args>(args)...);
+        if (instance) {
+          instances.emplace_back(std::move(instance));
+        }
+      }
+    }
+    return instances;
+  }
+};
+
+}  // namespace xe
+
+#endif