4 files changed, 51 insertions, 6 deletions

diff --git a/include/cru/ui/ThemeManager.hpp b/include/cru/ui/ThemeManager.hpp
index be9daa47..68c2b121 100644
--- a/include/cru/ui/ThemeManager.hpp
+++ b/include/cru/ui/ThemeManager.hpp
@@ -8,6 +8,9 @@
 #include "cru/ui/style/StyleRuleSet.hpp"
 #include "cru/xml/XmlNode.hpp"
 
+#include <any>
+#include <typeindex>
+#include <typeinfo>
 #include <unordered_map>
 
 namespace cru::ui {
@@ -40,6 +43,8 @@ class CRU_UI_API ThemeManager : public Object {
 
   void ReadResourcesFile(const String& file_path);
 
+  void SetThemeXml(xml::XmlElementNode* root);
+
   template <typename T>
   T GetResource(const String& key) {
     auto find_result = theme_resource_map_.find(key);
@@ -48,9 +53,17 @@ class CRU_UI_API ThemeManager : public Object {
           Format(u"Theme resource key \"%s\" not exist.", key));
     }
 
+    auto& cache = find_result->second.cache;
+    auto cache_find_result = cache.find(typeid(T));
+    if (cache_find_result != cache.cend()) {
+      return std::any_cast<T>(cache_find_result->second);
+    }
+
     auto mapper_registry = mapper::MapperRegistry::GetInstance();
     auto mapper = mapper_registry->GetMapper<T>();
-    return mapper->MapFromXml(find_result->second);
+    auto resource = mapper->MapFromXml(find_result->second.xml_node);
+    cache[typeid(T)] = resource;
+    return resource;
   }
 
   std::shared_ptr<platform::graphics::IBrush> GetResourceBrush(
@@ -62,8 +75,18 @@ class CRU_UI_API ThemeManager : public Object {
       const String& key);
 
  private:
+  struct ResourceEntry {
+    CRU_DEFAULT_CONSTRUCTOR_DESTRUCTOR(ResourceEntry)
+    CRU_DEFAULT_COPY(ResourceEntry)
+    CRU_DEFAULT_MOVE(ResourceEntry)
+
+    String name;
+    xml::XmlElementNode* xml_node;
+    std::unordered_map<std::type_index, std::any> cache;
+  };
+
   Event<std::nullptr_t> theme_resource_change_event_;
   std::unique_ptr<xml::XmlElementNode> theme_resource_xml_root_;
-  std::unordered_map<String, xml::XmlElementNode*> theme_resource_map_;
+  std::unordered_map<String, ResourceEntry> theme_resource_map_;
 };
 }  // namespace cru::ui
diff --git a/include/cru/xml/XmlNode.hpp b/include/cru/xml/XmlNode.hpp
index d1cb9430..cfe6e155 100644
--- a/include/cru/xml/XmlNode.hpp
+++ b/include/cru/xml/XmlNode.hpp
@@ -121,6 +121,7 @@ class CRU_XML_API XmlElementNode : public XmlNode {
   void AddAttribute(String key, String value);
   void AddChild(XmlNode* child);
 
+  Index GetChildElementCount() const;
   XmlElementNode* GetFirstChildElement() const;
 
   XmlNode* Clone() const override;
diff --git a/src/ui/ThemeManager.cpp b/src/ui/ThemeManager.cpp
index dc08edb3..be980e8c 100644
--- a/src/ui/ThemeManager.cpp
+++ b/src/ui/ThemeManager.cpp
@@ -49,11 +49,15 @@ void ThemeManager::ReadResourcesFile(const String& file_path) {
   io::FileStream stream(file_path, io::OpenFileFlags::Read);
   auto xml_string = stream.ReadAllAsString();
   auto parser = xml::XmlParser(xml_string);
-  theme_resource_xml_root_.reset(parser.Parse());
+  SetThemeXml(parser.Parse());
+}
+
+void ThemeManager::SetThemeXml(xml::XmlElementNode* root) {
+  theme_resource_xml_root_.reset(root);
   theme_resource_map_.clear();
 
   if (!theme_resource_xml_root_->GetTag().CaseInsensitiveEqual(u"Theme")) {
-    throw Exception(u"Root tag of theme resource file must be \"Theme\".");
+    throw Exception(u"Root tag of theme must be \"Theme\".");
   }
 
   for (auto child : theme_resource_xml_root_->GetChildren()) {
@@ -64,10 +68,20 @@ void ThemeManager::ReadResourcesFile(const String& file_path) {
         if (!key_attr) {
           throw Exception(u"\"key\" attribute is required for resource.");
         }
-        theme_resource_map_[*key_attr] = c->GetFirstChildElement();
+        if (!c->GetChildElementCount()) {
+          throw Exception(u"Resource must have only one child element.");
+        }
+
+        ResourceEntry entry;
+
+        entry.name = *key_attr;
+        entry.xml_node = c->GetFirstChildElement();
+
+        theme_resource_map_[entry.name] = std::move(entry);
       }
     }
   }
-}
 
+  theme_resource_change_event_.Raise(nullptr);
+}
 }  // namespace cru::ui
diff --git a/src/xml/XmlNode.cpp b/src/xml/XmlNode.cpp
index 79847544..00437f9b 100644
--- a/src/xml/XmlNode.cpp
+++ b/src/xml/XmlNode.cpp
@@ -1,4 +1,5 @@
 #include "cru/xml/XmlNode.hpp"
+#include <algorithm>
 
 namespace cru::xml {
 
@@ -32,6 +33,12 @@ void XmlElementNode::AddChild(XmlNode* child) {
   child->parent_ = this;
 }
 
+Index XmlElementNode::GetChildElementCount() const {
+  return std::count_if(
+      children_.cbegin(), children_.cend(),
+      [](xml::XmlNode* node) { return node->IsElementNode(); });
+}
+
 XmlElementNode* XmlElementNode::GetFirstChildElement() const {
   for (auto child : children_) {
     if (child->GetType() == XmlNode::Type::Element) {