game: add missing file

src/game/caching-source-builder.h

@@ -0,0 +1,61 @@
+#pragma once
+
+#include <tb/tb_select_item.h>
+
+static inline bool operator==(const tb::TBGenericStringItem &item0, const tb::TBGenericStringItem &item1)
+{
+  return item0.str == item1.str && item0.id == item1.id
+      && item0.skin_image == item1.skin_image && item0.sub_source == item1.sub_source && item0.state == item1.state
+      && item0.tag.Equals(item1.tag);
+}
+
+template<class T>
+class CachingSourceBuilder
+{
+private:
+  struct holder_t: public tb::TBGenericStringItem
+  {
+    T *item;
+
+    holder_t(T *item): TBGenericStringItem(""), item(item) {}
+  };
+
+public:
+  CachingSourceBuilder(tb::TBSelectItemSourceList<T> &source): old_source(source) {}
+
+  ~CachingSourceBuilder()
+  {
+    const int n_items = new_source.GetNumItems();
+    if (!Changed())
+    {
+      for (int i = 0; i < n_items; ++i)
+        delete new_source.GetItem(i)->item;
+      return;
+    }
+    old_source.DeleteAllItems();
+    for (int i = 0; i < n_items; ++i)
+    {
+      old_source.AddItem(new_source.GetItem(i)->item);
+    }
+  }
+
+  void AddItem(T *item) { new_source.AddItem(new holder_t(item)); }
+
+protected:
+  bool Changed() const
+  {
+    if (old_source.GetNumItems() != new_source.GetNumItems())
+      return true;
+    const int n_items = old_source.GetNumItems();
+    for (int i = 0; i < n_items; ++i)
+    {
+      if (!(*old_source.GetItem(i) == *new_source.GetItem(i)->item))
+        return true;
+    }
+    return false;
+  }
+
+private:
+  tb::TBSelectItemSourceList<T> &old_source;
+  tb::TBSelectItemSourceList<holder_t> new_source;
+};