4 files changed, 49 insertions, 17 deletions
diff --git a/include/cru/common/Exception.h b/include/cru/common/Exception.h
index d7e32a5a..06a10030 100644
--- a/include/cru/common/Exception.h
+++ b/include/cru/common/Exception.h
@@ -1,6 +1,8 @@
 #pragma once
 #include "String.h"
 
+#include <optional>
+
 namespace cru {
 #ifdef _MSC_VER
 #pragma warning(disable : 4275)
@@ -23,6 +25,9 @@ class CRU_BASE_API Exception : public std::exception {
  protected:
   void SetMessage(String message) { message_ = std::move(message); }
 
+  void AppendMessage(StringView additional_message);
+  void AppendMessage(std::optional<StringView> additional_message);
+
  private:
   String message_;
   mutable std::string utf8_message_;
diff --git a/include/cru/platform/Check.h b/include/cru/platform/Check.h
index 8dc4faac..453521cc 100644
--- a/include/cru/platform/Check.h
+++ b/include/cru/platform/Check.h
@@ -2,7 +2,6 @@
 #include "Exception.h"
 #include "Resource.h"
 
-#include "cru/common/Format.h"
 #include "cru/common/String.h"
 
 #include <memory>
@@ -15,10 +14,9 @@ TTarget* CheckPlatform(IPlatformResource* resource,
   if (resource == nullptr) return nullptr;
   const auto result = dynamic_cast<TTarget*>(resource);
   if (result == nullptr) {
-    throw UnsupportPlatformException(Format(
-        u"Try to convert resource to target platform failed. Platform id of "
-        "resource to convert: {} . Target platform id: {} .",
-        resource->GetPlatformId(), target_platform));
+    throw PlatformNotMatchException(
+        resource->GetPlatformId(), target_platform,
+        u"Try to convert resource to target platform failed.");
   }
   return result;
 }
@@ -31,10 +29,9 @@ std::shared_ptr<TTarget> CheckPlatform(const std::shared_ptr<TSource>& resource,
                 "TSource must be a subclass of INativeResource.");
   const auto result = std::dynamic_pointer_cast<TTarget>(resource);
   if (result == nullptr) {
-    throw UnsupportPlatformException(Format(
-        u"Try to convert resource to target platform failed. Platform id of "
-        "resource to convert: {} . Target platform id: {} .",
-        resource->GetPlatformId(), target_platform));
+    throw PlatformNotMatchException(
+        resource->GetPlatformId(), target_platform,
+        u"Try to convert resource to target platform failed.");
   }
   return result;
 }
diff --git a/include/cru/platform/Exception.h b/include/cru/platform/Exception.h
index 7d194d41..d6cda815 100644
--- a/include/cru/platform/Exception.h
+++ b/include/cru/platform/Exception.h
@@ -4,18 +4,26 @@
 #include "cru/common/Exception.h"
 #include "cru/common/platform/Exception.h"
 
+#include <optional>
+
 namespace cru::platform {
 // This exception is thrown when a resource is used on another platform.
 // Of course, you can't mix resources of two different platform.
 // For example, Win32 Brush (may add in the future) with Direct Painter.
-class CRU_PLATFORM_API UnsupportPlatformException : public Exception {
+class CRU_PLATFORM_API PlatformNotMatchException : public PlatformException {
  public:
-  using Exception::Exception;  // inherit constructors
+  PlatformNotMatchException(
+      String resource_platform, String target_platform,
+      std::optional<StringView> additional_message = std::nullopt);
+
+  ~PlatformNotMatchException() override;
 
-  CRU_DEFAULT_COPY(UnsupportPlatformException)
-  CRU_DEFAULT_MOVE(UnsupportPlatformException)
+  String GetResourcePlatform() const;
+  String GetTargetPlatform() const;
 
-  CRU_DEFAULT_DESTRUCTOR(UnsupportPlatformException)
+ private:
+  String resource_platform_;
+  String target_platform_;
 };
 
 // This exception is thrown when a resource has been disposed and not usable
@@ -31,4 +39,19 @@ class CRU_PLATFORM_API ReuseException : public Exception {
 
   CRU_DEFAULT_DESTRUCTOR(ReuseException)
 };
+
+class CRU_PLATFORM_API PlatformUnsupportedException : public PlatformException {
+ public:
+  PlatformUnsupportedException(String platform, String operation,
+                               std::optional<StringView> additional_message);
+
+  ~PlatformUnsupportedException() override;
+
+  String GetPlatform() const;
+  String GetOperation() const;
+
+ private:
+  String platform_;
+  String operation_;
+};
 }  // namespace cru::platform
diff --git a/include/cru/platform/graphics/SvgGeometry.h b/include/cru/platform/graphics/SvgGeometry.h
index 281158f0..742a68ca 100644
--- a/include/cru/platform/graphics/SvgGeometry.h
+++ b/include/cru/platform/graphics/SvgGeometry.h
@@ -3,8 +3,15 @@
 #include "Geometry.h"
 
 namespace cru::platform::graphics {
-class CRU_PLATFORM_GRAPHICS_API SvgGeometryBuilder : public virtual IGeometryBuilder {
+class CRU_PLATFORM_GRAPHICS_API SvgGeometryBuilder
+    : public Object,
+      public virtual IGeometryBuilder {
+ public:
+  SvgGeometryBuilder();
 
-};
-}
+  ~SvgGeometryBuilder() override;
 
+ private:
+  String current_;
+};
+}  // namespace cru::platform::graphics