mjblack · mjblack · Oct 26, 2024 · Oct 26, 2024
diff --git a/src/winmd.cr b/src/winmd.cr
@@ -170,6 +170,11 @@ module WinMD
         f.write_string(main_file_slice)
         f.close
       end
+      comptr_file_slice = ECR.render("./src/winmd/ecr/com_ptr.ecr").to_slice
+      ::File.open(dir.join("src/" + WinMD.top_level_namespace.downcase + "/com_ptr.cr"), "w") do |f|
+        f.write_string(comptr_file_slice)
+        f.close
+      end
     rescue e : Exception
       puts "Failed to create main file"
       puts e.message

diff --git a/src/winmd/ecr/com_ptr.ecr b/src/winmd/ecr/com_ptr.ecr
@@ -0,0 +1,43 @@
+module <%= WinMD.top_level_namespace %>
+  class ComPtr(T)
+    @ptr : Pointer(T)
+
+    def initialize(@ptr : T*)
+    end
+
+    def address
+      @ptr.address
+    end
+
+    def to_unsafe
+      @ptr
+    end
+
+    def release
+      if @ptr
+        @ptr.value.release(@ptr)
+      end
+    end
+
+    def finalize
+      release
+    end
+
+    def self.new(clsid : LibC::GUID, iid : LibC::GUID, clsctx : Win32cr::System::Com::CLSCTX = Win32cr::System::Com::CLSCTX::CLSCTX_ALL)
+      result = Win32cr::System::Com::C.CoCreateInstance(pointerof(clsid), nil, clsctx, pointerof(iid), out ptr)
+      unless result == Win32cr::Foundation::S_OK
+        raise RuntimeError.new "Failed to create COM instance. (error #{result})"
+      end
+      new(ptr.as(Pointer(T)))
+    end
+
+    macro method_missing(method)
+      \{% begin %}
+        \{% unless m = T.instance.methods.find(&.name. == {{method.name.stringify}}) %}
+          \{% raise "No method named #{{{method.name.stringify}}} in #{T.name.stringify}" %}
+        \{% end %}
+        @ptr.value.{{method.name}}(@ptr, {{method.args.splat}})
+      \{% end %}
+    end
+  end
+end
diff --git a/src/winmd/ecr/library_main.ecr b/src/winmd/ecr/library_main.ecr
@@ -1,3 +1,5 @@
+require "./<%= WinMD.top_level_namespace.downcase %>/com_ptr"
+
 module <%= WinMD.top_level_namespace %>
   VERSION = {{ `shards version #{__DIR__}`.chomp.stringify }}
 end