pull from android: use registry to build up list of image codecs

git-svn-id: http://skia.googlecode.com/svn/trunk@76 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 50 insertions, 0 deletions

diff --git a/include/core/SkTRegistry.h b/include/core/SkTRegistry.h
new file mode 100644
index 0000000000..83c08de171
--- /dev/null
+++ b/include/core/SkTRegistry.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2009, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef SkTRegistry_DEFINED
+#define SkTRegistry_DEFINED
+
+#include "SkTypes.h"
+
+/** Template class that registers itself (in the constructor) into a linked-list
+    and provides a function-pointer. This can be used to auto-register a set of
+    services, e.g. a set of image codecs.
+ */
+template <typename T, typename P> class SkTRegistry : SkNoncopyable {
+public:
+    typedef T (*Factory)(P);
+
+    SkTRegistry(Factory fact) {
+        fFact = fact;
+        fChain = gHead;
+        gHead = this;
+    }
+
+    static const SkTRegistry* Head() { return gHead; }
+
+    const SkTRegistry* next() const { return fChain; }
+    Factory factory() const { return fFact; }
+
+private:
+    Factory      fFact;
+    SkTRegistry* fChain;
+
+    static SkTRegistry* gHead;
+};
+
+template <typename T, typename P> SkTRegistry<T, P>* SkTRegistry<T, P>::gHead;
+
+#endif