AAPT2

First checking of AAPT2. The individual phases of AAPT2 work, but there
are some missing pieces.

For early testing we are missing:
- Need to properly mark file references and include them in package
- Need to package into zip

Final AAPT for apps we are missing:
- Need to crush PNGs
- Need to parse 9-patches
- Need to validate all of AndroidManifest.xml
- Need to write align method to align resource tables for splits.

Final AAPT for apps + system we are missing:
- Need to handle overlays
- Need to store comments for R file
- Need to handle --shared-lib (dynamic references too).

New AAPT features coming:
- Need to import compiled libraries
    - Name mangling
    - R file generation for library code

Change-Id: I95f8a63581b81a1f424ae6fb2c373c883b72c18d
diff --git a/tools/aapt2/JavaClassGenerator.h b/tools/aapt2/JavaClassGenerator.h
new file mode 100644
index 0000000..5b8e500
--- /dev/null
+++ b/tools/aapt2/JavaClassGenerator.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2015 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 AAPT_JAVA_CLASS_GENERATOR_H
+#define AAPT_JAVA_CLASS_GENERATOR_H
+
+#include "ResourceTable.h"
+#include "ResourceValues.h"
+
+#include <ostream>
+#include <string>
+
+namespace aapt {
+
+/*
+ * Generates the R.java file for a resource table.
+ */
+class JavaClassGenerator : ConstValueVisitor {
+public:
+    /*
+     * A set of options for this JavaClassGenerator.
+     */
+    struct Options {
+        /*
+         * Specifies whether to use the 'final' modifier
+         * on resource entries. Default is true.
+         */
+        bool useFinal = true;
+    };
+
+    JavaClassGenerator(std::shared_ptr<const ResourceTable> table, Options options);
+
+    /*
+     * Writes the R.java file to `out`. Returns true on success.
+     */
+    bool generate(std::ostream& out);
+
+    /*
+     * ConstValueVisitor implementation.
+     */
+    void visit(const Styleable& styleable, ValueVisitorArgs& args);
+
+    const std::string& getError() const;
+
+private:
+    bool generateType(std::ostream& out, const ResourceTableType& type, size_t packageId);
+
+    std::shared_ptr<const ResourceTable> mTable;
+    Options mOptions;
+    std::string mError;
+};
+
+inline const std::string& JavaClassGenerator::getError() const {
+    return mError;
+}
+
+} // namespace aapt
+
+#endif // AAPT_JAVA_CLASS_GENERATOR_H