libtwrpgui: convert gui to use new ziparchive library

Change-Id: Iea94855257c6d02c2f663c25d390cb1cfb91a727
diff --git a/minuitwrp/include/private/resources.h b/minuitwrp/include/private/resources.h
new file mode 100644
index 0000000..047ebe2
--- /dev/null
+++ b/minuitwrp/include/private/resources.h
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#pragma once
+
+#include <stdio.h>
+
+#include <memory>
+#include <string>
+
+#include <png.h>
+
+// This class handles the PNG file parsing. It also holds the ownership of the PNG pointer and the
+// opened file pointer. Both will be destroyed / closed when this object goes out of scope.
+class PngHandler {
+ public:
+  // Constructs an instance by loading the PNG file from '/res/images/<name>.png', or '<name>'.
+  PngHandler(const std::string& name);
+
+  ~PngHandler();
+
+  png_uint_32 width() const {
+    return width_;
+  }
+
+  png_uint_32 height() const {
+    return height_;
+  }
+
+  png_byte channels() const {
+    return channels_;
+  }
+
+  int bit_depth() const {
+    return bit_depth_;
+  }
+
+  int color_type() const {
+    return color_type_;
+  }
+
+  png_structp png_ptr() const {
+    return png_ptr_;
+  }
+
+  png_infop info_ptr() const {
+    return info_ptr_;
+  }
+
+  int error_code() const {
+    return error_code_;
+  };
+
+  operator bool() const {
+    return error_code_ == 0;
+  }
+
+ private:
+  png_structp png_ptr_{ nullptr };
+  png_infop info_ptr_{ nullptr };
+  png_uint_32 width_;
+  png_uint_32 height_;
+  png_byte channels_;
+  int bit_depth_;
+  int color_type_;
+
+  // The |error_code_| is set to a negative value if an error occurs when opening the png file.
+  int error_code_{ 0 };
+  // After initialization, we'll keep the file pointer open before destruction of PngHandler.
+  std::unique_ptr<FILE, decltype(&fclose)> png_fp_{ nullptr, fclose };
+};
+
+// Overrides the default resource dir, for testing purpose.
+void res_set_resource_dir(const std::string&);