CUSceneLoader.h

//
//  CUSceneLoader.h
//  Cornell University Game Library (CUGL)
//
//  This module provides a specific implementation of the Loader class to load
//  a scene graph. Scene graphs are always specified as a JSON tree.  This
//  loader is very experiment, as the language  is still evolving, particularly
//  with regards to layout managers.
//
//  As with all of our loaders, this loader is designed to be attached to an
//  asset manager.  In addition, this class uses our standard shared-pointer
//  architecture.
//
//  1. The constructor does not perform any initialization; it just sets all
//     attributes to their defaults.
//
//  2. All initialization takes place via init methods, which can fail if an
//     object is initialized more than once.
//
//  3. All allocation takes place via static constructors which return a shared
//     pointer.
//
//  WARNING: This loader is highly experimental.  It has only minimal error
//  checking.  It is provided as-is for the UX designers to mock-up simple
//  scenes.
//
//
//  CUGL MIT License:
//      This software is provided 'as-is', without any express or implied
//      warranty.  In no event will the authors be held liable for any damages
//      arising from the use of this software.
//
//      Permission is granted to anyone to use this software for any purpose,
//      including commercial applications, and to alter it and redistribute it
//      freely, subject to the following restrictions:
//
//      1. The origin of this software must not be misrepresented; you must not
//      claim that you wrote the original software. If you use this software
//      in a product, an acknowledgment in the product documentation would be
//      appreciated but is not required.
//
//      2. Altered source versions must be plainly marked as such, and must not
//      be misrepresented as being the original software.
//
//      3. This notice may not be removed or altered from any source distribution.
//
//  Author: Walker White
//  Version: 1/8/18
//
#ifndef __CU_SCENE_LOADER_H__
#define __CU_SCENE_LOADER_H__
#include <cugl/assets/CULoader.h>
#include <cugl/2d/CUNode.h>
#include <unordered_map>

namespace cugl {
    
class AssetManager;

class SceneLoader : public Loader<Node> {
private:
    CU_DISALLOW_COPY_AND_ASSIGN(SceneLoader);
    
protected:
    enum class Widget {
        NODE,
        IMAGE,
        POLY,
        PATH,
        WIRE,
        ANIMATE,
        NINE,
        LABEL,
        BUTTON,
        PROGRESS,
        SLIDER,
        TEXTFIELD,
        UNKNOWN
    };

    enum class Form {
        NONE,
        ANCHORED,
        FLOAT,
        GRID,
        UNKNOWN
    };

    std::unordered_map<std::string,Widget> _types;
    
    std::unordered_map<std::string,Form> _forms;
    
    void materialize(const std::shared_ptr<Node>& node, LoaderCallback callback);
    
    virtual bool read(const std::string& key, const std::string& source,
                      LoaderCallback callback, bool async) override;
    
    virtual bool read(const std::shared_ptr<JsonValue>& json,
                      LoaderCallback callback, bool async) override;
    virtual bool purge(const std::shared_ptr<JsonValue>& json) override;
    
    bool attach(const std::string& key, const std::shared_ptr<Node>& node);
    
public:
#pragma mark -
#pragma mark Constructors

    SceneLoader() {}
    
    virtual bool init() override {
        return init(nullptr);
    }
    
    virtual bool init(const std::shared_ptr<ThreadPool>& threads) override;
    
    void dispose() override {
        _manager = nullptr;
        _assets.clear();
        _loader = nullptr;
        _types.clear();
        _forms.clear();
    }
    
    static std::shared_ptr<SceneLoader> alloc() {
        std::shared_ptr<SceneLoader> result = std::make_shared<SceneLoader>();
        return (result->init() ? result : nullptr);
    }
    
    static std::shared_ptr<SceneLoader> alloc(const std::shared_ptr<ThreadPool>& threads) {
        std::shared_ptr<SceneLoader> result = std::make_shared<SceneLoader>();
        return (result->init(threads) ? result : nullptr);
    }
    
    std::shared_ptr<Node> build(const std::string& key, const std::shared_ptr<JsonValue>& json) const;
    
};
    
}

#endif /* __CU_SCENE_LOADER_H__ */