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Diffstat (limited to 'api/dead/src/resources/Resource.h')
-rw-r--r-- | api/dead/src/resources/Resource.h | 132 |
1 files changed, 0 insertions, 132 deletions
diff --git a/api/dead/src/resources/Resource.h b/api/dead/src/resources/Resource.h deleted file mode 100644 index 63e97b88..00000000 --- a/api/dead/src/resources/Resource.h +++ /dev/null @@ -1,132 +0,0 @@ -#pragma once - -#include <QString> -#include <QMap> -#include <QVariant> -#include <functional> -#include <memory> - -#include "ResourceObserver.h" -#include "TypeMagic.h" - -#include "multimc_logic_export.h" - -class ResourceHandler; - -/** Frontend class for resources - * - * Usage: - * Resource::create("icon:noaccount")->applyTo(accountsAction); - * Resource::create("web:http://asdf.com/image.png")->applyTo(imageLbl)->placeholder(Resource::create("icon:loading")); - * - * Memory management: - * Resource caches ResourcePtrs using weak pointers, so while a resource is still existing - * when a new resource is created the resources will be the same (including the same handler). - * - * ResourceObservers keep a shared pointer to the resource, as does the Resource itself to it's - * placeholder (if present). This means a resource stays valid while it's still used ("applied to" etc.) - * by something. When nothing uses it anymore it gets deleted. - * - * @note Always pass resource around using Resource::Ptr! Copy and move constructors are disabled for a reason. - */ -class MULTIMC_LOGIC_EXPORT Resource : public std::enable_shared_from_this<Resource> -{ - // only allow creation from Resource::create and disallow passing around non-pointers - explicit Resource(const QString &resource); - Resource(const Resource &) = delete; - Resource(Resource &&) = delete; -public: - using Ptr = std::shared_ptr<Resource>; - - ~Resource(); - - /// The returned pointer needs to be stored until either Resource::applyTo or Resource::then is called, or it is passed as - /// a placeholder to Resource::create itself. - static Ptr create(const QString &resource, Ptr placeholder = nullptr); - - /// Use these functions to specify what should happen when e.g. the resource changes - Ptr applyTo(ResourceObserver *observer); - Ptr applyTo(QObject *target, const char *property = nullptr); - template<typename Func> - Ptr then(Func &&func) - { - // Arg will be the functions argument with references and cv-qualifiers (const, volatile) removed - using Arg = TypeMagic::CleanType<typename TypeMagic::Function<Func>::Argument>; - // Ret will be the functions return type - using Ret = typename TypeMagic::Function<Func>::ReturnType; - - // FunctionResourceObserver<ReturnType, ArgumentType, FunctionSignature> - return applyTo(new FunctionResourceObserver<Ret, Arg, Func>(std::forward<Func>(func))); - } - - /// Retrieve the currently active resource. If it's type is different from T a conversion will be attempted. - template<typename T> - T getResource() const { return getResourceInternal(qMetaTypeId<T>()).template value<T>(); } - - /// @internal Used by ResourceObserver and ResourceProxyModel - QVariant getResourceInternal(const int typeId) const; - - /** Register a new ResourceHandler. T needs to inherit from ResourceHandler - * Usage: Resource::registerHandler<MyResourceHandler>("myid"); - */ - template<typename T> - static void registerHandler(const QString &id) - { - m_handlers.insert(id, [](const QString &res) { return std::make_shared<T>(res); }); - } - /** Register a new resource transformer - * Resource transformers are functions that are responsible for converting between different types, - * for example converting from a QByteArray to a QPixmap. They are registered "externally" because not - * all types might be available in this library, for example gui types like QPixmap. - * - * Usage: Resource::registerTransformer([](const InputType &type) { return OutputType(type); }); - * This assumes that OutputType has a constructor that takes InputType as an argument. More - * complicated transformers can of course also be registered. - * - * When a ResourceObserver requests a type that's different from the actual resource type, a matching - * transformer will be looked up from the list of transformers. - * @note Only one-stage transforms will be performed (you can't registerTransformers for QString => int - * and int => float and expect QString to automatically be transformed into a float. - */ - template<typename Func> - static void registerTransformer(Func &&func) - { - using Out = typename TypeMagic::Function<Func>::ReturnType; - using In = TypeMagic::CleanType<typename TypeMagic::Function<Func>::Argument>; - static_assert(!std::is_same<Out, In>::value, "It does not make sense to transform a value to itself"); - m_transfomers.insert(qMakePair(qMetaTypeId<In>(), qMetaTypeId<Out>()), [func](const QVariant &in) - { - return QVariant::fromValue<Out>(func(in.value<In>())); - }); - } - -private: // half private, implementation details - friend class ResourceHandler; - // the following three functions are called by ResourceHandlers - /** Notifies the observers. They will call Resource::getResourceInternal which will call ResourceHandler::result - * or delegate to it's placeholder. - */ - void reportResult(); - void reportFailure(const QString &reason); - void reportProgress(const int progress); - - friend class ResourceObserver; - /// Removes observer from the list of observers so that we don't attempt to notify something that doesn't exist - void notifyObserverDeleted(ResourceObserver *observer); - -private: // truly private - QList<ResourceObserver *> m_observers; - std::shared_ptr<ResourceHandler> m_handler = nullptr; - Ptr m_placeholder = nullptr; - const QString m_resource; - - static QString storageIdentifier(const QString &id, Ptr placeholder = nullptr); - QString storageIdentifier() const; - - // a list of resource handler factories, registered using registerHandler - static QMap<QString, std::function<std::shared_ptr<ResourceHandler>(const QString &)>> m_handlers; - // a list of resource transformers, registered using registerTransformer - static QMap<QPair<int, int>, std::function<QVariant(QVariant)>> m_transfomers; - // a list of resources so that we can reuse them - static QMap<QString, std::weak_ptr<Resource>> m_resources; -}; |