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authorPetr Mrázek <peterix@gmail.com>2016-04-10 15:53:05 +0200
committerPetr Mrázek <peterix@gmail.com>2016-05-01 00:00:14 +0200
commitb6d455a02bd338e9dc0faa09d4d8177ecd8d569a (patch)
tree41982bca1ede50049f2f8c7109dd18edeefde6d0 /api/logic/resources
parent47e37635f50c09b4f9a9ee7699e3120bab3e4088 (diff)
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NOISSUE reorganize and document libraries
Diffstat (limited to 'api/logic/resources')
-rw-r--r--api/logic/resources/Resource.cpp155
-rw-r--r--api/logic/resources/Resource.h132
-rw-r--r--api/logic/resources/ResourceHandler.cpp28
-rw-r--r--api/logic/resources/ResourceHandler.h36
-rw-r--r--api/logic/resources/ResourceObserver.cpp55
-rw-r--r--api/logic/resources/ResourceObserver.h73
-rw-r--r--api/logic/resources/ResourceProxyModel.cpp89
-rw-r--r--api/logic/resources/ResourceProxyModel.h39
8 files changed, 607 insertions, 0 deletions
diff --git a/api/logic/resources/Resource.cpp b/api/logic/resources/Resource.cpp
new file mode 100644
index 00000000..e95675d7
--- /dev/null
+++ b/api/logic/resources/Resource.cpp
@@ -0,0 +1,155 @@
+#include "Resource.h"
+
+#include <QDebug>
+
+#include "ResourceObserver.h"
+#include "ResourceHandler.h"
+
+// definition of static members of Resource
+QMap<QString, std::function<std::shared_ptr<ResourceHandler>(const QString &)>> Resource::m_handlers;
+QMap<QPair<int, int>, std::function<QVariant(QVariant)>> Resource::m_transfomers;
+QMap<QString, std::weak_ptr<Resource>> Resource::m_resources;
+
+struct NullResourceResult {};
+Q_DECLARE_METATYPE(NullResourceResult)
+class NullResourceHandler : public ResourceHandler
+{
+public:
+ explicit NullResourceHandler()
+ {
+ setResult(QVariant::fromValue<NullResourceResult>(NullResourceResult()));
+ }
+};
+
+Resource::Resource(const QString &resource)
+ : m_resource(resource)
+{
+ if (!resource.isEmpty())
+ {
+ // a valid resource identifier has the format <id>:<data>
+ Q_ASSERT(resource.contains(':'));
+ // "parse" the resource identifier into id and data
+ const QString resourceId = resource.left(resource.indexOf(':'));
+ const QString resourceData = resource.mid(resource.indexOf(':') + 1);
+
+ // create and set up the handler
+ Q_ASSERT(m_handlers.contains(resourceId));
+ m_handler = m_handlers.value(resourceId)(resourceData);
+ }
+ else
+ {
+ m_handler = std::make_shared<NullResourceHandler>();
+ }
+
+ Q_ASSERT(m_handler);
+ m_handler->init(m_handler);
+ m_handler->setResource(this);
+}
+Resource::~Resource()
+{
+ qDeleteAll(m_observers);
+}
+
+Resource::Ptr Resource::create(const QString &resource, Ptr placeholder)
+{
+ const QString storageId = storageIdentifier(resource, placeholder);
+
+ // do we already have a resource? even if m_resources contains it it might not be valid any longer (weak_ptr)
+ Resource::Ptr ptr = m_resources.contains(storageId)
+ ? m_resources.value(storageId).lock()
+ : nullptr;
+ // did we have one? and is it still valid?
+ if (!ptr)
+ {
+ /* We don't want Resource to have a public constructor, but std::make_shared needs it,
+ * so we create a subclass of Resource here that exposes the constructor as public.
+ * The alternative would be making the allocator for std::make_shared a friend, but it
+ * differs between different STL implementations, so that would be a pain.
+ */
+ struct ConstructableResource : public Resource
+ {
+ explicit ConstructableResource(const QString &resource)
+ : Resource(resource) {}
+ };
+ ptr = std::make_shared<ConstructableResource>(resource);
+ ptr->m_placeholder = placeholder;
+ m_resources.insert(storageId, ptr);
+ }
+ return ptr;
+}
+
+Resource::Ptr Resource::applyTo(ResourceObserver *observer)
+{
+ m_observers.append(observer);
+ observer->setSource(shared_from_this()); // give the observer a shared_ptr for us so we don't get deleted
+ observer->resourceUpdated(); // ask the observer to poll us immediently, we might already have data
+ return shared_from_this(); // allow chaining
+}
+Resource::Ptr Resource::applyTo(QObject *target, const char *property)
+{
+ // the cast to ResourceObserver* is required to ensure the right overload gets choosen,
+ // since QObjectResourceObserver also inherits from QObject
+ return applyTo(static_cast<ResourceObserver *>(new QObjectResourceObserver(target, property)));
+}
+
+QVariant Resource::getResourceInternal(const int typeId) const
+{
+ // no result (yet), but a placeholder? delegate to the placeholder.
+ if (m_handler->result().isNull() && m_placeholder)
+ {
+ return m_placeholder->getResourceInternal(typeId);
+ }
+ const QVariant variant = m_handler->result();
+ const auto typePair = qMakePair(int(variant.type()), typeId);
+
+ // do we have an explicit transformer? use it.
+ if (m_transfomers.contains(typePair))
+ {
+ return m_transfomers.value(typePair)(variant);
+ }
+ else
+ {
+ // we do not have an explicit transformer, so we just pass the QVariant, which will automatically
+ // transform some types for us (different numbers to each other etc.)
+ return variant;
+ }
+}
+
+void Resource::reportResult()
+{
+ for (ResourceObserver *observer : m_observers)
+ {
+ observer->resourceUpdated();
+ }
+}
+void Resource::reportFailure(const QString &reason)
+{
+ for (ResourceObserver *observer : m_observers)
+ {
+ observer->setFailure(reason);
+ }
+}
+void Resource::reportProgress(const int progress)
+{
+ for (ResourceObserver *observer : m_observers)
+ {
+ observer->setProgress(progress);
+ }
+}
+
+void Resource::notifyObserverDeleted(ResourceObserver *observer)
+{
+ m_observers.removeAll(observer);
+}
+
+QString Resource::storageIdentifier(const QString &id, Resource::Ptr placeholder)
+{
+ if (placeholder)
+ {
+ return id + '#' + storageIdentifier(placeholder->m_resource, placeholder->m_placeholder);
+ }
+ else
+ {
+ return id;
+ }
+}
diff --git a/api/logic/resources/Resource.h b/api/logic/resources/Resource.h
new file mode 100644
index 00000000..63e97b88
--- /dev/null
+++ b/api/logic/resources/Resource.h
@@ -0,0 +1,132 @@
+#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;
+};
diff --git a/api/logic/resources/ResourceHandler.cpp b/api/logic/resources/ResourceHandler.cpp
new file mode 100644
index 00000000..46a4422c
--- /dev/null
+++ b/api/logic/resources/ResourceHandler.cpp
@@ -0,0 +1,28 @@
+#include "ResourceHandler.h"
+
+#include "Resource.h"
+
+void ResourceHandler::setResult(const QVariant &result)
+{
+ m_result = result;
+ if (m_resource)
+ {
+ m_resource->reportResult();
+ }
+}
+
+void ResourceHandler::setFailure(const QString &reason)
+{
+ if (m_resource)
+ {
+ m_resource->reportFailure(reason);
+ }
+}
+
+void ResourceHandler::setProgress(const int progress)
+{
+ if (m_resource)
+ {
+ m_resource->reportProgress(progress);
+ }
+}
diff --git a/api/logic/resources/ResourceHandler.h b/api/logic/resources/ResourceHandler.h
new file mode 100644
index 00000000..f09d8904
--- /dev/null
+++ b/api/logic/resources/ResourceHandler.h
@@ -0,0 +1,36 @@
+#pragma once
+
+#include <QVariant>
+#include <memory>
+
+#include "multimc_logic_export.h"
+
+class Resource;
+
+/** Base class for things that can retrieve a resource.
+ *
+ * Subclass, provide a constructor that takes a single QString as argument, and
+ * call Resource::registerHandler<MyResourceHandler>("<id>"), where <id> is the
+ * prefix of the resource ("web", "icon", etc.)
+ */
+class MULTIMC_LOGIC_EXPORT ResourceHandler
+{
+public:
+ virtual ~ResourceHandler() {}
+
+ void setResource(Resource *resource) { m_resource = resource; }
+ /// reimplement this if you need to do something after you have been put in a shared pointer
+ // we do this instead of inheriting from std::enable_shared_from_this
+ virtual void init(std::shared_ptr<ResourceHandler>&) {}
+
+ QVariant result() const { return m_result; }
+
+protected: // use these methods to notify the resource of changes
+ void setResult(const QVariant &result);
+ void setFailure(const QString &reason);
+ void setProgress(const int progress);
+
+private:
+ QVariant m_result;
+ Resource *m_resource = nullptr;
+};
diff --git a/api/logic/resources/ResourceObserver.cpp b/api/logic/resources/ResourceObserver.cpp
new file mode 100644
index 00000000..4f168fd2
--- /dev/null
+++ b/api/logic/resources/ResourceObserver.cpp
@@ -0,0 +1,55 @@
+#include "ResourceObserver.h"
+
+#include <QDebug>
+
+#include "Resource.h"
+
+static const char *defaultPropertyForTarget(QObject *target)
+{
+ if (target->inherits("QLabel"))
+ {
+ return "pixmap";
+ }
+ else if (target->inherits("QAction") ||
+ target->inherits("QMenu") ||
+ target->inherits("QAbstractButton"))
+ {
+ return "icon";
+ }
+ // for unit tests
+ else if (target->inherits("DummyObserverObject"))
+ {
+ return "property";
+ }
+ else
+ {
+ Q_ASSERT_X(false, "ResourceObserver.cpp: defaultPropertyForTarget", "Unrecognized QObject subclass");
+ return nullptr;
+ }
+}
+
+QObjectResourceObserver::QObjectResourceObserver(QObject *target, const char *property)
+ : QObject(target), m_target(target)
+{
+ const QMetaObject *mo = m_target->metaObject();
+ m_property = mo->property(mo->indexOfProperty(
+ property ?
+ property
+ : defaultPropertyForTarget(target)));
+}
+void QObjectResourceObserver::resourceUpdated()
+{
+ m_property.write(m_target, getInternal(m_property.type()));
+}
+
+
+ResourceObserver::~ResourceObserver()
+{
+ m_resource->notifyObserverDeleted(this);
+}
+
+QVariant ResourceObserver::getInternal(const int typeId) const
+{
+ Q_ASSERT(m_resource);
+ return m_resource->getResourceInternal(typeId);
+}
diff --git a/api/logic/resources/ResourceObserver.h b/api/logic/resources/ResourceObserver.h
new file mode 100644
index 00000000..c42e41ba
--- /dev/null
+++ b/api/logic/resources/ResourceObserver.h
@@ -0,0 +1,73 @@
+#pragma once
+
+#include <memory>
+#include <functional>
+
+#include <QObject>
+#include <QMetaProperty>
+#include "multimc_logic_export.h"
+
+class QVariant;
+class Resource;
+
+/// Base class for things that can use a resource
+class MULTIMC_LOGIC_EXPORT ResourceObserver
+{
+public:
+ virtual ~ResourceObserver();
+
+protected: // these methods are called by the Resource when something changes
+ virtual void resourceUpdated() = 0;
+ virtual void setFailure(const QString &) {}
+ virtual void setProgress(const int) {}
+
+private:
+ friend class Resource;
+ void setSource(std::shared_ptr<Resource> resource) { m_resource = resource; }
+
+protected:
+ template<typename T>
+ T get() const { return getInternal(qMetaTypeId<T>()).template value<T>(); }
+ QVariant getInternal(const int typeId) const;
+
+private:
+ std::shared_ptr<Resource> m_resource;
+};
+
+/** Observer for QObject properties
+ *
+ * Give it a target and the name of a property, and that property will be set when the resource changes.
+ *
+ * If no name is given an attempt to find a default property for some common classes is done.
+ */
+class MULTIMC_LOGIC_EXPORT QObjectResourceObserver : public QObject, public ResourceObserver
+{
+public:
+ explicit QObjectResourceObserver(QObject *target, const char *property = nullptr);
+
+ void resourceUpdated() override;
+
+private:
+ QObject *m_target;
+ QMetaProperty m_property;
+};
+
+/** Observer for functions, lambdas etc.
+ * Template arguments:
+ * * We need Ret and Arg in order to create the std::function
+ * * We need Func in order to std::forward the function
+ */
+template <typename Ret, typename Arg, typename Func>
+class FunctionResourceObserver : public ResourceObserver
+{
+ std::function<Ret(Arg)> m_function;
+public:
+ template <typename T>
+ explicit FunctionResourceObserver(T &&func)
+ : m_function(std::forward<Func>(func)) {}
+
+ void resourceUpdated() override
+ {
+ m_function(get<Arg>());
+ }
+};
diff --git a/api/logic/resources/ResourceProxyModel.cpp b/api/logic/resources/ResourceProxyModel.cpp
new file mode 100644
index 00000000..f026d9a9
--- /dev/null
+++ b/api/logic/resources/ResourceProxyModel.cpp
@@ -0,0 +1,89 @@
+#include "ResourceProxyModel.h"
+
+#include <QItemSelectionRange>
+
+#include "Resource.h"
+#include "ResourceObserver.h"
+
+class ModelResourceObserver : public ResourceObserver
+{
+public:
+ explicit ModelResourceObserver(const QModelIndex &index, const int role)
+ : m_index(index), m_role(role)
+ {
+ qRegisterMetaType<QVector<int>>("QVector<int>");
+ }
+
+ void resourceUpdated() override
+ {
+ if (m_index.isValid())
+ {
+ // the resource changed, pretend to be the model and notify the views of the update. they will re-poll the model which will return the new resource value
+ QMetaObject::invokeMethod(const_cast<QAbstractItemModel *>(m_index.model()),
+ "dataChanged", Qt::QueuedConnection,
+ Q_ARG(QModelIndex, m_index), Q_ARG(QModelIndex, m_index), Q_ARG(QVector<int>, QVector<int>() << m_role));
+ }
+ }
+
+private:
+ QPersistentModelIndex m_index;
+ int m_role;
+};
+
+ResourceProxyModel::ResourceProxyModel(const int resultTypeId, QObject *parent)
+ : QIdentityProxyModel(parent), m_resultTypeId(resultTypeId)
+{
+}
+
+QVariant ResourceProxyModel::data(const QModelIndex &proxyIndex, int role) const
+{
+ const QModelIndex mapped = mapToSource(proxyIndex);
+ // valid cell that's a Qt::DecorationRole and that contains a non-empty string
+ if (mapped.isValid() && role == Qt::DecorationRole && !mapToSource(proxyIndex).data(role).toString().isEmpty())
+ {
+ // do we already have a resource for this index?
+ if (!m_resources.contains(mapped))
+ {
+ Resource::Ptr placeholder;
+ const QVariant placeholderIdentifier = mapped.data(PlaceholderRole);
+ if (!placeholderIdentifier.isNull() && placeholderIdentifier.type() == QVariant::String)
+ {
+ placeholder = Resource::create(placeholderIdentifier.toString());
+ }
+
+ // create the Resource and apply the observer for models
+ Resource::Ptr res = Resource::create(mapToSource(proxyIndex).data(role).toString(), placeholder)
+ ->applyTo(new ModelResourceObserver(proxyIndex, role));
+
+ m_resources.insert(mapped, res);
+ }
+
+ return m_resources.value(mapped)->getResourceInternal(m_resultTypeId);
+ }
+ // otherwise fall back to the source model
+ return mapped.data(role);
+}
+
+void ResourceProxyModel::setSourceModel(QAbstractItemModel *model)
+{
+ if (sourceModel())
+ {
+ disconnect(sourceModel(), 0, this, 0);
+ }
+ if (model)
+ {
+ connect(model, &QAbstractItemModel::dataChanged, this, [this](const QModelIndex &tl, const QModelIndex &br, const QVector<int> &roles)
+ {
+ // invalidate resources so that they will be re-created
+ if (roles.contains(Qt::DecorationRole) || roles.contains(PlaceholderRole) || roles.isEmpty())
+ {
+ const QItemSelectionRange range(tl, br);
+ for (const QModelIndex &index : range.indexes())
+ {
+ m_resources.remove(index);
+ }
+ }
+ });
+ }
+ QIdentityProxyModel::setSourceModel(model);
+}
diff --git a/api/logic/resources/ResourceProxyModel.h b/api/logic/resources/ResourceProxyModel.h
new file mode 100644
index 00000000..98a3dbd1
--- /dev/null
+++ b/api/logic/resources/ResourceProxyModel.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <QIdentityProxyModel>
+#include <memory>
+
+#include "multimc_logic_export.h"
+
+/// Convenience proxy model that transforms resource identifiers (strings) for Qt::DecorationRole into other types.
+class MULTIMC_LOGIC_EXPORT ResourceProxyModel : public QIdentityProxyModel
+{
+ Q_OBJECT
+public:
+ // resultTypeId is found using qMetaTypeId<T>()
+ explicit ResourceProxyModel(const int resultTypeId, QObject *parent = nullptr);
+
+ enum
+ {
+ // provide this role from your model if you want to show a placeholder
+ PlaceholderRole = Qt::UserRole + 0xabc // some random offset to not collide with other stuff
+ };
+
+ QVariant data(const QModelIndex &proxyIndex, int role) const override;
+ void setSourceModel(QAbstractItemModel *model) override;
+
+ /// Helper function, usage: m_view->setModel(ResourceProxyModel::mixin<QIcon>(m_model));
+ template <typename T>
+ static QAbstractItemModel *mixin(QAbstractItemModel *model)
+ {
+ ResourceProxyModel *proxy = new ResourceProxyModel(qMetaTypeId<T>(), model);
+ proxy->setSourceModel(model);
+ return proxy;
+ }
+
+private:
+ // mutable because it needs to be available from the const data()
+ mutable QMap<QPersistentModelIndex, std::shared_ptr<class Resource>> m_resources;
+
+ const int m_resultTypeId;
+};