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Diffstat (limited to 'lib/roomstateview.h')
| -rw-r--r-- | lib/roomstateview.h | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/lib/roomstateview.h b/lib/roomstateview.h new file mode 100644 index 00000000..c5261a1e --- /dev/null +++ b/lib/roomstateview.h @@ -0,0 +1,211 @@ +// SPDX-FileCopyrightText: 2021 Kitsune Ral <kitsune-ral@users.sf.net> +// SPDX-License-Identifier: LGPL-2.1-or-later + +#pragma once + +#include "events/stateevent.h" + +#include <QtCore/QHash> + +namespace Quotient { + +class Room; + +// NB: Both concepts below expect EvT::needsStateKey to exist so you can't +// express one via negation of the other (there's still an invalid case of +// a non-state event where needsStateKey is not even defined). + +template <typename FnT, class EvT = std::decay_t<fn_arg_t<FnT>>> +concept Keyed_State_Fn = EvT::needsStateKey; + +template <typename FnT, class EvT = std::decay_t<fn_arg_t<FnT>>> +concept Keyless_State_Fn = !EvT::needsStateKey; + +class QUOTIENT_API RoomStateView + : private QHash<StateEventKey, const StateEvent*> { + Q_GADGET +public: + const QHash<StateEventKey, const StateEvent*>& events() const + { + return *this; + } + + //! \brief Get a state event with the given event type and state key + //! \return A state event corresponding to the pair of event type + //! \p evtType and state key \p stateKey, or nullptr if there's + //! no such \p evtType / \p stateKey combination in the current + //! state. + //! \warning In libQuotient 0.7 the return type changed to an OmittableCref + //! which is effectively a nullable const reference wrapper. You + //! have to check that it has_value() before using. Alternatively + //! you can now use queryCurrentState() to access state safely. + //! \sa getCurrentStateContentJson + const StateEvent* get(const QString& evtType, + const QString& stateKey = {}) const; + + //! \brief Get a state event with the given event type and state key + //! + //! This is a typesafe overload that accepts a C++ event type instead of + //! its Matrix name. It is only defined for events with state key (i.e., + //! derived from KeyedStateEvent). + template <Keyed_State_Event EvT> + const EvT* get(const QString& stateKey = {}) const + { + if (const auto* evt = get(EvT::TypeId, stateKey)) { + Q_ASSERT(evt->matrixType() == EvT::TypeId + && evt->stateKey() == stateKey); + return eventCast<const EvT>(evt); + } + return nullptr; + } + + //! \brief Get a state event with the given event type + //! + //! This is a typesafe overload that accepts a C++ event type instead of + //! its Matrix name. This overload only defined for events that do not use + //! state key (i.e., derived from KeylessStateEvent). + template <Keyless_State_Event EvT> + const EvT* get() const + { + if (const auto* evt = get(EvT::TypeId)) { + Q_ASSERT(evt->matrixType() == EvT::TypeId); + return eventCast<const EvT>(evt); + } + return nullptr; + } + + using QHash::contains; + + bool contains(const QString& evtType, const QString& stateKey = {}) const; + + template <Keyed_State_Event EvT> + bool contains(const QString& stateKey = {}) const + { + return contains(EvT::TypeId, stateKey); + } + + template <Keyless_State_Event EvT> + bool contains() const + { + return contains(EvT::TypeId); + } + + template <Keyed_State_Event EvT> + auto content(const QString& stateKey, + typename EvT::content_type defaultValue = {}) const + { + // EventBase<>::content is special in that it returns a const-ref, + // and lift() inside queryOr() can't wrap that in a temporary Omittable. + if (const auto evt = get<EvT>(stateKey)) + return evt->content(); + return std::move(defaultValue); + } + + template <Keyless_State_Event EvT> + auto content(typename EvT::content_type defaultValue = {}) const + { + // Same as above + if (const auto evt = get<EvT>()) + return evt->content(); + return defaultValue; + } + + //! \brief Get the content of the current state event with the given + //! event type and state key + //! \return An empty object if there's no event in the current state with + //! this event type and state key; the contents of the event + //! <tt>'content'</tt> object otherwise + Q_INVOKABLE QJsonObject contentJson(const QString& evtType, + const QString& stateKey = {}) const; + + //! \brief Get all state events in the room of a certain type. + //! + //! This method returns all known state events that have occured in + //! the room of the given type. + const QVector<const StateEvent*> eventsOfType(const QString& evtType) const; + + //! \brief Run a function on a state event with the given type and key + //! + //! Use this overload when there's no predefined event type or the event + //! type is unknown at compile time. + //! \return an Omittable with either the result of the function call, or + //! with `none` if the event is not found or the function fails + template <typename FnT> + auto query(const QString& evtType, const QString& stateKey, FnT&& fn) const + { + return lift(std::forward<FnT>(fn), get(evtType, stateKey)); + } + + //! \brief Run a function on a state event with the given type and key + //! + //! This is an overload for keyed state events (those that have + //! `needsStateKey == true`) with type defined at compile time. + //! \return an Omittable with either the result of the function call, or + //! with `none` if the event is not found or the function fails + template <Keyed_State_Fn FnT> + auto query(const QString& stateKey, FnT&& fn) const + { + using EventT = std::decay_t<fn_arg_t<FnT>>; + return lift(std::forward<FnT>(fn), get<EventT>(stateKey)); + } + + //! \brief Run a function on a keyless state event with the given type + //! + //! This is an overload for keyless state events (those having + //! `needsStateKey == false`) with type defined at compile time. + //! \return an Omittable with either the result of the function call, or + //! with `none` if the event is not found or the function fails + template <Keyless_State_Fn FnT> + auto query(FnT&& fn) const + { + using EventT = std::decay_t<fn_arg_t<FnT>>; + return lift(std::forward<FnT>(fn), get<EventT>()); + } + + //! \brief Same as query() but with a fallback value + //! + //! This is a shortcut for `query().value_or()`, passing respective + //! arguments to the respective functions. This is an overload for the case + //! when the event type cannot be fixed at compile time. + //! \return the result of \p fn execution, or \p fallback if the requested + //! event doesn't exist or the function fails + template <typename FnT, typename FallbackT> + auto queryOr(const QString& evtType, const QString& stateKey, FnT&& fn, + FallbackT&& fallback) const + { + return query(evtType, stateKey, std::forward<FnT>(fn)) + .value_or(std::forward<FallbackT>(fallback)); + } + + //! \brief Same as query() but with a fallback value + //! + //! This is a shortcut for `query().value_or()`, passing respective + //! arguments to the respective functions. This is an overload for the case + //! when the event type cannot be fixed at compile time. + //! \return the result of \p fn execution, or \p fallback if the requested + //! event doesn't exist or the function fails + template <typename FnT, typename FallbackT> + auto queryOr(const QString& stateKey, FnT&& fn, FallbackT&& fallback) const + { + return query(stateKey, std::forward<FnT>(fn)) + .value_or(std::forward<FallbackT>(fallback)); + } + + //! \brief Same as query() but with a fallback value + //! + //! This is a shortcut for `query().value_or()`, passing respective + //! arguments to the respective functions. This is an overload for the case + //! when the event type cannot be fixed at compile time. + //! \return the result of \p fn execution, or \p fallback if the requested + //! event doesn't exist or the function fails + template <typename FnT, typename FallbackT> + auto queryOr(FnT&& fn, FallbackT&& fallback) const + { + return query(std::forward<FnT>(fn)) + .value_or(std::forward<FallbackT>(fallback)); + } + +private: + friend class Room; +}; +} // namespace Quotient |