Declarative.h

/*
 * AUI Framework - Declarative UI toolkit for modern C++20
 * Copyright (C) 2020-2025 Alex2772 and Contributors
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
 
#pragma once
 
#include <AUI/View/AViewContainer.h>
#include <AUI/Util/kAUI.h>
#include <AUI/Traits/callables.h>
#include <AUI/Traits/parameter_pack.h>
#include <AUI/ASS/ASS.h>
 
namespace aui::ui_building {
 
using View = _<AView>;
using ViewContainer = _<AViewContainer>;
using ViewGroup = AVector<_<AView>>;
using ViewOrViewGroup = std::variant<_<AView>, AVector<_<AView>>>;
 
namespace detail {
template <typename ViewFactory>
struct view_helper {
public:
   view_helper() {}
 
   operator View() const { return asViewFactory()->operator()(); }
   operator ViewContainer() const { return asViewFactory()->operator()(); }
   auto operator<<(const AString& assEntry) const { return asViewFactory()->operator()() << assEntry; }
   template <typename T>
   auto operator^(const T& t) const {
       return asViewFactory()->operator()() ^ t;
   }
   template <typename T>
   auto operator+(const T& t) const {
       return asViewFactory()->operator()() + t;
   }
 
   template <typename T>
   auto operator&(const T& t) const {
       return asViewFactory()->operator()() & t;
   }
 
   template <typename T>
   auto operator|(const T& t) const {
       return asViewFactory()->operator()() | t;
   }
 
   template <typename T>
   auto operator^(T&& t) const {
       return asViewFactory()->operator()() ^ std::forward<T>(t);
   }
   template <typename T>
   auto operator&(T&& t) const {
       return asViewFactory()->operator()() & std::forward<T>(t);
   }
   template <typename T>
   auto operator&&(T&& t) const {
       return asViewFactory()->operator()() && std::forward<T>(t);
   }
   template <typename T>
   auto operator+(T&& t) const {
       return asViewFactory()->operator()() + std::forward<T>(t);
   }
 
   auto operator->() const { return asViewFactory()->operator()(); }
 
   template <typename SignalField, typename Object, typename Function>
   auto connect(SignalField&& signalField, Object&& object, Function&& function) {
       return asViewFactory()->operator()().connect(
           std::forward<SignalField>(signalField), std::forward<Object>(object), std::forward<Function>(function));
   }
 
   template <typename Object, typename Function>
   auto clicked(Object&& object, Function&& function) {
       return connect(&AView::clicked, std::forward<Object>(object), std::forward<Function>(function));
   }
 
   template <typename SignalField, typename Function>
   auto connect(SignalField&& signalField, Function&& function) {
       return asViewFactory()->operator()().connect(
           std::forward<SignalField>(signalField), std::forward<Function>(function));
   }
 
private:
   [[nodiscard]] ViewFactory* asViewFactory() const {
       return const_cast<ViewFactory*>(static_cast<const ViewFactory*>(this));
   }
};
 
template <typename Item>
concept LayoutItemView = aui::convertible_to<Item, View>;
template <typename Item>
concept LayoutItemViewGroup = aui::convertible_to<Item, ViewGroup>;
template <typename Item>
concept LayoutItemViewFactory = aui::factory<Item, View>;
 
template <typename Item>
concept ValidLayoutItem = LayoutItemView<Item> || LayoutItemViewGroup<Item> || LayoutItemViewFactory<Item>;
 
template <typename Layout, aui::derived_from<AViewContainer> Container = AViewContainer>
struct layouted_container_factory_impl {
private:
   AVector<View> mViews;
 
public:
   template <typename... Views>
   layouted_container_factory_impl(Views&&... views) {
       mViews.reserve(sizeof...(views));
       static_assert(
           (ValidLayoutItem<Views> && ...),
           "One of the items passed to declarative container is not valid. "
           "Please check your compiler's diagnostics on constraint satisfaction.");
       aui::parameter_pack::for_each(
           [this]<ValidLayoutItem Item>(Item&& item) {
               constexpr bool isView = LayoutItemView<Item>;
               constexpr bool isViewGroup = LayoutItemViewGroup<Item>;
               constexpr bool isInvokable = LayoutItemViewFactory<Item>;
 
               if constexpr (isViewGroup) {
                   auto asViewGroup = ViewGroup(item);
                   mViews << std::move(asViewGroup);
               } else if constexpr (isView) {
                   auto asView = View(item);
                   mViews << std::move(asView);
               } else if constexpr (isInvokable) {
                   mViews << item();
               }
           },
           std::forward<Views>(views)...);
   }
 
   _<Container> operator()() {
       auto c = _new<Container>();
       if constexpr (!std::is_same_v<Layout, std::nullopt_t>) {
           c->setLayout(std::make_unique<Layout>());
       }
       c->setViews(std::move(mViews));
       return c;
   }
};
 
template <typename Layout, aui::derived_from<AViewContainer> Container = AViewContainer>
struct layouted_container_factory_impl_with_expanding : layouted_container_factory_impl<Layout, Container> {
public:
   using layouted_container_factory_impl<Layout, Container>::layouted_container_factory_impl;
 
   struct Expanding : view_helper<Expanding>, layouted_container_factory_impl<Layout, Container> {
   public:
       template <typename... Views>
       Expanding(Views&&... views) : layouted_container_factory_impl<Layout>(std::forward<Views>(views)...) {}
 
       _<Container> operator()() {
           return layouted_container_factory_impl<Layout>::operator()() let { it->setExpanding(); };
       }
   };
};
 
template <typename Layout, aui::derived_from<AViewContainer> Container = AViewContainer>
struct layouted_container_factory
 : view_helper<layouted_container_factory<Layout, Container>>,
   layouted_container_factory_impl_with_expanding<Layout, Container> {
   template <typename... Views>
   layouted_container_factory(Views&&... views)
     : layouted_container_factory_impl_with_expanding<Layout, Container>(std::forward<Views>(views)...) {}
};
 
}   // namespace detail

template <typename View>
struct view : detail::view_helper<view<View>> {
public:
   template <typename... Args>
   view(Args&&... args) : mView(_new<View>(std::forward<Args>(args)...)) {}
 
   _<View>& operator()() { return mView; }
 
   operator _<View>&() { return mView; }
 
private:
   _<View> mView;
};
 
static_assert(std::is_convertible_v<view<AView>, View>,
            "====================> AUI: declarative view wrapper (declarative::view) must be convertible to _<AView>");
 

template <typename Layout, aui::derived_from<AViewContainer> Container = AViewContainer>
using view_container_layout = detail::layouted_container_factory<Layout, Container>;
 
}   // namespace aui::ui_building
 
namespace declarative {

struct Style {
public:
   Style(std::initializer_list<Rule> rules) : mStylesheet(_new<AStylesheet>(AStylesheet(rules))) {}
 
   Style& operator()(AVector<_<AView>> views) {
       for (const auto& view : views) {
           AUI_ASSERTX(view->extraStylesheet() == nullptr, "extra stylesheet already specified");
           view->setExtraStylesheet(mStylesheet);
       }
       mViews = std::move(views);
       return *this;
   }
 
   operator AVector<_<AView>>() noexcept { return std::move(mViews); }
 
private:
   _<AStylesheet> mStylesheet;
   AVector<_<AView>> mViews;
};
}   // namespace declarative

© 2025 AUI Framework Contributors. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. All trademarks are property of their respective owners.