ASplitterHelper.h

/*
 * AUI Framework - Declarative UI toolkit for modern C++20
 * Copyright (C) 2020-2024 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/Util/ALayoutDirection.h>
#include <AUI/View/AView.h>
 
class ASplitterHelper {
    friend class ASplitter;
public:
    struct Item {
        _<AView> view;
        AOptional<int> overridedSize;
    };
 
    ASplitterHelper() = default;
    ASplitterHelper(ALayoutDirection direction) : mDirection(direction) {}
 
    void setDirection(ALayoutDirection direction) {
        mDirection = direction;
    }
 
    void beginDrag(const glm::ivec2& mousePos);
    bool mouseDrag(const glm::ivec2& mousePos);
    void endDrag() {
        mDraggingDividerIndex = -1;
    }
 
    [[nodiscard]]
    const AVector<Item>& items() const { return mItems; }
 
    void setItems(AVector<Item> items) {
        mItems = std::move(items);
    }
 
    void setItems(const AVector<_<AView>>& items) {
        mItems = items.map([](const _<AView>& view) { return Item { .view = view }; });
    }
 
    [[nodiscard]]
    bool isDragging() const {
        return mDraggingDividerIndex != -1;
    }
 
    bool isDraggingArea(glm::ivec2 position);
 
    int reclaimSpace(int space, size_t dividerIndex);
 
    int reclaimSpace(int space) {
        return reclaimSpace(space, mItems.size() - 1);
    }
 
private:
    ALayoutDirection mDirection; // will be initialized in the Builder
    size_t mDraggingDividerIndex = -1;
    int mDragOffset; // may be uninitialized
    AVector<Item> mItems;
 
    float getTotalOccupiedSizeOf(const _<AView>& view) {
        return mDirection == ALayoutDirection::VERTICAL ? view->getTotalOccupiedHeight() : view->getTotalOccupiedWidth();
    }
 
    template<typename T>
    [[nodiscard]]
    T& getAxisValue(glm::tvec2<T>& v) {
        return aui::layout_direction::getAxisValue(mDirection, v);
    }
 
    template<typename T>
    [[nodiscard]]
    T getAxisValue(const glm::tvec2<T>& v) {
        return aui::layout_direction::getAxisValue(mDirection, v);
    }
 
};