APointerIndex.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 <compare>
#include <AUI/Platform/AInput.h>
 
class APointerIndex {
public:
    constexpr APointerIndex() noexcept: mValue(AInput::LBUTTON) {}
 
    static constexpr APointerIndex button(AInput::Key button) {
        assert((button == AInput::LBUTTON ||
                button == AInput::RBUTTON ||
                button == AInput::CBUTTON));
        return APointerIndex((int)button);
    }
 
    static constexpr APointerIndex finger(int fingerIndex) {
        return APointerIndex(fingerIndex + MAX_BUTTON_VALUE + 1);
    }
 
 
    [[nodiscard]]
    bool isButton() const noexcept {
        return mValue <= MAX_BUTTON_VALUE;
    }
 
    [[nodiscard]]
    bool isFinger() const noexcept {
        return mValue > MAX_BUTTON_VALUE;
    }
 
    AOptional<AInput::Key> button() const noexcept {
        if (!isButton()) {
            return std::nullopt;
        }
        return (AInput::Key)mValue;
    }
 
    AOptional<int> finger() const noexcept {
        if (!isFinger()) {
            return std::nullopt;
        }
        return mValue - MAX_BUTTON_VALUE - 1;
    }
 
    [[nodiscard]]
    auto operator<=>(const APointerIndex& rhs) const noexcept = default;
 
    [[nodiscard]]
    constexpr int rawValue() const noexcept {
        return mValue;
    }
 
private:
    int mValue;
    static constexpr int MAX_BUTTON_VALUE = AInput::RBUTTON;
 
    explicit constexpr APointerIndex(int value) : mValue(value) {}
};
 
 
inline std::ostream& operator<<(std::ostream& o, const APointerIndex& color) {
    o << "APointerIndex{";
    if (auto b = color.button()) {
        o << "button=";
        switch (*b) {
            case AInput::LBUTTON:
                o << "l";
                break;
            case AInput::RBUTTON:
                o << "r";
                break;
            case AInput::CBUTTON:
                o << "c";
                break;
            default:
                o << (int)*b;
                break;
        }
    } else if (auto b = color.finger()) {
        o << "finger=" << *b;
    }
    o << "}";
    return o;
}