serenity/Userland/Libraries/LibGUI/Margins.h

/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <LibGfx/Orientation.h>
#include <LibGfx/Rect.h>

namespace GUI {

class Margins {
public:
    Margins() = default;
    Margins(int all)
        : m_top(all)
        , m_right(all)
        , m_bottom(all)
        , m_left(all)
    {
    }
    Margins(int vertical, int horizontal)
        : m_top(vertical)
        , m_right(horizontal)
        , m_bottom(vertical)
        , m_left(horizontal)
    {
    }
    Margins(int top, int horizontal, int bottom)
        : m_top(top)
        , m_right(horizontal)
        , m_bottom(bottom)
        , m_left(horizontal)
    {
    }
    Margins(int top, int right, int bottom, int left)
        : m_top(top)
        , m_right(right)
        , m_bottom(bottom)
        , m_left(left)
    {
    }
    ~Margins() = default;

    [[nodiscard]] Gfx::IntRect applied_to(Gfx::IntRect const& input) const
    {
        Gfx::IntRect output = input;
        output.take_from_left(left());
        output.take_from_top(top());
        output.take_from_right(right());
        output.take_from_bottom(bottom());
        return output;
    }

    bool is_null() const { return !m_left && !m_top && !m_right && !m_bottom; }

    int top() const { return m_top; }
    int right() const { return m_right; }
    int bottom() const { return m_bottom; }
    int left() const { return m_left; }

    void set_top(int value) { m_top = value; }
    void set_right(int value) { m_right = value; }
    void set_bottom(int value) { m_bottom = value; }
    void set_left(int value) { m_left = value; }

    bool operator==(Margins const& other) const
    {
        return m_left == other.m_left
            && m_top == other.m_top
            && m_right == other.m_right
            && m_bottom == other.m_bottom;
    }

    Margins operator+(Margins const& other) const
    {
        return Margins { top() + other.top(), right() + other.right(), bottom() + other.bottom(), left() + other.left() };
    }

    [[nodiscard]] int primary_total_for_orientation(Gfx::Orientation const orientation) const
    {
        if (orientation == Gfx::Orientation::Horizontal)
            return m_left + m_right;
        else
            return m_top + m_bottom;
    }

    [[nodiscard]] int secondary_total_for_orientation(Gfx::Orientation const orientation) const
    {
        if (orientation == Gfx::Orientation::Vertical)
            return m_left + m_right;
        else
            return m_top + m_bottom;
    }

    [[nodiscard]] int horizontal_total() const
    {
        return m_left + m_right;
    }

    [[nodiscard]] int vertical_total() const
    {
        return m_top + m_bottom;
    }

private:
    int m_top { 0 };
    int m_right { 0 };
    int m_bottom { 0 };
    int m_left { 0 };
};

}

#define REGISTER_MARGINS_PROPERTY(property_name, getter, setter) \
    register_property(                                           \
        property_name, [this]() {                                  \
            auto m = getter();                                     \
            JsonObject margins_object;                             \
            margins_object.set("left", m.left());                  \
            margins_object.set("right", m.right());                \
            margins_object.set("top", m.top());                    \
            margins_object.set("bottom", m.bottom());              \
            return margins_object; },                             \
        [this](auto& value) {                                    \
            if (!value.is_array())                               \
                return false;                                    \
            auto size = value.as_array().size();                 \
            if (size == 0 || size > 4)                           \
                return false;                                    \
            int m[4];                                            \
            for (size_t i = 0; i < size; ++i)                    \
                m[i] = value.as_array().at(i).to_i32();          \
            if (size == 1)                                       \
                setter({ m[0] });                                \
            else if (size == 2)                                  \
                setter({ m[0], m[1] });                          \
            else if (size == 3)                                  \
                setter({ m[0], m[1], m[2] });                    \
            else                                                 \
                setter({ m[0], m[1], m[2], m[3] });              \
            return true;                                         \
        });