Renderive/Core/plottable/Hover_Tooltip.h

#pragma once
#include <functional>
#include <string>
#include <utility>
#include <vector>
#include "../Axis/export.h"
#include "../base/Color.h"
#include "../base/Geometry.h"
#include "../base/Style.h"
#include "../base/Text.h"
#include "../render/Canvas.h"
namespace renderive {
struct Hover_Tooltip_State;
struct Hover_Tooltip_Provider;
struct LIB_DECL Hover_Tooltip_State {
    virtual ~Hover_Tooltip_State() = default;
    Hover_Tooltip_State() {
        tooltip_background_brush = Brush{Color::white(), Brush_Style::Solid};
        tooltip_text_pen = Pen{Color::black()};
    }
    int hover_info_left = 4;
    int hover_info_top = 4;
    int hover_info_right = 4;
    int hover_info_bottom = 4;
    Brush tooltip_background_brush;
    Font hover_info_font;
    Pen tooltip_text_pen;
    bool use_hover_tooltip = true;
    bool hover_info_active = false;
    Point hover_position;
    void draw_hover_tooltip(Canvas* canvas, Abs_Axis* domain_axis, Abs_Axis* value_axis, Hover_Tooltip_Provider* renderable);
    bool can_show_hover(Renderable* able) const;
};
struct LIB_DECL Hover_Tooltip_Provider {
    struct Hover_State_Edit {
        Hover_State_Edit() = default;
        Hover_State_Edit(Hover_Tooltip_Provider* owner, Hover_Tooltip_State* state, std::function<void()> on_finish)
            : owner(owner), state(state), on_finish(std::move(on_finish)) {}
        Hover_State_Edit(const Hover_State_Edit&) = delete;
        Hover_State_Edit& operator=(const Hover_State_Edit&) = delete;
        Hover_State_Edit(Hover_State_Edit&& other) noexcept
            : owner(std::exchange(other.owner, nullptr)),
              state(std::exchange(other.state, nullptr)),
              on_finish(std::move(other.on_finish)) {}
        Hover_State_Edit& operator=(Hover_State_Edit&& other) noexcept {
            if (this == &other)
                return *this;
            finish();
            owner = std::exchange(other.owner, nullptr);
            state = std::exchange(other.state, nullptr);
            on_finish = std::move(other.on_finish);
            return *this;
        }
        ~Hover_State_Edit() {
            finish();
        }
        Hover_Tooltip_State* operator->() const {
            return state;
        }
    private:
        void finish() {
            if (!owner)
                return;
            if (on_finish)
                on_finish();
            on_finish = {};
            owner = nullptr;
            state = nullptr;
        }
        Hover_Tooltip_Provider* owner{};
        Hover_Tooltip_State* state{};
        std::function<void()> on_finish{};
    };
    virtual std::vector<std::string> build_hover_lines(Abs_Axis* h, Abs_Axis* v, Point pos);
    virtual ~Hover_Tooltip_Provider() = default;
    virtual void draw_hover_tooltip(Canvas* canvas, Abs_Axis* h, Abs_Axis* v) {
        return hover_render_state()->draw_hover_tooltip(canvas, h, v, this);
    }
    virtual bool hover_ok(Renderable* able) {
        return hover_render_state()->can_show_hover(able);
    }
    virtual bool hit_test_hover(Point pos) {
        (void)pos;
        return true;
    }
    bool hover_tooltip_enabled() {
        return hover_edit_state()->use_hover_tooltip;
    }
    void set_use_hover_info(bool use) {
        auto edit = begin_hover_edit();
        edit->use_hover_tooltip = use;
    }
    void set_hover_tooltip_font(const Font& font) {
        auto edit = begin_hover_edit();
        edit->hover_info_font = font;
    }
    Font hover_tooltip_font() {
        return hover_edit_state()->hover_info_font;
    }
    Brush hover_info_background_brush() {
        return hover_edit_state()->tooltip_background_brush;
    }
    void set_hover_tooltip_background_brush(const Brush& brush) {
        auto edit = begin_hover_edit();
        edit->tooltip_background_brush = brush.color.a != 0 ? brush : Brush{};
    }
    Pen tooltip_text_pen() {
        return hover_edit_state()->tooltip_text_pen;
    }
    void set_tooltip_text_pen(const Pen& pen) {
        auto edit = begin_hover_edit();
        edit->tooltip_text_pen = pen.color.a != 0 ? pen : Pen{.style = Line_Style::None};
    }
    void get_hover_tooltip_contents_margins(int& left, int& top, int& right, int& bottom) {
        auto s = hover_edit_state();
        left = s->hover_info_left;
        top = s->hover_info_top;
        right = s->hover_info_right;
        bottom = s->hover_info_bottom;
    }
    void set_hover_tooltip_contents_margins(int left, int top, int right, int bottom) {
        auto edit = begin_hover_edit();
        edit->hover_info_left = left;
        edit->hover_info_top = top;
        edit->hover_info_right = right;
        edit->hover_info_bottom = bottom;
    }
    Hover_State_Edit begin_hover_edit() {
        return begin_hover_edit_impl();
    }
private:
    virtual Hover_Tooltip_State* hover_edit_state() = 0;
    virtual Hover_Tooltip_State* hover_render_state() = 0;
    virtual Hover_State_Edit begin_hover_edit_impl() = 0;
};
template <typename That>
struct LIB_DECL Hover_Tooltip_Mixin : Hover_Tooltip_Provider {
private:
    That* that() {
        return static_cast<That*>(this);
    }
    Hover_Tooltip_State* hover_edit_state() override {
        auto t = that();
        return dynamic_cast<Hover_Tooltip_State*>(t->d_ptr->state(State_Edit));
    }
    Hover_Tooltip_State* hover_render_state() override {
        auto t = that();
        return dynamic_cast<Hover_Tooltip_State*>(t->d_ptr->state(State_Render));
    }
    Hover_State_Edit begin_hover_edit_impl() override {
        auto t = that();
        auto record = t->d_ptr->state_control.try_acquire_role(State_Edit);
        if (record.result != Triple_Buffer_Result::Success)
            return {};
        auto lease = record.lease;
        auto* data = t->d_ptr;
        auto* state = dynamic_cast<Hover_Tooltip_State*>(data->state_by_index(lease.index));
        return Hover_State_Edit(this, state, [data, lease]() mutable {
            ++data->state_by_index(lease.index)->version;
            if (data->q_ptr)
                data->q_ptr->mark_render_dirty();
            data->state_control.unmark_use(lease);
        });
    }
};
} // namespace renderive