python.h

/*
    nanogui/python.h -- Macros to facilitate Python bindings of custom widgets

    NanoGUI was developed by Wenzel Jakob <wenzel.jakob@epfl.ch>.
    The widget drawing code is based on the NanoVG demo application
    by Mikko Mononen.

    All rights reserved. Use of this source code is governed by a
    BSD-style license that can be found in the LICENSE.txt file.
*/
/** \file */

#pragma once

#if defined(_MSC_VER)
#  pragma warning (disable:5033) // 'register' is no longer a supported storage class
#endif

#include <nanogui/common.h>
#include <nanobind/nanobind.h>
#include <nanobind/trampoline.h>

extern "C" {
    /* Dummy handle types -- will never be instantiated */
    typedef struct NVGcontext { int unused; } NVGcontext;
    typedef struct GLFWwindow { int unused; } GLFWwindow;
};

/// Provides a ``NB_OVERRIDE`` for any relevant Widget items that need to be bound.
#define NANOGUI_WIDGET_OVERLOADS(Parent)                                       \
    NB_TRAMPOLINE(Parent, 18);                                                 \
    bool mouse_button_event(const ::nanogui::Vector2i &p, int button,          \
                            bool down, int modifiers) override {               \
        NB_OVERRIDE(mouse_button_event, p, button, down, modifiers);           \
    }                                                                          \
    bool mouse_motion_event(const ::nanogui::Vector2i &p,                      \
                            const ::nanogui::Vector2i &rel, int button,        \
                            int modifiers) override {                          \
        NB_OVERRIDE(mouse_motion_event, p, rel, button, modifiers);            \
    }                                                                          \
    bool mouse_drag_event(const ::nanogui::Vector2i &p,                        \
                          const ::nanogui::Vector2i &rel, int button,          \
                          int modifiers) override {                            \
        NB_OVERRIDE(mouse_drag_event, p, rel, button, modifiers);              \
    }                                                                          \
    bool mouse_enter_event(const ::nanogui::Vector2i &p, bool enter)           \
        override {                                                             \
        NB_OVERRIDE(mouse_enter_event, p, enter);                              \
    }                                                                          \
    bool scroll_event(const ::nanogui::Vector2i &p,                            \
                      const ::nanogui::Vector2f &rel) override {               \
        NB_OVERRIDE(scroll_event, p, rel);                                     \
    }                                                                          \
    bool focus_event(bool focused) override {                                  \
        NB_OVERRIDE(focus_event, focused);                                     \
    }                                                                          \
    bool keyboard_event(int key, int scancode, int action, int modifiers)      \
        override {                                                             \
        NB_OVERRIDE(keyboard_event, key, scancode, action, modifiers);         \
    }                                                                          \
    bool keyboard_character_event(unsigned int codepoint) override {           \
        NB_OVERRIDE(keyboard_character_event, codepoint);                      \
    }                                                                          \
    ::nanogui::Vector2i preferred_size_impl(NVGcontext *ctx) const override {  \
        NB_OVERRIDE(preferred_size_impl, ctx);                                 \
    }                                                                          \
    void perform_layout(NVGcontext *ctx) override {                            \
        NB_OVERRIDE(perform_layout, ctx);                                      \
    }                                                                          \
    void draw(NVGcontext *ctx) override { NB_OVERRIDE(draw, ctx); }

/// Provides a ``NB_OVERRIDE`` for any relevant Layout items that need to be bound.
#define NANOGUI_LAYOUT_OVERLOADS(Parent)                                       \
    NB_TRAMPOLINE(Parent, 2);                                                  \
    ::nanogui::Vector2i preferred_size(                                        \
        NVGcontext *ctx, const ::nanogui::Widget *widget) const override {     \
        NB_OVERRIDE(preferred_size, ctx, widget);                              \
    }                                                                          \
    void perform_layout(NVGcontext *ctx, ::nanogui::Widget *widget)            \
        const override {                                                       \
        NB_OVERRIDE(perform_layout, ctx, widget);                              \
    }

/// Provides a ``NB_OVERRIDE`` for any relevant Screen items that need to be bound.
#define NANOGUI_SCREEN_OVERLOADS(Parent)                                       \
    virtual void draw_all() override { NB_OVERRIDE(draw_all); }                \
    virtual void draw_contents() override { NB_OVERRIDE(draw_contents); }      \
    virtual bool drop_event(const std::vector<std::string> &filenames)         \
        override {                                                             \
        NB_OVERRIDE(drop_event, filenames);                                    \
    }                                                                          \
    virtual bool maximize_event(bool maximized) override {                     \
        NB_OVERRIDE(maximize_event, maximized);                                \
    }                                                                          \
    bool mouse_motion_event_f(const ::nanogui::Vector2f &p,                    \
                              const ::nanogui::Vector2f &rel, int button,      \
                              int modifiers) override {                        \
        NB_OVERRIDE(mouse_motion_event_f, p, rel, button, modifiers);          \
    }                                                                          \
    virtual bool resize_event(const ::nanogui::Vector2i &size) override {      \
        NB_OVERRIDE(resize_event, size);                                       \
    }

NAMESPACE_BEGIN(nanobind)
NAMESPACE_BEGIN(detail)

template <typename T> struct type_caster<nanogui::ref<T>> {
    using Value = nanogui::ref<T>;
    using Caster = make_caster<T>;
    static constexpr auto Name = Caster::Name;
    static constexpr bool IsClass = true;

    template <typename T_> using Cast = movable_cast_t<T_>;

    Value value;

    bool from_python(handle src, uint8_t flags,
                     cleanup_list *cleanup) noexcept {
        Caster caster;
        if (!caster.from_python(src, flags, cleanup))
            return false;

        value = Value(caster.operator T *());

        return true;
    }

    static handle from_cpp(const Value &value, rv_policy policy,
                           cleanup_list *cleanup) noexcept {
        return Caster::from_cpp(value.get(), policy, cleanup);
    }

    explicit operator Value *() { return &value; }
    explicit operator Value &() { return value; }
    explicit operator Value &&() && { return (Value &&) value; }
};

NAMESPACE_END(detail)
NAMESPACE_END(nanobind)