Compositor.h

/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include <AK/OwnPtr.h>
#include <AK/RefPtr.h>
#include <LibCore/Object.h>
#include <LibGfx/Color.h>
#include <LibGfx/DisjointRectSet.h>

namespace WindowServer {

class ClientConnection;
class Cursor;
class Window;
class WindowManager;

enum class WallpaperMode {
    Simple,
    Tile,
    Center,
    Stretch,
    Unchecked
};

class Compositor final : public Core::Object {
    C_OBJECT(Compositor)
public:
    static Compositor& the();

    void compose();
    void invalidate_window();
    void invalidate_screen();
    void invalidate_screen(const Gfx::IntRect&);

    bool set_resolution(int desired_width, int desired_height, int scale_factor);

    bool set_background_color(const String& background_color);

    bool set_wallpaper_mode(const String& mode);

    bool set_wallpaper(const String& path, Function<void(bool)>&& callback);
    String wallpaper_path() const { return m_wallpaper_path; }

    void invalidate_cursor(bool = false);
    Gfx::IntRect current_cursor_rect() const;

    void increment_display_link_count(Badge<ClientConnection>);
    void decrement_display_link_count(Badge<ClientConnection>);

    void invalidate_occlusions() { m_occlusions_dirty = true; }

    void did_construct_window_manager(Badge<WindowManager>);

private:
    Compositor();
    void init_bitmaps();
    void flip_buffers();
    void flush(const Gfx::IntRect&);
    void run_animations(Gfx::DisjointRectSet&);
    void notify_display_links();
    void start_compose_async_timer();
    void recompute_occlusions();
    bool any_opaque_window_above_this_one_contains_rect(const Window&, const Gfx::IntRect&);
    void change_cursor(const Cursor*);
    void draw_cursor(const Gfx::IntRect&);
    void restore_cursor_back();
    bool draw_geometry_label(Gfx::IntRect&);

    RefPtr<Core::Timer> m_compose_timer;
    RefPtr<Core::Timer> m_immediate_compose_timer;
    bool m_flash_flush { false };
    bool m_buffers_are_flipped { false };
    bool m_screen_can_set_buffer { false };
    bool m_occlusions_dirty { true };
    bool m_invalidated_any { true };
    bool m_invalidated_window { false };
    bool m_invalidated_cursor { false };

    RefPtr<Gfx::Bitmap> m_front_bitmap;
    RefPtr<Gfx::Bitmap> m_back_bitmap;
    RefPtr<Gfx::Bitmap> m_temp_bitmap;
    OwnPtr<Gfx::Painter> m_back_painter;
    OwnPtr<Gfx::Painter> m_front_painter;
    OwnPtr<Gfx::Painter> m_temp_painter;

    Gfx::DisjointRectSet m_dirty_screen_rects;
    Gfx::DisjointRectSet m_opaque_wallpaper_rects;

    RefPtr<Gfx::Bitmap> m_cursor_back_bitmap;
    OwnPtr<Gfx::Painter> m_cursor_back_painter;
    Gfx::IntRect m_last_cursor_rect;
    Gfx::IntRect m_last_dnd_rect;
    Gfx::IntRect m_last_geometry_label_damage_rect;

    String m_wallpaper_path { "" };
    WallpaperMode m_wallpaper_mode { WallpaperMode::Unchecked };
    RefPtr<Gfx::Bitmap> m_wallpaper;

    const Cursor* m_current_cursor { nullptr };
    unsigned m_current_cursor_frame { 0 };
    RefPtr<Core::Timer> m_cursor_timer;

    RefPtr<Core::Timer> m_display_link_notify_timer;
    size_t m_display_link_count { 0 };

    Optional<Gfx::Color> m_custom_background_color;
};

}