text: /*
   * Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>
   * Copyright (c) 2021-2022, Mustafa Quraish <mustafa@serenityos.org>
   * Copyright (c) 2021, Tobias Christiansen <tobyase@serenityos.org>
   *
   * SPDX-License-Identifier: BSD-2-Clause
   */
  
  #pragma once
  
  #include <AK/HashTable.h>
  #include <AK/JsonObjectSerializer.h>
  #include <AK/NonnullRefPtrVector.h>
  #include <AK/RefCounted.h>
  #include <AK/RefPtr.h>
  #include <AK/Result.h>
  #include <AK/Vector.h>
  #include <LibCore/File.h>
  #include <LibGUI/Command.h>
  #include <LibGUI/Forward.h>
  #include <LibGfx/Bitmap.h>
  #include <LibGfx/Forward.h>
  #include <LibGfx/Rect.h>
  #include <LibGfx/Size.h>
  
  namespace PixelPaint {
  
  class Layer;
  class Selection;
  
  class ImageClient {
  public:
      virtual void image_did_add_layer(size_t) { }
      virtual void image_did_remove_layer(size_t) { }
      virtual void image_did_modify_layer_properties(size_t) { }
      virtual void image_did_modify_layer_bitmap(size_t) { }
      virtual void image_did_modify_layer_stack() { }
      virtual void image_did_change(Gfx::IntRect const&) { }
      virtual void image_did_change_rect(Gfx::IntRect const&) { }
      virtual void image_select_layer(Layer*) { }
  
  protected:
      virtual ~ImageClient() = default;
  };
  
  class Image : public RefCounted<Image> {
  public:
      static ErrorOr<NonnullRefPtr<Image>> try_create_with_size(Gfx::IntSize const&);
      static ErrorOr<NonnullRefPtr<Image>> try_create_from_pixel_paint_json(JsonObject const&);
      static ErrorOr<NonnullRefPtr<Image>> try_create_from_bitmap(NonnullRefPtr<Gfx::Bitmap>);
  
      static ErrorOr<NonnullRefPtr<Gfx::Bitmap>> try_decode_bitmap(ReadonlyBytes);
  
      // This generates a new Bitmap with the final image (all layers composed according to their attributes.)
      ErrorOr<NonnullRefPtr<Gfx::Bitmap>> try_compose_bitmap(Gfx::BitmapFormat format) const;
      RefPtr<Gfx::Bitmap> try_copy_bitmap(Selection const&) const;
  
      size_t layer_count() const { return m_layers.size(); }
      Layer const& layer(size_t index) const { return m_layers.at(index); }
      Layer& layer(size_t index) { return m_layers.at(index); }
  
      Gfx::IntSize const& size() const { return m_size; }
      Gfx::IntRect rect() const { return { {}, m_size }; }
  
      void add_layer(NonnullRefPtr<Layer>);
      ErrorOr<NonnullRefPtr<Image>> take_snapshot() const;
      ErrorOr<void> restore_snapshot(Image const&);
  
      void paint_into(GUI::Painter&, Gfx::IntRect const& dest_rect) const;
  
      void serialize_as_json(JsonObjectSerializer<StringBuilder>& json) const;
      ErrorOr<void> write_to_file(String const& file_path) const;
      ErrorOr<void> export_bmp_to_file(Core::File&, bool preserve_alpha_channel);
      ErrorOr<void> export_png_to_file(Core::File&, bool preserve_alpha_channel);
  
      void move_layer_to_front(Layer&);
      void move_layer_to_back(Layer&);
      void move_layer_up(Layer&);
      void move_layer_down(Layer&);
      void change_layer_index(size_t old_index, size_t new_index);
      void remove_layer(Layer&);
      void select_layer(Layer*);
      void flatten_all_layers();
      void merge_visible_layers();
      void merge_active_layer_down(Layer& layer);
  
      void add_client(ImageClient&);
      void remove_client(ImageClient&);
  
      void layer_did_modify_bitmap(Badge<Layer>, Layer const&, Gfx::IntRect const& modified_layer_rect);
      void layer_did_modify_properties(Badge<Layer>, Layer const&);
  
      size_t index_of(Layer const&) const;
  
      void flip(Gfx::Orientation orientation);
      void rotate(Gfx::RotationDirection direction);
      void crop(Gfx::IntRect const& rect);
  
      Color color_at(Gfx::IntPoint const& point) const;
  
  private:
      explicit Image(Gfx::IntSize const&);
  
      void did_change(Gfx::IntRect const& modified_rect = {});
      void did_change_rect(Gfx::IntRect const& modified_rect = {});
      void did_modify_layer_stack();
  
      Gfx::IntSize m_size;
      NonnullRefPtrVector<Layer> m_layers;
  
      HashTable<ImageClient*> m_clients;
  };
  
  class ImageUndoCommand : public GUI::Command {
  public:
      ImageUndoCommand(Image& image);
  
      virtual void undo() override;
      virtual void redo() override;
  
  private:
      RefPtr<Image> m_snapshot;
      Image& m_image;
  };
  
  }
  