online_image.h

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#pragma once

#include "esphome/core/component.h"
#include "esphome/core/defines.h"
#include "esphome/core/helpers.h"
#include "esphome/components/http_request/http_request.h"
#include "esphome/components/image/image.h"

#include "image_decoder.h"

namespace esphome {
namespace online_image {

using t_http_codes = enum {
  HTTP_CODE_OK = 200,
  HTTP_CODE_NOT_MODIFIED = 304,
  HTTP_CODE_NOT_FOUND = 404,
};

enum ImageFormat {
  AUTO,
  JPEG,
  PNG,
};

class OnlineImage : public PollingComponent,
                    public image::Image,
                    public Parented<esphome::http_request::HttpRequestComponent> {
 public:
  OnlineImage(const std::string &url, int width, int height, ImageFormat format, image::ImageType type,
              uint32_t buffer_size);

  void draw(int x, int y, display::Display *display, Color color_on, Color color_off) override;

  void update() override;
  void loop() override;

  void set_url(const std::string &url) {
    if (this->validate_url_(url)) {
      this->url_ = url;
    }
  }

  void set_placeholder(image::Image *placeholder) { this->placeholder_ = placeholder; }

  void release();

  void add_on_finished_callback(std::function<void()> &&callback);
  void add_on_error_callback(std::function<void()> &&callback);

 protected:
  bool validate_url_(const std::string &url);

  using Allocator = ExternalRAMAllocator<uint8_t>;
  Allocator allocator_{Allocator::Flags::ALLOW_FAILURE};

  uint32_t get_buffer_size_() const { return get_buffer_size_(this->buffer_width_, this->buffer_height_); }
  int get_buffer_size_(int width, int height) const {
    return std::ceil(image::image_type_to_bpp(this->type_) * width * height / 8.0);
  }

  int get_position_(int x, int y) const {
    return ((x + y * this->buffer_width_) * image::image_type_to_bpp(this->type_)) / 8;
  }

  ESPHOME_ALWAYS_INLINE bool auto_resize_() const { return this->fixed_width_ == 0 || this->fixed_height_ == 0; }

  bool resize_(int width, int height);

  void draw_pixel_(int x, int y, Color color);

  void end_connection_();

  CallbackManager<void()> download_finished_callback_{};
  CallbackManager<void()> download_error_callback_{};

  std::shared_ptr<http_request::HttpContainer> downloader_{nullptr};
  std::unique_ptr<ImageDecoder> decoder_{nullptr};

  uint8_t *buffer_;
  DownloadBuffer download_buffer_;

  const ImageFormat format_;
  image::Image *placeholder_{nullptr};

  std::string url_{""};

  const int fixed_width_;
  const int fixed_height_;
  int buffer_width_;
  int buffer_height_;

  friend void ImageDecoder::set_size(int width, int height);
  friend void ImageDecoder::draw(int x, int y, int w, int h, const Color &color);
};

template<typename... Ts> class OnlineImageSetUrlAction : public Action<Ts...> {
 public:
  OnlineImageSetUrlAction(OnlineImage *parent) : parent_(parent) {}
  TEMPLATABLE_VALUE(const char *, url)
  void play(Ts... x) override {
    this->parent_->set_url(this->url_.value(x...));
    this->parent_->update();
  }

 protected:
  OnlineImage *parent_;
};

template<typename... Ts> class OnlineImageReleaseAction : public Action<Ts...> {
 public:
  OnlineImageReleaseAction(OnlineImage *parent) : parent_(parent) {}
  TEMPLATABLE_VALUE(const char *, url)
  void play(Ts... x) override { this->parent_->release(); }

 protected:
  OnlineImage *parent_;
};

class DownloadFinishedTrigger : public Trigger<> {
 public:
  explicit DownloadFinishedTrigger(OnlineImage *parent) {
    parent->add_on_finished_callback([this]() { this->trigger(); });
  }
};

class DownloadErrorTrigger : public Trigger<> {
 public:
  explicit DownloadErrorTrigger(OnlineImage *parent) {
    parent->add_on_error_callback([this]() { this->trigger(); });
  }
};

}  // namespace online_image
}  // namespace esphome