chromium/ash/assistant/model/ui/assistant_ui_element.h

// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef ASH_ASSISTANT_MODEL_UI_ASSISTANT_UI_ELEMENT_H_
#define ASH_ASSISTANT_MODEL_UI_ASSISTANT_UI_ELEMENT_H_

#include "base/component_export.h"
#include "base/functional/callback.h"

namespace ash {

// AssistantUiElementType ------------------------------------------------------

// Defines possible types of Assistant UI elements.
enum class AssistantUiElementType {
  kCard,   // See AssistantCardElement.
  kError,  // See AssistantErrorElement.
  kText,   // See AssistantTextElement.
};

// AssistantUiElement ----------------------------------------------------------

// Base class for a UI element that will be rendered inside of Assistant UI.
class COMPONENT_EXPORT(ASSISTANT_MODEL) AssistantUiElement {
 public:
  AssistantUiElement(const AssistantUiElement&) = delete;
  AssistantUiElement& operator=(const AssistantUiElement&) = delete;

  virtual ~AssistantUiElement();

  bool operator==(const AssistantUiElement& other) const {
    return this->Compare(other);
  }

  AssistantUiElementType type() const { return type_; }

  // Invoke to being processing the UI element for rendering. The specified
  // |callback| will be run upon completion. Note that we don't include the
  // processing result in the callback, as in |AssistantResponse| we handle
  // success/failure cases the same because failures will be skipped in view
  // handling.
  using ProcessingCallback = base::OnceCallback<void()>;
  virtual void Process(ProcessingCallback callback);

 protected:
  explicit AssistantUiElement(AssistantUiElementType type);

 private:
  const AssistantUiElementType type_;

  virtual bool Compare(const AssistantUiElement& other) const = 0;
};

}  // namespace ash

#endif  // ASH_ASSISTANT_MODEL_UI_ASSISTANT_UI_ELEMENT_H_