// Aseprite UI Library
// Copyright (C) 2020-2024  Igara Studio S.A.
// Copyright (C) 2001-2017  David Capello
//
// This file is released under the terms of the MIT license.
// Read LICENSE.txt for more information.

#ifndef UI_LISTBOX_H_INCLUDED
#define UI_LISTBOX_H_INCLUDED
#pragma once

#include "obs/signal.h"
#include "ui/widget.h"

#include <vector>

namespace ui {

class ListItem;

class ListBox : public Widget {
public:
  ListBox();

  bool isMultiselect() const { return m_multiselect; }
  void setMultiselect(const bool multiselect);

  Widget* getSelectedChild();
  int getSelectedIndex();

  void selectChild(Widget* item, Message* msg = nullptr);
  void selectIndex(int index, Message* msg = nullptr);

  int getItemsCount() const;

  void makeChildVisible(Widget* item);
  void centerScroll();
  virtual void sortItems();
  void sortItems(const std::function<bool(Widget*, Widget*)>& cmp);

  obs::signal<void()> Change;
  obs::signal<void()> DoubleClickItem;

protected:
  virtual bool onProcessMessage(Message* msg) override;
  virtual void onPaint(PaintEvent& ev) override;
  virtual void onResize(ResizeEvent& ev) override;
  virtual void onSizeHint(SizeHintEvent& ev) override;
  virtual void onChange();
  virtual void onDoubleClickItem();
  virtual bool onAcceptKeyInput();

  int advanceIndexThroughVisibleItems(int startIndex, int delta, const bool loop);

  // True if this listbox accepts selecting multiple items at the
  // same time.
  bool m_multiselect;

  // Range of items selected when we click down/up. Used to specify
  // the range of selected items in a multiselect operation.
  int m_firstSelectedIndex;
  int m_lastSelectedIndex;

  // Initial state (isSelected()) of each list item when the
  // selection operation started. It's used to switch the state of
  // items in case that the user is Ctrl+clicking items several
  // items at the same time.
  std::vector<bool> m_states;

private:
  // Finds the parent ListItem that contains the specified descendant.
  ListItem* findParentListItem(Widget* descendant);
};

} // namespace ui

#endif
