Hint

// SPDX-FileCopyrightText: © 2024 Alexander Kromm <mmaulwurff@gmail.com>
// SPDX-License-Identifier: BSD-3-Clause

// Hint module version: 1.1.0
// Hint is a part of DoomToolbox: https://github.com/mmaulwurff/doom-toolbox/

// This class provides the Hint Option Menu item.
// Hint is a static text that is visible only if the items above are selected.
// The number of items above is configurable, and by default is 1.
class OptionMenuItemNAMESPACE_Hint : OptionMenuItemStaticText
{
  // nAbove means for how many selectable items above this hint should appear.
  OptionMenuItemNAMESPACE_Hint Init(String label, int nAbove = 1)
  {
    Super.InitDirect(label, Font.CR_WHITE);
    if (nAbove < 1) { nAbove = 1; }
    _nAbove = nAbove;
    return self;
  }

  override int Draw(OptionMenuDescriptor desc, int y, int indent, bool selected)
  {
    return isAboveSelected(desc)
      ? Super.Draw(desc, y, indent, selected)
      : -1;
  }

  private bool isAboveSelected(OptionMenuDescriptor desc)
  {
    int selfIndex = desc.mItems.find(self);
    int aboveEnd  = selfIndex - 1;

    while (aboveEnd >= 0 && !desc.mItems[aboveEnd].Selectable()) { --aboveEnd; }

    int aboveBegin      = aboveEnd;
    int foundSelectable = 0;
    for (; aboveBegin >= 0 && foundSelectable < _nAbove; --aboveBegin)
    {
      if (desc.mItems[aboveBegin].Selectable())
      {
        ++foundSelectable;
      }
    }
    ++aboveBegin;

    int  selected        = desc.mSelectedItem;
    bool isAboveSelected = (aboveBegin <= selected && selected <= aboveEnd);

    return isAboveSelected;
  }

  private int _nAbove;
}