Method EncoderActionScrollItemHelper

src/Display/Menu.cpp:618–658

}

void Menu::EncoderActionScrollItemHelper(int action) noexcept
{
	// Based mainly on file listing requiring we handle list of unknown length
	// before moving on to the next selectable item at the Menu level, we let the
	// currently selected MenuItem try to handle the scroll action itself.  It will
	// return the remainder of the scrolling that it was unable to accommodate.
	if (highlightedItem != nullptr && highlightedItem->IsVisible())
	{
		// Let the current menu item attempt to handle scroll wheel first
		action = highlightedItem->Advance(action);
	}

	if (action != 0)
	{
		// Otherwise we move through the remaining selectable menu items
		AdvanceHighlightedItem(action);

		if (highlightedItem != nullptr)
		{
			// Let the newly selected MenuItem handle any selection setup
			highlightedItem->Enter(action > 0);

			PixelNumber tLastOffset = rowOffset;
			rowOffset = highlightedItem->GetVisibilityRowOffset(tLastOffset, lcd.GetFontHeight(highlightedItem->GetFontNumber()));

			if (rowOffset != tLastOffset)
			{
				// We have scrolled the whole menu, so redraw it
				lcd.ClearAll();
				for (MenuItem *_ecv_from _ecv_null item = selectableItems; item != nullptr; item = item->GetNext())
				{
					item->SetChanged();
				}
				for (MenuItem *_ecv_from _ecv_null item = unSelectableItems; item != nullptr; item = item->GetNext())
				{
					item->SetChanged();
				}
			}
		}
	}
}

// Perform the specified encoder action
// If 'action' is zero then the button was pressed, else 'action' is the number of clicks (+ve for clockwise)