codegenerator

inc/system/system.textinput.lua

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+--- @section TextInput
+
+TextInput = {}
+
+local LETTERS  = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+local _pos     = {}
+local _cursor  = 1
+local _max_len = 3
+
+--- Initialises a new text input session.
+--- @within TextInput
+--- @param max_len number Maximum character count (default 3).
+function TextInput.init(max_len)
+  _max_len = max_len or 3
+  _pos     = {}
+  for i = 1, _max_len do _pos[i] = 1 end
+  _cursor = 1
+end
+
+--- Advances to the next letter at the cursor position (wraps Z→A).
+--- @within TextInput
+function TextInput.next_letter()
+  _pos[_cursor] = (_pos[_cursor] % #LETTERS) + 1
+end
+
+--- Goes back to the previous letter at the cursor position (wraps A→Z).
+--- @within TextInput
+function TextInput.prev_letter()
+  _pos[_cursor] = ((_pos[_cursor] - 2) % #LETTERS) + 1
+end
+
+--- Confirms the current letter and advances the cursor to the next position.
+--- When called on the last position the cursor moves into the done state.
+--- @within TextInput
+function TextInput.select_letter()
+  if _cursor <= _max_len then _cursor = _cursor + 1 end
+end
+
+--- Moves the cursor one position to the right (stops at last position).
+--- @within TextInput
+function TextInput.next_position()
+  if _cursor < _max_len then _cursor = _cursor + 1 end
+end
+
+--- Moves the cursor one position to the left (stops at first position).
+--- Also steps back out of the done state.
+--- @within TextInput
+function TextInput.prev_position()
+  if _cursor > 1 then _cursor = _cursor - 1 end
+end
+
+--- Returns the assembled name string.
+--- @within TextInput
+--- @return string
+function TextInput.get_name()
+  local s = ""
+  for i = 1, _max_len do s = s .. LETTERS:sub(_pos[i], _pos[i]) end
+  return s
+end
+
+--- Returns the current 1-based cursor position.
+--- @within TextInput
+--- @return number
+function TextInput.get_position()
+  return _cursor
+end
+
+--- Returns the letter at the given 1-based position.
+--- @within TextInput
+--- @param i number
+--- @return string
+function TextInput.get_letter(i)
+  return LETTERS:sub(_pos[i], _pos[i])
+end
+
+--- Returns true when all positions have been confirmed.
+--- @within TextInput
+--- @return boolean
+function TextInput.is_done()
+  return _cursor > _max_len
+end