NULL mag Issue 07 24 Python Lightbar menu

eZine lover (@eZine)

Published in 

null magazine

 · 26 Dec 2020

  

 

 
    lets create a lightbar menu, with some special uses. the following  
    code assumes that you are using my pycrt.py library from here: 
     
                      http://github.com/xqtr/pycrt/ 
                       
    with small changes in the readkey() function, you can easily use the  
    python_bbs library and convert it to a mystic MPY script. 
     
    our lightbar will have the following features: 
     
    1.  each item, can be displayed anywhere in the screen. we can put the  
        items next to each other, below, diagonal or even in random  
        places. this way we can have a very interesting menu and not just  
        a "classic" vertical one. 
    2.  each item, can have a low/normal attribute and a highlighted /  
        selected one. to achieve this, we can just use color attributes or  
        pipe codes inside the text description. 
    3.  we will be able to select items, by using cursor keys but also by  
        using hotkeys, for more quick use of the menu. 
    4.  each item will have a code, that it will be returned when the  
        specific item is selected with enter or the hotkey. it's more easy  
        to remember a string code, than index numbers. 
    5.  we can use as many items we want. the only limitation is the size  
        of the screen... :p 
         
         
    just to make it easy on ourselves, we use the following function to  
    create an item. each item, is a dictionary, so instead of trying to  
    remember each value for the dictionary fields, we use this function,  
    which is straightforward.         

def baradditem(x,y,low,high,lowtext,hightext,key,code): 
  return {'x':x,'y':y,'low':low,'high':high,'textlow':lowtext, \ 
  'texthigh':hightext, 'key':key, 'code':code} 
   
    to create an item, we just do this: 
     
    item1 = baradditem(10,10,7,14,'|01[h]|03ello','|17|15[H]ELLO','hH','hello') 

    to hold all items information we just put each item inside a list like  
    this: 
     
    allitems.append(item1) 
    allitems.append(item2) 
    ... 
    allitems.append(itemx) 

     
    now lets go to our main function... our function expects the list of  
    the items and if we want we can select the default selected item. by  
    default item index 0, will be selected. remember our list is zero  
    based, which means that if we have 5 items, their index number will be  
    0,1,2,3,4. 
     
def lightbarmenu(items,sel=0): 
  # initialize our result variable 
  res = "" 
   
  # go into a loop 
  while True: 
   
  # display the normal/unselected string of each item 
    for i in range(len(items)): 
      writexypipe(items[i]['x'],items[i]['y'],items[i]['low'], \ 
      mcilen(items[i]['textlow']),items[i]['textlow']) 
       
  # after we displayed all items, we also display the highlighted string  
  # of our selected item. 
    writexypipe(items[sel]['x'],items[sel]['y'],items[sel]['high'], \ 
    mcilen(items[sel]['texthigh']),items[sel]['texthigh']) 
   
  # expect user input   
    ans = readkey() 
     
  # if user presses up/left cursor keys, decrease the selection index 
    if ans == "#up" or ans == "#left": 
      sel -= 1 
      if sel < 0: sel = len(items) - 1 
   
  # if user presses down/right cursor keys, increase the selection index 
    elif ans == "#down" or ans == "#right": 
      sel += 1 
      if sel > len(items) - 1 : sel = 0 
  # if esc is pressed, exit with an #esc code 
    elif ans == "#esc": 
      res == "#esc" 
      break 
  # if the user pressed enter, return the 'code' value of the selected 
  # item. 
    elif ans == "#enter": 
      res = items[sel]['code'] 
      break 
  # if the user pressed something else, check to see if it's a hotkey. we  
  # check each items hotkey to see if matches the pressed key. if it is 
  # return the item 'code' field. 
    else: 
      for i in range(len(items)): 
        if ans in items[i]['key']: 
          res = items[i]['code'] 
          return res 
  return res 
   
   
  that was it!!! simple and short! you can create very cool lightbar menus  
  to use in your bbs or a door game or just a simple local terminal game  
  or script. 
   
  below is the code for the main function, with no comments to easily copy  
  paste. 
   
,./,./,./,./,./,./,./,./,./,./,./,./,./,./,./,./,./,./,./,./,./,./,./,./,./,. 
   
def lightbarmenu(items,sel=0): 
  res = "" 
  while True: 
    for i in range(len(items)): 
      writexypipe(items[i]['x'],items[i]['y'],items[i]['low'], \ 
      mcilen(items[i]['textlow']),items[i]['textlow']) 
    writexypipe(items[sel]['x'],items[sel]['y'],items[sel]['high'], \ 
    mcilen(items[sel]['texthigh']),items[sel]['texthigh']) 
     
    ans = readkey() 
    if ans == "#up" or ans == "#left": 
      sel -= 1 
      if sel < 0: sel = len(items) - 1 
    elif ans == "#down" or ans == "#right": 
      sel += 1 
      if sel > len(items) - 1 : sel = 0 
    elif ans == "#esc": 
      res == "#esc" 
      break 
    elif ans == "#enter": 
      res = items[sel]['code'] 
      break 
    else: 
      for i in range(len(items)): 
        if ans in items[i]['key']: 
          res = items[i]['code'] 
          return res 
  return res