utils.py

import tkinter as tk

class ScrolledList(tk.Frame):
  ''' Scrolled list box.  Respsonds to double click.
      Override runCommand
      Bind actions such as button press to handleList
  '''
  def __init__(self, parent, items, **kwargs):
    # Items is an iterable of list box items
    super().__init__(parent)
    self.pack(expand=tk.YES, fill=tk.BOTH)
    self.makeWidgets(items, **kwargs)
    
  def __getattr__(self, name):
    # Delegate unknown methods to the listbox
    
    return getattr(self.listbox, name)  
    
  def handleList(self, event):
    item = self.listbox.get(tk.ACTIVE)
    self.runCommand(item)
    
  def makeWidgets(self, items, **kwargs):
    sbar = tk.Scrollbar(self)
    list = tk.Listbox(self, **kwargs)
    list.configure(**kwargs)
    sbar.configure(command=list.yview)
    list.configure(yscrollcommand=sbar.set)
    sbar.pack(side=tk.RIGHT, fill=tk.Y)
    list.pack(side=tk.LEFT, expand=tk.YES, fill=tk.BOTH)
    list.insert(0, *items)
    list.config(selectmode=tk.SINGLE, setgrid=1)
    list.bind('<Double-1>', self.handleList)
    self.listbox = list
    
  def runCommand(self, selection):
    # override me
    print(selection)
    
class ScrolledCanvas(tk.Frame):
  '''
  A canvas with scrollbars.
  It automatically delegates unknown methods to the Canvas widget with __getattr__,
  so we don't have to put in a one-line definition every time we use another method.
  '''
  
  def __init__(self, master, scrolls, **kwargs):
    tk.Frame.__init__(self, master)
    canv = self.canvas = tk.Canvas(self, **kwargs)
    canv.grid(row = 0, column = 0, sticky = 'news')
    
    if scrolls in (tk.BOTH, tk.VERTICAL):
      ybar = tk.Scrollbar(self, orient = tk.VERTICAL)
      ybar.config(command=canv.yview)                   # xlink sbar and canv
      canv.config(yscrollcommand=ybar.set)              # move one moves other
      ybar.grid(row = 0, column = 1, sticky = 'ns')

    if scrolls in (tk.BOTH, tk.HORIZONTAL):
      xbar = tk.Scrollbar(self, orient = tk.HORIZONTAL)
      xbar.config(command=canv.xview)                   # xlink sbar and canv
      canv.config(xscrollcommand=xbar.set)              # move one moves other
      xbar.grid(row = 1, column = 0, sticky = 'ew')

    self.columnconfigure(0, weight = 1)
    self.rowconfigure(0, weight = 1)

  def __getattr__(self, name):
    return getattr(self.canvas, name)
  
  def setCursor(self, cursor):
    self.canvas.configure(cursor = cursor)