Programming Python, Second Edition

Listboxes and Scrollbars

Listbox widgets allow you to display a list of items for selection, and Scrollbarsare designed for navigating through the contents of other widgets. Because it is common to use these widgets together, let’s study them both at once. Example 8-9 builds both a Listbox and a Scrollbar, as a packaged set.

Example 8-9. PP2E\Gui\Tour\scrolledlist.py

from Tkinter import * class ScrolledList(Frame): def __init__(self, options, parent=None): Frame.__init__(self, parent) self.pack(expand=YES, fill=BOTH) # make me expandable self.makeWidgets(options) def handleList(self, event): index = self.listbox.curselection() # on list double-click label = self.listbox.get(index) # fetch selection text self.runCommand(label) # and call action here def makeWidgets(self, options): # or get(ACTIVE) sbar = Scrollbar(self) list = Listbox(self, relief=SUNKEN) sbar.config(command=list.yview) # xlink sbar and list list.config(yscrollcommand=sbar.set) # move one moves other sbar.pack(side=RIGHT, fill=Y) # pack first=clip last list.pack(side=LEFT, expand=YES, fill=BOTH) # list clipped first pos = 0 for label in options: # add to list-box list.insert(pos, label) # or insert(END,label) pos = pos + 1 #list.config(selectmode=SINGLE, setgrid=1) # select,resize modes list.bind('<Double-1>', self.handleList) # set event handler self.listbox = list def runCommand(self, selection): # redefine me lower print 'You selected:', selection if __name__ == '__main__': options = map((lambda x: 'Lumberjack-' ...