Example 9-11. PP4E\Gui\Tour\simpleedit.py
"""
add common edit tools to ScrolledText by inheritance;
composition (embedding) would work just as well here;
this is not robust!--see PyEdit for a feature superset;
"""
from tkinter import *
from tkinter.simpledialog import askstring
from tkinter.filedialog import asksaveasfilename
from quitter import Quitter
from scrolledtext import ScrolledText # here, not Python's
class SimpleEditor(ScrolledText): # see PyEdit for more
def init(self, parent=None, file=None):
frm = Frame(parent)
frm.pack(fill=X)
Button(frm, text='Save', command=self.onSave).pack(side=LEFT)
Button(frm, text='Cut', command=self.onCut).pack(side=LEFT)
Button(frm, text='Paste', command=self.onPaste).pack(side=LEFT)
Button(frm, text='Find', command=self.onFind).pack(side=LEFT)
Quitter(frm).pack(side=LEFT)
ScrolledText.init(self, parent, file=file)
self.text.config(font=('courier', 9, 'normal'))
def onSave(self):
filename = asksaveasfilename()
if filename:
alltext = self.gettext() # first through last
open(filename, 'w').write(alltext) # store text in file
def onCut(self):
text = self.text.get(SEL_FIRST, SEL_LAST) # error if no select
self.text.delete(SEL_FIRST, SEL_LAST) # should wrap in try
self.clipboard_clear()
self.clipboard_append(text)
def onPaste(self): # add clipboard text
try:
text = self.selection_get(selection='CLIPBOARD')
self.text.insert(INSERT, text)
except TclError:
pass # not to be pasted
def onFind(self):
target = askstring('SimpleEditor', 'Search String?')
if target:
where = self.text.search(target, INSERT, END) # from insert cursor
if where: # returns an index
print(where)
pastit = where + ('+%dc' % len(target)) # index past target
#self.text.tag_remove(SEL, '1.0', END) # remove selection
self.text.tag_add(SEL, where, pastit) # select found target
self.text.mark_set(INSERT, pastit) # set insert mark
self.text.see(INSERT) # scroll display
534 | Chapter 9: A tkinter Tour, Part 2