def test_trace(self):
v = Variable(self.root)
vname = str(v)
trace = []
def read_tracer(*args):
trace.append(('read', ) + args)
def write_tracer(*args):
trace.append(('write', ) + args)
tr1 = v.trace_add('read', read_tracer)
tr2 = v.trace_add(['write', 'unset'], write_tracer)
self.assertEqual(sorted(v.trace_info()), [(('read', ), tr1),
(('write', 'unset'), tr2)])
self.assertEqual(trace, [])
v.set('spam')
self.assertEqual(trace, [('write', vname, '', 'write')])
trace = []
v.get()
self.assertEqual(trace, [('read', vname, '', 'read')])
trace = []
info = sorted(v.trace_info())
v.trace_remove('write', tr1) # Wrong mode
self.assertEqual(sorted(v.trace_info()), info)
with self.assertRaises(TclError):
v.trace_remove('read', 'spam') # Wrong command name
self.assertEqual(sorted(v.trace_info()), info)
v.get()
self.assertEqual(trace, [('read', vname, '', 'read')])
trace = []
v.trace_remove('read', tr1)
self.assertEqual(v.trace_info(), [(('write', 'unset'), tr2)])
v.get()
self.assertEqual(trace, [])
trace = []
del write_tracer
gc.collect()
v.set('eggs')
self.assertEqual(trace, [('write', vname, '', 'write')])
trace = []
del v
gc.collect()
self.assertEqual(trace, [('write', vname, '', 'unset')])
def test_trace(self):
v = Variable(self.root)
vname = str(v)
trace = []
def read_tracer(*args):
trace.append(('read',) + args)
def write_tracer(*args):
trace.append(('write',) + args)
tr1 = v.trace_add('read', read_tracer)
tr2 = v.trace_add(['write', 'unset'], write_tracer)
self.assertEqual(sorted(v.trace_info()), [
(('read',), tr1),
(('write', 'unset'), tr2)])
self.assertEqual(trace, [])
v.set('spam')
self.assertEqual(trace, [('write', vname, '', 'write')])
trace = []
v.get()
self.assertEqual(trace, [('read', vname, '', 'read')])
trace = []
info = sorted(v.trace_info())
v.trace_remove('write', tr1) # Wrong mode
self.assertEqual(sorted(v.trace_info()), info)
with self.assertRaises(TclError):
v.trace_remove('read', 'spam') # Wrong command name
self.assertEqual(sorted(v.trace_info()), info)
v.get()
self.assertEqual(trace, [('read', vname, '', 'read')])
trace = []
v.trace_remove('read', tr1)
self.assertEqual(v.trace_info(), [(('write', 'unset'), tr2)])
v.get()
self.assertEqual(trace, [])
trace = []
del write_tracer
gc.collect()
v.set('eggs')
self.assertEqual(trace, [('write', vname, '', 'write')])
trace = []
del v
gc.collect()
self.assertEqual(trace, [('write', vname, '', 'unset')])
def SaveVar(var: _TK.Variable, master=None, value=None, name=None, filename='data.pkl') \
-> (_TK.Variable):
"""Save tkinter variable data in a pickle file and load the
same value when the program is executed next time.
#### If the content of the file changes, it might not load correct values \
to the assigned variables. To avoid this issue use `name` to \
refer to the exact assigned values later.
### Args:
- `var`: Give the `tkinter.Variable` class like (`tk.StringVar`, `tk.IntVar`).
- `master`: Parent widget.
- `value`: Set value.
- `name`: Set a name to group variables or to refer to assigned value when loaded.
- `filename`: Set the name of the save file. (To make the file invisible in the \
directory start the name of the file with "." like ".cache-savevar")
### Return:
- returns the tk.Variable instance passed to `var` argument.
### Example:
root = tk.Tk()
var1 = SaveVar(tk.StringVar,'Enter Username','Var1','.cache-savevar')
var2 = SaveVar(tk.StringVar,'Enter Password','Var2','.cache-savevar')
tk.Entry(root,textvariable=var1).pack()
tk.Entry(root,textvariable=var2).pack()
root.mainloop()"""
def update_val(*args):
"""Internal function for updating the value for variable"""
try: # try/except , if the file doesn't exists.
open1 = open(filename, 'rb')
tmpdict = pkl.load(open1) # load saved dictionary data.
# Block of code to check for the right value.
if tmpdict.get(str(var)):
old, default = tmpdict.get(str(var))
new = var.get()
if new != default:
var.set(new)
elif new == default and not startup[0]:
var.set(default)
else:
var.set(old)
tmpdict.update({str(var): (var.get(), defaultval)})
open1.close()
except Exception as e:
tmpdict = {}
tmpdict[str(var)] = (var.get(), defaultval)
open2 = open(filename, 'wb')
pkl.dump(tmpdict, open2)
startup[0] = False
open2.close()
startup = [True]
if not(filename.endswith('.pickle') or filename.endswith('.pkl')) \
and not filename.startswith('.'):
filename = filename + '.pkl'
var = var(master=master, value=value, name=name)
defaultval = var.get() # get a default value of the variable
update_val()
for mode, cbname in (var.trace_info()):
if mode[0] == 'write' and update_val.__name__ in cbname:
try:
var.trace_remove('write', cbname)
except:
pass
res = var.trace_add('write', update_val)
return var