Changes per chapter 5 revision 2

Author: alandmoore

Chapter05/DateEntry.py

@@ -9,17 +9,17 @@ def __init__(self, parent, *args, **kwargs):
     super().__init__(parent, *args, **kwargs)
     self.configure(
       validate='all',
-      validatecommand=(self.register(self._validate),  '%S', '%i', '%V', '%d'),
+      validatecommand=(
+        self.register(self._validate),
+        '%S', '%i', '%V', '%d'
+      ),
       invalidcommand=(self.register(self._on_invalid), '%V')
     )
     self.error = tk.StringVar()
 
   def _toggle_error(self, error=''):
     self.error.set(error)
-    if error:
-      self.config(foreground='red')
-    else:
-      self.config(foreground='black')
+    self.config(foreground='red' if error else 'black')
 
   def _validate(self, char, index, event, action):
 
@@ -53,7 +53,7 @@ def _on_invalid(self, event):
   entry = DateEntry(root)
   entry.pack()
   ttk.Label(
-      textvariable=entry.error, foreground='red'
+    textvariable=entry.error, foreground='red'
   ).pack()
 
   # add this so we can unfocus the DateEntry

Chapter05/data_entry_app.py

@@ -148,7 +148,7 @@ def _key_validate(self, proposed, action, **kwargs):
 
     # get our values list
     values = self.cget('values')
-    # Do a case-insensitve match against the entered text
+    # Do a case-insensitive match against the entered text
     matching = [
       x for x in values
       if x.lower().startswith(proposed.lower())
@@ -199,7 +199,7 @@ def _set_focus_update_var(self, event):
     if self.focus_update_var and not self.error.get():
       self.focus_update_var.set(value)
 
-  def _set_minimum(self, *args):
+  def _set_minimum(self, *_):
     current = self.get()
     try:
       new_min = self.min_var.get()
@@ -212,7 +212,7 @@ def _set_minimum(self, *args):
       self.variable.set(current)
     self.trigger_focusout_validation()
 
-  def _set_maximum(self, *args):
+  def _set_maximum(self, *_):
     current = self.get()
     try:
       new_max = self.max_var.get()
@@ -228,13 +228,13 @@ def _set_maximum(self, *args):
   def _key_validate(
     self, char, index, current, proposed, action, **kwargs
   ):
+    if action == '0':
+      return True
     valid = True
     min_val = self.cget('from')
     max_val = self.cget('to')
     no_negative = min_val >= 0
     no_decimal = self.precision >= 0
-    if action == '0':
-      return True
 
     # First, filter out obviously invalid keystrokes
     if any([
@@ -269,16 +269,17 @@ def _focusout_validate(self, **kwargs):
     max_val = self.cget('to')
 
     try:
-      value = Decimal(value)
+      d_value = Decimal(value)
     except InvalidOperation:
-      self.error.set('Invalid number string: {}'.format(value))
+      self.error.set(f'Invalid number string: {value}')
       return False
 
-    if value < min_val:
-      self.error.set('Value is too low (min {})'.format(min_val))
+    if d_value < min_val:
+      self.error.set(f'Value is too low (min {min_val})')
+      valid = False
+    if d_value > max_val:
+      self.error.set(f'Value is too high (max {max_val})')
       valid = False
-    if value > max_val:
-      self.error.set('Value is too high (max {})'.format(max_val))
 
     return valid
 
@@ -288,36 +289,23 @@ class BoundText(tk.Text):
   def __init__(self, *args, textvariable=None, **kwargs):
     super().__init__(*args, **kwargs)
     self._variable = textvariable
-    self._modifying = False
     if self._variable:
       # insert any default value
       self.insert('1.0', self._variable.get())
       self._variable.trace_add('write', self._set_content)
       self.bind('<<Modified>>', self._set_var)
 
-  def _clear_modified_flag(self):
-    # This also triggers a '<<Modified>>' Event
-    self.tk.call(self._w, 'edit', 'modified', 0)
-
   def _set_var(self, *_):
     """Set the variable to the text contents"""
-    if self._modifying:
-      return
-    self._modifying = True
-    # remove trailing newline from content
-    content = self.get('1.0', tk.END)[:-1]
-    self._variable.set(content)
-    self._clear_modified_flag()
-    self._modifying = False
+    if self.edit_modified():
+      content = self.get('1.0', 'end-1chars')
+      self._variable.set(content)
+      self.edit_modified(False)
 
   def _set_content(self, *_):
     """Set the text contents to the variable"""
-    if self._modifying:
-      return
-    self._modifying = True
     self.delete('1.0', tk.END)
     self.insert('1.0', self._variable.get())
-    self._modifying = False
 
 ##################
 # Module Classes #
@@ -595,7 +583,9 @@ def reset(self):
       plot = self._vars['Plot'].get()
     except tk.TclError:
       plot = ''
-    plot_values = self._vars['Plot'].label_widget.input.cget('values')
+    plot_values = (
+      self._vars['Plot'].label_widget.input.cget('values')
+    )
 
     # clear all values
     for var in self._vars.values():

Chapter05/validate_demo.py

@@ -6,51 +6,51 @@
 
 # create a pointless validation command
 def always_good():
-    return True
+  return True
 
 validate_ref = root.register(always_good)
 
 entry.configure(
-    validate='all',
-    validatecommand=(validate_ref,)
+  validate='all',
+  validatecommand=(validate_ref,)
 )
 
 # a more useful validation command
 
 
 entry2 = tk.Entry(root)
-entry2.grid()
+entry2.grid(pady=10)
 
 def no_t_for_me(proposed):
-    return 't' not in proposed
+  return 't' not in proposed
 
 validate2_ref = root.register(no_t_for_me)
 entry2.configure(
-    validate='all',
-    validatecommand=(validate2_ref, '%P')
+  validate='all',
+  validatecommand=(validate2_ref, '%P')
 )
 
 # An Entry that displays an error
 
 entry3 = tk.Entry(root)
 entry3.grid()
 entry3_error = tk.Label(root, fg='red')
-entry3_error.grid()
+entry3_error.grid(pady=10)
 
 def only_five_chars(proposed):
-    return len(proposed) < 6
+  return len(proposed) < 6
 
 def only_five_chars_error(proposed):
-    entry3_error.configure(
-        text=f'{proposed} is too long, only 5 chars allowed.'
-    )
+  entry3_error.configure(
+    text=f'{proposed} is too long, only 5 chars allowed.'
+  )
 validate3_ref = root.register(only_five_chars)
 invalid3_ref = root.register(only_five_chars_error)
 
 entry3.configure(
-    validate='all',
-    validatecommand=(validate3_ref, '%P'),
-    invalidcommand=(invalid3_ref, '%P')
+  validate='all',
+  validatecommand=(validate3_ref, '%P'),
+  invalidcommand=(invalid3_ref, '%P')
 )
 
 root.mainloop()