From 7e24d24a37295eaf773d3167725e00036e8b73fc Mon Sep 17 00:00:00 2001
From: Alejandro Autalan <alejandroautalan@gmail.com>
Date: Thu, 5 Dec 2024 01:31:17 -0300
Subject: [PATCH] Avoid creating style on every <<ThemeChanged>> event.

---
 tkcalendar/calendar_.py | 20 ++++++++++++++++++--
 tkcalendar/dateentry.py | 10 ++++++++--
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/tkcalendar/calendar_.py b/tkcalendar/calendar_.py
index b3cecab..d6e3e7e 100644
--- a/tkcalendar/calendar_.py
+++ b/tkcalendar/calendar_.py
@@ -492,10 +492,13 @@ def __init__(self, master=None, **kw):
 
         self.config(state=state)
 
+        self._theme_name = None
+        self._setup_style()
+
         # --- bindings
-        self.bind('<<ThemeChanged>>', self._setup_style)
+        self.theme_change_cbid = None
+        self.bind('<<ThemeChanged>>', self.schedule_style_update)
 
-        self._setup_style()
         self._display_calendar()
         self._btns_date_range()
         self._check_sel_date()
@@ -746,6 +749,18 @@ def _textvariable_trace(self, *args):
                     self._display_calendar()
                     self._display_selection()
 
+    def schedule_style_update(self, event=None):
+        if self.theme_change_cbid is None:
+            self.theme_change_cbid = self.after(10, self._on_theme_change)
+
+    def _on_theme_change(self):
+        theme = self.style.theme_use()
+        if self._theme_name != theme:
+            # the theme has changed, update the DateEntry style to look like a combobox
+            self._theme_name = theme
+            self._setup_style()
+        self.theme_change_cbid = None
+
     def _setup_style(self, event=None):
         """Configure style."""
         self.style.layout('L.%s.TButton' % self._style_prefixe,
@@ -819,6 +834,7 @@ def _setup_style(self, event=None):
         self.style.map(self._style_prefixe + '.TLabel',
                        background=[('disabled', dis_day_bg)],
                        foreground=[('disabled', dis_day_fg)])
+        self._theme_name = self.style.theme_use()
 
     # --- display
     def _display_calendar(self):
diff --git a/tkcalendar/dateentry.py b/tkcalendar/dateentry.py
index e6d782e..7500cc6 100644
--- a/tkcalendar/dateentry.py
+++ b/tkcalendar/dateentry.py
@@ -159,8 +159,8 @@ def __init__(self, master=None, **kw):
 
         # --- bindings
         # reconfigure style if theme changed
-        self.bind('<<ThemeChanged>>',
-                  lambda e: self.after(10, self._on_theme_change))
+        self.theme_change_cbid = None
+        self.bind('<<ThemeChanged>>', self.schedule_style_update)
         # determine new downarrow button bbox
         self.bind('<Configure>', self._determine_downarrow_name)
         self.bind('<Map>', self._determine_downarrow_name)
@@ -181,6 +181,10 @@ def __getitem__(self, key):
     def __setitem__(self, key, value):
         self.configure(**{key: value})
 
+    def schedule_style_update(self, event=None):
+        if self.theme_change_cbid is None:
+            self.theme_change_cbid = self.after(10, self._on_theme_change)
+
     def _setup_style(self, event=None):
         """Style configuration to make the DateEntry look like a Combobbox."""
         self.style.layout('DateEntry', self.style.layout('TCombobox'))
@@ -202,6 +206,7 @@ def _setup_style(self, event=None):
             # nothing to cancel
             pass
         self._determine_downarrow_name_after_id = self.after(10, self._determine_downarrow_name)
+        self._theme_name = self.style.theme_use()
 
     def _determine_downarrow_name(self, event=None):
         """Determine downarrow button name."""
@@ -237,6 +242,7 @@ def _on_theme_change(self):
             # the theme has changed, update the DateEntry style to look like a combobox
             self._theme_name = theme
             self._setup_style()
+        self.theme_change_cbid = None
 
     def _on_b1_press(self, event):
         """Trigger self.drop_down on downarrow button press and set widget state to ['pressed', 'active']."""