bpo-3405: Add support for user data of Tk virtual events to tkinter

Lib/tkinter/__init__.py

@@ -218,6 +218,10 @@ class Event:
     type - type of the event as a number
     widget - widget in which the event occurred
     delta - delta of wheel movement (MouseWheel)
+    detail - certain fixed strings (see tcl/tk documentation)
+             (Enter, Leave, FocusIn, FocusOut, ConfigureRequest)
+    user_data - data string which was passed to event_generate or empty string
+                (VirtualEvent)
     """
     def __repr__(self):
         attrs = {k: v for k, v in self.__dict__.items() if v != '??'}
@@ -1378,7 +1382,7 @@ def _root(self):
         w = self
         while w.master: w = w.master
         return w
-    _subst_format = ('%#', '%b', '%f', '%h', '%k',
+    _subst_format = ('%#', '%b', '%d', '%f', '%h', '%k',
              '%s', '%t', '%w', '%x', '%y',
              '%A', '%E', '%K', '%N', '%W', '%T', '%X', '%Y', '%D')
     _subst_format_str = " ".join(_subst_format)
@@ -1395,11 +1399,14 @@ def getint_event(s):
             except (ValueError, TclError):
                 return s
 
-        nsign, b, f, h, k, s, t, w, x, y, A, E, K, N, W, T, X, Y, D = args
-        # Missing: (a, c, d, m, o, v, B, R)
+        nsign, b, d, f, h, k, s, t, w, x, y, A, E, K, N, W, T, X, Y, D = args
+        # Missing: (a, c, m, o, v, B, R)
         e = Event()
         # serial field: valid for all events
         # number of button: ButtonPress and ButtonRelease events only
+        # detail: for Enter, Leave, FocusIn, FocusOut and ConfigureRequest
+        # events certain fixed strings (see tcl/tk documentation)
+        # user_data: data string from a virtual event or an empty string
         # height field: Configure, ConfigureRequest, Create,
         # ResizeRequest, and Expose events only
         # keycode field: KeyPress and KeyRelease events only
@@ -1413,6 +1420,8 @@ def getint_event(s):
         # KeyRelease, and Motion events
         e.serial = getint(nsign)
         e.num = getint_event(b)
+        e.user_data = d
+        e.detail = d
         try: e.focus = getboolean(f)
         except TclError: pass
         e.height = getint_event(h)

Lib/tkinter/test/test_tkinter/test_event.py

@@ -0,0 +1,49 @@
+import unittest
+import tkinter
+import _tkinter
+from test.support import requires, run_unittest
+from tkinter.test.support import AbstractTkTest
+
+requires('gui')
+
+class EventTest(AbstractTkTest, unittest.TestCase):
+
+    called = False
+    test_data = None
+
+    # pump_events function 'borrowed' from ivan_pozdeev on stackoverflow
+    def pump_events(self):
+        while self.root.dooneevent(_tkinter.ALL_EVENTS | _tkinter.DONT_WAIT):
+            pass
+
+    def test_virtual_event(self):
+        def receive(e):
+            EventTest.called = True
+            self.assertIsInstance(e, tkinter.Event)
+            self.assertEqual(e.type, tkinter.EventType.VirtualEvent)
+            self.assertIsInstance(e.user_data, str)
+            if EventTest.test_data is not None:
+                self.assertEqual(e.user_data, EventTest.test_data)
+            else:
+                self.assertEqual(e.user_data, '')
+        self.pump_events()
+        EventTest.called = False
+        b = self.root.bind('<<TEST>>', lambda e:receive(e))
+        self.root.event_generate('<<TEST>>')
+        self.pump_events()
+        self.assertTrue(EventTest.called)
+        EventTest.called = False
+        EventTest.test_data = 'test'
+        self.root.event_generate('<<TEST>>', data='test')
+        self.pump_events()
+        self.assertTrue(EventTest.called)
+        self.root.unbind('<<TEST>>', b)
+        EventTest.called = False
+        self.root.event_generate('<<TEST>>')
+        self.pump_events()
+        self.assertFalse(EventTest.called)
+
+tests_gui = (EventTest, )
+
+if __name__ == "__main__":
+    run_unittest(*tests_gui)

Misc/NEWS.d/next/Library/2018-05-11-12-26-16.bpo-3405.CacMw9.rst

@@ -0,0 +1 @@
+Add support for user data of Tk virtual events to :mod:`tkinter`.