Added support for cursor visibility in WinForms.

changes/1894.feature.rst

@@ -0,0 +1 @@
+Winforms now supports hiding and re-showing the app cursor.

examples/window/window/app.py

@@ -75,6 +75,15 @@ async def do_current_window_cycling(self, widget, **kwargs):
             self.label.text = f"Current window is {self.current_window.id}"
             await asyncio.sleep(1)
 
+    async def do_hide_cursor(self, widget, **kwargs):
+        self.hide_cursor()
+        self.label.text = "Momentarily hiding cursor..."
+
+        await asyncio.sleep(2)
+
+        self.show_cursor()
+        self.label.text = "Cursor should be back!"
+
     def do_report(self, widget, **kwargs):
         self.label.text = (
             f"Window {self.main_window.title!r} "
@@ -148,6 +157,11 @@ def startup(self):
             on_press=self.do_current_window_cycling,
             style=btn_style,
         )
+        btn_do_hide_cursor = toga.Button(
+            "Hide cursor",
+            on_press=self.do_hide_cursor,
+            style=btn_style,
+        )
         btn_do_report = toga.Button("Report", on_press=self.do_report, style=btn_style)
         btn_change_content = toga.Button(
             "Change content", on_press=self.do_next_content, style=btn_style
@@ -165,6 +179,7 @@ def startup(self):
                 btn_do_title,
                 btn_do_new_windows,
                 btn_do_current_window_cycling,
+                btn_do_hide_cursor,
                 btn_do_report,
                 btn_change_content,
                 btn_hide,

winforms/src/toga_winforms/app.py

@@ -49,6 +49,11 @@ def __init__(self, interface):
         # window-level close handling.
         self._is_exiting = False
 
+        # Winforms cursor visibility is a stack; If you call hide N times, you
+        # need to call Show N times to make the cursor re-appear. Store a local
+        # boolean to allow us to avoid building a deep stack.
+        self._cursor_visible = True
+
         self.loop = WinformsProactorEventLoop()
         asyncio.set_event_loop(self.loop)
 
@@ -305,14 +310,15 @@ def exit_full_screen(self, windows):
         for window in windows:
             window._impl.set_full_screen(False)
 
-    def set_cursor(self, value):
-        self.interface.factory.not_implemented("App.set_cursor()")
-
     def show_cursor(self):
-        self.interface.factory.not_implemented("App.show_cursor()")
+        if not self._cursor_visible:
+            WinForms.Cursor.Show()
+        self._cursor_visible = True
 
     def hide_cursor(self):
-        self.interface.factory.not_implemented("App.hide_cursor()")
+        if self._cursor_visible:
+            WinForms.Cursor.Hide()
+        self._cursor_visible = False
 
 
 class DocumentApp(App):