Replace GBulb with PyGObject's native asyncio handling

android/tests_backend/widgets/optioncontainer.py

@@ -21,6 +21,9 @@ def select_tab(self, index):
             item.setChecked(True)
             self.impl.onItemSelectedListener(item)
 
+    async def wait_for_tab(self, message):
+        await self.redraw(message)
+
     def tab_enabled(self, index):
         return self.native_navigationview.getMenu().getItem(index).isEnabled()
 

changes/2550.feature.rst

@@ -0,0 +1 @@
+The GTK backend was modified to use PyGObject's native asyncio handling, instead of GBulb.

cocoa/tests_backend/widgets/optioncontainer.py

@@ -43,6 +43,9 @@ def height(self):
     def select_tab(self, index):
         self.native.selectTabViewItemAtIndex(index)
 
+    async def wait_for_tab(self, message):
+        await self.redraw(message)
+
     def tab_enabled(self, index):
         # _isTabEnabled() is a hidden method, so the naming messes with Rubicon's
         # property lookup mechanism. Invoke it by passing the message directly.

examples/handlers/handlers/app.py

@@ -1,6 +1,8 @@
 import asyncio
 import random
 
+import httpx
+
 import toga
 from toga.constants import COLUMN
 from toga.style import Pack
@@ -10,7 +12,8 @@ class HandlerApp(toga.App):
     # Button callback functions
     def do_clear(self, widget, **kwargs):
         self.counter = 0
-        self.label.text = "Ready."
+        self.on_running_label.text = "Ready."
+        self.background_label.text = "Ready."
         self.function_label.text = "Ready."
         self.generator_label.text = "Ready."
         self.async_label.text = "Ready."
@@ -44,27 +47,47 @@ async def do_async(self, widget, **kwargs):
         self.async_label.text = "Ready."
         widget.enabled = True
 
-    async def do_background_task(self, widget, **kwargs):
+    async def on_running(self, **kwargs):
+        """A task started when the app is running."""
+        # This task runs in the background, without blocking the main event loop
+        while True:
+            self.counter += 1
+            self.on_running_label.text = f"On Running: Iteration {self.counter}"
+            await asyncio.sleep(1)
+
+    async def do_background_task(self, **kwargs):
         """A background task."""
         # This task runs in the background, without blocking the main event loop
         while True:
             self.counter += 1
-            self.label.text = f"Background: Iteration {self.counter}"
+            self.background_label.text = f"Background: Iteration {self.counter}"
             await asyncio.sleep(1)
 
+    async def do_web_get(self, widget, **kwargs):
+        async with httpx.AsyncClient() as client:
+            response = await client.get(
+                f"https://jsonplaceholder.typicode.com/posts/{random.randint(0, 100)}"
+            )
+
+        payload = response.json()
+
+        self.web_label.text = payload["title"]
+
     def startup(self):
         # Set up main window
         self.main_window = toga.MainWindow()
 
         # Labels to show responses.
-        self.label = toga.Label("Ready.", style=Pack(padding=10))
+        self.on_running_label = toga.Label("Ready.", style=Pack(padding=10))
+        self.background_label = toga.Label("Ready.", style=Pack(padding=10))
         self.function_label = toga.Label("Ready.", style=Pack(padding=10))
         self.generator_label = toga.Label("Ready.", style=Pack(padding=10))
         self.async_label = toga.Label("Ready.", style=Pack(padding=10))
+        self.web_label = toga.Label("Ready.", style=Pack(padding=10))
 
         # Add a background task.
         self.counter = 0
-        self.add_background_task(self.do_background_task)
+        asyncio.create_task(self.do_background_task())
 
         # Buttons
         btn_style = Pack(flex=1)
@@ -78,17 +101,23 @@ def startup(self):
             "Async callback", on_press=self.do_async, style=btn_style
         )
         btn_clear = toga.Button("Clear", on_press=self.do_clear, style=btn_style)
+        btn_web = toga.Button(
+            "Get web content", on_press=self.do_web_get, style=btn_style
+        )
 
         # Outermost box
         box = toga.Box(
             children=[
-                self.label,
+                self.on_running_label,
+                self.background_label,
                 btn_function,
                 self.function_label,
                 btn_generator,
                 self.generator_label,
                 btn_async,
                 self.async_label,
+                btn_web,
+                self.web_label,
                 btn_clear,
             ],
             style=Pack(flex=1, direction=COLUMN, padding=10),

examples/handlers/pyproject.toml

@@ -16,6 +16,7 @@ description = "A testing app"
 sources = ["handlers"]
 requires = [
     "../../core",
+    "httpx",
 ]
 
 

gtk/pyproject.toml

@@ -64,12 +64,8 @@ root = ".."
 
 [tool.setuptools_dynamic_dependencies]
 dependencies = [
-    "gbulb >= 0.5.3",
     "pycairo >= 1.17.0",
-    # New asyncio handling introduced in 3.50.0; that code is incompatible
-    # with gbulb, See #2550 for the code that replaces GBulb with the new
-    # asyncio code.
-    "pygobject < 3.50.0",
+    "pygobject>=3.50.0",
     "toga-core == {version}",
 ]
 

gtk/src/toga_gtk/app.py

@@ -1,13 +1,19 @@
 import asyncio
 import signal
 
-import gbulb
-
 from toga.app import App as toga_App
 from toga.command import Separator
 
 from .keys import gtk_accel
-from .libs import IS_WAYLAND, TOGA_DEFAULT_STYLES, Gdk, Gio, GLib, Gtk
+from .libs import (
+    IS_WAYLAND,
+    TOGA_DEFAULT_STYLES,
+    Gdk,
+    Gio,
+    GLib,
+    GLibEventLoopPolicy,
+    Gtk,
+)
 from .screens import Screen as ScreenImpl
 
 
@@ -21,8 +27,9 @@ def __init__(self, interface):
         self.interface = interface
         self.interface._impl = self
 
-        gbulb.install(gtk=True)
-        self.loop = asyncio.new_event_loop()
+        self.policy = GLibEventLoopPolicy()
+        asyncio.set_event_loop_policy(self.policy)
+        self.loop = asyncio.get_event_loop()
 
         # Stimulate the build of the app
         self.native = Gtk.Application(
@@ -146,7 +153,8 @@ def main_loop(self):
         # Retain a reference to the app so that no-window apps can exist
         self.native.hold()
 
-        self.loop.run_forever(application=self.native)
+        # Start the app event loop
+        self.native.run()
 
         # Release the reference to the app. This can't be invoked by the testbed,
         # because it's after the `run_forever()` that runs the testbed.

gtk/src/toga_gtk/libs/gtk.py

@@ -3,6 +3,7 @@
 gi.require_version("Gdk", "3.0")
 gi.require_version("Gtk", "3.0")
 
+from gi.events import GLibEventLoopPolicy  # noqa: E402, F401
 from gi.repository import (  # noqa: E402, F401
     Gdk,
     GdkPixbuf,

gtk/tests_backend/widgets/optioncontainer.py

@@ -19,6 +19,9 @@ def select_tab(self, index):
         if self.tab_enabled(index):
             self.native.set_current_page(index)
 
+    async def wait_for_tab(self, message):
+        await self.redraw(message, delay=0.1)
+
     def tab_enabled(self, index):
         return self.impl.sub_containers[index].get_visible()
 

iOS/tests_backend/widgets/optioncontainer.py

@@ -39,6 +39,9 @@ def select_more(self):
         more = self.impl.native_controller.moreNavigationController
         self.impl.native_controller.selectedViewController = more
 
+    async def wait_for_tab(self, message):
+        await self.redraw(message)
+
     def reset_more(self):
         more = self.impl.native_controller.moreNavigationController
         more.popToRootViewControllerAnimated(False)