Added on_gain_focus, on_lose_focus, on_show & on_hide handlers on toga.Window

changes/2009.feature.rst

@@ -0,0 +1 @@
+Added `on_gain_focus` and `on_lose_focus` handlers both on the `toga.App` and `toga.Window`.

core/src/toga/app.py

@@ -132,6 +132,8 @@ def __init__(
  minimizable: bool = True,
  factory: None = None, # DEPRECATED !
  on_close: None = None,
+ on_gain_focus: callable | None = None,
+ on_lose_focus: callable | None = None,
  ) -> None:
  ######################################################################
  # 2022-09: Backwards compatibility
@@ -152,6 +154,8 @@ def __init__(
  closeable=True,
  minimizable=minimizable,
  on_close=on_close,
+ on_gain_focus=on_gain_focus,
+ on_lose_focus=on_lose_focus,
  )
 
  @Window.on_close.setter
@@ -185,6 +189,8 @@ def __init__(
  startup: AppStartupMethod | None = None,
  windows: Iterable[Window] = (),
  on_exit: OnExitHandler | None = None,
+ on_gain_focus: callable | None = None,
+ on_lose_focus: callable | None = None,
  factory: None = None, # DEPRECATED !
  ):
  """An App is the top level of any GUI program.
@@ -384,6 +390,9 @@ class is defined, and look for a ``.dist-info`` file matching that name.
  self._impl = self._create_impl()
  self.on_exit = on_exit
 
+ self.on_gain_focus = on_gain_focus
+ self.on_lose_focus = on_lose_focus
+
  def _create_impl(self):
  return self.factory.App(interface=self)
 
@@ -628,6 +637,22 @@ def add_background_task(self, handler: BackgroundTask) -> None:
  """
  self._impl.loop.call_soon_threadsafe(wrapped_handler(self, handler), None)
 
+ @property
+ def on_gain_focus(self) -> callable:
+ return self._on_gain_focus
+
+ @on_gain_focus.setter
+ def on_gain_focus(self, handler):
+ self._on_gain_focus = wrapped_handler(self, handler)
+
+ @property
+ def on_lose_focus(self) -> callable:
+ return self._on_lose_focus
+
+ @on_lose_focus.setter
+ def on_lose_focus(self, handler):
+ self._on_lose_focus = wrapped_handler(self, handler)
+
 
 class DocumentApp(App):
  def __init__(

core/src/toga/window.py

@@ -88,6 +88,8 @@ def __init__(
  minimizable: bool = True,
  factory: None = None, # DEPRECATED !
  on_close: OnCloseHandler | None = None,
+ on_gain_focus: callable | None = None,
+ on_lose_focus: callable | None = None,
  ) -> None:
  ######################################################################
  # 2022-09: Backwards compatibility
@@ -123,6 +125,9 @@ def __init__(
 
  self.on_close = on_close
 
+ self.on_gain_focus = on_gain_focus
+ self.on_lose_focus = on_lose_focus
+
  @property
  def id(self) -> str:
  """The DOM identifier for the window.
@@ -271,6 +276,22 @@ def close(self) -> None:
  self.app.windows -= self
  self._impl.close()
 
+ @property
+ def on_gain_focus(self) -> callable:
+ return self._on_gain_focus
+
+ @on_gain_focus.setter
+ def on_gain_focus(self, handler):
+ self._on_gain_focus = wrapped_handler(self, handler)
+
+ @property
+ def on_lose_focus(self) -> callable:
+ return self._on_lose_focus
+
+ @on_lose_focus.setter
+ def on_lose_focus(self, handler):
+ self._on_lose_focus = wrapped_handler(self, handler)
+
  ############################################################
  # Dialogs
  ############################################################

gtk/src/toga_gtk/window.py

@@ -20,6 +20,8 @@ def __init__(self, interface, title, position, size):
  self.native._impl = self
 
  self.native.connect("delete-event", self.gtk_delete_event)
+ self.native.connect("focus-in-event", self.window_on_gain_focus)
+ self.native.connect("focus-out-event", self.window_on_lose_focus)
 
  self.native.set_default_size(size[0], size[1])
 
@@ -138,3 +140,11 @@ def set_full_screen(self, is_full_screen):
  self.native.fullscreen()
  else:
  self.native.unfullscreen()
+
+ def window_on_gain_focus(self, sender, event):
+ self.interface.app.on_gain_focus(self.interface)
+ self.interface.on_gain_focus(self.interface)
+
+ def window_on_lose_focus(self, sender, event):
+ self.interface.app.on_lose_focus(self.interface)
+ self.interface.on_lose_focus(self.interface)

winforms/src/toga_winforms/window.py

@@ -43,6 +43,9 @@ def __init__(self, interface, title, position, size):
  self.native.FormBorderStyle = self.native.FormBorderStyle.FixedSingle
  self.native.MaximizeBox = False
 
+ self.native.Activated += self.window_on_gain_focus
+ self.native.Deactivate += self.window_on_lose_focus
+
  def create_toolbar(self):
  if self.interface.toolbar:
  if self.toolbar_native:
@@ -173,3 +176,11 @@ def resize_content(self):
  self.native.ClientSize.Width,
  self.native.ClientSize.Height - vertical_shift,
  )
+
+ def window_on_gain_focus(self, sender, event):
+ self.interface.app.on_gain_focus(self.interface)
+ self.interface.on_gain_focus(self.interface)
+
+ def window_on_lose_focus(self, sender, event):
+ self.interface.app.on_lose_focus(self.interface)
+ self.interface.on_lose_focus(self.interface)