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

android/src/toga_android/app.py

@@ -3,6 +3,7 @@
 
 from android.graphics.drawable import BitmapDrawable
 from android.media import RingtoneManager
+from android.os import Build
 from android.view import Menu, MenuItem
 from java import dynamic_proxy
 from org.beeware.android import IPythonApp, MainActivity
@@ -36,22 +37,46 @@ def onCreate(self):
 
  def onStart(self):
  print("Toga app: onStart")
+ for window in self._impl.interface.windows:
+ window.on_show()
 
- def onResume(self):
+ def onResume(self): # pragma: no cover
  print("Toga app: onResume")
-
- def onPause(self):
- print("Toga app: onPause") # pragma: no cover
-
- def onStop(self):
- print("Toga app: onStop") # pragma: no cover
+ # onTopResumedActivityChanged is not available on android versions less
+ # than Q. onResume is the best indicator for the gain input focus event.
+ # https://developer.android.com/reference/android/app/Activity#onWindowFocusChanged(boolean):~:text=If%20the%20intent,the%20best%20indicator.
+ if Build.VERSION.SDK_INT < Build.VERSION_CODES.Q:
+ for window in self._impl.interface.windows:
+ window.on_gain_focus()
+
+ def onPause(self): # pragma: no cover
+ print("Toga app: onPause")
+ # onTopResumedActivityChanged is not available on android versions less
+ # than Q. onPause is the best indicator for the lost input focus event.
+ if Build.VERSION.SDK_INT < Build.VERSION_CODES.Q:
+ for window in self._impl.interface.windows:
+ window.on_lose_focus()
+
+ def onStop(self): # pragma: no cover
+ print("Toga app: onStop")
+ for window in self._impl.interface.windows:
+ window.on_hide()
 
  def onDestroy(self):
  print("Toga app: onDestroy") # pragma: no cover
 
  def onRestart(self):
  print("Toga app: onRestart") # pragma: no cover
 
+ def onTopResumedActivityChanged(self, isTopResumedActivity): # pragma: no cover
+ print("Toga app: onTopResumedActivityChanged")
+ if isTopResumedActivity:
+ for window in self._impl.interface.windows:
+ window.on_gain_focus()
+ else:
+ for window in self._impl.interface.windows:
+ window.on_lose_focus()
+
  # TODO #1798: document and test this somehow
  def onActivityResult(self, requestCode, resultCode, resultData): # pragma: no cover
  """Callback method, called from MainActivity when an Intent ends.

changes/2009.feature.rst

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

cocoa/src/toga_cocoa/window.py

@@ -40,6 +40,60 @@ def windowDidResize_(self, notification) -> None:
  # Set the window to the new size
  self.interface.content.refresh()
 
+ @objc_method
+ def windowDidBecomeMain_(self, notification):
+ self.impl.interface.on_gain_focus()
+
+ @objc_method
+ def windowDidResignMain_(self, notification):
+ self.impl.interface.on_lose_focus()
+
+ @objc_method
+ def windowDidBecomeKey_(self, notification):
+ if bool(self.impl.native.isVisible) and not self.impl._is_previously_shown:
+ self.impl._is_previously_shown = True
+ self.impl.interface.on_show()
+
+ @objc_method
+ def windowDidMiniaturize_(self, notification): # pragma: no cover
+ if not bool(self.impl.native.isVisible) and self.impl._is_previously_shown:
+ self.impl._is_previously_shown = False
+ self.impl.interface.on_hide()
+
+ @objc_method
+ def windowDidDeminiaturize_(self, notification): # pragma: no cover
+ if bool(self.impl.native.isVisible) and not self.impl._is_previously_shown:
+ self.impl._is_previously_shown = True
+ self.impl.interface.on_show()
+
+ @objc_method
+ def windowDidEnterFullScreen_(self, notification): # pragma: no cover
+ if bool(self.impl.native.isVisible) and not self.impl._is_previously_shown:
+ self.impl._is_previously_shown = True
+ self.impl.interface.on_show()
+
+ @objc_method
+ def windowDidExitFullScreen_(self, notification): # pragma: no cover
+ if bool(self.impl.native.isVisible) and not self.impl._is_previously_shown:
+ self.impl._is_previously_shown = True
+ self.impl.interface.on_show()
+
+ # when the user clicks the zoom button to unzoom a window
+ @objc_method
+ def windowWillUseStandardFrame_defaultFrame_(
+ self, window, defaultFrame
+ ): # pragma: no cover
+ if bool(self.impl.native.isVisible) and not self.impl._is_previously_shown:
+ self.impl._is_previously_shown = True
+ self.impl.interface.on_show()
+
+ # when the user clicks the zoom button to zoom a window
+ @objc_method
+ def windowShouldZoom_toFrame_(self, window, toFrame): # pragma: no cover
+ if bool(self.impl.native.isVisible) and not self.impl._is_previously_shown:
+ self.impl._is_previously_shown = True
+ self.impl.interface.on_show()
+
  ######################################################################
  # Toolbar delegate methods
  ######################################################################
@@ -122,6 +176,8 @@ def __init__(self, interface, title, position, size):
  self.interface = interface
  self.interface._impl = self
 
+ self._is_previously_shown = False
+
  mask = NSWindowStyleMask.Titled
  if self.interface.closable:
  mask |= NSWindowStyleMask.Closable
@@ -278,9 +334,11 @@ def set_app(self, app):
 
  def show(self):
  self.native.makeKeyAndOrderFront(None)
+ self.interface.on_show()
 
  def hide(self):
  self.native.orderOut(self.native)
+ self.interface.on_hide()
 
  def get_visible(self):
  return bool(self.native.isVisible)

core/src/toga/app.py

@@ -139,6 +139,10 @@ def __init__(
  size: tuple[int, int] = (640, 480),
  resizable: bool = True,
  minimizable: bool = True,
+ on_gain_focus: callable | None = None,
+ on_lose_focus: callable | None = None,
+ on_show: callable | None = None,
+ on_hide: callable | None = None,
  resizeable=None, # DEPRECATED
  closeable=None, # DEPRECATED
  ):
@@ -164,6 +168,10 @@ def __init__(
  resizable=resizable,
  closable=True,
  minimizable=minimizable,
+ on_gain_focus=on_gain_focus,
+ on_lose_focus=on_lose_focus,
+ on_show=on_show,
+ on_hide=on_hide,
  # Deprecated arguments
  resizeable=resizeable,
  closeable=closeable,

core/src/toga/window.py

@@ -70,6 +70,10 @@ def __init__(
  closable: bool = True,
  minimizable: bool = True,
  on_close: OnCloseHandler | None = None,
+ on_gain_focus: callable | None = None,
+ on_lose_focus: callable | None = None,
+ on_show: callable | None = None,
+ on_hide: callable | None = None,
  resizeable=None, # DEPRECATED
  closeable=None, # DEPRECATED
  ) -> None:
@@ -143,6 +147,11 @@ def __init__(
 
  self.on_close = on_close
 
+ self.on_gain_focus = on_gain_focus
+ self.on_lose_focus = on_lose_focus
+ self.on_show = on_show
+ self.on_hide = on_hide
+
  @property
  def id(self) -> str:
  """A unique identifier for the window."""
@@ -335,6 +344,38 @@ def as_image(self) -> Image:
  :returns: A :class:`toga.Image` containing the window content."""
  return Image(data=self._impl.get_image_data())
 
+ @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)
+
+ @property
+ def on_show(self) -> callable:
+ return self._on_show
+
+ @on_show.setter
+ def on_show(self, handler):
+ self._on_show = wrapped_handler(self, handler)
+
+ @property
+ def on_hide(self) -> callable:
+ return self._on_hide
+
+ @on_hide.setter
+ def on_hide(self, handler):
+ self._on_hide = wrapped_handler(self, handler)
+
  ############################################################
  # Dialogs
  ############################################################

core/tests/test_window.py

@@ -353,6 +353,58 @@ def test_as_image(window):
  assert image.data == b"pretend this is PNG image data"
 
 
+def test_on_gain_focus(window):
+ assert window._on_gain_focus._raw is None
+
+ on_gain_focus_handler = Mock()
+ window.on_gain_focus = on_gain_focus_handler
+
+ assert window.on_gain_focus._raw == on_gain_focus_handler
+
+ window._impl.simulate_on_gain_focus()
+
+ on_gain_focus_handler.assert_called_once_with(window)
+
+
+def test_on_lose_focus(window):
+ assert window.on_lose_focus._raw is None
+
+ on_lose_focus_handler = Mock()
+ window.on_lose_focus = on_lose_focus_handler
+
+ assert window.on_lose_focus._raw == on_lose_focus_handler
+
+ window._impl.simulate_on_lose_focus()
+
+ on_lose_focus_handler.assert_called_once_with(window)
+
+
+def test_on_show(window):
+ assert window.on_show._raw is None
+
+ on_show_handler = Mock()
+ window.on_show = on_show_handler
+
+ assert window.on_show._raw == on_show_handler
+
+ window._impl.simulate_on_show()
+
+ on_show_handler.assert_called_once_with(window)
+
+
+def test_on_hide(window):
+ assert window.on_hide._raw is None
+
+ on_hide_handler = Mock()
+ window.on_hide = on_hide_handler
+
+ assert window.on_hide._raw == on_hide_handler
+
+ window._impl.simulate_on_hide()
+
+ on_hide_handler.assert_called_once_with(window)
+
+
 def test_info_dialog(window, app):
  """An info dialog can be shown"""
  on_result_handler = Mock()

dummy/src/toga_dummy/window.py

@@ -99,3 +99,15 @@ def set_full_screen(self, is_full_screen):
 
  def simulate_close(self):
  self.interface.on_close()
+
+ def simulate_on_gain_focus(self):
+ self.interface.on_gain_focus()
+
+ def simulate_on_lose_focus(self):
+ self.interface.on_lose_focus()
+
+ def simulate_on_show(self):
+ self.interface.on_show()
+
+ def simulate_on_hide(self):
+ self.interface.on_hide()

examples/window/window/app.py

@@ -122,17 +122,42 @@ def close_handler(self, window, **kwargs):
  return False
  return True
 
+ def on_window_gain_focus(self, widget, **kwargs):
+ self.window_focus_label.text = "MainWindow is in focus"
+ print("MainWindow is in focus")
+
+ def on_window_lose_focus(self, widget, **kwargs):
+ self.window_focus_label.text = "MainWindow is not in focus"
+ print("MainWindow is not in focus")
+
+ def on_window_show(self, widget, **kwargs):
+ self.window_visible_label.text = "MainWindow is visible"
+ print("MainWindow is visible")
+
+ def on_window_hide(self, widget, **kwargs):
+ self.window_visible_label.text = "MainWindow is not visible"
+ print("MainWindow is not visible")
+
  def startup(self):
  # Track in-app closes
  self.close_count = 0
 
  # Set up main window
- self.main_window = toga.MainWindow()
+ self.main_window = toga.MainWindow(
+ on_gain_focus=self.on_window_gain_focus,
+ on_lose_focus=self.on_window_lose_focus,
+ on_show=self.on_window_show,
+ on_hide=self.on_window_hide,
+ )
+
  self.on_exit = self.exit_handler
 
  # Label to show responses.
  self.label = toga.Label("Ready.")
 
+ self.window_focus_label = toga.Label("Window focus status")
+ self.window_visible_label = toga.Label("Window visible status")
+
  # Buttons
  btn_style = Pack(flex=1, padding=5)
  btn_do_origin = toga.Button(
@@ -180,6 +205,8 @@ def startup(self):
  self.inner_box = toga.Box(
  children=[
  self.label,
+ self.window_focus_label,
+ self.window_visible_label,
  btn_do_origin,
  btn_do_left,
  btn_do_right,