From 9e9bf161da55aeb1fc4ef393bda21df3f01c1672 Mon Sep 17 00:00:00 2001
From: Talley Lambert <talley.lambert@gmail.com>
Date: Fri, 24 Feb 2023 09:37:21 -0500
Subject: [PATCH 1/6] feat: wip on textual

---
 magicgui/_version.py                          |   4 -
 src/magicgui/backends/__init__.py             |   1 +
 src/magicgui/backends/_textual/__init__.py    |   4 +
 src/magicgui/backends/_textual/application.py |  79 ++++++++
 src/magicgui/backends/_textual/widgets.py     | 182 ++++++++++++++++++
 src/magicgui/widgets/protocols.py             |   2 +-
 x.py                                          |   6 +
 7 files changed, 273 insertions(+), 5 deletions(-)
 delete mode 100644 magicgui/_version.py
 create mode 100644 src/magicgui/backends/_textual/__init__.py
 create mode 100644 src/magicgui/backends/_textual/application.py
 create mode 100644 src/magicgui/backends/_textual/widgets.py
 create mode 100644 x.py

diff --git a/magicgui/_version.py b/magicgui/_version.py
deleted file mode 100644
index b921eea20..000000000
--- a/magicgui/_version.py
+++ /dev/null
@@ -1,4 +0,0 @@
-# file generated by setuptools_scm
-# don't change, don't track in version control
-__version__ = version = "0.5.2.dev30+ga5e272f.d20220824"
-__version_tuple__ = version_tuple = (0, 5, 2, "dev30", "ga5e272f.d20220824")
diff --git a/src/magicgui/backends/__init__.py b/src/magicgui/backends/__init__.py
index 214876cad..054e099e5 100644
--- a/src/magicgui/backends/__init__.py
+++ b/src/magicgui/backends/__init__.py
@@ -4,6 +4,7 @@
 BACKENDS: dict[str, tuple[str, str]] = {
     "Qt": ("_qtpy", "qtpy"),
     "ipynb": ("_ipynb", "ipynb"),
+    "textual": ("_textual", "textual"),
 }
 
 for key in list(BACKENDS):
diff --git a/src/magicgui/backends/_textual/__init__.py b/src/magicgui/backends/_textual/__init__.py
new file mode 100644
index 000000000..d0bccbd59
--- /dev/null
+++ b/src/magicgui/backends/_textual/__init__.py
@@ -0,0 +1,4 @@
+from .application import ApplicationBackend
+from .widgets import Label, LineEdit
+
+__all__ = ["ApplicationBackend", "Label", "LineEdit"]
diff --git a/src/magicgui/backends/_textual/application.py b/src/magicgui/backends/_textual/application.py
new file mode 100644
index 000000000..e92ac1d45
--- /dev/null
+++ b/src/magicgui/backends/_textual/application.py
@@ -0,0 +1,79 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Callable, ClassVar, Iterable
+
+from textual.app import App
+from textual.timer import Timer
+from textual.widget import Widget
+
+from magicgui.widgets.protocols import BaseApplicationBackend
+
+if TYPE_CHECKING:
+    from textual.message import Message
+
+
+class MguiApp(App):
+    _widgets: ClassVar[list[Widget]] = []
+
+    def compose(self) -> Iterable[Widget]:
+        return self._widgets
+
+
+class ApplicationBackend(BaseApplicationBackend):
+    _app: ClassVar[MguiApp | None] = None
+
+    @classmethod
+    def _instance(cls) -> MguiApp:
+        """Return the current instance of the application backend."""
+        if not hasattr(cls, "__instance"):
+            cls.__instance = MguiApp()
+        return cls.__instance
+
+    def _mgui_get_backend_name(self) -> str:
+        return "textual"
+
+    def _mgui_process_events(self) -> None:
+        ...
+
+    def _mgui_run(self) -> None:
+        self._mgui_get_native_app().run()
+
+    def _mgui_quit(self) -> None:
+        return self._mgui_get_native_app().exit()
+
+    def _mgui_get_native_app(self) -> App:
+        # Get native app
+        return self._instance()
+
+    def _mgui_start_timer(
+        self,
+        interval: int = 0,
+        on_timeout: Callable[[], None] | None = None,
+        single: bool = False,
+    ) -> None:
+        # TODO: not sure what to do with these yet...
+        event_target = MessageTarget()
+        sender = MessageTarget()
+        self._timer = Timer(
+            event_target=event_target,
+            interval=interval / 1000,
+            sender=sender,
+            callback=on_timeout,
+            repeat=1 if single else None,
+        )
+        self._timer.start()
+
+    def _mgui_stop_timer(self) -> None:
+        if getattr(self, "_timer", None):
+            self._timer.stop()
+
+
+class MessageTarget:
+    async def post_message(self, message: Message) -> bool:
+        ...
+
+    async def _post_priority_message(self, message: Message) -> bool:
+        ...
+
+    def post_message_no_wait(self, message: Message) -> bool:
+        ...
diff --git a/src/magicgui/backends/_textual/widgets.py b/src/magicgui/backends/_textual/widgets.py
new file mode 100644
index 000000000..8163118b5
--- /dev/null
+++ b/src/magicgui/backends/_textual/widgets.py
@@ -0,0 +1,182 @@
+from typing import TYPE_CHECKING, Any, Callable
+
+from textual import widgets as txtwdgs
+from textual.widget import Widget as TxWidget
+
+from magicgui.widgets import protocols
+
+from .application import MguiApp
+
+if TYPE_CHECKING:
+    import numpy as np
+    from textual.dom import DOMNode
+
+
+class TxtBaseWidget(protocols.WidgetProtocol):
+    """Base Widget Protocol: specifies methods that all widgets must provide."""
+
+    _txwidget: TxWidget
+
+    def __init__(
+        self, wdg_class: type[TxWidget] | None = None, parent: TxWidget | None = None
+    ):
+        if wdg_class is None:
+            wdg_class = type(self).__annotations__.get("_txwidget")
+        if wdg_class is None:
+            raise TypeError("Must provide a valid textual widget type")
+        self._txwidget = wdg_class()
+        MguiApp._widgets.append(self._txwidget)  # TODO
+
+        # TODO: assign parent
+
+    def _mgui_close_widget(self) -> None:
+        """Close widget."""
+        raise NotImplementedError()
+
+    def _mgui_get_visible(self) -> bool:
+        """Get widget visibility."""
+        return self._txwidget.visible
+
+    def _mgui_set_visible(self, value: bool) -> None:
+        """Set widget visibility."""
+        self._txwidget.visible = value
+
+    def _mgui_get_enabled(self) -> bool:
+        """Get the enabled state of the widget."""
+        raise NotImplementedError()
+
+    def _mgui_set_enabled(self, enabled: bool) -> None:
+        """Set the enabled state of the widget to `enabled`."""
+        print("set enabled", enabled)
+
+    def _mgui_get_parent(self) -> "DOMNode | None":
+        """Return the parent widget of this widget."""
+        return self._txwidget.parent
+
+    def _mgui_set_parent(self, widget: TxWidget) -> None:
+        """Set the parent widget of this widget."""
+        raise NotImplementedError()
+
+    def _mgui_get_native_widget(self) -> Any:
+        """Return the native backend widget instance.
+
+        This is generally the widget that has the layout.
+        """
+        return self._txwidget
+
+    def _mgui_get_root_native_widget(self) -> Any:
+        """Return the root native backend widget.
+
+        In most cases, this is the same as ``_mgui_get_native_widget``.  However, in
+        cases where the native widget is in a scroll layout, this might be different.
+        """
+        return self._txwidget
+
+    def _mgui_bind_parent_change_callback(
+        self, callback: Callable[[Any], None]
+    ) -> None:
+        """Bind callback to parent change event."""
+        print("bind parent change callback", callback)
+
+    def _mgui_render(self) -> "np.ndarray":
+        """Return an RGBA (MxNx4) numpy array bitmap of the rendered widget."""
+        raise NotImplementedError()
+
+    def _mgui_get_width(self) -> int:
+        """Get the width of the widget.
+
+        The intention is to get the width of the widget after it is shown, for the
+        purpose of unifying widget width in a layout. Backends may do what they need to
+        accomplish this. For example, Qt can use ``sizeHint().width()``, since
+        ``width()`` may return something large if the widget has not yet been painted
+        on screen.
+        """
+        raise NotImplementedError()
+
+    def _mgui_set_width(self, value: int) -> None:
+        """Set the width of the widget."""
+        raise NotImplementedError()
+
+    def _mgui_get_min_width(self) -> int:
+        """Get the minimum width of the widget."""
+        raise NotImplementedError()
+
+    def _mgui_set_min_width(self, value: int) -> None:
+        """Set the minimum width of the widget."""
+        raise NotImplementedError()
+
+    def _mgui_get_max_width(self) -> int:
+        """Get the maximum width of the widget."""
+        raise NotImplementedError()
+
+    def _mgui_set_max_width(self, value: int) -> None:
+        """Set the maximum width of the widget."""
+        raise NotImplementedError()
+
+    def _mgui_get_height(self) -> int:
+        """Get the height of the widget.
+
+        The intention is to get the height of the widget after it is shown, for the
+        purpose of unifying widget height in a layout. Backends may do what they need to
+        accomplish this. For example, Qt can use ``sizeHint().height()``, since
+        ``height()`` may return something large if the widget has not yet been painted
+        on screen.
+        """
+        raise NotImplementedError()
+
+    def _mgui_set_height(self, value: int) -> None:
+        """Set the height of the widget."""
+        raise NotImplementedError()
+
+    def _mgui_get_min_height(self) -> int:
+        """Get the minimum height of the widget."""
+        raise NotImplementedError()
+
+    def _mgui_set_min_height(self, value: int) -> None:
+        """Set the minimum height of the widget."""
+        raise NotImplementedError()
+
+    def _mgui_get_max_height(self) -> int:
+        """Get the maximum height of the widget."""
+        raise NotImplementedError()
+
+    def _mgui_set_max_height(self, value: int) -> None:
+        """Set the maximum height of the widget."""
+        raise NotImplementedError()
+
+    def _mgui_get_tooltip(self) -> str:
+        """Get the tooltip for this widget."""
+        raise NotImplementedError()
+
+    def _mgui_set_tooltip(self, value: str | None) -> None:
+        """Set a tooltip for this widget."""
+        pass
+
+
+class TxtValueWidget(TxtBaseWidget, protocols.ValueWidgetProtocol):
+    _txwidget: txtwdgs.Static
+
+    def _mgui_get_value(self) -> Any:
+        """Get current value of the widget."""
+        return self._txwidget.renderable
+
+    def _mgui_set_value(self, value: Any) -> None:
+        """Set current value of the widget."""
+        self._txwidget.renderable = value
+
+    def _mgui_bind_change_callback(self, callback: Callable[[Any], Any]) -> None:
+        """Bind callback to value change event."""
+        print("bind change callback", callback)
+
+
+class TxtStringWidget(TxtValueWidget):
+    def _mgui_set_value(self, value) -> None:
+        super()._mgui_set_value(str(value))
+
+
+class Label(TxtStringWidget):
+    _txwidget: txtwdgs.Label
+
+
+class LineEdit(TxtStringWidget):
+    _txwidget: txtwdgs.Input
diff --git a/src/magicgui/widgets/protocols.py b/src/magicgui/widgets/protocols.py
index 6380b4a87..4e17472b4 100644
--- a/src/magicgui/widgets/protocols.py
+++ b/src/magicgui/widgets/protocols.py
@@ -579,7 +579,7 @@ def _mgui_start_timer(
         Parameters
         ----------
         interval : int, optional
-            Interval between timeouts, by default 0
+            Interval (in msec) between timeouts, by default 0
         on_timeout : Optional[Callable[[], None]], optional
             Function to call when timer finishes, by default None
         single : bool, optional
diff --git a/x.py b/x.py
new file mode 100644
index 000000000..b831316d4
--- /dev/null
+++ b/x.py
@@ -0,0 +1,6 @@
+from magicgui import use_app, widgets
+
+app = use_app("textual")
+l1 = widgets.Label(value="Hello World")
+l2 = widgets.LineEdit(value="Hello World")
+app.run()

From a1cfb956b1e2e5592ada46603ca16e6e2d128c67 Mon Sep 17 00:00:00 2001
From: Talley Lambert <talley.lambert@gmail.com>
Date: Fri, 24 Feb 2023 13:52:14 -0500
Subject: [PATCH 2/6] a start

---
 pyproject.toml                                |  1 +
 src/magicgui/backends/_textual/__init__.py    |  4 +-
 src/magicgui/backends/_textual/application.py | 17 ++++-
 src/magicgui/backends/_textual/widgets.py     | 66 ++++++++++++++++---
 x.py                                          | 24 ++++++-
 5 files changed, 97 insertions(+), 15 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index 93837ecd2..8b1cdaf4b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -61,6 +61,7 @@ pyside2 = [
 pyside6 = ["pyside6"]
 tqdm = ["tqdm>=4.30.0"]
 jupyter = ["ipywidgets>=8.0.0"]
+textual = ["textual"]  # TODO: figure min version
 image = ["pillow>=4.0"]
 quantity = ["pint>=0.13.0"]
 testing = [
diff --git a/src/magicgui/backends/_textual/__init__.py b/src/magicgui/backends/_textual/__init__.py
index d0bccbd59..9a87f7416 100644
--- a/src/magicgui/backends/_textual/__init__.py
+++ b/src/magicgui/backends/_textual/__init__.py
@@ -1,4 +1,4 @@
 from .application import ApplicationBackend
-from .widgets import Label, LineEdit
+from .widgets import CheckBox, Label, LineEdit, PushButton
 
-__all__ = ["ApplicationBackend", "Label", "LineEdit"]
+__all__ = ["ApplicationBackend", "Label", "LineEdit", "PushButton", "CheckBox"]
diff --git a/src/magicgui/backends/_textual/application.py b/src/magicgui/backends/_textual/application.py
index e92ac1d45..03c623d23 100644
--- a/src/magicgui/backends/_textual/application.py
+++ b/src/magicgui/backends/_textual/application.py
@@ -3,8 +3,10 @@
 from typing import TYPE_CHECKING, Callable, ClassVar, Iterable
 
 from textual.app import App
+from textual.binding import Binding
 from textual.timer import Timer
 from textual.widget import Widget
+from textual.widgets import Footer, Header
 
 from magicgui.widgets.protocols import BaseApplicationBackend
 
@@ -13,10 +15,21 @@
 
 
 class MguiApp(App):
-    _widgets: ClassVar[list[Widget]] = []
+    BINDINGS = [
+        ("ctrl+t", "app.toggle_dark", "Toggle Dark mode"),
+        ("ctrl+s", "app.screenshot()", "Screenshot"),
+        Binding("ctrl+c,ctrl+q", "app.quit", "Quit", show=True),
+    ]
+
+    HEADER = Header()
+    FOOTER = Footer()
+
+    _mgui_widgets: ClassVar[list[Widget]] = []
 
     def compose(self) -> Iterable[Widget]:
-        return self._widgets
+        yield self.HEADER
+        yield from self._mgui_widgets
+        yield self.FOOTER
 
 
 class ApplicationBackend(BaseApplicationBackend):
diff --git a/src/magicgui/backends/_textual/widgets.py b/src/magicgui/backends/_textual/widgets.py
index 8163118b5..113ec193a 100644
--- a/src/magicgui/backends/_textual/widgets.py
+++ b/src/magicgui/backends/_textual/widgets.py
@@ -1,4 +1,4 @@
-from typing import TYPE_CHECKING, Any, Callable
+from typing import TYPE_CHECKING, Any, Callable, cast
 
 from textual import widgets as txtwdgs
 from textual.widget import Widget as TxWidget
@@ -12,6 +12,32 @@
     from textual.dom import DOMNode
 
 
+# Convert class events to instance events...
+# FIXME: there must be a better pattern, also need weakrefs
+class _Button(txtwdgs.Button):
+    _callbacks: list[Callable[[Any], Any]] = []
+
+    def on_button_pressed(self):
+        for callback in self._callbacks:
+            callback(True)
+
+
+class _Input(txtwdgs.Input):
+    _callbacks: list[Callable[[Any], Any]] = []
+
+    def on_input_changed(self):
+        for callback in self._callbacks:
+            callback(self.value)
+
+
+class _Switch(txtwdgs.Switch):
+    _callbacks: list[Callable[[Any], Any]] = []
+
+    def on_switch_changed(self):
+        for callback in self._callbacks:
+            callback(self.value)
+
+
 class TxtBaseWidget(protocols.WidgetProtocol):
     """Base Widget Protocol: specifies methods that all widgets must provide."""
 
@@ -25,13 +51,14 @@ def __init__(
         if wdg_class is None:
             raise TypeError("Must provide a valid textual widget type")
         self._txwidget = wdg_class()
-        MguiApp._widgets.append(self._txwidget)  # TODO
+        MguiApp._mgui_widgets.append(self._txwidget)  # TODO
 
         # TODO: assign parent
 
     def _mgui_close_widget(self) -> None:
         """Close widget."""
-        raise NotImplementedError()
+        # not sure there is a textual equivalent of closing?
+        self._mgui_set_visible(False)
 
     def _mgui_get_visible(self) -> bool:
         """Get widget visibility."""
@@ -43,11 +70,11 @@ def _mgui_set_visible(self, value: bool) -> None:
 
     def _mgui_get_enabled(self) -> bool:
         """Get the enabled state of the widget."""
-        raise NotImplementedError()
+        return not self._txwidget.disabled
 
     def _mgui_set_enabled(self, enabled: bool) -> None:
         """Set the enabled state of the widget to `enabled`."""
-        print("set enabled", enabled)
+        self._txwidget.disabled = not enabled
 
     def _mgui_get_parent(self) -> "DOMNode | None":
         """Return the parent widget of this widget."""
@@ -76,7 +103,7 @@ def _mgui_bind_parent_change_callback(
         self, callback: Callable[[Any], None]
     ) -> None:
         """Bind callback to parent change event."""
-        print("bind parent change callback", callback)
+        pass
 
     def _mgui_render(self) -> "np.ndarray":
         """Return an RGBA (MxNx4) numpy array bitmap of the rendered widget."""
@@ -146,7 +173,7 @@ def _mgui_set_max_height(self, value: int) -> None:
 
     def _mgui_get_tooltip(self) -> str:
         """Get the tooltip for this widget."""
-        raise NotImplementedError()
+        return ""
 
     def _mgui_set_tooltip(self, value: str | None) -> None:
         """Set a tooltip for this widget."""
@@ -166,7 +193,8 @@ def _mgui_set_value(self, value: Any) -> None:
 
     def _mgui_bind_change_callback(self, callback: Callable[[Any], Any]) -> None:
         """Bind callback to value change event."""
-        print("bind change callback", callback)
+        if hasattr(self._txwidget, "_callbacks"):
+            cast("list", self._txwidget._callbacks).append(callback)
 
 
 class TxtStringWidget(TxtValueWidget):
@@ -179,4 +207,24 @@ class Label(TxtStringWidget):
 
 
 class LineEdit(TxtStringWidget):
-    _txwidget: txtwdgs.Input
+    _txwidget: _Input
+
+
+class TxtBaseButtonWidget(TxtValueWidget, protocols.SupportsText):
+    _txwidget: _Button
+
+    def _mgui_set_text(self, value: str) -> None:
+        """Set text."""
+        self._txwidget.label = value
+
+    def _mgui_get_text(self) -> str:
+        """Get text."""
+        return self._txwidget.label
+
+
+class PushButton(TxtBaseButtonWidget):
+    pass
+
+
+class CheckBox(TxtBaseButtonWidget):
+    _txwidget: _Switch
diff --git a/x.py b/x.py
index b831316d4..7c044a27e 100644
--- a/x.py
+++ b/x.py
@@ -1,6 +1,26 @@
 from magicgui import use_app, widgets
 
 app = use_app("textual")
-l1 = widgets.Label(value="Hello World")
-l2 = widgets.LineEdit(value="Hello World")
+l1 = widgets.Label(value="I'm a label")
+l2 = widgets.LineEdit(value="I'm a line edit")
+btn = widgets.PushButton(text="I'm a button")
+chx = widgets.CheckBox(text="I'm a checkbox")
+
+
+@l2.changed.connect
+def _on_click(newval) -> None:
+    print("line edit changed", newval)
+
+
+@btn.clicked.connect
+def _on_click() -> None:
+    print("Button clicked!")
+
+
+@chx.changed.connect
+def _on_click(newval) -> None:
+    print("Checkbox changed", newval)
+    btn.enabled = not newval
+
+
 app.run()

From 5ab07461cc59288cd0de5d65c6e20c3cb1e48256 Mon Sep 17 00:00:00 2001
From: Talley Lambert <talley.lambert@gmail.com>
Date: Fri, 24 Feb 2023 13:57:44 -0500
Subject: [PATCH 3/6] fix line edit value

---
 src/magicgui/backends/_textual/widgets.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/magicgui/backends/_textual/widgets.py b/src/magicgui/backends/_textual/widgets.py
index 113ec193a..128bdbb05 100644
--- a/src/magicgui/backends/_textual/widgets.py
+++ b/src/magicgui/backends/_textual/widgets.py
@@ -209,6 +209,14 @@ class Label(TxtStringWidget):
 class LineEdit(TxtStringWidget):
     _txwidget: _Input
 
+    def _mgui_get_value(self) -> Any:
+        """Get current value of the widget."""
+        return self._txwidget.value
+
+    def _mgui_set_value(self, value: Any) -> None:
+        """Set current value of the widget."""
+        self._txwidget.value = value
+
 
 class TxtBaseButtonWidget(TxtValueWidget, protocols.SupportsText):
     _txwidget: _Button

From 9f76d58295bb3adf397b9cbef09e6c7d47756f9a Mon Sep 17 00:00:00 2001
From: Talley Lambert <talley.lambert@gmail.com>
Date: Mon, 27 Feb 2023 11:46:23 -0500
Subject: [PATCH 4/6] feat: update

---
 src/magicgui/application.py                   |  4 +-
 src/magicgui/backends/_textual/application.py | 11 ++--
 src/magicgui/backends/_textual/widgets.py     | 55 ++++++++++++-------
 x.py                                          | 26 ---------
 4 files changed, 43 insertions(+), 53 deletions(-)
 delete mode 100644 x.py

diff --git a/src/magicgui/application.py b/src/magicgui/application.py
index 278a1bc3c..65aa22ced 100644
--- a/src/magicgui/application.py
+++ b/src/magicgui/application.py
@@ -68,9 +68,9 @@ def get_obj(self, name: str) -> Any:
                 f"Could not import object {name!r} from backend {self.backend_module}"
             ) from e
 
-    def run(self) -> None:
+    def run(self, **kwargs: Any) -> None:
         """Enter the native GUI event loop."""
-        return self._backend._mgui_run()
+        return self._backend._mgui_run(**kwargs)
 
     @property
     def native(self) -> Any:
diff --git a/src/magicgui/backends/_textual/application.py b/src/magicgui/backends/_textual/application.py
index 03c623d23..5dfffcfb7 100644
--- a/src/magicgui/backends/_textual/application.py
+++ b/src/magicgui/backends/_textual/application.py
@@ -6,7 +6,7 @@
 from textual.binding import Binding
 from textual.timer import Timer
 from textual.widget import Widget
-from textual.widgets import Footer, Header
+from textual.widgets import Footer
 
 from magicgui.widgets.protocols import BaseApplicationBackend
 
@@ -21,13 +21,14 @@ class MguiApp(App):
         Binding("ctrl+c,ctrl+q", "app.quit", "Quit", show=True),
     ]
 
-    HEADER = Header()
+    HEADER = None
     FOOTER = Footer()
 
     _mgui_widgets: ClassVar[list[Widget]] = []
 
     def compose(self) -> Iterable[Widget]:
-        yield self.HEADER
+        if self.HEADER is not None:
+            yield self.HEADER
         yield from self._mgui_widgets
         yield self.FOOTER
 
@@ -48,8 +49,8 @@ def _mgui_get_backend_name(self) -> str:
     def _mgui_process_events(self) -> None:
         ...
 
-    def _mgui_run(self) -> None:
-        self._mgui_get_native_app().run()
+    def _mgui_run(self, **kwargs) -> None:
+        self._mgui_get_native_app().run(**kwargs)
 
     def _mgui_quit(self) -> None:
         return self._mgui_get_native_app().exit()
diff --git a/src/magicgui/backends/_textual/widgets.py b/src/magicgui/backends/_textual/widgets.py
index 128bdbb05..973bd793b 100644
--- a/src/magicgui/backends/_textual/widgets.py
+++ b/src/magicgui/backends/_textual/widgets.py
@@ -7,6 +7,17 @@
 
 from .application import MguiApp
 
+try:
+    # useful, but not yet public...
+    from psygnal._weak_callback import WeakCallback, weak_callback
+
+except ImportError:
+    WeakCallback = Callable[[Any], Any]
+
+    def weak_callback(callback: Callable[[Any], Any]) -> WeakCallback:
+        return callback
+
+
 if TYPE_CHECKING:
     import numpy as np
     from textual.dom import DOMNode
@@ -15,7 +26,7 @@
 # Convert class events to instance events...
 # FIXME: there must be a better pattern, also need weakrefs
 class _Button(txtwdgs.Button):
-    _callbacks: list[Callable[[Any], Any]] = []
+    _callbacks: list[WeakCallback] = []
 
     def on_button_pressed(self):
         for callback in self._callbacks:
@@ -23,7 +34,7 @@ def on_button_pressed(self):
 
 
 class _Input(txtwdgs.Input):
-    _callbacks: list[Callable[[Any], Any]] = []
+    _callbacks: list[WeakCallback] = []
 
     def on_input_changed(self):
         for callback in self._callbacks:
@@ -31,7 +42,7 @@ def on_input_changed(self):
 
 
 class _Switch(txtwdgs.Switch):
-    _callbacks: list[Callable[[Any], Any]] = []
+    _callbacks: list[WeakCallback] = []
 
     def on_switch_changed(self):
         for callback in self._callbacks:
@@ -51,9 +62,12 @@ def __init__(
         if wdg_class is None:
             raise TypeError("Must provide a valid textual widget type")
         self._txwidget = wdg_class()
-        MguiApp._mgui_widgets.append(self._txwidget)  # TODO
 
-        # TODO: assign parent
+        # TODO: here we add the widget to our global app instance... but perhaps
+        # we should be using `mount()`?
+        MguiApp._mgui_widgets.append(self._txwidget)
+
+        # TODO: assign parent ?
 
     def _mgui_close_widget(self) -> None:
         """Close widget."""
@@ -82,7 +96,7 @@ def _mgui_get_parent(self) -> "DOMNode | None":
 
     def _mgui_set_parent(self, widget: TxWidget) -> None:
         """Set the parent widget of this widget."""
-        raise NotImplementedError()
+        raise NotImplementedError("Setting parent of textual widget not supported")
 
     def _mgui_get_native_widget(self) -> Any:
         """Return the native backend widget instance.
@@ -107,7 +121,7 @@ def _mgui_bind_parent_change_callback(
 
     def _mgui_render(self) -> "np.ndarray":
         """Return an RGBA (MxNx4) numpy array bitmap of the rendered widget."""
-        raise NotImplementedError()
+        raise NotImplementedError("Textual widget screenshots not yet implemented")
 
     def _mgui_get_width(self) -> int:
         """Get the width of the widget.
@@ -118,27 +132,27 @@ def _mgui_get_width(self) -> int:
         ``width()`` may return something large if the widget has not yet been painted
         on screen.
         """
-        raise NotImplementedError()
+        return self._txwidget.styles.width
 
     def _mgui_set_width(self, value: int) -> None:
         """Set the width of the widget."""
-        raise NotImplementedError()
+        self._txwidget.styles.width = value
 
     def _mgui_get_min_width(self) -> int:
         """Get the minimum width of the widget."""
-        raise NotImplementedError()
+        return self._txwidget.styles.min_width
 
     def _mgui_set_min_width(self, value: int) -> None:
         """Set the minimum width of the widget."""
-        raise NotImplementedError()
+        self._txwidget.styles.min_width = value
 
     def _mgui_get_max_width(self) -> int:
         """Get the maximum width of the widget."""
-        raise NotImplementedError()
+        return self._txwidget.styles.max_width
 
     def _mgui_set_max_width(self, value: int) -> None:
         """Set the maximum width of the widget."""
-        raise NotImplementedError()
+        self._txwidget.styles.max_width = value
 
     def _mgui_get_height(self) -> int:
         """Get the height of the widget.
@@ -149,27 +163,27 @@ def _mgui_get_height(self) -> int:
         ``height()`` may return something large if the widget has not yet been painted
         on screen.
         """
-        raise NotImplementedError()
+        return self._txwidget.styles.height
 
     def _mgui_set_height(self, value: int) -> None:
         """Set the height of the widget."""
-        raise NotImplementedError()
+        self._txwidget.styles.height = value
 
     def _mgui_get_min_height(self) -> int:
         """Get the minimum height of the widget."""
-        raise NotImplementedError()
+        return self._txwidget.styles.min_height
 
     def _mgui_set_min_height(self, value: int) -> None:
         """Set the minimum height of the widget."""
-        raise NotImplementedError()
+        self._txwidget.styles.min_height = value
 
     def _mgui_get_max_height(self) -> int:
         """Get the maximum height of the widget."""
-        raise NotImplementedError()
+        return self._txwidget.styles.max_height
 
     def _mgui_set_max_height(self, value: int) -> None:
         """Set the maximum height of the widget."""
-        raise NotImplementedError()
+        self._txwidget.styles.max_height = value
 
     def _mgui_get_tooltip(self) -> str:
         """Get the tooltip for this widget."""
@@ -194,7 +208,8 @@ def _mgui_set_value(self, value: Any) -> None:
     def _mgui_bind_change_callback(self, callback: Callable[[Any], Any]) -> None:
         """Bind callback to value change event."""
         if hasattr(self._txwidget, "_callbacks"):
-            cast("list", self._txwidget._callbacks).append(callback)
+            callbacks = cast("list", self._txwidget._callbacks)
+            callbacks.append(weak_callback(callback))
 
 
 class TxtStringWidget(TxtValueWidget):
diff --git a/x.py b/x.py
deleted file mode 100644
index 7c044a27e..000000000
--- a/x.py
+++ /dev/null
@@ -1,26 +0,0 @@
-from magicgui import use_app, widgets
-
-app = use_app("textual")
-l1 = widgets.Label(value="I'm a label")
-l2 = widgets.LineEdit(value="I'm a line edit")
-btn = widgets.PushButton(text="I'm a button")
-chx = widgets.CheckBox(text="I'm a checkbox")
-
-
-@l2.changed.connect
-def _on_click(newval) -> None:
-    print("line edit changed", newval)
-
-
-@btn.clicked.connect
-def _on_click() -> None:
-    print("Button clicked!")
-
-
-@chx.changed.connect
-def _on_click(newval) -> None:
-    print("Checkbox changed", newval)
-    btn.enabled = not newval
-
-
-app.run()

From 690ba0aef3f267038c93c3d9ccc7e1530a712f78 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Wed, 4 Oct 2023 15:15:27 +0000
Subject: [PATCH 5/6] style(pre-commit.ci): auto fixes [...]

---
 src/magicgui/backends/_textual/application.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/magicgui/backends/_textual/application.py b/src/magicgui/backends/_textual/application.py
index 5dfffcfb7..2d87bca53 100644
--- a/src/magicgui/backends/_textual/application.py
+++ b/src/magicgui/backends/_textual/application.py
@@ -5,13 +5,13 @@
 from textual.app import App
 from textual.binding import Binding
 from textual.timer import Timer
-from textual.widget import Widget
 from textual.widgets import Footer
 
 from magicgui.widgets.protocols import BaseApplicationBackend
 
 if TYPE_CHECKING:
     from textual.message import Message
+    from textual.widget import Widget
 
 
 class MguiApp(App):

From a42eb0713592f81dc578da8d75ecdd2e303573bb Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Thu, 8 Feb 2024 14:09:22 +0000
Subject: [PATCH 6/6] style(pre-commit.ci): auto fixes [...]

---
 src/magicgui/backends/_textual/application.py | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/magicgui/backends/_textual/application.py b/src/magicgui/backends/_textual/application.py
index 2d87bca53..7e198de66 100644
--- a/src/magicgui/backends/_textual/application.py
+++ b/src/magicgui/backends/_textual/application.py
@@ -46,8 +46,7 @@ def _instance(cls) -> MguiApp:
     def _mgui_get_backend_name(self) -> str:
         return "textual"
 
-    def _mgui_process_events(self) -> None:
-        ...
+    def _mgui_process_events(self) -> None: ...
 
     def _mgui_run(self, **kwargs) -> None:
         self._mgui_get_native_app().run(**kwargs)
@@ -83,11 +82,8 @@ def _mgui_stop_timer(self) -> None:
 
 
 class MessageTarget:
-    async def post_message(self, message: Message) -> bool:
-        ...
+    async def post_message(self, message: Message) -> bool: ...
 
-    async def _post_priority_message(self, message: Message) -> bool:
-        ...
+    async def _post_priority_message(self, message: Message) -> bool: ...
 
-    def post_message_no_wait(self, message: Message) -> bool:
-        ...
+    def post_message_no_wait(self, message: Message) -> bool: ...