POC Feat: Qt support

reacton/core.py

@@ -728,23 +728,27 @@ def get_widget(el: Element):
     element will be returned.
     """
     rc = get_render_context()
-    if rc.context is None:
-        raise RuntimeError("get_widget() can only be used in use_effect")
-    if el.is_shared:
-        if el not in rc._shared_widgets:
-            if id(el) in rc._old_element_ids:
-                raise KeyError(f"Element {el} was found to be in a previous render, you may have used a stale element")
-            else:
-                raise KeyError(f"Element {el} not found in all known widgets for the component {rc._shared_widgets}")
-        return rc._shared_widgets[el]
-    else:
+    context = rc.context
+    # context0 = context
+    while context is not None:
+        if context is None:
+            raise RuntimeError("get_widget() can only be used in use_effect")
+        if el.is_shared:
+            if el not in rc._shared_widgets:
+                if id(el) in rc._old_element_ids:
+                    raise KeyError(f"Element {el} was found to be in a previous render, you may have used a stale element")
+                else:
+                    raise KeyError(f"Element {el} not found in all known widgets for the component {rc._shared_widgets}")
+            return rc._shared_widgets[el]
+        else:
 
-        if el not in rc.context.element_to_widget:
-            if id(el) in rc._old_element_ids:
-                raise KeyError(f"Element {el} was found to be in a previous render, you may have used a stale element")
-            else:
-                raise KeyError(f"Element {el} not found in all known widgets for the component {rc.context.widgets}")
-        return rc.context.element_to_widget[el]
+            if el not in context.element_to_widget:
+                if id(el) in rc._old_element_ids:
+                    raise KeyError(f"Element {el} was found to be in a previous render, you may have used a stale element")
+            if el in context.element_to_widget:
+                return context.element_to_widget[el]
+        context = context.parent
+    raise KeyError(f"Element {el} not found in all known widgets")  # for the component {context.widgets}")
 
 
 def use_state(initial: T, key: str = None, eq: Callable[[Any, Any], bool] = None) -> Tuple[T, Callable[[Union[T, Callable[[T], T]]], None]]:

reacton/qt.py

@@ -0,0 +1,192 @@
+import sys
+from typing import Any, Callable, Generic, TypeVar
+
+from PyQt5 import QtCore, QtGui
+from PyQt5 import QtWidgets as Qt
+
+import reacton
+from reacton.core import ComponentFunction, ComponentWidget
+
+W = TypeVar("W")  # used for widgets
+T = TypeVar("T")  # used for widgets
+
+
+def snake_to_setter(name):
+    parts = name.split("_")
+    name = "".join([k.title() for k in parts])
+    return f"set{name}"
+
+
+def snake_to_camel(name):
+    parts = name.split("_")
+    name = parts[0] + "".join([k.title() for k in parts[1:]])
+    return name
+
+
+class Element(Generic[T], reacton.core.Element[T]):
+    def add_children(self, children):
+        if len(children) == 1 and isinstance(children[0].component, ComponentFunction) and children[0].component.name.endswith("Layout"):
+            self.kwargs["layout"] = children[0]
+        elif isinstance(self.component, ComponentWidget) and self.component.widget == Qt.QMainWindow:
+            self.kwargs["central_widget"] = children[0]
+        else:
+            import pdb
+
+            pdb.set_trace()
+
+    def _create_widget(self, kwargs):
+        kwargs, listeners = self._split_kwargs(kwargs)
+        assert isinstance(self.component, ComponentWidget)
+        widget = self.component.widget()
+        for name, value in kwargs.items():
+            self._update_widget_prop(widget, name, value)
+        for name, callback in listeners.items():
+            self._add_widget_event_listener(widget, name, callback)
+        return widget, []
+
+    def _get_widget_args(self):
+        return []
+
+    def _update_widget_prop(self, widget, name, value):
+        name = snake_to_setter(name)
+        try:
+            method = getattr(widget, name)
+            method(value)
+        except AttributeError:
+            # setChildren gets treated differently
+            # in layouts
+            if name != "setChildren":
+                raise
+
+    def _update_widget(self, widget: Qt.QWidget, el_prev: "Element[Any]", kwargs):
+        args: Any = []
+        for name, value in kwargs.items():
+            if name.startswith("on_") and name not in args:
+                self._update_widget_event_listener(widget, name, value, el_prev.kwargs.get(name))
+            else:
+                self._update_widget_prop(widget, name, value)
+
+    def _add_widget_event_listener(self, widget: Qt.QWidget, name: str, callback: Callable):
+        target_name = snake_to_camel(name[3:])
+
+        signal = getattr(widget, target_name)
+        signal.connect(callback)
+
+    def _remove_widget_event_listener(self, widget: Qt.QWidget, name: str, callback: Callable):
+        target_name = snake_to_camel(name[3:])
+        signal = getattr(widget, target_name)
+        signal.disconnect(callback)
+
+
+def QPushButton(text="Push button", **kwargs):
+    comp = reacton.core.ComponentWidget(widget=Qt.QPushButton)
+    kwargs = {**locals(), **kwargs}
+    del kwargs["comp"]
+    del kwargs["kwargs"]
+    return Element(comp, **kwargs)
+
+
+def QMainWindow(window_title="React-Qt", **kwargs):
+    comp = reacton.core.ComponentWidget(widget=Qt.QMainWindow)
+    kwargs = {**locals(), **kwargs}
+    del kwargs["comp"]
+    del kwargs["kwargs"]
+    return Element(comp, kwargs=kwargs)
+
+
+def QWidget(**kwargs):
+    comp = reacton.core.ComponentWidget(widget=Qt.QWidget)
+    kwargs = {**locals(), **kwargs}
+    del kwargs["comp"]
+    del kwargs["kwargs"]
+    return Element(comp, **kwargs)
+
+
+def QLabel(**kwargs):
+    comp = reacton.core.ComponentWidget(widget=Qt.QLabel)
+    kwargs = {**locals(), **kwargs}
+    del kwargs["comp"]
+    del kwargs["kwargs"]
+    return Element(comp, kwargs=kwargs)
+
+
+def QLineEdit(**kwargs):
+    comp = reacton.core.ComponentWidget(widget=Qt.QLineEdit)
+    kwargs = {**locals(), **kwargs}
+    del kwargs["comp"]
+    del kwargs["kwargs"]
+    return Element(comp, kwargs=kwargs)
+
+
+def QVBoxLayoutRaw(children=[], **kwargs):
+    comp = reacton.core.ComponentWidget(widget=Qt.QVBoxLayout)
+    kwargs = {"children": children, **kwargs}
+
+    def add_children():
+        widgets = [reacton.get_widget(child) for child in children]
+        layout_widget: Qt.QLayout = reacton.get_widget(layout)
+        for i in range(layout_widget.count()):
+            widget = layout_widget.itemAt(0).widget()
+            layout_widget.removeWidget(widget)
+        for widget in widgets:
+            layout_widget.addWidget(widget)
+        print(layout_widget, widgets)
+
+    reacton.use_effect(add_children, children)
+    # del kwargs["comp"]
+    # del kwargs["kwargs"]
+    layout = Element(comp, kwargs=kwargs)
+    return layout
+
+
+def QSlider(**kwargs):
+    comp = reacton.core.ComponentWidget(widget=Qt.QSlider)
+    kwargs = {**locals(), **kwargs}
+    del kwargs["comp"]
+    del kwargs["kwargs"]
+    return Element(comp, kwargs=kwargs)
+
+
+@reacton.component
+def QVBoxLayout(**kwargs):
+    layout = QVBoxLayoutRaw(**kwargs)
+
+    return layout
+
+
+@reacton.component
+def ClickApp():
+    clicked, set_clicked = reacton.use_state(0)
+    toomuch = clicked > 3
+    button = QPushButton(text=f"Clicked {clicked} times", on_clicked=lambda: set_clicked(clicked + 1), enabled=not toomuch)
+    return QMainWindow(window_title="Stop" if toomuch else "First React-Qt app", central_widget=button)
+
+
+@reacton.component
+def App():
+    text, set_text = reacton.use_state("text")
+    value, set_value = reacton.use_state(4)
+    with QMainWindow(window_title="First React-Qt app") as main:
+        with QWidget():
+            with QVBoxLayout():
+                QSlider(orientation=QtCore.Qt.Horizontal, minimum=1, maximum=10, value=value, on_value_changed=set_value)
+                QLabel(text=f"Value = {value}", font=QtGui.QFont("monospace", value + 10))
+                QLineEdit(on_text_changed=set_text)
+                QLabel(text=text)
+    return main
+
+
+@reacton.component
+def SliderDemo():
+    size, set_size = reacton.use_state(20)
+    with QWidget(window_title="Slider demo with React-Qt") as main:
+        with QVBoxLayout():
+            QLabel(text="Hello", font=QtGui.QFont("Arial", size), alignment=QtCore.Qt.AlignCenter)
+            QSlider(orientation=QtCore.Qt.Horizontal, minimum=10, maximum=30, tick_position=Qt.QSlider.TicksBelow, tick_interval=5, on_value_changed=set_size)
+    return main
+
+
+app = Qt.QApplication(sys.argv)
+widget, rc = reacton.core.render_fixed(App(), handle_error=False)
+widget.show()
+app.exec()