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qt.py

Enhanced Qt components and patterns for consistent UI implementation.

This module provides a comprehensive set of base classes, mixins, and utilities for building Qt interfaces in Houdini. It focuses on: - Consistent styling and theming - Reusable UI patterns - Type-safe signal/slot connections - State management - Resource handling

BaseWidget

Bases: QWidget, WindowMixin, DialogMixin

Base widget with common functionality.

Source code in utils/qt.py 
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class BaseWidget(QtWidgets.QWidget, WindowMixin, DialogMixin):
    """Base widget with common functionality."""

    theme_manager = ThemeManager()

    def __init__(self, parent: Optional[QtWidgets.QWidget] = None):
        super().__init__(parent)
        self.setup_ui()
        self.theme_manager.apply_theme(self)

    def setup_ui(self) -> None:
        """Set up the widget's UI."""
        pass

setup_ui()

Set up the widget's UI.

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def setup_ui(self) -> None:
    """Set up the widget's UI."""
    pass

DialogMixin

Provides common dialog functionality for widgets.

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class DialogMixin:
    """Provides common dialog functionality for widgets."""

    def show_error(self, message: str, title: str = "Error") -> None:
        """Show error dialog."""
        QtWidgets.QMessageBox.critical(self, title, message)

    def show_warning(self, message: str, title: str = "Warning") -> None:
        """Show warning dialog."""
        QtWidgets.QMessageBox.warning(self, title, message)

    def confirm(self, message: str, title: str = "Confirm") -> bool:
        """Show confirmation dialog.

        Returns:
            True if user confirmed, False otherwise
        """
        return QtWidgets.QMessageBox.question(
            self, title, message,
            QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.No
        ) == QtWidgets.QMessageBox.Yes

confirm(message, title='Confirm')

Show confirmation dialog.

Returns:

Type Description
bool

True if user confirmed, False otherwise
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def confirm(self, message: str, title: str = "Confirm") -> bool:
    """Show confirmation dialog.

    Returns:
        True if user confirmed, False otherwise
    """
    return QtWidgets.QMessageBox.question(
        self, title, message,
        QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.No
    ) == QtWidgets.QMessageBox.Yes

show_error(message, title='Error')

Show error dialog.

Source code in utils/qt.py 
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def show_error(self, message: str, title: str = "Error") -> None:
    """Show error dialog."""
    QtWidgets.QMessageBox.critical(self, title, message)

show_warning(message, title='Warning')

Show warning dialog.

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def show_warning(self, message: str, title: str = "Warning") -> None:
    """Show warning dialog."""
    QtWidgets.QMessageBox.warning(self, title, message)

ResultsList

Bases: BaseWidget

Reusable widget for displaying search/operation results.

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class ResultsList(BaseWidget):
    """Reusable widget for displaying search/operation results."""

    item_selected = Signal(dict)  # Emitted when user selects a result

    def __init__(self, parent: Optional[QtWidgets.QWidget] = None):
        super().__init__(parent)

    def setup_ui(self) -> None:
        layout = QtWidgets.QVBoxLayout(self)

        self.list_widget = QtWidgets.QListWidget()
        self.list_widget.itemClicked.connect(self._on_item_clicked)

        self.status_label = QtWidgets.QLabel()

        layout.addWidget(self.status_label)
        layout.addWidget(self.list_widget)

    def set_results(self, results: List[Dict[str, Any]]) -> None:
        """Update displayed results."""
        self.list_widget.clear()
        self.status_label.setText(f"Found {len(results)} results")

        for result in results:
            item = QtWidgets.QListWidgetItem()
            item.setText(result["display_text"])
            item.setData(Qt.UserRole, result)
            self.list_widget.addItem(item)

    @Slot(QtWidgets.QListWidgetItem)
    def _on_item_clicked(self, item: QtWidgets.QListWidgetItem) -> None:
        """Handle result selection."""
        result_data = item.data(Qt.UserRole)
        self.item_selected.emit(result_data)

set_results(results)

Update displayed results.

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def set_results(self, results: List[Dict[str, Any]]) -> None:
    """Update displayed results."""
    self.list_widget.clear()
    self.status_label.setText(f"Found {len(results)} results")

    for result in results:
        item = QtWidgets.QListWidgetItem()
        item.setText(result["display_text"])
        item.setData(Qt.UserRole, result)
        self.list_widget.addItem(item)

SearchWidget

Bases: BaseWidget

Reusable search widget with common functionality.

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class SearchWidget(BaseWidget):
    """Reusable search widget with common functionality."""

    search_triggered = Signal(str)  # Emitted when search should be performed

    def __init__(self, parent: Optional[QtWidgets.QWidget] = None):
        super().__init__(parent)

    def setup_ui(self) -> None:
        layout = QtWidgets.QHBoxLayout(self)

        self.search_input = QtWidgets.QLineEdit()
        self.search_input.setPlaceholderText("Search...")
        self.search_input.textChanged.connect(self._on_text_changed)

        self.case_sensitive = QtWidgets.QCheckBox("Case Sensitive")

        layout.addWidget(self.search_input)
        layout.addWidget(self.case_sensitive)

    @Slot(str)
    def _on_text_changed(self, text: str) -> None:
        """Handle search text changes."""
        if len(text) >= 3:  # Minimum search length
            self.search_triggered.emit(text)

ThemeManager

Manages application-wide theming and styling.

Uses a configuration-driven approach to maintain consistent visual styling across the application.

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class ThemeManager:
    """Manages application-wide theming and styling.

    Uses a configuration-driven approach to maintain consistent visual styling
    across the application.
    """

    def __init__(self):
        self._current_theme = "dark"
        self._themes: Dict[str, Dict[str, str]] = {
            "dark": {
                "primary": "#2B5B84",
                "secondary": "#538cc6",
                "background": "#2b2b2b",
                "surface": "#333333",
                "error": "#cf6679",
                "text": "#ffffff",
                "border": "#444444"
            },
            "light": {
                "primary": "#1976d2",
                "secondary": "#42a5f5",
                "background": "#fafafa",
                "surface": "#ffffff",
                "error": "#b00020",
                "text": "#000000",
                "border": "#e0e0e0"
            }
        }

    def get_color(self, name: str) -> str:
        """Get color value from current theme."""
        return self._themes[self._current_theme][name]

    def apply_theme(self, widget: QtWidgets.QWidget) -> None:
        """Apply current theme to widget and all children."""
        theme = self._themes[self._current_theme]
        widget.setStyleSheet(f"""
            QWidget {{
                background-color: {theme["background"]};
                color: {theme["text"]};
                font-size: 12px;
            }}

            QPushButton {{
                background-color: {theme["primary"]};
                border: none;
                padding: 8px 16px;
                border-radius: 4px;
            }}

            QPushButton:hover {{
                background-color: {theme["secondary"]};
            }}

            QLineEdit {{
                padding: 8px;
                border: 1px solid {theme["border"]};
                border-radius: 4px;
                background-color: {theme["surface"]};
            }}

            QComboBox {{
                padding: 8px;
                border: 1px solid {theme["border"]};
                border-radius: 4px;
                background-color: {theme["surface"]};
            }}
        """)

apply_theme(widget)

Apply current theme to widget and all children.

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def apply_theme(self, widget: QtWidgets.QWidget) -> None:
    """Apply current theme to widget and all children."""
    theme = self._themes[self._current_theme]
    widget.setStyleSheet(f"""
        QWidget {{
            background-color: {theme["background"]};
            color: {theme["text"]};
            font-size: 12px;
        }}

        QPushButton {{
            background-color: {theme["primary"]};
            border: none;
            padding: 8px 16px;
            border-radius: 4px;
        }}

        QPushButton:hover {{
            background-color: {theme["secondary"]};
        }}

        QLineEdit {{
            padding: 8px;
            border: 1px solid {theme["border"]};
            border-radius: 4px;
            background-color: {theme["surface"]};
        }}

        QComboBox {{
            padding: 8px;
            border: 1px solid {theme["border"]};
            border-radius: 4px;
            background-color: {theme["surface"]};
        }}
    """)

get_color(name)

Get color value from current theme.

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def get_color(self, name: str) -> str:
    """Get color value from current theme."""
    return self._themes[self._current_theme][name]

WindowMixin

Provides window management functionality.

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class WindowMixin:
    """Provides window management functionality."""

    def center_on_screen(self) -> None:
        """Center window on screen."""
        screen = QtWidgets.QDesktopWidget().screenGeometry()
        size = self.geometry()
        x = (screen.width() - size.width()) // 2
        y = (screen.height() - size.height()) // 2
        self.move(x, y)

    def make_stay_on_top(self) -> None:
        """Make window stay on top."""
        self.setWindowFlags(self.windowFlags() | Qt.WindowStaysOnTopHint)

    @contextlib.contextmanager
    def block_signals(self):
        """Temporarily block widget signals."""
        self.blockSignals(True)
        try:
            yield
        finally:
            self.blockSignals(False)

block_signals()

Temporarily block widget signals.

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@contextlib.contextmanager
def block_signals(self):
    """Temporarily block widget signals."""
    self.blockSignals(True)
    try:
        yield
    finally:
        self.blockSignals(False)

center_on_screen()

Center window on screen.

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def center_on_screen(self) -> None:
    """Center window on screen."""
    screen = QtWidgets.QDesktopWidget().screenGeometry()
    size = self.geometry()
    x = (screen.width() - size.width()) // 2
    y = (screen.height() - size.height()) // 2
    self.move(x, y)

make_stay_on_top()

Make window stay on top.

Source code in utils/qt.py 
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def make_stay_on_top(self) -> None:
    """Make window stay on top."""
    self.setWindowFlags(self.windowFlags() | Qt.WindowStaysOnTopHint)

create_widget_with_layout(widget_type, layout_type, parent=None)

Create a widget with a layout in one step.

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def create_widget_with_layout(
    widget_type: Type[W],
    layout_type: Type[QtWidgets.QLayout],
    parent: Optional[QtWidgets.QWidget] = None
) -> W:
    """Create a widget with a layout in one step."""
    widget = widget_type(parent)
    layout = layout_type(widget)
    widget.setLayout(layout)
    return widget