pyqt_reactive.widgets.no_scroll_spinbox

No-scroll spinbox widgets for PyQt6.

Prevents accidental value changes from mouse wheel events.

Classes

CheckboxValueState(*values)	Value ownership state for None-aware checkboxes.
IgnoreWheelEventMixin()	Shared wheel-event policy for widgets that should not scroll values.
NoScrollComboBox([parent, placeholder])	ComboBox that ignores wheel events to prevent accidental value changes.
NoScrollDoubleSpinBox([parent])	DoubleSpinBox that ignores wheel events to prevent accidental value changes.
NoScrollSpinBox([parent])	SpinBox that ignores wheel events to prevent accidental value changes.
NoneAwareCheckBox([parent])	QCheckBox that supports None state for lazy dataclass contexts.

class pyqt_reactive.widgets.no_scroll_spinbox.IgnoreWheelEventMixin

Shared wheel-event policy for widgets that should not scroll values.

wheelEvent(event: QWheelEvent) → None

class pyqt_reactive.widgets.no_scroll_spinbox.NoScrollSpinBox(parent=None)

SpinBox that ignores wheel events to prevent accidental value changes.

Inherits from SpinBoxAdapter which already implements ValueGettable/ValueSettable ABCs.

class pyqt_reactive.widgets.no_scroll_spinbox.NoScrollDoubleSpinBox(parent=None)

DoubleSpinBox that ignores wheel events to prevent accidental value changes.

Inherits from DoubleSpinBoxAdapter which already implements ValueGettable/ValueSettable ABCs.

textFromValue(value: float) → str

Convert value to string without trailing zeros for clean display.

Users can still type additional digits when editing - this only affects the display format, not the underlying precision.

Examples

1.5 -> “1.5” 1.0 -> “1” 1.567 -> “1.567” 0.0001 -> “0.0001”

class pyqt_reactive.widgets.no_scroll_spinbox.NoScrollComboBox(parent=None, placeholder='')

ComboBox that ignores wheel events to prevent accidental value changes.

Inherits from ComboBoxAdapter which already implements ValueGettable/ValueSettable ABCs. Supports placeholder text when currentIndex == -1 (for None values).

__init__(parent=None, placeholder='')

setPlaceholder(text: str)

Set the placeholder text shown when currentIndex == -1.

setCurrentIndex(index: int)

Override to track when placeholder should be active.

get_value()

Get current value (item data at current index).

set_value(value)

Set current value by finding matching item data.

paintEvent(event)

Override to draw placeholder text when currentIndex == -1.

class pyqt_reactive.widgets.no_scroll_spinbox.CheckboxValueState(*values)

Value ownership state for None-aware checkboxes.

PLACEHOLDER = 'placeholder'

CONCRETE = 'concrete'

class pyqt_reactive.widgets.no_scroll_spinbox.NoneAwareCheckBox(parent=None)

QCheckBox that supports None state for lazy dataclass contexts.

Shows inherited value as grayed placeholder when value is None. Clicking converts placeholder to explicit value.

PLACEHOLDER_PAINT_OPACITY = 0.45

__init__(parent=None)

get_value()

Get value, returning None if in placeholder state.

is_placeholder() → bool

Return whether the checkbox is currently displaying inherited state.

set_value(value)

Set value, handling None by leaving in placeholder state.

connect_change_signal(callback: Callable[[bool | None], None]) → None

Implement ChangeSignalEmitter ABC.

disconnect_change_signal(callback: Callable[[bool | None], None]) → None

Implement ChangeSignalEmitter ABC.

set_placeholder_preview(checked: bool) → None

Display an inherited checkbox value without making it concrete.

set_resolved_value_preview(value) → None

Display an inherited resolved bool while preserving raw None.

convert_placeholder_to_concrete() → None

Keep the displayed value but mark it as a user-controlled value.

toggle() → None

Toggle as a user action, committing placeholder state first.

mousePressEvent(event)

On click, switch from placeholder to explicit value.

paintEvent(event)

Draw with placeholder styling.

For placeholder state, draw the checkbox with grey text color to make the checkmark appear dimmed.