Class: QgsUnitSelectionWidget

A widget displaying a combobox allowing the user to choose between various display units, such as millimeters or map units.

If the user chooses map units, a button appears allowing adjustment of minimum and maximum scaling.

See also

QgsMapUnitScaleWidget

See also

QgsMapUnitScaleDialog

Class Hierarchy

Base classes

QWidget
QObject
QPaintDevice

Methods

getMapUnitScale	Returns the map unit scale
getUnit	Gets the selected unit index
setMapCanvas	Sets the map canvas associated with the widget.
setMapUnitScale	Sets the map unit scale
setShowMapScaleButton	Sets whether the widget can show the map scale button when the Map Units option is selected.
setUnit	Sets the selected unit
setUnitIndex	Sets the selected unit index
setUnits	Sets the units which the user can choose from in the combobox.
showMapScaleButton	Returns True if the widget can show the map scale button when the Map Units option is selected.
unit	Returns the current predefined selected unit (if applicable).

Signals

changed

Emitted when the selected unit is changed, or the definition of the map unit scale is changed.

class qgis.gui.QgsUnitSelectionWidget

Bases: QWidget

__init__(parent: QWidget | None = None)

Constructor for QgsUnitSelectionWidget.

Parameters:

parent (Optional[QWidget] = None) – parent widget

signal changed

Emitted when the selected unit is changed, or the definition of the map unit scale is changed.

getMapUnitScale(self) → QgsMapUnitScale

Returns the map unit scale

Return type:

QgsMapUnitScale

getUnit(self) → int

Gets the selected unit index

Return type:

int

setMapCanvas(self, canvas: QgsMapCanvas | None)

Sets the map canvas associated with the widget. This allows the widget to retrieve the current map scale from the canvas.

Parameters:

canvas (Optional[QgsMapCanvas]) – map canvas

setMapUnitScale(self, scale: QgsMapUnitScale)

Sets the map unit scale

Parameters:

scale (QgsMapUnitScale)

setShowMapScaleButton(self, show: bool)

Sets whether the widget can show the map scale button when the Map Units option is selected.

See also

showMapScaleButton()

Added in version 3.22.

Parameters:

show (bool)

setUnit(self, unit: Qgis.RenderUnit)

Sets the selected unit

Parameters:

unit (Qgis.RenderUnit) – predefined unit to set as current

setUnitIndex(self, unitIndex: int)

Sets the selected unit index

Parameters:

unitIndex (int) – index of unit to set as current

setUnits(self, units: Iterable[str | None], mapUnitIdx: int)

Sets the units which the user can choose from in the combobox.

Parameters:

• units (Iterable[Optional[str]]) – list of strings for custom units to display in the widget

• mapUnitIdx (int) – specifies which entry corresponds to the map units, or -1 if none

setUnits(self, units: Iterable[Qgis.RenderUnit])

Sets the units which the user can choose from in the combobox. Clears any existing units.

Parameters:

units (Iterable[Qgis.RenderUnit]) – list of valid units

showMapScaleButton(self) → bool

Returns True if the widget can show the map scale button when the Map Units option is selected.

See also

setShowMapScaleButton()

Added in version 3.22.

Return type:

bool

unit(self) → Qgis.RenderUnit

Returns the current predefined selected unit (if applicable).

Return type:

Qgis.RenderUnit

Returns:

selected output unit, or QgsUnitTypes.RenderUnknownUnit if the widget was populated with custom unit types