A combobox which displays a dynamic list of layers from a QGIS project. More...

#include <qgsmaplayercombobox.h>

Inheritance diagram for QgsMapLayerComboBox:

Public Slots
void	setLayer (QgsMapLayer *layer)
	Sets the current layer selected in the combo box.

Signals
void	layerChanged (QgsMapLayer *layer)
	Emitted whenever the currently selected layer changes.

Public Member Functions
	QgsMapLayerComboBox (QWidget *parent=nullptr)
	QgsMapLayerComboBox creates a combo box to display the list of layers currently in the project.

QStringList	additionalItems () const
	Returns the list of additional (non map layer) items included at the end of the combo box.

QList< QgsMapLayer * >	additionalLayers () const
	Returns the list of additional layers added to the combobox.

bool	allowEmptyLayer () const
	Returns `true` if the combo box allows the empty layer ("not set") choice.

QgsMapLayer *	currentLayer () const
	Returns the current layer selected in the combo box.

QList< QgsMapLayer * >	exceptedLayerList () const
	Returns a list of layers which should be excluded from the combo box.

QStringList	excludedProviders () const
	Returns the list of data providers which are excluded from the combobox.

Qgis::LayerFilters	filters () const
	Returns any currently used filters on the listed layers.

QgsMapLayer *	layer (int layerIndex) const
	Returns the layer currently shown at the specified index within the combo box.

void	setAdditionalItems (const QStringList &items)
	Sets a list of additional (non map layer) items to include at the end of the combobox.

void	setAdditionalLayers (const QList< QgsMapLayer * > &layers)
	Sets a list of additional layers to include in the combobox.

void	setAllowEmptyLayer (bool allowEmpty, const QString &text=QString(), const QIcon &icon=QIcon())
	Sets whether an optional empty layer ("not set") option is shown in the combo box.

void	setExceptedLayerList (const QList< QgsMapLayer * > &layerList)
	Sets a list of layers which should be excluded from the combo box.

void	setExcludedProviders (const QStringList &providers)
	Sets a list of data providers which should be excluded from the combobox.

Q_DECL_DEPRECATED void	setFilters (int filters)
	Filters according to layer type and/or geometry type.

void	setFilters (Qgis::LayerFilters filters)
	Sets filters for the layers displayed in the combo box.

void	setProject (QgsProject *project)
	Sets the project from which map layers are shown.

void	setShowCrs (bool showCrs)
	Sets whether the CRS of layers is also included in the combo box text.

bool	showCrs () const
	Returns `true` if the combo box shows the layer's CRS.

Protected Slots
void	indexChanged (int i)

void	rowsChanged ()

Protected Member Functions
void	dragEnterEvent (QDragEnterEvent *event) override

void	dragLeaveEvent (QDragLeaveEvent *event) override

void	dropEvent (QDropEvent *event) override

void	paintEvent (QPaintEvent *e) override

Properties
bool	allowEmptyLayer

QStringList	excludedProviders

Qgis::LayerFilters	filters

bool	showCrs

Friends
class	QgsProcessingMapLayerComboBox

Detailed Description

A combobox which displays a dynamic list of layers from a QGIS project.

QgsMapLayerComboBox is automatically populated with all the layers from the project. Any changes to the project's layers are immediately reflected in the combobox, such as addition of new layers, layer renaming, or layer removal. Accordingly, this widget should ALWAYS be used when presenting a choice of layers to a user, instead of manually populated comboboxes.

In addition to the automatic layer population, QgsMapLayerComboBox also presents a user-friendly choice of layers by showing standard icons representing the different layer types (eg raster, mesh, or polygon/point/line icons for vector layers). Helpful tooltips will be shown if the user hovers over any of the layers, helping guide the user to the correct layer choice.

Optionally, the list of available layers can be filtered to a subset of the project's layers (such as only showing raster layers, or only spatial layers) by calling setFilters().

By default, the combobox will be populated using layers from the current project (see QgsProject::instance()), however a specific source project can be set via setProject().

Definition at line 53 of file qgsmaplayercombobox.h.

Constructor & Destructor Documentation

◆ QgsMapLayerComboBox()

QgsMapLayerComboBox::QgsMapLayerComboBox ( QWidget * parent = nullptr )

explicit

QgsMapLayerComboBox creates a combo box to display the list of layers currently in the project.

The layers can be filtered and/or ordered.

Definition at line 24 of file qgsmaplayercombobox.cpp.

Member Function Documentation

◆ additionalItems()

QStringList QgsMapLayerComboBox::additionalItems ( ) const

Returns the list of additional (non map layer) items included at the end of the combo box.

See also: setAdditionalItems()

Definition at line 80 of file qgsmaplayercombobox.cpp.

◆ additionalLayers()

QList< QgsMapLayer * > QgsMapLayerComboBox::additionalLayers ( ) const

Returns the list of additional layers added to the combobox.

See also: setAdditionalLayers()

Since: QGIS 3.22

Definition at line 90 of file qgsmaplayercombobox.cpp.

◆ allowEmptyLayer()

bool QgsMapLayerComboBox::allowEmptyLayer ( ) const

Returns true if the combo box allows the empty layer ("not set") choice.

See also: setAllowEmptyLayer()

Definition at line 60 of file qgsmaplayercombobox.cpp.

◆ currentLayer()

QgsMapLayer * QgsMapLayerComboBox::currentLayer ( ) const

Returns the current layer selected in the combo box.

See also: layer

Definition at line 122 of file qgsmaplayercombobox.cpp.

◆ dragEnterEvent()

void QgsMapLayerComboBox::dragEnterEvent ( QDragEnterEvent * event )

overrideprotected

Definition at line 184 of file qgsmaplayercombobox.cpp.

◆ dragLeaveEvent()

void QgsMapLayerComboBox::dragLeaveEvent ( QDragLeaveEvent * event )

overrideprotected

Definition at line 206 of file qgsmaplayercombobox.cpp.

◆ dropEvent()

void QgsMapLayerComboBox::dropEvent ( QDropEvent * event )

overrideprotected

Definition at line 220 of file qgsmaplayercombobox.cpp.

◆ exceptedLayerList()

QList< QgsMapLayer * > QgsMapLayerComboBox::exceptedLayerList ( ) const

inline

Returns a list of layers which should be excluded from the combo box.

See also: setExceptedLayerList()

Definition at line 105 of file qgsmaplayercombobox.h.

◆ excludedProviders()

QStringList QgsMapLayerComboBox::excludedProviders ( ) const

Returns the list of data providers which are excluded from the combobox.

See also: setExcludedProviders()

Definition at line 50 of file qgsmaplayercombobox.cpp.

◆ filters()

Qgis::LayerFilters QgsMapLayerComboBox::filters ( ) const

inline

Returns any currently used filters on the listed layers.

See also: setFilters()

Definition at line 91 of file qgsmaplayercombobox.h.

◆ indexChanged

void QgsMapLayerComboBox::indexChanged ( int i )

protectedslot

Definition at line 149 of file qgsmaplayercombobox.cpp.

◆ layer()

QgsMapLayer * QgsMapLayerComboBox::layer ( int layerIndex ) const

Returns the layer currently shown at the specified index within the combo box.

Parameters

layerIndex position of layer to return

See also: currentLayer

Definition at line 127 of file qgsmaplayercombobox.cpp.

◆ layerChanged

void QgsMapLayerComboBox::layerChanged ( QgsMapLayer * layer )

signal

Emitted whenever the currently selected layer changes.

◆ paintEvent()

void QgsMapLayerComboBox::paintEvent ( QPaintEvent * e )

overrideprotected

Definition at line 245 of file qgsmaplayercombobox.cpp.

◆ rowsChanged

void QgsMapLayerComboBox::rowsChanged ( )

protectedslot

Definition at line 156 of file qgsmaplayercombobox.cpp.

◆ setAdditionalItems()

void QgsMapLayerComboBox::setAdditionalItems ( const QStringList & items )

Sets a list of additional (non map layer) items to include at the end of the combobox.

These may represent additional layers such as layers which are not included in the project, or paths to layers which have not yet been loaded into QGIS.

See also: additionalItems()

Definition at line 75 of file qgsmaplayercombobox.cpp.

◆ setAdditionalLayers()

void QgsMapLayerComboBox::setAdditionalLayers ( const QList< QgsMapLayer * > & layers )

Sets a list of additional layers to include in the combobox.

This method allows adding additional layers, which are not part of a project's layers, into the combobox.

See also: additionalLayers()

Since: QGIS 3.22

Definition at line 85 of file qgsmaplayercombobox.cpp.

◆ setAllowEmptyLayer()

void QgsMapLayerComboBox::setAllowEmptyLayer	(	bool	allowEmpty,
		const QString &	text = `QString()`,
		const QIcon &	icon = `QIcon()`
	)

Sets whether an optional empty layer ("not set") option is shown in the combo box.

Since QGIS 3.20, the optional text and icon arguments allows the text and icon for the empty layer item to be set.

See also: allowEmptyLayer()

Definition at line 55 of file qgsmaplayercombobox.cpp.

◆ setExceptedLayerList()

void QgsMapLayerComboBox::setExceptedLayerList ( const QList< QgsMapLayer * > & layerList )

inline

Sets a list of layers which should be excluded from the combo box.

See also: exceptedLayerList()

Definition at line 98 of file qgsmaplayercombobox.h.

◆ setExcludedProviders()

void QgsMapLayerComboBox::setExcludedProviders ( const QStringList & providers )

Sets a list of data providers which should be excluded from the combobox.

See also: excludedProviders()

Definition at line 39 of file qgsmaplayercombobox.cpp.

◆ setFilters() [1/2]

Q_DECL_DEPRECATED void QgsMapLayerComboBox::setFilters ( int filters )

inline

Filters according to layer type and/or geometry type.

Note: for API compatibility

Since: QGIS 3.34

Deprecated:: QGIS 3.34. Use the flag signature instead.

Definition at line 84 of file qgsmaplayercombobox.h.

◆ setFilters() [2/2]

void QgsMapLayerComboBox::setFilters ( Qgis::LayerFilters filters )

inline

Sets filters for the layers displayed in the combo box.

This method allows filtering layers according to layer type and/or geometry type.

See also: filters()

Definition at line 76 of file qgsmaplayercombobox.h.

◆ setLayer

void QgsMapLayerComboBox::setLayer ( QgsMapLayer * layer )

slot

Sets the current layer selected in the combo box.

Definition at line 95 of file qgsmaplayercombobox.cpp.

◆ setProject()

void QgsMapLayerComboBox::setProject ( QgsProject * project )

Sets the project from which map layers are shown.

If project is nullptr then QgsProject::instance() will be used.

Since: QGIS 3.24

Definition at line 44 of file qgsmaplayercombobox.cpp.

◆ setShowCrs()

void QgsMapLayerComboBox::setShowCrs ( bool showCrs )

Sets whether the CRS of layers is also included in the combo box text.

See also: showCrs()

Definition at line 65 of file qgsmaplayercombobox.cpp.

◆ showCrs()

bool QgsMapLayerComboBox::showCrs ( ) const

Returns true if the combo box shows the layer's CRS.

See also: setShowCrs()

Definition at line 70 of file qgsmaplayercombobox.cpp.

Friends And Related Symbol Documentation

◆ QgsProcessingMapLayerComboBox

friend class QgsProcessingMapLayerComboBox

friend

Definition at line 234 of file qgsmaplayercombobox.h.

Property Documentation

◆ allowEmptyLayer

bool QgsMapLayerComboBox::allowEmptyLayer

readwrite

Definition at line 57 of file qgsmaplayercombobox.h.

◆ excludedProviders

QStringList QgsMapLayerComboBox::excludedProviders

readwrite

Definition at line 59 of file qgsmaplayercombobox.h.

◆ filters

Qgis::LayerFilters QgsMapLayerComboBox::filters

readwrite

Definition at line 56 of file qgsmaplayercombobox.h.

◆ showCrs

bool QgsMapLayerComboBox::showCrs

readwrite

Definition at line 58 of file qgsmaplayercombobox.h.

The documentation for this class was generated from the following files:

/build/qgis-3.43.0+git20250511+69d1901085b+99sid/src/gui/qgsmaplayercombobox.h
/build/qgis-3.43.0+git20250511+69d1901085b+99sid/src/gui/qgsmaplayercombobox.cpp

Public Slots

Signals

Public Member Functions

Protected Slots

Protected Member Functions

Properties

Friends

Detailed Description

Constructor & Destructor Documentation

◆ QgsMapLayerComboBox()

Member Function Documentation

◆ additionalItems()

◆ additionalLayers()

◆ allowEmptyLayer()

◆ currentLayer()

◆ dragEnterEvent()

◆ dragLeaveEvent()

◆ dropEvent()

◆ exceptedLayerList()

◆ excludedProviders()

◆ filters()

◆ indexChanged

◆ layer()

◆ layerChanged

◆ paintEvent()

◆ rowsChanged

◆ setAdditionalItems()

◆ setAdditionalLayers()

◆ setAllowEmptyLayer()

◆ setExceptedLayerList()

◆ setExcludedProviders()

◆ setFilters() [1/2]

◆ setFilters() [2/2]

◆ setLayer

◆ setProject()

◆ setShowCrs()

◆ showCrs()

Friends And Related Symbol Documentation

◆ QgsProcessingMapLayerComboBox

Property Documentation

◆ allowEmptyLayer

◆ excludedProviders

◆ filters

◆ showCrs