Class: QgsMapToolIdentifyFeature¶

class qgis.gui.QgsMapToolIdentifyFeature(canvas: QgsMapCanvas, vl: QgsVectorLayer = None)¶

Bases: QgsMapToolIdentify

QgsMapToolIdentifyFeature is a map tool to identify a feature on a chosen layer

Parameters

canvas – the map canvas
vl – the vector layer. The map tool can be initialized without any layer and can be set afterward.

The QgsMapToolIdentifyFeature class is a map tool to identify a feature on a chosen layer. Once the map tool is enable, user can click on the map canvas to identify a feature. A signal will then be emitted.

Methods

canvasReleaseEvent

param e

childEvent

connectNotify

customEvent

derivedAttributesForPoint

Returns derived attributes map for a clicked point in map coordinates.

disconnectNotify

identify

Performs the identification.

identifyLayer

Call the right method depending on layer type

identifyMeshLayer

Identifies data from active scalar and vector dataset from the mesh layer

identifyRasterLayer

Performs the identification against a given raster layer.

identifyVectorLayer

Performs the identification against a given vector layer.

isSignalConnected

keyPressEvent

param e

receivers

restoreCanvasPropertiesOverrides

Clears canvas properties overrides previously set with setCanvasPropertiesOverrides()

sender

senderSignalIndex

setCanvasPropertiesOverrides

Overrides some map canvas properties inside the map tool for the upcoming identify requests.

setLayer

change the layer used by the map tool to identify

timerEvent

toCanvasCoordinates

Transforms a point from map coordinates to screen coordinates.

toLayerCoordinates

Transforms a point from screen coordinates to layer coordinates.

toMapCoordinates

Transforms a point from screen coordinates to map coordinates.

toMapCoordinatesV2

Transforms a point from layer coordinates to map coordinates (which is different in case reprojection is used).

Signals

featureIdentified

featureIdentified(self, QgsFeature) [signal] featureIdentified(self, int) [signal]

canvasReleaseEvent(self, e: QgsMapMouseEvent)¶

Parameters: e (QgsMapMouseEvent) –

childEvent(self, QChildEvent)¶

connectNotify(self, QMetaMethod)¶

customEvent(self, QEvent)¶

derivedAttributesForPoint(self, point: QgsPoint) → Dict[str, str]¶: Returns derived attributes map for a clicked point in map coordinates. May be 2D or 3D point.

disconnectNotify(self, QMetaMethod)¶

featureIdentified¶: featureIdentified(self, QgsFeature) [signal] featureIdentified(self, int) [signal]

identify(self, x: int, y: int, layerList: Iterable[QgsMapLayer] = [], mode: QgsMapToolIdentify.IdentifyMode = QgsMapToolIdentify.DefaultQgsSetting, identifyContext: QgsIdentifyContext = QgsIdentifyContext()) → List[QgsMapToolIdentify.IdentifyResult]¶

Performs the identification.

Parameters

x – x coordinates of mouseEvent
y – y coordinates of mouseEvent
layerList – Performs the identification within the given list of layers. Default value is an empty list, i.e. uses all the layers.
mode – Identification mode. Can use QGIS default settings or a defined mode. Default mode is DefaultQgsSetting.
identifyContext – Identify context object.

Returns

a list of IdentifyResult

identify(self, x: int, y: int, mode: QgsMapToolIdentify.IdentifyMode, layerType: Union[QgsMapToolIdentify.LayerType, QgsMapToolIdentify.Type] = QgsMapToolIdentify.AllLayers, identifyContext: QgsIdentifyContext = QgsIdentifyContext()) -> List[QgsMapToolIdentify.IdentifyResult] Performs the identification. To avoid being forced to specify IdentifyMode with a list of layers this has been made private and two publics methods are offered

Parameters

x – x coordinates of mouseEvent
y – y coordinates of mouseEvent
mode – Identification mode. Can use QGIS default settings or a defined mode.
layerType – Only performs identification in a certain type of layers (raster, vector, mesh). Default value is AllLayers.
identifyContext – Identify context object.

Returns

a list of IdentifyResult

identify(self, geometry: QgsGeometry, mode: QgsMapToolIdentify.IdentifyMode, layerType: Union[QgsMapToolIdentify.LayerType, QgsMapToolIdentify.Type], identifyContext: QgsIdentifyContext = QgsIdentifyContext()) -> List[QgsMapToolIdentify.IdentifyResult] Performs identification based on a geometry (in map coordinates)

identify(self, geometry: QgsGeometry, mode: QgsMapToolIdentify.IdentifyMode, layerList: Iterable[QgsMapLayer], layerType: Union[QgsMapToolIdentify.LayerType, QgsMapToolIdentify.Type], identifyContext: QgsIdentifyContext = QgsIdentifyContext()) -> List[QgsMapToolIdentify.IdentifyResult] Performs identification based on a geometry (in map coordinates)

identify(self, x: int, y: int, mode: QgsMapToolIdentify.IdentifyMode, layerList: Iterable[QgsMapLayer], layerType: Union[QgsMapToolIdentify.LayerType, QgsMapToolIdentify.Type] = QgsMapToolIdentify.AllLayers, identifyContext: QgsIdentifyContext = QgsIdentifyContext()) -> List[QgsMapToolIdentify.IdentifyResult] Performs the identification. To avoid being forced to specify IdentifyMode with a list of layers this has been made private and two publics methods are offered

Parameters

x – x coordinates of mouseEvent
y – y coordinates of mouseEvent
mode – Identification mode. Can use QGIS default settings or a defined mode.
layerList – Performs the identification within the given list of layers.
layerType – Only performs identification in a certain type of layers (raster, vector, mesh).
identifyContext – Identify context object.

Returns

a list of IdentifyResult

identifyLayer(self, results: Iterable[QgsMapToolIdentify.IdentifyResult], layer: QgsMapLayer, point: QgsPointXY, viewExtent: QgsRectangle, mapUnitsPerPixel: float, layerType: Union[QgsMapToolIdentify.LayerType, QgsMapToolIdentify.Type] = QgsMapToolIdentify.AllLayers, identifyContext: QgsIdentifyContext = QgsIdentifyContext()) → bool¶: Call the right method depending on layer type

identifyMeshLayer(self, results: Iterable[QgsMapToolIdentify.IdentifyResult], layer: QgsMeshLayer, point: QgsPointXY, identifyContext: QgsIdentifyContext = QgsIdentifyContext()) → bool¶

Identifies data from active scalar and vector dataset from the mesh layer

Works only if layer was already rendered (triangular mesh is created)

New in version 3.6.

identifyRasterLayer(self, results: Iterable[QgsMapToolIdentify.IdentifyResult], layer: QgsRasterLayer, point: QgsPointXY, viewExtent: QgsRectangle, mapUnitsPerPixel: float, identifyContext: QgsIdentifyContext = QgsIdentifyContext()) → bool¶

Performs the identification against a given raster layer.

Parameters

results – list of identify results
layer – raster layer to identify from
point – point coordinate to identify
viewExtent – view extent
mapUnitsPerPixel – map units per pixel value
identifyContext – identify context object

identifyVectorLayer(self, results: Iterable[QgsMapToolIdentify.IdentifyResult], layer: QgsVectorLayer, point: QgsPointXY, identifyContext: QgsIdentifyContext = QgsIdentifyContext()) → bool¶

Performs the identification against a given vector layer.

Parameters

results – list of identify results
layer – raster layer to identify from
point – point coordinate to identify
identifyContext – identify context object

isSignalConnected(self, QMetaMethod) → bool¶

keyPressEvent(self, e: QKeyEvent)¶

Parameters: e (QKeyEvent) –

receivers(self, PYQT_SIGNAL) → int¶

restoreCanvasPropertiesOverrides(self)¶: Clears canvas properties overrides previously set with setCanvasPropertiesOverrides()

See also

setCanvasPropertiesOverrides()

New in version 3.4.

sender(self) → QObject¶

senderSignalIndex(self) → int¶

setCanvasPropertiesOverrides(self, searchRadiusMapUnits: float)¶

Overrides some map canvas properties inside the map tool for the upcoming identify requests.

This is useful when the identification is triggered by some other piece of GUI like a 3D map view and some properties like search radius need to be adjusted so that identification returns correct results. Currently only search radius may be overridden.

When the custom identification has finished, restoreCanvasPropertiesOverrides() should be called to erase any overrides.