Map tool for identifying features in layers. More...

#include <qgsmaptoolidentify.h>

Inheritance diagram for QgsMapToolIdentify:

Collaboration diagram for QgsMapToolIdentify:

Classes
struct	IdentifyResult

Public Types
enum	IdentifyMode { DefaultQgsSetting = -1, ActiveLayer, TopDownStopAtFirst, TopDownAll }
enum	LayerType { AllLayers = -1, VectorLayer, RasterLayer }

Public Slots
void	formatChanged (QgsRasterLayer *layer)

Signals
void	identifyProgress (int, int)
void	identifyMessage (QString)
void	changedRasterResults (QList< IdentifyResult > &)

Public Member Functions
	QgsMapToolIdentify (QgsMapCanvas *canvas)
	constructor
virtual	~QgsMapToolIdentify ()
virtual void	canvasMoveEvent (QMouseEvent *e)
	Overridden mouse move event.
virtual void	canvasPressEvent (QMouseEvent *e)
	Overridden mouse press event.
virtual void	canvasReleaseEvent (QMouseEvent *e)
	Overridden mouse release event.
virtual void	activate ()
	called when set as currently active map tool
virtual void	deactivate ()
	called when map tool is being deactivated
QList< IdentifyResult >	identify (int x, int y, QList< QgsMapLayer * > layerList=QList< QgsMapLayer * >(), IdentifyMode mode=DefaultQgsSetting)
	Performs the identification.
QList< IdentifyResult >	identify (int x, int y, IdentifyMode mode, LayerType layerType=AllLayers)
	Performs the identification.
Public Member Functions inherited from QgsMapTool
virtual	~QgsMapTool ()
	virtual destructor
virtual void	canvasDoubleClickEvent (QMouseEvent *e)
	Mouse double click event for overriding. Default implementation does nothing.
virtual void	wheelEvent (QWheelEvent *e)
	Mouse wheel event for overriding.
virtual void	keyPressEvent (QKeyEvent *e)
	Key event for overriding. Default implementation does nothing.
virtual void	keyReleaseEvent (QKeyEvent *e)
	Key event for overriding.
virtual void	renderComplete ()
	Called when rendering has finished. Default implementation does nothing.
void	setAction (QAction *action)
	Use this to associate a QAction to this maptool.
QAction *	action ()
	Return associated action with map tool or NULL if no action is associated.
void	setButton (QAbstractButton *button)
	Use this to associate a button to this maptool.
QAbstractButton *	button ()
	Return associated button with map tool or NULL if no button is associated.
virtual void	setCursor (QCursor cursor)
	Set a user defined cursor.
virtual bool	isTransient ()
	Check whether this MapTool performs a zoom or pan operation.
virtual bool	isEditTool ()
	Check whether this MapTool performs an edit operation.
QgsMapCanvas *	canvas ()
	returns pointer to the tool's map canvas

Private Member Functions
QList< IdentifyResult >	identify (int x, int y, IdentifyMode mode, QList< QgsMapLayer * > layerList, LayerType layerType=AllLayers)
	Performs the identification.
bool	identifyLayer (QList< IdentifyResult > results, QgsMapLayer layer, QgsPoint point, QgsRectangle viewExtent, double mapUnitsPerPixel, LayerType layerType=AllLayers)
	call the right method depending on layer type
bool	identifyRasterLayer (QList< IdentifyResult > results, QgsRasterLayer layer, QgsPoint point, QgsRectangle viewExtent, double mapUnitsPerPixel)
bool	identifyVectorLayer (QList< IdentifyResult > results, QgsVectorLayer layer, QgsPoint point)
virtual void	convertMeasurement (QgsDistanceArea &calc, double &measure, QGis::UnitType &u, bool isArea)
	Private helper.
virtual QGis::UnitType	displayUnits ()
	Transforms the measurements of derived attributes in the desired units.
QMap< QString, QString >	featureDerivedAttributes (QgsFeature feature, QgsMapLayer layer)

Private Attributes
QgsPoint	mLastPoint
double	mLastMapUnitsPerPixel
QgsRectangle	mLastExtent

Additional Inherited Members
Protected Member Functions inherited from QgsMapTool
	QgsMapTool (QgsMapCanvas *canvas)
	constructor takes map canvas as a parameter
QgsPoint	toMapCoordinates (const QPoint &point)
	transformation from screen coordinates to map coordinates
QgsPoint	toLayerCoordinates (QgsMapLayer *layer, const QPoint &point)
	transformation from screen coordinates to layer's coordinates
QgsPoint	toLayerCoordinates (QgsMapLayer *layer, const QgsPoint &point)
	transformation from map coordinates to layer's coordinates
QgsPoint	toMapCoordinates (QgsMapLayer *layer, const QgsPoint &point)
	transformation from layer's coordinates to map coordinates (which is different in case reprojection is used)
QgsRectangle	toLayerCoordinates (QgsMapLayer *layer, const QgsRectangle &rect)
	trnasformation of the rect from map coordinates to layer's coordinates
QPoint	toCanvasCoordinates (const QgsPoint &point)
	transformation from map coordinates to screen coordinates
Protected Attributes inherited from QgsMapTool
QgsMapCanvas *	mCanvas
	pointer to map canvas
QCursor	mCursor
	cursor used in map tool
QAction *	mAction
	optionally map tool can have pointer to action which will be used to set that action as active
QAbstractButton *	mButton
	optionally map tool can have pointer to a button which will be used to set that action as active

Detailed Description

Map tool for identifying features in layers.

after selecting a point, performs the identification:

for raster layers shows value of underlying pixel
for vector layers shows feature attributes within search radius (allows to edit values when vector layer is in editing mode)

Definition at line 43 of file qgsmaptoolidentify.h.

Member Enumeration Documentation

enum QgsMapToolIdentify::IdentifyMode

Enumerator:

DefaultQgsSetting
ActiveLayer
TopDownStopAtFirst
TopDownAll

Definition at line 49 of file qgsmaptoolidentify.h.

enum QgsMapToolIdentify::LayerType

Enumerator:

AllLayers
VectorLayer
RasterLayer

Definition at line 57 of file qgsmaptoolidentify.h.

Constructor & Destructor Documentation

QgsMapToolIdentify::QgsMapToolIdentify ( QgsMapCanvas * canvas )

constructor

Definition at line 45 of file qgsmaptoolidentify.cpp.

References identify_cursor, and QgsMapTool::mCursor.

QgsMapToolIdentify::~QgsMapToolIdentify ( )

virtual

Definition at line 53 of file qgsmaptoolidentify.cpp.

Member Function Documentation

void QgsMapToolIdentify::activate ( )

virtual

called when set as currently active map tool

Reimplemented from QgsMapTool.

Definition at line 159 of file qgsmaptoolidentify.cpp.

void QgsMapToolIdentify::canvasMoveEvent ( QMouseEvent * e )

virtual

Overridden mouse move event.

Reimplemented from QgsMapTool.

Definition at line 57 of file qgsmaptoolidentify.cpp.

void QgsMapToolIdentify::canvasPressEvent ( QMouseEvent * e )

virtual

Overridden mouse press event.

Reimplemented from QgsMapTool.

Definition at line 62 of file qgsmaptoolidentify.cpp.

void QgsMapToolIdentify::canvasReleaseEvent ( QMouseEvent * e )

virtual

Overridden mouse release event.

Reimplemented from QgsMapTool.

Definition at line 67 of file qgsmaptoolidentify.cpp.

void QgsMapToolIdentify::changedRasterResults ( QList< IdentifyResult > & )

signal

Referenced by formatChanged().

void QgsMapToolIdentify::convertMeasurement	(	QgsDistanceArea &	calc,
		double &	measure,
		QGis::UnitType &	u,
		bool	isArea
	)

privatevirtual

Private helper.

Definition at line 525 of file qgsmaptoolidentify.cpp.

References QgsDistanceArea::convertMeasurement(), displayUnits(), QgsMapCanvas::mapUnits(), and QgsMapTool::mCanvas.

Referenced by featureDerivedAttributes().

void QgsMapToolIdentify::deactivate ( )

virtual

called when map tool is being deactivated

Reimplemented from QgsMapTool.

Definition at line 164 of file qgsmaptoolidentify.cpp.

QGis::UnitType QgsMapToolIdentify::displayUnits ( )

privatevirtual

Transforms the measurements of derived attributes in the desired units.

Definition at line 537 of file qgsmaptoolidentify.cpp.

References QgsMapCanvas::mapUnits(), and QgsMapTool::mCanvas.

Referenced by convertMeasurement().

QMap< QString, QString > QgsMapToolIdentify::featureDerivedAttributes	(	QgsFeature *	feature,
		QgsMapLayer *	layer
	)

private

Definition at line 281 of file qgsmaptoolidentify.cpp.

References QgsGeometry::asPoint(), QgsGeometry::asPolyline(), convertMeasurement(), QgsMapLayer::crs(), GEO_NONE, QgsFeature::geometry(), QgsMapCanvas::hasCrsTransformEnabled(), QgsProject::instance(), QgsMapRenderer::layerToMapCoordinates(), QGis::Line, QgsMapCanvas::mapRenderer(), QgsMapTool::mCanvas, QgsDistanceArea::measure(), QgsDistanceArea::measurePerimeter(), QGis::NoGeometry, QGis::Point, QGis::Polygon, QgsProject::readEntry(), QgsDistanceArea::setEllipsoid(), QgsDistanceArea::setEllipsoidalMode(), QgsDistanceArea::setSourceCrs(), QgsCoordinateReferenceSystem::srsid(), QgsDistanceArea::textUnit(), QgsPoint::toString(), tr, QgsGeometry::type(), QGis::WKBLineString, QGis::WKBLineString25D, QGis::WKBNoGeometry, QGis::WKBPoint, QGis::WKBPoint25D, QgsGeometry::wkbType(), QgsPoint::x(), and QgsPoint::y().

Referenced by identifyRasterLayer(), and identifyVectorLayer().

void QgsMapToolIdentify::formatChanged ( QgsRasterLayer * layer )

slot

Definition at line 542 of file qgsmaptoolidentify.cpp.

References changedRasterResults(), identifyRasterLayer(), mLastExtent, mLastMapUnitsPerPixel, mLastPoint, and QgsDebugMsg.

QList< QgsMapToolIdentify::IdentifyResult > QgsMapToolIdentify::identify	(	int	x,
		int	y,
		QList< QgsMapLayer * >	layerList = `QList<QgsMapLayer*>()`,
		IdentifyMode	mode = `DefaultQgsSetting`
	)

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.

Returns: a list of IdentifyResult

Definition at line 72 of file qgsmaptoolidentify.cpp.

References AllLayers.

Referenced by identify().

QList< QgsMapToolIdentify::IdentifyResult > QgsMapToolIdentify::identify	(	int	x,
		int	y,
		IdentifyMode	mode,
		LayerType	layerType = `AllLayers`
	)

Performs the identification.

To avoid beeing 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). Default value is AllLayers.

Returns: a list of IdentifyResult

Definition at line 77 of file qgsmaptoolidentify.cpp.

References identify().

QList< QgsMapToolIdentify::IdentifyResult > QgsMapToolIdentify::identify	(	int	x,
		int	y,
		IdentifyMode	mode,
		QList< QgsMapLayer * >	layerList,
		LayerType	layerType = `AllLayers`
	)

private

Performs the identification.

To avoid beeing 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).

Returns: true if identification succeeded and a feature has been found, false otherwise.

Definition at line 82 of file qgsmaptoolidentify.cpp.

References ActiveLayer, QgsMapCanvas::currentLayer(), DefaultQgsSetting, QgsMapCanvas::extent(), QgsMapCanvas::getCoordinateTransform(), QgsMapLayer::id(), identifyLayer(), identifyMessage(), identifyProgress(), QgsProject::instance(), QgsMapCanvas::isDrawing(), QgsMapCanvas::layer(), QgsMapCanvas::layerCount(), QgsMapCanvas::mapUnitsPerPixel(), QgsMapTool::mCanvas, mLastExtent, mLastMapUnitsPerPixel, mLastPoint, QgsMapLayer::name(), QgsProject::readListEntry(), QgsMapToPixel::toMapCoordinates(), TopDownStopAtFirst, and tr.

bool QgsMapToolIdentify::identifyLayer	(	QList< IdentifyResult > *	results,
		QgsMapLayer *	layer,
		QgsPoint	point,
		QgsRectangle	viewExtent,
		double	mapUnitsPerPixel,
		LayerType	layerType = `AllLayers`
	)

private

call the right method depending on layer type

Definition at line 169 of file qgsmaptoolidentify.cpp.

References AllLayers, identifyRasterLayer(), identifyVectorLayer(), QgsMapLayer::RasterLayer, RasterLayer, QgsMapLayer::type(), QgsMapLayer::VectorLayer, and VectorLayer.

Referenced by identify().

void QgsMapToolIdentify::identifyMessage ( QString )

signal

Referenced by identify().

void QgsMapToolIdentify::identifyProgress	(	int	,
		int
	)

signal

Referenced by identify().

bool QgsMapToolIdentify::identifyRasterLayer	(	QList< IdentifyResult > *	results,
		QgsRasterLayer *	layer,
		QgsPoint	point,
		QgsRectangle	viewExtent,
		double	mapUnitsPerPixel
	)