QgsMapMouseEvent class

A QgsMapMouseEvent is the result of a user interaction with the mouse on a QgsMapCanvas.

Reference
- Constructors, destructors, conversion operators
- Public functions

It is sent whenever the user moves, clicks, releases or double clicks the mouse. In addition to the coordinates in pixel space it also knows the coordinates in the mapcanvas' CRS as well as it knows the concept of snapping.

Constructors, destructors, conversion operators

QgsMapMouseEvent(QgsMapCanvas* mapCanvas, QMouseEvent* event): Creates a new QgsMapMouseEvent.
QgsMapMouseEvent(QgsMapCanvas* mapCanvas, QEvent::Type type, QPoint pos, Qt::MouseButton button = Qt::NoButton, Qt::MouseButtons buttons = Qt::NoButton, Qt::KeyboardModifiers modifiers = Qt::NoModifier): Creates a new QgsMapMouseEvent.

Public functions

auto isSnapped() const -> bool: Returns true if there is a snapped point cached.
auto mapPoint() const -> QgsPointXY: mapPoint returns the point in coordinates
auto mapPointMatch() const -> QgsPointLocator::Match: Returns the matching data from the most recently snapped point.
auto originalMapPoint() const -> QgsPointXY: Returns the original, unmodified map point of the mouse cursor.
auto originalPixelPoint() const -> QPoint: The unsnapped, real mouse cursor position in pixel coordinates.
auto pixelPoint() const -> QPoint: The snapped mouse cursor in pixel coordinates.
void setMapPoint(const QgsPointXY& point): Set the (snapped) point this event points to in map coordinates.
auto snapPoint() -> QgsPointXY: snapPoint will snap the points using the map canvas snapping utils configuration
void snapToGrid(double precision, const QgsCoordinateReferenceSystem& crs): Snaps the mapPoint to a grid with the given precision.

Function documentation

QgsMapMouseEvent::QgsMapMouseEvent(QgsMapCanvas* mapCanvas, QMouseEvent* event)

Creates a new QgsMapMouseEvent.

Parameters
mapCanvas	The map canvas on which the event occurred
event	The original mouse event

Should only be required to be called from the QgsMapCanvas.

QgsMapMouseEvent::QgsMapMouseEvent(QgsMapCanvas* mapCanvas, QEvent::Type type, QPoint pos, Qt::MouseButton button = Qt::NoButton, Qt::MouseButtons buttons = Qt::NoButton, Qt::KeyboardModifiers modifiers = Qt::NoModifier)

Creates a new QgsMapMouseEvent.

Parameters
mapCanvas	The map canvas on which the event occurred
type	The type of the event
pos	The pixel position of the mouse
button	The pressed button
buttons	Further buttons that are pressed
modifiers	Keyboard modifiers

Should only be required to be called from the QgsMapCanvas.

bool QgsMapMouseEvent::isSnapped() const

Returns true if there is a snapped point cached.

Returns	True if there is a snapped point cached.

Will only be useful after snapPoint has previously been called.

QgsPointXY QgsMapMouseEvent::mapPoint() const

mapPoint returns the point in coordinates

Returns	the point in map coordinates, after snapping if requested in the event.

QgsPointLocator::Match QgsMapMouseEvent::mapPointMatch() const

Returns the matching data from the most recently snapped point.

Returns	the snapping data structure

QgsPointXY QgsMapMouseEvent::originalMapPoint() const

Returns the original, unmodified map point of the mouse cursor.

Returns	The cursor position in map coordinates.

QPoint QgsMapMouseEvent::originalPixelPoint() const

The unsnapped, real mouse cursor position in pixel coordinates.

Returns	Mouse position in pixel coordinates

Alias to pos()

QPoint QgsMapMouseEvent::pixelPoint() const

The snapped mouse cursor in pixel coordinates.

Returns	The snapped mouse cursor position in pixel coordinates.

void QgsMapMouseEvent::setMapPoint(const QgsPointXY& point)

Set the (snapped) point this event points to in map coordinates.

Parameters
point	The point in map coordinates

The point in pixel coordinates will be calculated accordingly.

QgsPointXY QgsMapMouseEvent::snapPoint()

snapPoint will snap the points using the map canvas snapping utils configuration

void QgsMapMouseEvent::snapToGrid(double precision, const QgsCoordinateReferenceSystem& crs)

Snaps the mapPoint to a grid with the given precision.

The snapping will be done in the specified crs. If this crs is different from the mapCanvas crs, it will be reprojected on the fly.