QgsQuickMapSettings class

The QgsQuickMapSettings class encapsulates QgsMapSettings class to offer settings of configuration of map rendering via QML properties.

Contents

On top of QgsMapSettings functionality, when QgsProject is attached, it automatically loads its default settings from the project. QgsProject should be attached before it is read.

Constructors, destructors, conversion operators

QgsQuickMapSettings(QObject* parent = nullptr)
Create new map settings.

Public functions

auto coordinateToScreen(const QgsPoint& point) const -> Q_INVOKABLE QPointF
Convert a map coordinate to screen pixel coordinates.
auto destinationCrs() const -> QgsCoordinateReferenceSystem
returns CRS of destination coordinate reference system
auto extent() const -> QgsRectangle
Returns geographical coordinates of the rectangle that should be rendered.
auto layers() const -> QList<QgsMapLayer*>
Gets list of layers for map rendering The layers are stored in the reverse order of how they are rendered (layer with index 0 will be on top)
auto mapSettings() const -> QgsMapSettings
Clone map settings.
auto mapUnitsPerPixel() const -> double
Returns the distance in geographical coordinates that equals to one pixel in the map.
auto outputDpi() const -> double
Returns DPI used for conversion between real world units (e.g.
auto outputSize() const -> QSize
Returns the size of the resulting map image.
auto project() const -> QgsProject*
A project property should be used as a primary source of project all other components in the application.
auto rotation() const -> double
The rotation of the resulting map image, in degrees clockwise.
auto screenToCoordinate(const QPointF& point) const -> Q_INVOKABLE QgsPoint
Convert a screen coordinate to a map coordinate.
auto setCenter(const QgsPoint& center) -> Q_INVOKABLE void
Move current map extent to have center point defined by center.
void setDestinationCrs(const QgsCoordinateReferenceSystem& destinationCrs)
sets destination coordinate reference system
void setExtent(const QgsRectangle& extent)
Set coordinates of the rectangle which should be rendered.
void setLayers(const QList<QgsMapLayer*>& layers)
Set list of layers for map rendering.
void setOutputDpi(double outputDpi)
Sets DPI used for conversion between real world units (e.g. mm) and pixels.
void setOutputSize(const QSize& outputSize)
Sets the size of the resulting map image.
void setProject(QgsProject* project)
A project property should be used as a primary source of project all other components in the application.
void setRotation(double rotation)
The rotation of the resulting map image, in degrees clockwise.
void setTransformContext(const QgsCoordinateTransformContext& context)
Sets the coordinate transform context, which stores various information regarding which datum transforms should be used when transforming points from a source to destination coordinate reference system.
auto transformContext() const -> Q_INVOKABLE QgsCoordinateTransformContext
Returns the coordinate transform context, which stores various information regarding which datum transforms should be used when transforming points from a source to destination coordinate reference system.
auto visibleExtent() const -> QgsRectangle
Returns the actual extent derived from requested extent that takes takes output image size into account.

Signals

void destinationCrsChanged()
CRS of destination coordinate reference system.
void extentChanged()
Geographical coordinates of the rectangle that should be rendered.
void layersChanged()
Set list of layers for map rendering.
void mapUnitsPerPixelChanged()
Returns the distance in geographical coordinates that equals to one pixel in the map.
void outputDpiChanged()
Output DPI used for conversion between real world units (e.g.
void outputSizeChanged()
The size of the resulting map image.
void projectChanged()
A project property should be used as a primary source of project all other components in the application.
void rotationChanged()
The rotation of the resulting map image, in degrees clockwise.
void visibleExtentChanged()
Returns the actual extent derived from requested extent that takes takes output image size into account.

Function documentation

Q_INVOKABLE QPointF QgsQuickMapSettings::coordinateToScreen(const QgsPoint& point) const

Convert a map coordinate to screen pixel coordinates.

Parameters
point A coordinate in map coordinates
Returns A coordinate in pixel / screen space

QgsRectangle QgsQuickMapSettings::extent() const

Returns geographical coordinates of the rectangle that should be rendered.

The actual visible extent used for rendering could be slightly different since the given extent may be expanded in order to fit the aspect ratio of output size. Use visibleExtent() to get the resulting extent.

double QgsQuickMapSettings::outputDpi() const

Returns DPI used for conversion between real world units (e.g.

mm) and pixels Default value is 96

QgsProject* QgsQuickMapSettings::project() const

A project property should be used as a primary source of project all other components in the application.

QgsProject should be attached to QgsQuickMapSettings before it is read (QgsProject::read)

When project is read, map settings (CRS, extent, ...) are automatically set from its DOM.

double QgsQuickMapSettings::rotation() const

The rotation of the resulting map image, in degrees clockwise.

Map canvas rotation support is not implemented, 0 is used

Q_INVOKABLE QgsPoint QgsQuickMapSettings::screenToCoordinate(const QPointF& point) const

Convert a screen coordinate to a map coordinate.

Parameters
point A coordinate in pixel / screen coordinates
Returns A coordinate in map coordinates

void QgsQuickMapSettings::setExtent(const QgsRectangle& extent)

Set coordinates of the rectangle which should be rendered.

The actual visible extent used for rendering could be slightly different since the given extent may be expanded in order to fit the aspect ratio of output size. Use visibleExtent() to get the resulting extent.

void QgsQuickMapSettings::setLayers(const QList<QgsMapLayer*>& layers)

Set list of layers for map rendering.

The layers must be registered in QgsProject. The layers are stored in the reverse order of how they are rendered (layer with index 0 will be on top)

void QgsQuickMapSettings::setProject(QgsProject* project)

A project property should be used as a primary source of project all other components in the application.

QgsProject should be attached to QgsQuickMapSettings before it is read (QgsProject::read)

When project is read, map settings (CRS, extent, ...) are automatically set from its DOM.

void QgsQuickMapSettings::setRotation(double rotation)

The rotation of the resulting map image, in degrees clockwise.

Map canvas rotation support is not implemented, 0 is used

void QgsQuickMapSettings::setTransformContext(const QgsCoordinateTransformContext& context)

Sets the coordinate transform context, which stores various information regarding which datum transforms should be used when transforming points from a source to destination coordinate reference system.

Q_INVOKABLE QgsCoordinateTransformContext QgsQuickMapSettings::transformContext() const

Returns the coordinate transform context, which stores various information regarding which datum transforms should be used when transforming points from a source to destination coordinate reference system.

void QgsQuickMapSettings::destinationCrsChanged() signal

CRS of destination coordinate reference system.

Automatically loaded from project on QgsProject::readProject

void QgsQuickMapSettings::extentChanged() signal

Geographical coordinates of the rectangle that should be rendered.

The actual visible extent used for rendering could be slightly different since the given extent may be expanded in order to fit the aspect ratio of output size. Use QgsQuickMapSettings::visibleExtent to get the resulting extent.

Automatically loaded from project on QgsProject::readProject

void QgsQuickMapSettings::layersChanged() signal

Set list of layers for map rendering.

The layers must be registered in QgsProject. The layers are stored in the reverse order of how they are rendered (layer with index 0 will be on top)

Not loaded automatically from the associated project

void QgsQuickMapSettings::outputDpiChanged() signal

Output DPI used for conversion between real world units (e.g.

mm) and pixels

Automatically loaded from project on QgsProject::readProject

void QgsQuickMapSettings::outputSizeChanged() signal

The size of the resulting map image.

Automatically loaded from project on QgsProject::readProject

void QgsQuickMapSettings::projectChanged() signal

A project property should be used as a primary source of project all other components in the application.

QgsProject should be attached to QgsQuickMapSettings before it is read (QgsProject::read)

When project is read, map settings (CRS, extent, ...) are automatically set from its DOM.

void QgsQuickMapSettings::rotationChanged() signal

The rotation of the resulting map image, in degrees clockwise.

Map canvas rotation support is not implemented, 0 is used