QGIS API Documentation  3.6.0-Noosa (5873452)
Classes | Signals | Public Member Functions | List of all members
QgsMeshLayer Class Reference

Represents a mesh layer supporting display of data on structured or unstructured meshes. More...

#include <qgsmeshlayer.h>

Inheritance diagram for QgsMeshLayer:
Inheritance graph
[legend]

Classes

struct  LayerOptions
 Setting options for loading mesh layers. More...
 

Signals

void activeScalarDatasetChanged (const QgsMeshDatasetIndex &index)
 Emitted when active scalar dataset is changed. More...
 
void activeVectorDatasetChanged (const QgsMeshDatasetIndex &index)
 Emitted when active vector dataset is changed. More...
 
- Signals inherited from QgsMapLayer
void autoRefreshIntervalChanged (int interval)
 Emitted when the auto refresh interval changes. More...
 
void blendModeChanged (QPainter::CompositionMode blendMode)
 Signal emitted when the blend mode is changed, through QgsMapLayer::setBlendMode() More...
 
void configChanged ()
 Emitted whenever the configuration is changed. More...
 
void crsChanged ()
 Emit a signal that layer's CRS has been reset. More...
 
void dataChanged ()
 Data of layer changed. More...
 
void dataSourceChanged ()
 Emitted whenever the layer's data source has been changed. More...
 
void dependenciesChanged ()
 Emitted when dependencies are changed. More...
 
void flagsChanged ()
 Emitted when layer's flags have been modified. More...
 
void legendChanged ()
 Signal emitted when legend of the layer has changed. More...
 
void metadataChanged ()
 Emitted when the layer's metadata is changed. More...
 
void nameChanged ()
 Emitted when the name has been changed. More...
 
void recalculateExtents () const
 This is used to send a request that any mapcanvas using this layer update its extents. More...
 
void renderer3DChanged ()
 Signal emitted when 3D renderer associated with the layer has changed. More...
 
void rendererChanged ()
 Signal emitted when renderer is changed. More...
 
void repaintRequested (bool deferredUpdate=false)
 By emitting this signal the layer tells that either appearance or content have been changed and any view showing the rendered layer should refresh itself. More...
 
void statusChanged (const QString &status)
 Emit a signal with status (e.g. to be caught by QgisApp and display a msg on status bar) More...
 
void styleChanged ()
 Signal emitted whenever a change affects the layer's style. More...
 
void willBeDeleted ()
 Emitted in the destructor when the layer is about to be deleted, but it is still in a perfectly valid state: the last chance for other pieces of code for some cleanup if they use the layer. More...
 

Public Member Functions

 QgsMeshLayer (const QString &path=QString(), const QString &baseName=QString(), const QString &providerLib="mesh_memory", const QgsMeshLayer::LayerOptions &options=QgsMeshLayer::LayerOptions())
 Constructor - creates a mesh layer. More...
 
 QgsMeshLayer (const QgsMeshLayer &rhs)=delete
 QgsMeshLayer cannot be copied. More...
 
 ~QgsMeshLayer () override
 
QgsMeshLayerclone () const override
 Returns a new instance equivalent to this one except for the id which is still unique. More...
 
QgsMapLayerRenderercreateMapRenderer (QgsRenderContext &rendererContext) override
 Returns new instance of QgsMapLayerRenderer that will be used for rendering of given context. More...
 
QgsMeshDataProviderdataProvider () override
 Returns the layer's data provider, it may be null. More...
 
const QgsMeshDataProviderdataProvider () const override
 Returns the layer's data provider in a const-correct manner, it may be null. More...
 
QgsMeshDatasetValue datasetValue (const QgsMeshDatasetIndex &index, const QgsPointXY &point) const
 Interpolates the value on the given point from given dataset. More...
 
QString decodedSource (const QString &source, const QString &provider, const QgsReadWriteContext &context) const override
 Called by readLayerXML(), used by derived classes to decode provider's specific data source from project files. More...
 
QString encodedSource (const QString &source, const QgsReadWriteContext &context) const override
 Called by writeLayerXML(), used by derived classes to encode provider's specific data source to project files. More...
 
QgsRectangle extent () const override
 Returns the extent of the layer. More...
 
QgsMeshnativeMesh ()
 Returns native mesh (nullptr before rendering) More...
 
const QgsMeshnativeMesh () const
 Returns native mesh (nullptr before rendering) More...
 
QgsMeshLayeroperator= (QgsMeshLayer const &rhs)=delete
 QgsMeshLayer cannot be copied. More...
 
QString providerType () const
 Returns the provider type for this layer. More...
 
bool readSymbology (const QDomNode &node, QString &errorMessage, QgsReadWriteContext &context, QgsMapLayer::StyleCategories categories=QgsMapLayer::AllStyleCategories) override
 
bool readXml (const QDomNode &layer_node, QgsReadWriteContext &context) override
 Called by readLayerXML(), used by children to read state specific to them from project files. More...
 
QgsMeshLayerRendererCache * rendererCache ()
 Returns native mesh (nullptr before rendering) More...
 
QgsMeshRendererSettings rendererSettings () const
 Returns renderer settings. More...
 
void setRendererSettings (const QgsMeshRendererSettings &settings)
 Sets new renderer settings. More...
 
QgsTriangularMeshtriangularMesh ()
 Returns triangular mesh (nullptr before rendering) More...
 
const QgsTriangularMeshtriangularMesh () const
 Returns triangular mesh (nullptr before rendering) More...
 
bool writeSymbology (QDomNode &node, QDomDocument &doc, QString &errorMessage, const QgsReadWriteContext &context, QgsMapLayer::StyleCategories categories=QgsMapLayer::AllStyleCategories) const override
 
bool writeXml (QDomNode &layer_node, QDomDocument &doc, const QgsReadWriteContext &context) const override
 Called by writeLayerXML(), used by children to write state specific to them to project files. More...
 
- Public Member Functions inherited from QgsMapLayer
 QgsMapLayer (QgsMapLayer::LayerType type=VectorLayer, const QString &name=QString(), const QString &source=QString())
 Constructor for QgsMapLayer. More...
 
 QgsMapLayer (QgsMapLayer const &)=delete
 QgsMapLayer cannot be copied. More...
 
 ~QgsMapLayer () override
 
QString abstract () const
 Returns the abstract of the layer used by QGIS Server in GetCapabilities request. More...
 
QString attribution () const
 Returns the attribution of the layer used by QGIS Server in GetCapabilities request. More...
 
QString attributionUrl () const
 Returns the attribution URL of the layer used by QGIS Server in GetCapabilities request. More...
 
int autoRefreshInterval () const
 Returns the auto refresh interval (in milliseconds). More...
 
QPainter::CompositionMode blendMode () const
 Returns the current blending mode for a layer. More...
 
QgsCoordinateReferenceSystem crs () const
 Returns the layer's spatial reference system. More...
 
QVariant customProperty (const QString &value, const QVariant &defaultValue=QVariant()) const
 Read a custom property from layer. More...
 
QStringList customPropertyKeys () const
 Returns list of all keys within custom properties. More...
 
QString dataUrl () const
 Returns the DataUrl of the layer used by QGIS Server in GetCapabilities request. More...
 
QString dataUrlFormat () const
 Returns the DataUrl format of the layer used by QGIS Server in GetCapabilities request. More...
 
virtual QSet< QgsMapLayerDependencydependencies () const
 Gets the list of dependencies. More...
 
virtual QgsError error () const
 Gets current status error. More...
 
void exportNamedMetadata (QDomDocument &doc, QString &errorMsg) const
 Export the current metadata of this layer as named metadata in a QDomDocument. More...
 
virtual void exportNamedStyle (QDomDocument &doc, QString &errorMsg, const QgsReadWriteContext &context=QgsReadWriteContext(), QgsMapLayer::StyleCategories categories=QgsMapLayer::AllStyleCategories) const
 Export the properties of this layer as named style in a QDomDocument. More...
 
virtual void exportSldStyle (QDomDocument &doc, QString &errorMsg) const
 Export the properties of this layer as SLD style in a QDomDocument. More...
 
QgsMapLayer::LayerFlags flags () const
 Returns the flags for this layer. More...
 
bool hasAutoRefreshEnabled () const
 Returns true if auto refresh is enabled for the layer. More...
 
bool hasScaleBasedVisibility () const
 Returns whether scale based visibility is enabled for the layer. More...
 
virtual QString htmlMetadata () const
 Obtain a formatted HTML string containing assorted metadata for this layer. More...
 
QString id () const
 Returns the layer's unique ID, which is used to access this layer from QgsProject. More...
 
bool importNamedMetadata (QDomDocument &document, QString &errorMessage)
 Import the metadata of this layer from a QDomDocument. More...
 
virtual bool importNamedStyle (QDomDocument &doc, QString &errorMsg, QgsMapLayer::StyleCategories categories=QgsMapLayer::AllStyleCategories)
 Import the properties of this layer from a QDomDocument. More...
 
virtual bool isEditable () const
 Returns true if the layer can be edited. More...
 
bool isInScaleRange (double scale) const
 Tests whether the layer should be visible at the specified scale. More...
 
bool isRefreshOnNotifyEnabled () const
 Returns true if the refresh on provider nofification is enabled. More...
 
virtual bool isSpatial () const
 Returns true if the layer is considered a spatial layer, ie it has some form of geometry associated with it. More...
 
bool isValid () const
 Returns the status of the layer. More...
 
QString keywordList () const
 Returns the keyword list of the layer used by QGIS Server in GetCapabilities request. More...
 
QgsMapLayerLegendlegend () const
 Can be null. More...
 
QString legendUrl () const
 Returns the URL for the layer's legend. More...
 
QString legendUrlFormat () const
 Returns the format for a URL based layer legend. More...
 
QString loadDefaultMetadata (bool &resultFlag)
 Retrieve the default metadata for this layer if one exists (either as a .qmd file on disk or as a record in the users metadata table in their personal qgis.db) More...
 
virtual QString loadDefaultStyle (bool &resultFlag)
 Retrieve the default style for this layer if one exists (either as a .qml file on disk or as a record in the users style table in their personal qgis.db) More...
 
virtual QString loadNamedMetadata (const QString &uri, bool &resultFlag)
 Retrieve a named metadata for this layer if one exists (either as a .qmd file on disk or as a record in the users style table in their personal qgis.db) More...
 
bool loadNamedMetadataFromDatabase (const QString &db, const QString &uri, QString &qmd)
 Retrieve a named metadata for this layer from a sqlite database. More...
 
virtual QString loadNamedStyle (const QString &uri, bool &resultFlag, QgsMapLayer::StyleCategories categories=QgsMapLayer::AllStyleCategories)
 Retrieve a named style for this layer if one exists (either as a .qml file on disk or as a record in the users style table in their personal qgis.db) More...
 
virtual bool loadNamedStyleFromDatabase (const QString &db, const QString &uri, QString &qml)
 Retrieve a named style for this layer from a sqlite database. More...
 
virtual QString loadSldStyle (const QString &uri, bool &resultFlag)
 Attempts to style the layer using the formatting from an SLD type file. More...
 
double maximumScale () const
 Returns the maximum map scale (i.e. More...
 
virtual const QgsLayerMetadatametadata () const
 Returns a reference to the layer's metadata store. More...
 
virtual QString metadataUri () const
 Retrieve the metadata URI for this layer (either as a .qmd file on disk or as a record in the users style table in their personal qgis.db) More...
 
QString metadataUrl () const
 Returns the metadata URL of the layer used by QGIS Server in GetCapabilities request. More...
 
QString metadataUrlFormat () const
 Returns the metadata format of the layer used by QGIS Server in GetCapabilities request. More...
 
QString metadataUrlType () const
 Returns the metadata type of the layer used by QGIS Server in GetCapabilities request. More...
 
double minimumScale () const
 Returns the minimum map scale (i.e. More...
 
QString name () const
 Returns the display name of the layer. More...
 
QgsMapLayeroperator= (QgsMapLayer const &)=delete
 QgsMapLayer cannot be copied. More...
 
QString originalXmlProperties () const
 Returns the XML properties of the original layer as they were when the layer was first read from the project file. More...
 
QString providerType () const
 Returns the provider type (provider key) for this layer. More...
 
QString publicSource () const
 Gets a version of the internal layer definition that has sensitive bits removed (for example, the password). More...
 
bool readLayerXml (const QDomElement &layerElement, QgsReadWriteContext &context)
 Sets state from DOM document. More...
 
bool readOnly () const
 Returns if this layer is read only. More...
 
virtual bool readSld (const QDomNode &node, QString &errorMessage)
 
virtual bool readStyle (const QDomNode &node, QString &errorMessage, QgsReadWriteContext &context, StyleCategories categories=AllStyleCategories)
 Read the style for the current layer from the DOM node supplied. More...
 
virtual bool readSymbology (const QDomNode &node, QString &errorMessage, QgsReadWriteContext &context, StyleCategories categories=AllStyleCategories)=0
 Read the symbology for the current layer from the DOM node supplied. More...
 
QString refreshOnNotifyMessage () const
 Returns the message that should be notified by the provider to triggerRepaint. More...
 
virtual void reload ()
 Synchronises with changes in the datasource. More...
 
void removeCustomProperty (const QString &key)
 Remove a custom property from layer. More...
 
QgsAbstract3DRendererrenderer3D () const
 Returns 3D renderer associated with the layer. More...
 
virtual void resolveReferences (QgsProject *project)
 Resolve references to other layers (kept as layer IDs after reading XML) into layer objects. More...
 
virtual QString saveDefaultMetadata (bool &resultFlag)
 Save the current metadata of this layer as the default metadata (either as a .qmd file on disk or as a record in the users style table in their personal qgis.db) More...
 
virtual QString saveDefaultStyle (bool &resultFlag)
 Save the properties of this layer as the default style (either as a .qml file on disk or as a record in the users style table in their personal qgis.db) More...
 
QString saveNamedMetadata (const QString &uri, bool &resultFlag)
 Save the current metadata of this layer as a named metadata (either as a .qmd file on disk or as a record in the users style table in their personal qgis.db) More...
 
virtual QString saveNamedStyle (const QString &uri, bool &resultFlag, StyleCategories categories=AllStyleCategories)
 Save the properties of this layer as a named style (either as a .qml file on disk or as a record in the users style table in their personal qgis.db) More...
 
virtual QString saveSldStyle (const QString &uri, bool &resultFlag) const
 Saves the properties of this layer to an SLD format file. More...
 
void setAbstract (const QString &abstract)
 Sets the abstract of the layer used by QGIS Server in GetCapabilities request. More...
 
void setAttribution (const QString &attrib)
 Sets the attribution of the layer used by QGIS Server in GetCapabilities request. More...
 
void setAttributionUrl (const QString &attribUrl)
 Sets the attribution URL of the layer used by QGIS Server in GetCapabilities request. More...
 
void setAutoRefreshEnabled (bool enabled)
 Sets whether auto refresh is enabled for the layer. More...
 
void setAutoRefreshInterval (int interval)
 Sets the auto refresh interval (in milliseconds) for the layer. More...
 
void setBlendMode (QPainter::CompositionMode blendMode)
 Set the blending mode used for rendering a layer. More...
 
void setCrs (const QgsCoordinateReferenceSystem &srs, bool emitSignal=true)
 Sets layer's spatial reference system. More...
 
void setCustomProperties (const QgsObjectCustomProperties &properties)
 Set custom properties for layer. More...
 
void setCustomProperty (const QString &key, const QVariant &value)
 Set a custom property for layer. More...
 
virtual void setDataSource (const QString &dataSource, const QString &baseName, const QString &provider, const QgsDataProvider::ProviderOptions &options, bool loadDefaultStyleFlag=false)
 Updates the data source of the layer. More...
 
void setDataUrl (const QString &dataUrl)
 Sets the DataUrl of the layer used by QGIS Server in GetCapabilities request. More...
 
void setDataUrlFormat (const QString &dataUrlFormat)
 Sets the DataUrl format of the layer used by QGIS Server in GetCapabilities request. More...
 
void setFlags (QgsMapLayer::LayerFlags flags)
 Returns the flags for this layer. More...
 
void setKeywordList (const QString &keywords)
 Sets the keyword list of the layer used by QGIS Server in GetCapabilities request. More...
 
virtual void setLayerOrder (const QStringList &layers)
 Reorders the previously selected sublayers of this layer from bottom to top. More...
 
void setLegend (QgsMapLayerLegend *legend)
 Assign a legend controller to the map layer. More...
 
void setLegendUrl (const QString &legendUrl)
 Sets the URL for the layer's legend. More...
 
void setLegendUrlFormat (const QString &legendUrlFormat)
 Sets the format for a URL based layer legend. More...
 
virtual void setMetadata (const QgsLayerMetadata &metadata)
 Sets the layer's metadata store. More...
 
void setMetadataUrl (const QString &metaUrl)
 Sets the metadata URL of the layer used by QGIS Server in GetCapabilities request. More...
 
void setMetadataUrlFormat (const QString &metaUrlFormat)
 Sets the metadata format of the layer used by QGIS Server in GetCapabilities request. More...
 
void setMetadataUrlType (const QString &metaUrlType)
 Set the metadata type of the layer used by QGIS Server in GetCapabilities request MetadataUrlType indicates the standard to which the metadata complies. More...
 
void setName (const QString &name)
 Set the display name of the layer. More...
 
void setOriginalXmlProperties (const QString &originalXmlProperties)
 Sets the original XML properties for the layer to originalXmlProperties. More...
 
void setRenderer3D (QgsAbstract3DRenderer *renderer)
 Sets 3D renderer for the layer. More...
 
void setShortName (const QString &shortName)
 Sets the short name of the layer used by QGIS Server to identify the layer. More...
 
virtual void setSubLayerVisibility (const QString &name, bool visible)
 Set the visibility of the given sublayer name. More...
 
void setTitle (const QString &title)
 Sets the title of the layer used by QGIS Server in GetCapabilities request. More...
 
QString shortName () const
 Returns the short name of the layer used by QGIS Server to identify the layer. More...
 
QString source () const
 Returns the source for the layer. More...
 
QgsMapLayerStyleManagerstyleManager () const
 Gets access to the layer's style manager. More...
 
virtual QString styleURI () const
 Retrieve the style URI for this layer (either as a .qml file on disk or as a record in the users style table in their personal qgis.db) More...
 
virtual QStringList subLayers () const
 Returns the sublayers of this layer. More...
 
virtual QDateTime timestamp () const
 Time stamp of data source in the moment when data/metadata were loaded by provider. More...
 
QString title () const
 Returns the title of the layer used by QGIS Server in GetCapabilities request. More...
 
QgsMapLayer::LayerType type () const
 Returns the type of the layer. More...
 
QUndoStack * undoStack ()
 Returns pointer to layer's undo stack. More...
 
QUndoStack * undoStackStyles ()
 Returns pointer to layer's style undo stack. More...
 
bool writeLayerXml (QDomElement &layerElement, QDomDocument &document, const QgsReadWriteContext &context) const
 Stores state in DOM node. More...
 
virtual bool writeStyle (QDomNode &node, QDomDocument &doc, QString &errorMessage, const QgsReadWriteContext &context, StyleCategories categories=AllStyleCategories) const
 Write just the symbology information for the layer into the document. More...
 
virtual bool writeSymbology (QDomNode &node, QDomDocument &doc, QString &errorMessage, const QgsReadWriteContext &context, StyleCategories categories=AllStyleCategories) const =0
 Write the style for the layer into the docment provided. More...
 

Additional Inherited Members

- Public Types inherited from QgsMapLayer
enum  LayerFlag { Identifiable = 1 << 0, Removable = 1 << 1, Searchable = 1 << 2 }
 Flags for the map layer. More...
 
enum  LayerType { VectorLayer, RasterLayer, PluginLayer, MeshLayer }
 Types of layers that can be added to a map. More...
 
enum  PropertyType { Style = 0, Metadata }
 Maplayer has a style and a metadata property. More...
 
enum  StyleCategory {
  LayerConfiguration = 1 << 0, Symbology = 1 << 1, Symbology3D = 1 << 2, Labeling = 1 << 3,
  Fields = 1 << 4, Forms = 1 << 5, Actions = 1 << 6, MapTips = 1 << 7,
  Diagrams = 1 << 8, AttributeTable = 1 << 9, Rendering = 1 << 10, CustomProperties = 1 << 11,
  GeometryOptions = 1 << 12, AllStyleCategories
}
 Categories of style to distinguish appropriate sections for import/export. More...
 
- Public Slots inherited from QgsMapLayer
void emitStyleChanged ()
 Triggers an emission of the styleChanged() signal. More...
 
virtual bool setDependencies (const QSet< QgsMapLayerDependency > &layers)
 Sets the list of dependencies. More...
 
void setMaximumScale (double scale)
 Sets the maximum map scale (i.e. More...
 
void setMinimumScale (double scale)
 Sets the minimum map scale (i.e. More...
 
void setRefreshOnNofifyMessage (const QString &message)
 Set the notification message that triggers repaine If refresh on notification is enabled, the notification will triggerRepaint only if the notification message is equal to. More...
 
void setRefreshOnNotifyEnabled (bool enabled)
 Set whether provider notification is connected to triggerRepaint. More...
 
void setScaleBasedVisibility (bool enabled)
 Sets whether scale based visibility is enabled for the layer. More...
 
void triggerRepaint (bool deferredUpdate=false)
 Will advise the map canvas (and any other interested party) that this layer requires to be repainted. More...
 
- Static Public Member Functions inherited from QgsMapLayer
static QString extensionPropertyType (PropertyType type)
 Returns the extension of a Property. More...
 
static QString formatLayerName (const QString &name)
 A convenience function to capitalize and format a layer name. More...
 
- Protected Member Functions inherited from QgsMapLayer
void appendError (const QgsErrorMessage &error)
 Add error message. More...
 
void clone (QgsMapLayer *layer) const
 Copies attributes like name, short name, ... More...
 
bool hasDependencyCycle (const QSet< QgsMapLayerDependency > &layers) const
 Checks whether a new set of dependencies will introduce a cycle. More...
 
void readCommonStyle (const QDomElement &layerElement, const QgsReadWriteContext &context, StyleCategories categories=AllStyleCategories)
 Read style data common to all layer types. More...
 
void readCustomProperties (const QDomNode &layerNode, const QString &keyStartsWith=QString())
 Read custom properties from project file. More...
 
void readStyleManager (const QDomNode &layerNode)
 Read style manager's configuration (if any). To be called by subclasses. More...
 
void setError (const QgsError &error)
 Sets error message. More...
 
virtual void setExtent (const QgsRectangle &rect)
 Sets the extent. More...
 
void setProviderType (const QString &providerType)
 Sets the providerType (provider key) More...
 
void setValid (bool valid)
 Sets whether layer is valid or not - should be used in constructor. More...
 
void writeCommonStyle (QDomElement &layerElement, QDomDocument &document, const QgsReadWriteContext &context, StyleCategories categories=AllStyleCategories) const
 Write style data common to all layer types. More...
 
void writeCustomProperties (QDomNode &layerNode, QDomDocument &doc) const
 Write custom properties to project file. More...
 
void writeStyleManager (QDomNode &layerNode, QDomDocument &doc) const
 Write style manager's configuration (if exists). To be called by subclasses. More...
 
- Protected Attributes inherited from QgsMapLayer
QString mAbstract
 Description of the layer. More...
 
QString mAttribution
 Attribution of the layer. More...
 
QString mAttributionUrl
 
QString mDataSource
 Data source description string, varies by layer type. More...
 
QString mDataUrl
 DataUrl of the layer. More...
 
QString mDataUrlFormat
 
QSet< QgsMapLayerDependencymDependencies
 List of layers that may modify this layer on modification. More...
 
QgsError mError
 Error. More...
 
QgsRectangle mExtent
 Extent of the layer. More...
 
bool mIsRefreshOnNofifyEnabled = false
 
QString mKeywordList
 
QString mLayerName
 Name of the layer - used for display. More...
 
QString mLegendUrl
 WMS legend. More...
 
QString mLegendUrlFormat
 
QString mMetadataUrl
 MetadataUrl of the layer. More...
 
QString mMetadataUrlFormat
 
QString mMetadataUrlType
 
QString mProviderKey
 Data provider key (name of the data provider) More...
 
QString mRefreshOnNofifyMessage
 
QString mShortName
 
QString mTitle
 
bool mValid = false
 Indicates if the layer is valid and can be drawn. More...
 
- Properties inherited from QgsMapLayer
int autoRefreshInterval
 
QgsCoordinateReferenceSystem crs
 
QgsLayerMetadata metadata
 
QString name
 

Detailed Description

Represents a mesh layer supporting display of data on structured or unstructured meshes.

The QgsMeshLayer is instantiated by specifying the name of a data provider, such as mdal, and url defining the specific data set to connect to. The vector layer constructor in turn instantiates a QgsMeshDataProvider subclass corresponding to the provider type, and passes it the url. The data provider connects to the data source.

The QgsMeshLayer provides a common interface to the different data types. It does not yet support editing transactions.

The main data providers supported by QGIS are listed below.

Mesh data providers

Memory data providerType (mesh_memory)

The memory data provider is used to construct in memory data, for example scratch data. There is no inherent persistent storage of the data. The data source uri is constructed. Data can be populated by setMesh(const QString &vertices, const QString &faces), where vertices and faces is comma separated coordinates and connections for mesh. E.g. to create mesh with one quad and one triangle

QString uri(
"1.0, 2.0 \n" \
"2.0, 2.0 \n" \
"3.0, 2.0 \n" \
"2.0, 3.0 \n" \
"1.0, 3.0 \n" \
"---"
"0, 1, 3, 4 \n" \
"1, 2, 3 \n"
);
QgsMeshLayer *scratchLayer = new QgsMeshLayer(uri, "My Scratch layer", "memory_mesh");

MDAL data provider (mdal)

Accesses data using the MDAL drivers (https://github.com/lutraconsulting/MDAL). The url is the MDAL connection string. QGIS must be built with MDAL support to allow this provider.

QString uri = "test/land.2dm";
QgsMeshLayer *scratchLayer = new QgsMeshLayer(uri, "My Scratch Layer", "mdal");
Note
The API is considered EXPERIMENTAL and can be changed without a notice
Since
QGIS 3.2

Definition at line 89 of file qgsmeshlayer.h.

Constructor & Destructor Documentation

◆ QgsMeshLayer() [1/2]

QgsMeshLayer::QgsMeshLayer ( const QString &  path = QString(),
const QString &  baseName = QString(),
const QString &  providerLib = "mesh_memory",
const QgsMeshLayer::LayerOptions options = QgsMeshLayer::LayerOptions() 
)
explicit

Constructor - creates a mesh layer.

The QgsMeshLayer is constructed by instantiating a data provider. The provider interprets the supplied path (url) of the data source to connect to and access the data.

Parameters
pathThe path or url of the parameter. Typically this encodes parameters used by the data provider as url query items.
baseNameThe name used to represent the layer in the legend
providerLibThe name of the data provider, e.g., "mesh_memory", "mdal"
optionsgeneral mesh layer options

Definition at line 37 of file qgsmeshlayer.cpp.

◆ ~QgsMeshLayer()

QgsMeshLayer::~QgsMeshLayer ( )
override

Definition at line 71 of file qgsmeshlayer.cpp.

◆ QgsMeshLayer() [2/2]

QgsMeshLayer::QgsMeshLayer ( const QgsMeshLayer rhs)
delete

QgsMeshLayer cannot be copied.

Member Function Documentation

◆ activeScalarDatasetChanged

void QgsMeshLayer::activeScalarDatasetChanged ( const QgsMeshDatasetIndex index)
signal

Emitted when active scalar dataset is changed.

Since
QGIS 3.4

◆ activeVectorDatasetChanged

void QgsMeshLayer::activeVectorDatasetChanged ( const QgsMeshDatasetIndex index)
signal

Emitted when active vector dataset is changed.

Since
QGIS 3.4

◆ clone()

QgsMeshLayer * QgsMeshLayer::clone ( ) const
overridevirtual

Returns a new instance equivalent to this one except for the id which is still unique.

Returns
a new layer instance
Since
QGIS 3.0

Implements QgsMapLayer.

Definition at line 86 of file qgsmeshlayer.cpp.

◆ createMapRenderer()

QgsMapLayerRenderer * QgsMeshLayer::createMapRenderer ( QgsRenderContext rendererContext)
overridevirtual

Returns new instance of QgsMapLayerRenderer that will be used for rendering of given context.

Since
QGIS 2.4

Implements QgsMapLayer.

Definition at line 248 of file qgsmeshlayer.cpp.

◆ dataProvider() [1/2]

QgsMeshDataProvider * QgsMeshLayer::dataProvider ( )
overridevirtual

Returns the layer's data provider, it may be null.

Reimplemented from QgsMapLayer.

Definition at line 76 of file qgsmeshlayer.cpp.

◆ dataProvider() [2/2]

const QgsMeshDataProvider * QgsMeshLayer::dataProvider ( ) const
overridevirtual

Returns the layer's data provider in a const-correct manner, it may be null.

Note
not available in Python bindings

Reimplemented from QgsMapLayer.

Definition at line 81 of file qgsmeshlayer.cpp.

◆ datasetValue()

QgsMeshDatasetValue QgsMeshLayer::datasetValue ( const QgsMeshDatasetIndex index,
const QgsPointXY point 
) const

Interpolates the value on the given point from given dataset.

Note
It uses previously cached and indexed triangular mesh and so if the layer has not been rendered previously (e.g. when used in a script) it returns NaN value
Parameters
indexdataset index specifying group and dataset to extract value from
pointpoint to query in map coordinates
Returns
interpolated value at the point. Returns NaN values for values outside the mesh layer, nodata values and in case triangular mesh was not previously used for rendering
Since
QGIS 3.4

Definition at line 147 of file qgsmeshlayer.cpp.

◆ decodedSource()

QString QgsMeshLayer::decodedSource ( const QString &  source,
const QString &  dataProvider,
const QgsReadWriteContext context 
) const
overridevirtual

Called by readLayerXML(), used by derived classes to decode provider's specific data source from project files.

Typically resolving absolute or relative paths, usernames and passwords or drivers prefixes ("HDF5:")

Parameters
sourcedata source to decode, typically read from layer's DOM element "datasource"
dataProviderstring identification of data provider (e.g. "ogr"), typically read from layer's DOM element
contextreading context (e.g. for conversion between relative and absolute paths)
Returns
decoded source, typically to be used as the layer's datasource
Since
QGIS 3.2

Reimplemented from QgsMapLayer.

Definition at line 317 of file qgsmeshlayer.cpp.

◆ encodedSource()

QString QgsMeshLayer::encodedSource ( const QString &  source,
const QgsReadWriteContext context 
) const
overridevirtual

Called by writeLayerXML(), used by derived classes to encode provider's specific data source to project files.

Typically resolving absolute or relative paths, usernames and passwords or drivers prefixes ("HDF5:")

Parameters
sourcedata source to encode, typically QgsMapLayer::source()
contextwriting context (e.g. for conversion between relative and absolute paths)
Returns
encoded source, typically to be written in the DOM element "datasource"
Since
QGIS 3.2

Reimplemented from QgsMapLayer.

Definition at line 327 of file qgsmeshlayer.cpp.

◆ extent()

QgsRectangle QgsMeshLayer::extent ( ) const
overridevirtual

Returns the extent of the layer.

Reimplemented from QgsMapLayer.

Definition at line 93 of file qgsmeshlayer.cpp.

◆ nativeMesh() [1/2]

QgsMesh * QgsMeshLayer::nativeMesh ( )

Returns native mesh (nullptr before rendering)

Note
Not available in Python bindings

Definition at line 110 of file qgsmeshlayer.cpp.

◆ nativeMesh() [2/2]

const QgsMesh * QgsMeshLayer::nativeMesh ( ) const

Returns native mesh (nullptr before rendering)

Note
Not available in Python bindings

Definition at line 115 of file qgsmeshlayer.cpp.

◆ operator=()

QgsMeshLayer& QgsMeshLayer::operator= ( QgsMeshLayer const &  rhs)
delete

QgsMeshLayer cannot be copied.

◆ providerType()

QString QgsMeshLayer::providerType ( ) const

Returns the provider type for this layer.

Definition at line 105 of file qgsmeshlayer.cpp.

◆ readSymbology()

bool QgsMeshLayer::readSymbology ( const QDomNode &  node,
QString &  errorMessage,
QgsReadWriteContext context,
QgsMapLayer::StyleCategories  categories = QgsMapLayer::AllStyleCategories 
)
override

Definition at line 270 of file qgsmeshlayer.cpp.

◆ readXml()

bool QgsMeshLayer::readXml ( const QDomNode &  layer_node,
QgsReadWriteContext context 
)
overridevirtual

Called by readLayerXML(), used by children to read state specific to them from project files.

Reimplemented from QgsMapLayer.

Definition at line 337 of file qgsmeshlayer.cpp.

◆ rendererCache()

QgsMeshLayerRendererCache * QgsMeshLayer::rendererCache ( )

Returns native mesh (nullptr before rendering)

Note
Not available in Python bindings

Definition at line 130 of file qgsmeshlayer.cpp.

◆ rendererSettings()

QgsMeshRendererSettings QgsMeshLayer::rendererSettings ( ) const

Returns renderer settings.

Definition at line 135 of file qgsmeshlayer.cpp.

◆ setRendererSettings()

void QgsMeshLayer::setRendererSettings ( const QgsMeshRendererSettings settings)

Sets new renderer settings.

Definition at line 140 of file qgsmeshlayer.cpp.

◆ triangularMesh() [1/2]

QgsTriangularMesh * QgsMeshLayer::triangularMesh ( )

Returns triangular mesh (nullptr before rendering)

Note
Not available in Python bindings

Definition at line 120 of file qgsmeshlayer.cpp.

◆ triangularMesh() [2/2]

const QgsTriangularMesh * QgsMeshLayer::triangularMesh ( ) const

Returns triangular mesh (nullptr before rendering)

Note
Not available in Python bindings

Definition at line 125 of file qgsmeshlayer.cpp.

◆ writeSymbology()

bool QgsMeshLayer::writeSymbology ( QDomNode &  node,
QDomDocument &  doc,
QString &  errorMessage,
const QgsReadWriteContext context,
QgsMapLayer::StyleCategories  categories = QgsMapLayer::AllStyleCategories 
) const
override

Definition at line 295 of file qgsmeshlayer.cpp.

◆ writeXml()

bool QgsMeshLayer::writeXml ( QDomNode &  layer_node,
QDomDocument &  document,
const QgsReadWriteContext context 
) const
overridevirtual

Called by writeLayerXML(), used by children to write state specific to them to project files.

Reimplemented from QgsMapLayer.

Definition at line 385 of file qgsmeshlayer.cpp.


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