/** \class QgsMapLayer
* \brief Base class for all map layer types.
* This class is the base class for all map layer types (vector, raster).
*/
class QgsMapLayer : QObject
{
%TypeHeaderCode
#include <qgsmaplayer.h>
%End
%ConvertToSubClassCode
QgsMapLayer* layer = qobject_cast<QgsMapLayer*>( sipCpp );
sipType = 0;
if ( layer )
{
if (layer->type() == QgsMapLayer::VectorLayer)
{
sipType = sipType_QgsVectorLayer;
}
else if (layer->type() == QgsMapLayer::RasterLayer)
{
sipType = sipType_QgsRasterLayer;
}
else if (layer->type() == QgsMapLayer::PluginLayer)
{
sipType = sipType_QgsPluginLayer;
}
}
%End
public:
//! Types of layers that can be added to a map
enum LayerType
{
VectorLayer,
RasterLayer,
PluginLayer
};
/** Constructor for QgsMapLayer
* @param type layer type
* @param name display name for the layer
* @param source datasource of layer
*/
QgsMapLayer( QgsMapLayer::LayerType type = VectorLayer, const QString& name = QString::null, const QString& source = QString::null );
virtual ~QgsMapLayer();
/** Returns the type of the layer.
*/
QgsMapLayer::LayerType type() const;
/** Returns the layer's unique ID, which is used to access this layer from QgsProject. */
QString id() const;
/**
* Set the display name of the layer
* @param name new name for the layer
* @note added in 2.16
* @see name()
*/
void setName( const QString& name );
/** Returns the display name of the layer.
* @return the layer name
* @see setName()
*/
QString name() const;
/** Returns the original name of the layer.
* @return the original layer name
*/
QString originalName() const;
/** Sets the short name of the layer
* used by QGIS Server to identify the layer.
* @return the layer short name
* @see shortName()
*/
void setShortName( const QString& shortName );
/** Returns the short name of the layer
* used by QGIS Server to identify the layer.
* @return the layer short name
* @see setShortName()
*/
QString shortName() const;
/** Sets the title of the layer
* used by QGIS Server in GetCapabilities request.
* @return the layer title
* @see title()
*/
void setTitle( const QString& title );
/** Returns the title of the layer
* used by QGIS Server in GetCapabilities request.
* @return the layer title
* @see setTitle()
*/
QString title() const;
/** Sets the abstract of the layer
* used by QGIS Server in GetCapabilities request.
* @return the layer abstract
* @see abstract()
*/
void setAbstract( const QString& abstract );
/** Returns the abstract of the layer
* used by QGIS Server in GetCapabilities request.
* @return the layer abstract
* @see setAbstract()
*/
QString abstract() const;
/** Sets the keyword list of the layer
* used by QGIS Server in GetCapabilities request.
* @return the layer keyword list
* @see keywordList()
*/
void setKeywordList( const QString& keywords );
/** Returns the keyword list of the layer
* used by QGIS Server in GetCapabilities request.
* @return the layer keyword list
* @see setKeywordList()
*/
QString keywordList() const;
/* Layer dataUrl information */
/** Sets the DataUrl of the layer
* used by QGIS Server in GetCapabilities request.
* DataUrl is a a link to the underlying data represented by a particular layer.
* @return the layer DataUrl
* @see dataUrl()
*/
void setDataUrl( const QString& dataUrl );
/** Returns the DataUrl of the layer
* used by QGIS Server in GetCapabilities request.
* DataUrl is a a link to the underlying data represented by a particular layer.
* @return the layer DataUrl
* @see setDataUrl()
*/
QString dataUrl() const;
/** Sets the DataUrl format of the layer
* used by QGIS Server in GetCapabilities request.
* DataUrl is a a link to the underlying data represented by a particular layer.
* @return the layer DataUrl format
* @see dataUrlFormat()
*/
void setDataUrlFormat( const QString& dataUrlFormat );
/** Returns the DataUrl format of the layer
* used by QGIS Server in GetCapabilities request.
* DataUrl is a a link to the underlying data represented by a particular layer.
* @return the layer DataUrl format
* @see setDataUrlFormat()
*/
QString dataUrlFormat() const;
/* Layer attribution information */
/** Sets the attribution of the layer
* used by QGIS Server in GetCapabilities request.
* Attribution indicates the provider of a layer or collection of layers.
* @return the layer attribution
* @see attribution()
*/
void setAttribution( const QString& attrib );
/** Returns the attribution of the layer
* used by QGIS Server in GetCapabilities request.
* Attribution indicates the provider of a layer or collection of layers.
* @return the layer attribution
* @see setAttribution()
*/
QString attribution() const;
/** Sets the attribution URL of the layer
* used by QGIS Server in GetCapabilities request.
* Attribution indicates the provider of a layer or collection of layers.
* @return the layer attribution URL
* @see attributionUrl()
*/
void setAttributionUrl( const QString& attribUrl );
/** Returns the attribution URL of the layer
* used by QGIS Server in GetCapabilities request.
* Attribution indicates the provider of a layer or collection of layers.
* @return the layer attribution URL
* @see setAttributionUrl()
*/
QString attributionUrl() const;
/* Layer metadataUrl information */
/** Sets the metadata URL of the layer
* used by QGIS Server in GetCapabilities request.
* MetadataUrl is a a link to the detailed, standardized metadata about the data.
* @return the layer metadata URL
* @see metadataUrl()
*/
void setMetadataUrl( const QString& metaUrl );
/** Returns the metadata URL of the layer
* used by QGIS Server in GetCapabilities request.
* MetadataUrl is a a link to the detailed, standardized metadata about the data.
* @return the layer metadata URL
* @see setMetadataUrl()
*/
QString metadataUrl() const;
/** Set the metadata type of the layer
* used by QGIS Server in GetCapabilities request
* MetadataUrlType indicates the standard to which the metadata complies.
* @return the layer metadata type
* @see metadataUrlType()
*/
void setMetadataUrlType( const QString& metaUrlType );
/** Returns the metadata type of the layer
* used by QGIS Server in GetCapabilities request.
* MetadataUrlType indicates the standard to which the metadata complies.
* @return the layer metadata type
* @see setMetadataUrlType()
*/
QString metadataUrlType() const;
/** Sets the metadata format of the layer
* used by QGIS Server in GetCapabilities request.
* MetadataUrlType indicates how the metadata is structured.
* @return the layer metadata format
* @see metadataUrlFormat()
*/
void setMetadataUrlFormat( const QString& metaUrlFormat );
/** Returns the metadata format of the layer
* used by QGIS Server in GetCapabilities request.
* MetadataUrlType indicates how the metadata is structured.
* @return the layer metadata format
* @see setMetadataUrlFormat()
*/
QString metadataUrlFormat() const;
/** Set the blending mode used for rendering a layer.
* @param blendMode new blending mode
* @see blendMode()
*/
void setBlendMode( QPainter::CompositionMode blendMode );
/** Returns the current blending mode for a layer.
* @see setBlendMode()
*/
QPainter::CompositionMode blendMode() const;
/** Returns if this layer is read only. */
bool readOnly() const;
/** Synchronises with changes in the datasource
*/
virtual void reload();
/** Return new instance of QgsMapLayerRenderer that will be used for rendering of given context
* @note added in 2.4
*/
virtual QgsMapLayerRenderer* createMapRenderer( QgsRenderContext& rendererContext ) = 0 /Factory/;
/** Returns the extent of the layer. */
virtual QgsRectangle extent() const;
/** Return the status of the layer. An invalid layer is one which has a bad datasource
* or other problem. Child classes set this flag when initialized.
* @return true if the layer is valid and can be accessed
*/
bool isValid() const;
/** Gets a version of the internal layer definition that has sensitive
* bits removed (for example, the password). This function should
* be used when displaying the source name for general viewing.
* @see source()
*/
QString publicSource() const;
/** Returns the source for the layer. This source may contain usernames, passwords
* and other sensitive information.
* @see publicSource()
*/
QString source() const;
/**
* Returns the sublayers of this layer
* (Useful for providers that manage their own layers, such as WMS)
*/
virtual QStringList subLayers() const;
/**
* Reorders the *previously selected* sublayers of this layer from bottom to top.
* (Useful for providers that manage their own layers, such as WMS).
*/
virtual void setLayerOrder( const QStringList &layers );
/** Set the visibility of the given sublayer name.
* @param name sublayer name
* @param visible sublayer visibility
*/
virtual void setSubLayerVisibility( const QString& name, bool visible );
/** Returns true if the layer can be edited. */
virtual bool isEditable() const;
/** Returns true if the layer is considered a spatial layer, ie it has some form of geometry associated with it.
* @note added in QGIS 2.16
*/
virtual bool isSpatial() const;
/** Sets state from Dom document
@param layerElement The Dom element corresponding to ``maplayer'' tag
@note
The Dom node corresponds to a Dom document project file XML element read
by QgsProject.
This, in turn, calls readXml(), which is over-rideable by sub-classes so
that they can read their own specific state from the given Dom node.
Invoked by QgsProject::read().
@returns true if successful
*/
bool readLayerXml( const QDomElement& layerElement );
/** Stores state in Dom node
* @param layerElement is a Dom element corresponding to ``maplayer'' tag
* @param document is a the dom document being written
* @param relativeBasePath base path for relative paths
* @note
*
* The Dom node corresponds to a Dom document project file XML element to be
* written by QgsProject.
*
* This, in turn, calls writeXml(), which is over-rideable by sub-classes so
* that they can write their own specific state to the given Dom node.
*
* Invoked by QgsProject::write().
*
* @returns true if successful
*/
bool writeLayerXml( QDomElement& layerElement, QDomDocument& document, const QString& relativeBasePath = QString::null ) const;
/** Returns the given layer as a layer definition document
* Layer definitions store the data source as well as styling and custom properties.
*
* Layer definitions can be used to load a layer and styling all from a single file.
*/
static QDomDocument asLayerDefinition( const QList<QgsMapLayer*>& layers, const QString& relativeBasePath = QString::null );
/** Creates a new layer from a layer defininition document
*/
static QList<QgsMapLayer*> fromLayerDefinition( QDomDocument& document, bool addToRegistry = false, bool addToLegend = false );
static QList<QgsMapLayer*> fromLayerDefinitionFile( const QString &qlrfile );
/** Set a custom property for layer. Properties are stored in a map and saved in project file.
* @see customProperty()
* @see removeCustomProperty()
*/
void setCustomProperty( const QString& key, const QVariant& value );
/** Read a custom property from layer. Properties are stored in a map and saved in project file.
* @see setCustomProperty()
*/
QVariant customProperty( const QString& value, const QVariant& defaultValue = QVariant() ) const;
/** Remove a custom property from layer. Properties are stored in a map and saved in project file.
* @see setCustomProperty()
*/
void removeCustomProperty( const QString& key );
/** Get current status error. This error describes some principal problem
* for which layer cannot work and thus is not valid. It is not last error
* after accessing data by draw() etc.
*/
virtual QgsError error() const;
/** Returns the layer's spatial reference system.
@note This was introduced in QGIS 1.4
*/
QgsCoordinateReferenceSystem crs() const;
/** Sets layer's spatial reference system */
void setCrs( const QgsCoordinateReferenceSystem& srs, bool emitSignal = true );
/** A convenience function to (un)capitalize the layer name */
static QString capitalizeLayerName( const QString& name );
/** 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)
* @return a QString with the style file name
* @see also loadNamedStyle () and saveNamedStyle ();
*/
virtual QString styleURI() const;
/** 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)
* @param resultFlag a reference to a flag that will be set to false if
* we did not manage to load the default style.
* @return a QString with any status messages
* @see also loadNamedStyle ();
*/
virtual QString loadDefaultStyle( bool & resultFlag /Out/ );
/** 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)
* @param uri - the file name or other URI for the
* style file. First an attempt will be made to see if this
* is a file and load that, if that fails the qgis.db styles
* table will be consulted to see if there is a style who's
* key matches the URI.
* @param resultFlag a reference to a flag that will be set to false if
* we did not manage to load the default style.
* @return a QString with any status messages
* @see also loadDefaultStyle ();
*/
virtual QString loadNamedStyle( const QString& uri, bool &resultFlag /Out/ );
/** Retrieve a named style for this layer from a sqlite database.
* @param db path to sqlite database
* @param uri uri for table
* @param qml will be set to QML style content from database
* @returns true if style was successfully loaded
*/
virtual bool loadNamedStyleFromDb( const QString &db, const QString &uri, QString &qml /Out/ );
/**
* Import the properties of this layer from a QDomDocument
* @param doc source QDomDocument
* @param errorMsg this QString will be initialized on error
* during the execution of readSymbology
* @return true on success
* @note added in 2.8
*/
virtual bool importNamedStyle( QDomDocument& doc, QString &errorMsg /Out/ );
/**
* Export the properties of this layer as named style in a QDomDocument
* @param doc the target QDomDocument
* @param errorMsg this QString will be initialized on error
* during the execution of writeSymbology
*/
virtual void exportNamedStyle( QDomDocument &doc, QString &errorMsg ) const;
/**
* Export the properties of this layer as SLD style in a QDomDocument
* @param doc the target QDomDocument
* @param errorMsg this QString will be initialized on error
* during the execution of writeSymbology
*/
virtual void exportSldStyle( QDomDocument &doc, QString &errorMsg ) const;
/** 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)
* @param resultFlag a reference to a flag that will be set to false if
* we did not manage to save the default style.
* @return a QString with any status messages
* @sa loadNamedStyle() and @see saveNamedStyle()
*/
virtual QString saveDefaultStyle( bool & resultFlag /Out/ );
/** 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)
* @param uri the file name or other URI for the
* style file. First an attempt will be made to see if this
* is a file and save to that, if that fails the qgis.db styles
* table will be used to create a style entry who's
* key matches the URI.
* @param resultFlag a reference to a flag that will be set to false if
* we did not manage to save the default style.
* @return a QString with any status messages
* @sa saveDefaultStyle()
*/
virtual QString saveNamedStyle( const QString &uri, bool &resultFlag /Out/ );
/** Saves the properties of this layer to an SLD format file.
* @param uri uri of destination for exported SLD file.
* @param resultFlag a reference to a flag that will be set to false if
* the SLD file could not be generated
* @returns a string with any status or error messages
* @see loadSldStyle()
*/
virtual QString saveSldStyle( const QString &uri, bool &resultFlag ) const;
/** Attempts to style the layer using the formatting from an SLD type file.
* @param uri uri of source SLD file
* @param resultFlag a reference to a flag that will be set to false if
* the SLD file could not be loaded
* @returns a string with any status or error messages
* @see saveSldStyle()
*/
virtual QString loadSldStyle( const QString &uri, bool &resultFlag );
virtual bool readSld( const QDomNode &node, QString &errorMessage );
/** Read the symbology for the current layer from the Dom node supplied.
* @param node node that will contain the symbology definition for this layer.
* @param errorMessage reference to string that will be updated with any error messages
* @return true in case of success.
*/
virtual bool readSymbology( const QDomNode& node, QString& errorMessage ) = 0;
/** Read the style for the current layer from the Dom node supplied.
* @param node node that will contain the style definition for this layer.
* @param errorMessage reference to string that will be updated with any error messages
* @return true in case of success.
* @note added in 2.16
* @note To be implemented in subclasses. Default implementation does nothing and returns false.
*/
virtual bool readStyle( const QDomNode& node, QString& errorMessage );
/** Write the symbology for the layer into the docment provided.
* @param node the node that will have the style element added to it.
* @param doc the document that will have the QDomNode added.
* @param errorMessage reference to string that will be updated with any error messages
* @return true in case of success.
*/
virtual bool writeSymbology( QDomNode &node, QDomDocument& doc, QString& errorMessage ) const = 0;
/** Write just the style information for the layer into the document
* @param node the node that will have the style element added to it.
* @param doc the document that will have the QDomNode added.
* @param errorMessage reference to string that will be updated with any error messages
* @return true in case of success.
* @note added in 2.16
* @note To be implemented in subclasses. Default implementation does nothing and returns false.
*/
virtual bool writeStyle( QDomNode& node, QDomDocument& doc, QString& errorMessage ) const;
/** Return pointer to layer's undo stack */
QUndoStack *undoStack();
/** Return pointer to layer's style undo stack
* @note added in 2.16
*/
QUndoStack *undoStackStyles();
/* Layer legendUrl information */
void setLegendUrl( const QString& legendUrl );
QString legendUrl() const;
void setLegendUrlFormat( const QString& legendUrlFormat );
QString legendUrlFormat() const;
/**
* Assign a legend controller to the map layer. The object will be responsible for providing legend items.
* @param legend Takes ownership of the object. Can be null pointer
* @note added in 2.6
*/
void setLegend( QgsMapLayerLegend* legend /Transfer/ );
/**
* Can be null.
* @note added in 2.6
*/
QgsMapLayerLegend* legend() const;
/**
* Get access to the layer's style manager. Style manager allows switching between multiple styles.
* @note added in 2.8
*/
QgsMapLayerStyleManager* styleManager() const;
/** Tests whether the layer should be visible at the specified scale.
* @param scale scale denominator to test
* @returns true if the layer is visible at the given scale.
* @note added in QGIS 2.16
* @see minimumScale()
* @see maximumScale()
* @see hasScaleBasedVisibility()
*/
bool isInScaleRange( double scale ) const;
/** Returns the minimum scale denominator at which the layer is visible.
* Scale based visibility is only used if hasScaleBasedVisibility is true.
* @returns minimum scale denominator at which the layer will render
* @see setMinimumScale()
* @see maximumScale()
* @see hasScaleBasedVisibility()
* @see isInScaleRange()
*/
double minimumScale() const;
/** Returns the maximum scale denominator at which the layer is visible.
* Scale based visibility is only used if hasScaleBasedVisibility is true.
* @returns minimum scale denominator at which the layer will render
* @see setMaximumScale()
* @see minimumScale()
* @see hasScaleBasedVisibility()
* @see isInScaleRange()
*/
double maximumScale() const;
/** Returns whether scale based visibility is enabled for the layer.
* @returns true if scale based visibility is enabled
* @see minimumScale()
* @see maximumScale()
* @see setScaleBasedVisibility()
* @see isInScaleRange()
*/
bool hasScaleBasedVisibility() const;
public slots:
/** Event handler for when a coordinate transform fails due to bad vertex error */
virtual void invalidTransformInput();
/** Sets the minimum scale denominator at which the layer will be visible.
* Scale based visibility is only used if setScaleBasedVisibility is set to true.
* @param scale minimum scale denominator at which the layer should render
* @see minimumScale
* @see setMaximumScale
* @see setScaleBasedVisibility
*/
void setMinimumScale( double scale );
/** Sets the maximum scale denominator at which the layer will be visible.
* Scale based visibility is only used if setScaleBasedVisibility is set to true.
* @param scale maximum scale denominator at which the layer should render
* @see maximumScale
* @see setMinimumScale
* @see setScaleBasedVisibility
*/
void setMaximumScale( double scale );
/** Sets whether scale based visibility is enabled for the layer.
* @param enabled set to true to enable scale based visibility
* @see setMinimumScale
* @see setMaximumScale
* @see scaleBasedVisibility
*/
void setScaleBasedVisibility( const bool enabled );
/**
* Will advice the map canvas (and any other interested party) that this layer requires to be repainted.
* Will emit a repaintRequested() signal.
*
* @note in 2.6 function moved from vector/raster subclasses to QgsMapLayer
*/
void triggerRepaint();
/** \brief Obtain Metadata for this layer */
virtual QString metadata() const;
/** Time stamp of data source in the moment when data/metadata were loaded by provider */
virtual QDateTime timestamp() const;
/** Triggers an emission of the styleChanged() signal.
* @note added in QGIS 2.16
*/
void emitStyleChanged();
/**
* Sets the list of dependencies.
* @see dependencies()
*
* @param layers set of QgsMapLayerDependency. Only user-defined dependencies will be added
* @returns false if a dependency cycle has been detected
* @note added in QGIS 3.0
*/
virtual bool setDependencies( const QSet<QgsMapLayerDependency>& layers );
/**
* Gets the list of dependencies. This includes data dependencies set by the user (@see setDataDependencies)
* as well as dependencies given by the provider
*
* @returns a set of QgsMapLayerDependency
* @note added in QGIS 3.0
*/
virtual QSet<QgsMapLayerDependency> dependencies() const;
signals:
/** Emit a signal with status (e.g. to be caught by QgisApp and display a msg on status bar) */
void statusChanged( const QString& status );
/**
* Emitted when the name has been changed
*
* @note added in 2.16
*/
void nameChanged();
/** Emit a signal that layer's CRS has been reset */
void crsChanged();
/** 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.
*/
void repaintRequested();
/** This is used to send a request that any mapcanvas using this layer update its extents */
void recalculateExtents() const;
/** Data of layer changed */
void dataChanged();
/** Signal emitted when the blend mode is changed, through QgsMapLayer::setBlendMode() */
void blendModeChanged( QPainter::CompositionMode blendMode );
/** Signal emitted when renderer is changed.
* @see styleChanged()
*/
void rendererChanged();
/** Signal emitted whenever a change affects the layer's style. Ie this may be triggered
* by renderer changes, label style changes, or other style changes such as blend
* mode or layer opacity changes.
* @note added in QGIS 2.16
* @see rendererChanged()
*/
void styleChanged();
/**
* Signal emitted when legend of the layer has changed
* @note added in 2.6
*/
void legendChanged();
/**
* Emitted whenever the configuration is changed. The project listens to this signal
* to be marked as dirty.
*/
void configChanged();
/**
* Emitted when dependencies are changed.
*/
void dependenciesChanged();
/**
* 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.
* @note added in QGIS 3.0
*/
void willBeDeleted();
protected:
/** Set the extent */
virtual void setExtent( const QgsRectangle &rect );
/** Set whether layer is valid or not - should be used in constructor. */
void setValid( bool valid );
/** Called by readLayerXML(), used by children to read state specific to them from
* project files.
*/
virtual bool readXml( const QDomNode& layer_node );
/** Called by writeLayerXML(), used by children to write state specific to them to
* project files.
*/
virtual bool writeXml( QDomNode & layer_node, QDomDocument & document ) const;
/** Read custom properties from project file.
@param layerNode note to read from
@param keyStartsWith reads only properties starting with the specified string (or all if the string is empty)*/
void readCustomProperties( const QDomNode& layerNode, const QString& keyStartsWith = "" );
/** Write custom properties to project file. */
void writeCustomProperties( QDomNode & layerNode, QDomDocument & doc ) const;
/** Read style manager's configuration (if any). To be called by subclasses. */
void readStyleManager( const QDomNode& layerNode );
/** Write style manager's configuration (if exists). To be called by subclasses. */
void writeStyleManager( QDomNode& layerNode, QDomDocument& doc ) const;
/** Add error message */
void appendError( const QgsErrorMessage &error );
/** Set error message */
void setError( const QgsError &error );
//! Checks if new change dependency candidates introduce a cycle
bool hasDependencyCycle( const QSet<QgsMapLayerDependency>& layersIds ) const;
};