/** \ingroup core * Reads and writes project states. @note Has two general kinds of state to make persistent. (I.e., to read and write.) First, Qgis proprietary information. Second plug-in information. A singleton since there shall only be one active project at a time; and provides canonical location for plug-ins and main app to find/set properties. Might want to consider moving from Singleton; i.e., allowing more than one project. Just as the GIMP can have simultaneous multiple images, perhaps qgis can one day have simultaneous multiple projects. */ class QgsProject : QObject { %TypeHeaderCode #include %End public: /** * @todo XXX Should have semantics for saving project if dirty as last gasp? */ ~QgsProject(); /// access to canonical QgsProject instance static QgsProject * instance(); /** * Every project has an associated title string * * @deprecated Use setTitle instead. */ //@{ void title( const QString & title ) /Deprecated/; /** Set project title * @note added in 2.4 */ void setTitle( const QString& title ); /** Returns title */ QString title() const; //@} /** * the dirty flag is true if the project has been modified since the last * write() */ //@{ bool isDirty() const; // ### QGIS 3: remove in favor of setDirty(...) void dirty( bool b ); /** Set project as dirty (modified). * @note added in 2.4 */ void setDirty( bool b ); //@} /** * Every project has an associated file that contains its XML */ //@{ void setFileName( const QString & name ); /** Returns file name */ QString fileName() const; //@} /** Returns QFileInfo object for the project's associated file. * @note added in QGIS 2.9 */ QFileInfo fileInfo() const; /** Clear the project * @note added in 2.4 */ void clear(); /** Read project file * * @note Any current plug-in state is erased * * @note dirty set to false after successful invocation * * @note file name argument implicitly sets file * * @note * * - Gets the extents * - Creates maplayers * - Registers maplayers * * @note it's presumed that the caller has already reset the map canvas, map registry, and legend */ //@{ bool read( const QFileInfo & file ); bool read(); //@} /** Read the layer described in the associated Dom node * * @param layerNode represents a QgsProject Dom node that maps to a specific layer. * * QgsProject raises an exception when one of the QgsProject::read() * implementations fails. Since the read()s are invoked from qgisapp, * then qgisapp handles the exception. It prompts the user for the new * location of the data, if any. If there is a new location, the Dom * node associated with the layer has its datasource tag corrected. * Then that node is passed to this member function to be re-opened. * */ bool read( QDomNode & layerNode ); /** Write project file * * XXX How to best get read access to Qgis state? Actually we can finagle * that by searching for qgisapp in object hiearchy. * * @note file name argument implicitly sets file * * @note dirty set to false after successful invocation */ //@{ bool write( const QFileInfo & file ); bool write(); //@} /** * removes all project properties * * ### QGIS 3: remove in favor of clear() */ void clearProperties(); /* key value mutators * * keys would be the familiar QSettings-like '/' delimited entries, implying * a hierarchy of keys and corresponding values * * @note The key string must be valid xml tag names in order to be saved to the file. */ //@{ //! @note available in python bindings as writeEntryBool bool writeEntry( const QString & scope, const QString & key, bool value ) /PyName=writeEntryBool/; //! @note available in python bindings as writeEntryDouble bool writeEntry( const QString & scope, const QString & key, double value ) /PyName=writeEntryDouble/; bool writeEntry( const QString & scope, const QString & key, int value ); bool writeEntry( const QString & scope, const QString & key, const QString & value ); bool writeEntry( const QString & scope, const QString & key, const QStringList & value ); //@} /** Key value accessors * * keys would be the familiar QSettings-like '/' delimited entries, * implying a hierarchy of keys and corresponding values * */ //@{ QStringList readListEntry( const QString & scope, const QString & key, const QStringList& def = QStringList(), bool *ok = 0 ) const; QString readEntry( const QString & scope, const QString & key, const QString & def = QString::null, bool * ok = 0 ) const; int readNumEntry( const QString & scope, const QString & key, int def = 0, bool * ok = 0 ) const; double readDoubleEntry( const QString & scope, const QString & key, double def = 0, bool * ok = 0 ) const; bool readBoolEntry( const QString & scope, const QString & key, bool def = false, bool * ok = 0 ) const; //@} /** Remove the given key */ bool removeEntry( const QString & scope, const QString & key ); /** Return keys with values -- do not return keys that contain other keys * * @note equivalent to QSettings entryList() */ QStringList entryList( const QString & scope, const QString & key ) const; /** Return keys with keys -- do not return keys that contain only values * * @note equivalent to QSettings subkeyList() */ QStringList subkeyList( const QString & scope, const QString & key ) const; /** Dump out current project properties to stderr * * @todo XXX Now slightly broken since re-factoring. Won't print out top-level key * and redundantly prints sub-keys. */ void dumpProperties() const; /** Prepare a filename to save it to the project file */ QString writePath( const QString& filename, const QString& relativeBasePath = QString::null ) const; /** Turn filename read from the project file to an absolute path */ QString readPath( QString filename ) const; /** Return error message from previous read/write */ QString error() const; /** Change handler for missing layers. * Deletes old handler and takes ownership of the new one. */ void setBadLayerHandler( QgsProjectBadLayerHandler* handler /Transfer/ ); /** Returns project file path if layer is embedded from other project file. Returns empty string if layer is not embedded*/ QString layerIsEmbedded( const QString& id ) const; /** Creates a maplayer instance defined in an arbitrary project file. Caller takes ownership * @return the layer or 0 in case of error * @note not available in Python bindings */ /* bool createEmbeddedLayer( const QString& layerId, const QString& projectFilePath, QList& brokenNodes, QList< QPair< QgsVectorLayer*, QDomElement > >& vectorLayerList, bool saveFlag = true ); */ /** Create layer group instance defined in an arbitrary project file. * @note: added in version 2.4 */ QgsLayerTreeGroup* createEmbeddedGroup( const QString& groupName, const QString& projectFilePath, const QStringList &invisibleLayers ); /** Convenience function to set snap settings per layer */ void setSnapSettingsForLayer( const QString& layerId, bool enabled, QgsSnapper::SnappingType type, QgsTolerance::UnitType unit, double tolerance, bool avoidIntersection ); /** Convenience function to query snap settings of a layer */ bool snapSettingsForLayer( const QString& layerId, bool& enabled /Out/, QgsSnapper::SnappingType& type /Out/, QgsTolerance::UnitType& units /Out/, double& tolerance /Out/, bool& avoidIntersection /Out/ ) const; /** Convenience function to set topological editing */ void setTopologicalEditing( bool enabled ); /** Convenience function to query topological editing status */ bool topologicalEditing() const; /** Convenience function to query default distance measurement units for project. * @note added in QGIS 2.14 * @see areaUnits() */ QGis::UnitType distanceUnits() const; /** Convenience function to query default area measurement units for project. * @note added in QGIS 2.14 * @see distanceUnits() */ QgsUnitTypes::AreaUnit areaUnits() const; /** Return project's home path @return home path of project (or QString::null if not set) */ QString homePath() const; QgsRelationManager* relationManager() const; /** Return pointer to the root (invisible) node of the project's layer tree * @note added in 2.4 */ QgsLayerTreeGroup* layerTreeRoot() const; /** Return pointer to the helper class that synchronizes map layer registry with layer tree * @note added in 2.4 */ QgsLayerTreeRegistryBridge* layerTreeRegistryBridge() const; /** Returns pointer to the project's visibility preset collection. * @note added in QGIS 2.12 */ QgsVisibilityPresetCollection* visibilityPresetCollection(); protected: /** Set error message from read/write operation * @note not available in Python bindings */ //void setError( const QString& errorMessage ); /** Clear error message * @note not available in Python bindings */ //void clearError(); //! Creates layer and adds it to maplayer registry //! @note not available in python bindings // bool addLayer( const QDomElement& layerElem, QList& brokenNodes, QList< QPair< QgsVectorLayer*, QDomElement > >& vectorLayerList ); //! @note not available in python bindings // void initializeEmbeddedSubtree( const QString& projectFilePath, QgsLayerTreeGroup* group ); //! @note not available in python bindings // void loadEmbeddedNodes( QgsLayerTreeGroup* group ); signals: //! emitted when project is being read void readProject( const QDomDocument & ); //! emitted when project is being written void writeProject( QDomDocument & ); /** * Emitted, after the basic initialization of a layer from the project * file is done. You can use this signal to read additional information * from the project file. * * @param mapLayer The map layer which is being initialized * @param layerNode The layer node from the project file */ void readMapLayer( QgsMapLayer *mapLayer, const QDomElement &layerNode ); /** * Emitted, when a layer is being saved. You can use this method to save * additional information to the layer. * * @param mapLayer The map layer which is being initialized * @param layerElem The layer element from the project file * @param doc The document */ void writeMapLayer( QgsMapLayer *mapLayer, QDomElement &layerElem, QDomDocument &doc ); //! emitted when the project file has been written and closed void projectSaved(); //! emitted when an old project file is read. void oldProjectVersionWarning( const QString& ); //! emitted when a layer from a projects was read // @param i current layer // @param n number of layers void layerLoaded( int i, int n ); void loadingLayer( const QString& ); void snapSettingsChanged(); private: QgsProject(); // private 'cause it's a singleton }; // QgsProject /** Interface for classes that handle missing layer files when reading project file. */ class QgsProjectBadLayerHandler { %TypeHeaderCode #include %End public: virtual void handleBadLayers( const QList& layers, const QDomDocument& projectDom ) = 0; virtual ~QgsProjectBadLayerHandler(); }; /** Default bad layer handler which ignores any missing layers. */ class QgsProjectBadLayerDefaultHandler : QgsProjectBadLayerHandler { %TypeHeaderCode #include %End public: virtual void handleBadLayers( const QList& layers, const QDomDocument& projectDom ); };