Add Python bindings for map layer style manager

Author: wonder-sk

python/core/core.sip

@@ -54,6 +54,7 @@
 %Include qgsmaplayerlegend.sip
 %Include qgsmaplayerregistry.sip
 %Include qgsmaplayerrenderer.sip
+%Include qgsmaplayerstylemanager.sip
 %Include qgsmaprenderer.sip
 %Include qgsmaprenderercache.sip
 %Include qgsmaprenderercustompainterjob.sip

python/core/qgsmaplayer.sip

@@ -370,6 +370,21 @@ class QgsMapLayer : QObject
      */
     QgsMapLayerLegend* legend() const;
 
+    /**
+     * Enable or disable layer's style manager. When disabled (default), the styleManager() will return null pointer.
+     * By enabling the style manager will be created with one default style (same as the layer's active style).
+     * By disabling the style manager all associated styles will be lost (only the layer's active style will stay).
+     * @note added in 2.8
+     */
+    void enableStyleManager( bool enable = true );
+
+    /**
+     * Get access to the layer's style manager. Style manager allows switching between multiple styles.
+     * If the style manager is not enabled, null pointer will be returned.
+     * @note added in 2.8
+     */
+    QgsMapLayerStyleManager* styleManager() 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
@@ -517,6 +532,11 @@ class QgsMapLayer : QObject
     /** 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;
+
     /** debugging member - invoked when a connect() is made to this object */
     void connectNotify( const char * signal );
 

python/core/qgsmaplayerstylemanager.sip

@@ -0,0 +1,63 @@
+
+class QgsMapLayerStyle
+{
+%TypeHeaderCode
+#include <qgsmaplayerstylemanager.h>
+%End
+  public:
+    //! construct invalid style
+    QgsMapLayerStyle();
+
+    //! Tell whether the style is valid (i.e. there is something stored in it)
+    bool isValid() const;
+
+    //! Return information about the style - for debugging purposes only
+    QString dump() const;
+
+    //! Store layer's active style information in the instance
+    void readFromLayer( QgsMapLayer* layer );
+    //! Apply stored layer's style information to the layer
+    void writeToLayer( QgsMapLayer* layer ) const;
+
+    //! Read style configuration (for project file reading)
+    void readXml( const QDomElement& styleElement );
+    //! Write style configuration (for project file writing)
+    void writeXml( QDomElement& styleElement ) const;
+};
+
+
+class QgsMapLayerStyleManager
+{
+%TypeHeaderCode
+#include <qgsmaplayerstylemanager.h>
+%End
+  public:
+    //! Construct a style manager associated with a map layer (must not be null)
+    QgsMapLayerStyleManager( QgsMapLayer* layer );
+
+    //! Read configuration (for project loading)
+    void readXml( const QDomElement& mgrElement );
+    //! Write configuration (for project saving)
+    void writeXml( QDomElement& mgrElement ) const;
+
+    //! Return list of all defined style names
+    QStringList styles() const;
+    //! Return data of a stored style - accessed by its unique name
+    QgsMapLayerStyle style( const QString& name ) const;
+
+    //! Add a style with given name and data
+    //! @return true on success (name is unique and style is valid)
+    bool addStyle( const QString& name, const QgsMapLayerStyle& style );
+    //! Add style by cloning the current one
+    //! @return true on success
+    bool addStyleFromLayer( const QString& name );
+    //! Remove a stored style
+    //! @return true on success (style exists and it is not the last one)
+    bool removeStyle( const QString& name );
+
+    //! Return name of the current style
+    QString currentStyle() const;
+    //! Set a different style as the current style - will apply it to the layer
+    //! @return true on success
+    bool setCurrentStyle( const QString& name );
+};