Make sure to update visibility presets if any layer's style name changes

Also adds signals to the QgsMapLayerStyleManager so others can watch the changes

This code has been funded by Tuscany Region (Italy) - SITA (CIG: 6002233F59)
and commissioned to Gis3W s.a.s.

python/core/qgsmaplayerstylemanager.sip

@@ -32,7 +32,7 @@ class QgsMapLayerStyle
 };
 
 
-class QgsMapLayerStyleManager
+class QgsMapLayerStyleManager : QObject
 {
 %TypeHeaderCode
 #include <qgsmaplayerstylemanager.h>
@@ -41,6 +41,9 @@ class QgsMapLayerStyleManager
     //! Construct a style manager associated with a map layer (must not be null)
     QgsMapLayerStyleManager( QgsMapLayer* layer );
 
+    //! Get pointer to the associated map layer
+    QgsMapLayer* layer() const;
+
     //! Reset the style manager to a basic state - with one default style which is set as current
     void reset();
 
@@ -79,4 +82,14 @@ class QgsMapLayerStyleManager
     bool setOverrideStyle( const QString& styleDef );
     //! Restore the original store after a call to setOverrideStyle()
     bool restoreOverrideStyle();
+
+  signals:
+    //! Emitted when a new style has been added
+    void styleAdded( const QString& name );
+    //! Emitted when a style has been removed
+    void styleRemoved( const QString& name );
+    //! Emitted when a style has been renamed
+    void styleRenamed( const QString& oldName, const QString& newName );
+    //! Emitted when the current style has been changed
+    void currentStyleChanged( const QString& currentName );
 };

src/app/qgsvisibilitypresets.cpp

@@ -129,19 +129,6 @@ QgsVisibilityPresets::PresetRecord QgsVisibilityPresets::currentState()
   return rec;
 }
 
-QgsVisibilityPresets::PresetRecord QgsVisibilityPresets::currentStateFromLayerList( const QStringList& layerIDs, const QMap<QString, QString>& layerStyleOverrides )
-{
-  PresetRecord rec;
-  foreach ( const QString& layerID, layerIDs )
-    rec.mVisibleLayerIDs << layerID;
-  addPerLayerCheckedLegendSymbols( rec );
-  addPerLayerCurrentStyle( rec );
-  foreach ( const QString& layerID, layerStyleOverrides.keys() )
-    rec.mPerLayerCurrentStyle[layerID] = layerStyleOverrides[layerID];
-  return rec;
-}
-
-
 QgsVisibilityPresets* QgsVisibilityPresets::instance()
 {
   if ( !sInstance )
@@ -153,6 +140,8 @@ QgsVisibilityPresets* QgsVisibilityPresets::instance()
 void QgsVisibilityPresets::addPreset( const QString& name )
 {
   mPresets.insert( name, currentState() );
+
+  reconnectToLayersStyleManager();
 }
 
 void QgsVisibilityPresets::updatePreset( const QString& name )
@@ -161,16 +150,22 @@ void QgsVisibilityPresets::updatePreset( const QString& name )
     return;
 
   mPresets[name] = currentState();
+
+  reconnectToLayersStyleManager();
 }
 
 void QgsVisibilityPresets::removePreset( const QString& name )
 {
   mPresets.remove( name );
+
+  reconnectToLayersStyleManager();
 }
 
 void QgsVisibilityPresets::clear()
 {
   mPresets.clear();
+
+  reconnectToLayersStyleManager();
 }
 
 QStringList QgsVisibilityPresets::presets() const
@@ -392,6 +387,25 @@ void QgsVisibilityPresets::applyState( const QString& presetName )
   }
 }
 
+void QgsVisibilityPresets::reconnectToLayersStyleManager()
+{
+  disconnect( 0, 0, this, SLOT( layerStyleRenamed( QString, QString ) ) );
+
+  QSet<QString> layerIDs;
+  foreach ( const QString& grpName, mPresets.keys() )
+  {
+    const PresetRecord& rec = mPresets[grpName];
+    foreach ( const QString& layerID, rec.mPerLayerCurrentStyle.keys() )
+      layerIDs << layerID;
+  }
+
+  foreach ( const QString& layerID, layerIDs )
+  {
+    if ( QgsMapLayer* ml = QgsMapLayerRegistry::instance()->mapLayer( layerID ) )
+      connect( ml->styleManager(), SIGNAL( styleRenamed( QString, QString ) ), this, SLOT( layerStyleRenamed( QString, QString ) ) );
+  }
+}
+
 
 void QgsVisibilityPresets::removeCurrentPreset()
 {
@@ -480,6 +494,8 @@ void QgsVisibilityPresets::readProject( const QDomDocument& doc )
 
     visPresetElem = visPresetElem.nextSiblingElement( "visibility-preset" );
   }
+
+  reconnectToLayersStyleManager();
 }
 
 void QgsVisibilityPresets::writeProject( QDomDocument& doc )
@@ -531,3 +547,24 @@ void QgsVisibilityPresets::registryLayersRemoved( QStringList layerIDs )
     }
   }
 }
+
+void QgsVisibilityPresets::layerStyleRenamed( const QString& oldName, const QString& newName )
+{
+  QgsMapLayerStyleManager* styleMgr = qobject_cast<QgsMapLayerStyleManager*>( sender() );
+  if ( !styleMgr )
+    return;
+
+  QString layerID = styleMgr->layer()->id();
+
+  foreach ( QString presetName, mPresets.keys() )
+  {
+    PresetRecord& rec = mPresets[presetName];
+
+    if ( rec.mPerLayerCurrentStyle.contains( layerID ) )
+    {
+      QString styleName = rec.mPerLayerCurrentStyle[layerID];
+      if ( styleName == oldName )
+        rec.mPerLayerCurrentStyle[layerID] = newName;
+    }
+  }
+}

src/app/qgsvisibilitypresets.h

@@ -86,9 +86,6 @@ class QgsVisibilityPresets : public QObject
     //! Convenience menu that lists available presets and actions for management
     QMenu* menu();
 
-    //! Create preset record given a list of visible layers (needs to store per-layer checked legend symbols)
-    PresetRecord currentStateFromLayerList( const QStringList& layerIDs, const QMap<QString, QString>& layerStyleOverrides );
-
     //! Get layer style overrides (for QgsMapSettings) of the visible layers for given preset
     QMap<QString, QString> presetStyleOverrides( const QString& presetName );
 
@@ -106,6 +103,9 @@ class QgsVisibilityPresets : public QObject
 
     void registryLayersRemoved( QStringList layerIDs );
 
+    //! Update style name if a stored style gets renamed
+    void layerStyleRenamed( const QString& oldName, const QString& newName );
+
   protected:
     QgsVisibilityPresets(); // singleton
 
@@ -119,6 +119,8 @@ class QgsVisibilityPresets : public QObject
     PresetRecord currentState();
     void applyState( const QString& presetName );
 
+    void reconnectToLayersStyleManager();
+
     static QgsVisibilityPresets* sInstance;
 
     PresetRecordMap mPresets;

src/core/CMakeLists.txt

@@ -342,6 +342,7 @@ SET(QGIS_CORE_MOC_HDRS
   qgsmaplayer.h
   qgsmaplayerlegend.h
   qgsmaplayerregistry.h
+  qgsmaplayerstylemanager.h
   qgsmaprenderer.h
   qgsmaprenderercache.h
   qgsmaprenderercustompainterjob.h

src/core/qgsmaplayerstylemanager.cpp

@@ -91,6 +91,7 @@ bool QgsMapLayerStyleManager::addStyle( const QString& name, const QgsMapLayerSt
     return false;
 
   mStyles.insert( name, style );
+  emit styleAdded( name );
   return true;
 }
 
@@ -119,6 +120,7 @@ bool QgsMapLayerStyleManager::removeStyle( const QString& name )
   }
 
   mStyles.remove( name );
+  emit styleRemoved( name );
   return true;
 }
 
@@ -132,6 +134,7 @@ bool QgsMapLayerStyleManager::renameStyle( const QString& name, const QString& n
 
   mStyles[newName] = mStyles[name];
   mStyles.remove( name );
+  emit styleRenamed( name, newName );
   return true;
 }
 
@@ -152,6 +155,8 @@ bool QgsMapLayerStyleManager::setCurrentStyle( const QString& name )
   mCurrentStyle = name;
   mStyles[mCurrentStyle].writeToLayer( mLayer );
   mStyles[mCurrentStyle].clear(); // current style does not keep any stored data
+  emit currentStyleChanged( mCurrentStyle );
+
   mLayer->triggerRepaint();
   return true;
 }

src/core/qgsmaplayerstylemanager.h

@@ -87,12 +87,16 @@ class CORE_EXPORT QgsMapLayerStyle
  *
  * @note added in 2.8
  */
-class CORE_EXPORT QgsMapLayerStyleManager
+class CORE_EXPORT QgsMapLayerStyleManager : public QObject
 {
+    Q_OBJECT
   public:
     //! Construct a style manager associated with a map layer (must not be null)
     QgsMapLayerStyleManager( QgsMapLayer* layer );
 
+    //! Get pointer to the associated map layer
+    QgsMapLayer* layer() const { return mLayer; }
+
     //! Reset the style manager to a basic state - with one default style which is set as current
     void reset();
 
@@ -132,6 +136,16 @@ class CORE_EXPORT QgsMapLayerStyleManager
     //! Restore the original store after a call to setOverrideStyle()
     bool restoreOverrideStyle();
 
+  signals:
+    //! Emitted when a new style has been added
+    void styleAdded( const QString& name );
+    //! Emitted when a style has been removed
+    void styleRemoved( const QString& name );
+    //! Emitted when a style has been renamed
+    void styleRenamed( const QString& oldName, const QString& newName );
+    //! Emitted when the current style has been changed
+    void currentStyleChanged( const QString& currentName );
+
   private:
     QgsMapLayer* mLayer;
     QMap<QString, QgsMapLayerStyle> mStyles;