Add QgsMapLayerAction and QgsMapLayerActionRegistry, which can be

used as a generic api for registering actions which can apply to
a specific map layer or layer type.

Create a QgsMapLayerAction for setting features as the current
atlas feature for compositions.

This work was kindly sponsored by SIGE (www.sige.ch).

Author: nyalldawson

python/core/composer/qgsatlascomposition.sip

@@ -82,6 +82,9 @@ public:
     /** Prepare the atlas map for the given feature. Sets the extent and context variables */
     void prepareForFeature( int i );
 
+    /** Prepare the atlas map for the given feature. Sets the extent and context variables */
+    void prepareForFeature( QgsFeature * feat );
+
     /** Returns the current filename. Must be called after prepareForFeature( i ) */
     const QString& currentFilename() const;
 
@@ -108,4 +111,11 @@ public:
   signals:
     /** emitted when one of the parameters changes */
     void parameterChanged();
+
+    /** emitted when atlas is enabled or disabled */
+    void toggled( bool );
+
+    /**Is emitted when the coverage layer for an atlas changes*/
+    void coverageLayerChanged( QgsVectorLayer* layer );
+
 };

python/gui/attributetable/qgsattributetablemodel.sip

@@ -2,6 +2,7 @@ class QgsAttributeTableModel : QAbstractTableModel
 {
 %TypeHeaderCode
 #include <qgsattributetablemodel.h>
+#include <qgsmaplayeractionregistry.h>
 %End
   public:
     enum Role
@@ -133,6 +134,11 @@ class QgsAttributeTableModel : QAbstractTableModel
      */
     void executeAction( int action, const QModelIndex &idx ) const;
 
+    /**
+     * Execute a QgsMapLayerAction
+     */
+    void executeMapLayerAction( QgsMapLayerAction* action, const QModelIndex &idx ) const;
+
     /**
      * Return the feature attributes at given model index
      * @return feature attributes at given model index

python/gui/attributetable/qgsdualview.sip

@@ -132,3 +132,17 @@ class QgsAttributeTableAction : QAction
     void execute();
     void featureForm();
 };
+
+class QgsAttributeTableMapLayerAction : QAction
+{
+%TypeHeaderCode
+#include <qgsdualview.h>
+%End
+
+  public:
+    QgsAttributeTableMapLayerAction( const QString &name, QgsDualView *dualView, QgsMapLayerAction* action, const QModelIndex &fieldIdx );
+
+  public slots:
+    void execute();
+
+};

python/gui/gui.sip

@@ -42,6 +42,7 @@
 %Include qgsmapcanvasitem.sip
 %Include qgsmapcanvasmap.sip
 %Include qgsmapcanvassnapper.sip
+%Include qgsmaplayeractionregistry.sip
 %Include qgsmapoverviewcanvas.sip
 %Include qgsmaptip.sip
 %Include qgsmaptool.sip

python/gui/qgsmaplayeractionregistry.sip

@@ -0,0 +1,72 @@
+class QgsMapLayerAction : QAction
+{
+%TypeHeaderCode
+#include <qgsmaplayeractionregistry.h>
+%End
+
+  public:
+
+    /**Creates a map layer action which can run on any layer*/
+    QgsMapLayerAction( QString name, QObject *parent );
+    /**Creates a map layer action which can run only on a specific layer*/
+    QgsMapLayerAction( QString name, QObject *parent, QgsMapLayer* layer );
+    /**Creates a map layer action which can run on a specific type of layer*/
+    QgsMapLayerAction( QString name, QObject *parent, QgsMapLayer::LayerType layerType );
+
+    ~QgsMapLayerAction();
+
+    /** True if action can run using the specified layer */
+    bool canRunUsingLayer( QgsMapLayer* layer ) const;
+
+    /** Triggers the action with the specified layer and feature. This also emits the triggeredForLayer( QgsMapLayer *)
+     * and triggered() slots */
+    void triggerForFeature( QgsMapLayer* layer, QgsFeature* feature );
+
+    /** Triggers the action with the specified layer. This also emits the triggered() slot. */
+    void triggerForLayer( QgsMapLayer* layer );
+
+  signals:
+    /** Triggered when action has been run for a specific feature */
+    void triggeredForFeature( QgsMapLayer* layer, QgsFeature* feature );
+
+    /** Triggered when action has been run for a specific layer */
+    void triggeredForLayer( QgsMapLayer* layer );
+
+};
+
+class QgsMapLayerActionRegistry : QObject
+{
+%TypeHeaderCode
+#include <qgsmaplayeractionregistry.h>
+%End
+
+  public:
+
+    //! Returns the instance pointer, creating the object on the first call
+    static QgsMapLayerActionRegistry * instance();
+
+    ~QgsMapLayerActionRegistry();
+
+    /**Adds a map layer action to the registry*/
+    void addMapLayerAction( QgsMapLayerAction * action );
+
+    /**Returns the map layer actions which can run on the specified layer*/
+    QList<QgsMapLayerAction *> mapLayerActions( QgsMapLayer* layer );
+
+    /**Removes a map layer action from the registry*/
+    bool removeMapLayerAction( QgsMapLayerAction *action );
+
+    /**Sets the default action for a layer*/
+    void setDefaultActionForLayer( QgsMapLayer* layer, QgsMapLayerAction* action );
+    /**Returns the default action for a layer*/
+    QgsMapLayerAction * defaultActionForLayer( QgsMapLayer* layer );
+
+  protected:
+    //! protected constructor
+    QgsMapLayerActionRegistry( QObject * parent = 0 );
+
+  signals:
+    /** Triggered when an action is added or removed from the registry */
+    void changed();
+
+};

src/app/composer/qgscomposer.cpp

@@ -54,6 +54,8 @@
 #include "qgsmessageviewer.h"
 #include "qgscontexthelp.h"
 #include "qgscursors.h"
+#include "qgsmaplayeractionregistry.h"
+#include "qgsgeometry.h"
 
 #include <QCloseEvent>
 #include <QCheckBox>
@@ -94,6 +96,7 @@ QgsComposer::QgsComposer( QgisApp *qgis, const QString& title )
     , mTitle( title )
     , mQgis( qgis )
     , mUndoView( 0 )
+    , mAtlasFeatureAction( 0 )
 {
   setupUi( this );
   setWindowTitle( mTitle );
@@ -509,6 +512,7 @@ QgsComposer::QgsComposer( QgisApp *qgis, const QString& title )
   mActionExportAtlasAsPDF->setEnabled( false );
   QgsAtlasComposition* atlasMap = &mComposition->atlasComposition();
   connect( atlasMap, SIGNAL( toggled( bool ) ), this, SLOT( toggleAtlasControls( bool ) ) );
+  connect( atlasMap, SIGNAL( coverageLayerChanged( QgsVectorLayer* ) ), this, SLOT( updateAtlasMapLayerAction( QgsVectorLayer * ) ) );
 
   // Create size grip (needed by Mac OS X for QMainWindow if QStatusBar is not visible)
   //should not be needed now that composer has a status bar?
@@ -704,6 +708,12 @@ void QgsComposer::setTitle( const QString& title )
   {
     mWindowAction->setText( title );
   }
+
+  //update atlas map layer action name if required
+  if ( mAtlasFeatureAction )
+  {
+    mAtlasFeatureAction->setText( QString( tr( "Set as atlas feature for %1" ) ).arg( mTitle ) );
+  }
 }
 
 void QgsComposer::updateStatusCursorPos( QPointF cursorPosition )
@@ -820,6 +830,8 @@ void QgsComposer::toggleAtlasControls( bool atlasEnabled )
   mActionExportAtlasAsImage->setEnabled( atlasEnabled );
   mActionExportAtlasAsSVG->setEnabled( atlasEnabled );
   mActionExportAtlasAsPDF->setEnabled( atlasEnabled );
+
+  updateAtlasMapLayerAction( atlasEnabled );
 }
 
 void QgsComposer::on_mActionAtlasPreview_triggered( bool checked )
@@ -2655,6 +2667,8 @@ void QgsComposer::readXML( const QDomElement& composerElem, const QDomDocument&
   mActionExportAtlasAsSVG->setEnabled( atlasMap->enabled() );
   mActionExportAtlasAsPDF->setEnabled( atlasMap->enabled() );
   connect( atlasMap, SIGNAL( toggled( bool ) ), this, SLOT( toggleAtlasControls( bool ) ) );
+  connect( atlasMap, SIGNAL( coverageLayerChanged( QgsVectorLayer* ) ), this, SLOT( updateAtlasMapLayerAction( QgsVectorLayer * ) ) );
+  updateAtlasMapLayerAction( atlasMap->enabled() );
 
   setSelectionTool();
 }
@@ -3083,3 +3097,57 @@ void QgsComposer::writeWorldFile( QString worldFileName, double a, double b, dou
   fout << QString::number( c, 'f' ) << "\r\n";
   fout << QString::number( f, 'f' ) << "\r\n";
 }
+
+
+void QgsComposer::setAtlasFeature( QgsMapLayer* layer, QgsFeature * feat )
+{
+  //update expression variables
+  QgsExpression::setSpecialColumn( "$atlasfeatureid", feat->id() );
+  QgsExpression::setSpecialColumn( "$atlasgeometry", QVariant::fromValue( *( feat->geometry() ) ) );
+
+  emit atlasPreviewFeatureChanged();
+
+  //check if composition has atlas preview
+  QgsAtlasComposition& atlas = mComposition->atlasComposition();
+  if ( ! atlas.enabled() || ! mComposition->atlasMode() == QgsComposition::PreviewAtlas || atlas.coverageLayer() != layer )
+  {
+    //either atlas preview isn't enabled, or layer doesn't match
+    return;
+  }
+
+  //set current preview feature id
+  atlas.prepareForFeature( feat );
+}
+
+void QgsComposer::updateAtlasMapLayerAction( QgsVectorLayer *coverageLayer )
+{
+  if ( mAtlasFeatureAction )
+  {
+    delete mAtlasFeatureAction;
+    mAtlasFeatureAction = 0;
+  }
+
+  if ( coverageLayer )
+  {
+    mAtlasFeatureAction = new QgsMapLayerAction( QString( tr( "Set as atlas feature for %1" ) ).arg( mTitle ), this, coverageLayer );
+    QgsMapLayerActionRegistry::instance()->addMapLayerAction( mAtlasFeatureAction );
+    connect( mAtlasFeatureAction, SIGNAL( triggeredForFeature( QgsMapLayer*, QgsFeature* ) ), this, SLOT( setAtlasFeature( QgsMapLayer*, QgsFeature* ) ) );
+  }
+}
+
+void QgsComposer::updateAtlasMapLayerAction( bool atlasEnabled )
+{
+  if ( mAtlasFeatureAction )
+  {
+    delete mAtlasFeatureAction;
+    mAtlasFeatureAction = 0;
+  }
+
+  if ( atlasEnabled )
+  {
+    QgsAtlasComposition& atlas = mComposition->atlasComposition();
+    mAtlasFeatureAction = new QgsMapLayerAction( QString( tr( "Set as atlas feature for %1" ) ).arg( mTitle ), this, atlas.coverageLayer() );
+    QgsMapLayerActionRegistry::instance()->addMapLayerAction( mAtlasFeatureAction );
+    connect( mAtlasFeatureAction, SIGNAL( triggeredForFeature( QgsMapLayer*, QgsFeature* ) ), this, SLOT( setAtlasFeature( QgsMapLayer*, QgsFeature* ) ) );
+  }
+}

src/app/composer/qgscomposer.h

@@ -38,6 +38,7 @@ class QgsComposerView;
 class QgsComposition;
 class QgsMapCanvas;
 class QgsAtlasComposition;
+class QgsMapLayerAction;
 
 class QGridLayout;
 class QDomNode;
@@ -475,6 +476,9 @@ class QgsComposer: public QMainWindow, private Ui::QgsComposerBase
     //! Exports either either the whole atlas or just the current feature as a PDF, depending on mode
     void exportCompositionAsPDF( QgsComposer::OutputMode mode );
 
+    //! Updates the "set as atlas feature" map layer action, removing it if atlas is disabled
+    void updateAtlasMapLayerAction( bool atlasEnabled );
+
     /**Composer title*/
     QString mTitle;
 
@@ -551,6 +555,8 @@ class QgsComposer: public QMainWindow, private Ui::QgsComposerBase
     //! @note added in 1.9
     QMenu* mHelpMenu;
 
+    QgsMapLayerAction* mAtlasFeatureAction;
+
   signals:
     void printAsRasterChanged( bool state );
 
@@ -579,6 +585,13 @@ class QgsComposer: public QMainWindow, private Ui::QgsComposerBase
     //! Toggles the state of the atlas preview and navigation controls
     //! @note added in 2.1
     void toggleAtlasControls( bool atlasEnabled );
+
+    //! Sets the specified feature as the current atlas feature
+    //! @note added in 2.1
+    void setAtlasFeature( QgsMapLayer* layer, QgsFeature * feat );
+
+    //! Updates the "set as atlas feature" map layer action when atlas coverage layer changes
+    void updateAtlasMapLayerAction( QgsVectorLayer* coverageLayer );
 };
 
 #endif

src/app/qgisapp.cpp

@@ -192,6 +192,7 @@
 #include "qgsvectorlayerproperties.h"
 #include "qgsmessagelogviewer.h"
 #include "qgsdataitem.h"
+#include "qgsmaplayeractionregistry.h"
 
 #include "qgssublayersdialog.h"
 #include "ogr/qgsopenvectorlayerdialog.h"
@@ -609,6 +610,8 @@ QgisApp::QgisApp( QSplashScreen *splash, bool restorePlugins, QWidget * parent,
 
   activateDeactivateLayerRelatedActions( NULL ); // after members were created
 
+  connect( QgsMapLayerActionRegistry::instance(), SIGNAL( changed() ), this, SLOT( refreshActionFeatureAction() ) );
+
   // set application's caption
   QString caption = tr( "QGIS - %1 ('%2')" ).arg( QGis::QGIS_VERSION ).arg( QGis::QGIS_RELEASE_NAME );
   setWindowTitle( caption );
@@ -4276,7 +4279,27 @@ void QgisApp::updateDefaultFeatureAction( QAction *action )
   mFeatureActionMenu->setActiveAction( action );
 
   int index = mFeatureActionMenu->actions().indexOf( action );
-  vlayer->actions()->setDefaultAction( index );
+
+  if ( vlayer->actions()->size() > 0 && index < vlayer->actions()->size() )
+  {
+    vlayer->actions()->setDefaultAction( index );
+    QgsMapLayerActionRegistry::instance()->setDefaultActionForLayer( vlayer, 0 );
+  }
+  else
+  {
+    //action is from QgsMapLayerActionRegistry
+    vlayer->actions()->setDefaultAction( -1 );
+
+    QgsMapLayerAction * mapLayerAction = dynamic_cast<QgsMapLayerAction *>( action );
+    if ( mapLayerAction )
+    {
+      QgsMapLayerActionRegistry::instance()->setDefaultActionForLayer( vlayer, mapLayerAction );
+    }
+    else
+    {
+      QgsMapLayerActionRegistry::instance()->setDefaultActionForLayer( vlayer, 0 );
+    }
+  }
 
   doFeatureAction();
 }
@@ -4298,6 +4321,24 @@ void QgisApp::refreshFeatureActions()
       mFeatureActionMenu->setActiveAction( action );
     }
   }
+
+  //add actions registered in QgsMapLayerActionRegistry
+  QList<QgsMapLayerAction *> registeredActions = QgsMapLayerActionRegistry::instance()->mapLayerActions( vlayer );
+  if ( actions->size() > 0 && registeredActions.size() > 0 )
+  {
+    //add a seperator between user defined and standard actions
+    mFeatureActionMenu->addSeparator();
+  }
+
+  for ( int i = 0; i < registeredActions.size(); i++ )
+  {
+    mFeatureActionMenu->addAction( registeredActions.at( i ) );
+    if ( registeredActions.at( i ) == QgsMapLayerActionRegistry::instance()->defaultActionForLayer( vlayer ) )
+    {
+      mFeatureActionMenu->setActiveAction( registeredActions.at( i ) );
+    }
+  }
+
 }
 
 void QgisApp::measure()
@@ -8489,7 +8530,7 @@ void QgisApp::activateDeactivateLayerRelatedActions( QgsMapLayer* layer )
 
     bool isEditable = vlayer->isEditable();
     bool layerHasSelection = vlayer->selectedFeatureCount() > 0;
-    bool layerHasActions = vlayer->actions()->size() > 0;
+    bool layerHasActions = vlayer->actions()->size() + QgsMapLayerActionRegistry::instance()->mapLayerActions( vlayer ).size() > 0;
 
     bool canChangeAttributes = dprovider->capabilities() & QgsVectorDataProvider::ChangeAttributeValues;
     bool canDeleteFeatures = dprovider->capabilities() & QgsVectorDataProvider::DeleteFeatures;
@@ -8733,8 +8774,20 @@ void QgisApp::activateDeactivateLayerRelatedActions( QgsMapLayer* layer )
   }
 }
 
+void QgisApp::refreshActionFeatureAction()
+{
+  QgsMapLayer* layer = activeLayer();
 
+  if ( layer->type() != QgsMapLayer::VectorLayer )
+  {
+    return;
+  }
 
+  QgsVectorLayer* vlayer = qobject_cast<QgsVectorLayer *>( layer );
+
+  bool layerHasActions = vlayer->actions()->size() + QgsMapLayerActionRegistry::instance()->mapLayerActions( vlayer ).size() > 0;
+  mActionFeatureAction->setEnabled( layerHasActions );
+}
 
 /////////////////////////////////////////////////////////////////
 //