QgsMapLayerModel: allow direct retrieval of map layer

cmake_templates/Doxyfile.in

@@ -1371,7 +1371,7 @@ INCLUDE_FILE_PATTERNS  =
 # undefined via #undef or recursively expanded use the := operator
 # instead of the = operator.
 
-PREDEFINED             =
+PREDEFINED             = "QT_VERSION=0x040800"
 
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then
 # this tag can be used to specify a list of macro names that should be expanded.

python/gui/qgsmaplayermodel.sip

@@ -13,7 +13,11 @@ class QgsMapLayerModel : QAbstractItemModel
 %End
 
   public:
-    static const int LayerIdRole;
+    enum
+    {
+      LayerIdRole,
+      LayerRole
+    };
 
     /**
      * @brief QgsMapLayerModel creates a model to display layers in widgets.
@@ -56,6 +60,14 @@ class QgsMapLayerModel : QAbstractItemModel
     int rowCount( const QModelIndex &parent ) const;
     int columnCount( const QModelIndex &parent ) const;
     QVariant data( const QModelIndex &index, int role ) const;
+%If (QT5_SUPPORT)
+    /**
+     * Returns strings for all roles supported by this model.
+     *
+     * @note Available only with Qt5 (python and c++)
+     */
+    QHash<int, QByteArray> roleNames() const;
+%End
     bool setData( const QModelIndex &index, const QVariant &value, int role );
     Qt::ItemFlags flags( const QModelIndex &index ) const;
 };

src/core/qgsmaplayer.h

@@ -759,4 +759,6 @@ class CORE_EXPORT QgsMapLayer : public QObject
     QgsMapLayerStyleManager* mStyleManager;
 };
 
+Q_DECLARE_METATYPE( QgsMapLayer* )
+
 #endif

src/gui/qgsmaplayermodel.cpp

@@ -22,8 +22,6 @@
 #include "qgsvectorlayer.h"
 
 
-const int QgsMapLayerModel::LayerIdRole = Qt::UserRole + 1;
-
 QgsMapLayerModel::QgsMapLayerModel( const QList<QgsMapLayer *>& layers, QObject *parent )
     : QAbstractItemModel( parent )
     , mLayersChecked( QMap<QString, Qt::CheckState>() )
@@ -151,6 +149,11 @@ QVariant QgsMapLayerModel::data( const QModelIndex &index, int role ) const
     return layer->id();
   }
 
+  if ( role == LayerRole )
+  {
+    return QVariant::fromValue<QgsMapLayer*>( static_cast<QgsMapLayer*>( index.internalPointer() ) );
+  }
+
   if ( role == Qt::CheckStateRole && mItemCheckable )
   {
     QgsMapLayer* layer = static_cast<QgsMapLayer*>( index.internalPointer() );
@@ -213,6 +216,16 @@ QVariant QgsMapLayerModel::data( const QModelIndex &index, int role ) const
   return QVariant();
 }
 
+#if QT_VERSION >= 0x050000
+QHash<int, QByteArray> QgsMapLayerModel::roleNames() const
+{
+  QHash<int, QByteArray> roles  = QAbstractItemModel::roleNames();
+  roles[LayerIdRole]  = "layerId";
+  roles[LayerRole] = "layer";
+
+  return roles;
+}
+#endif
 
 Qt::ItemFlags QgsMapLayerModel::flags( const QModelIndex &index ) const
 {

src/gui/qgsmaplayermodel.h

@@ -29,11 +29,16 @@ class QgsMapLayer;
  * @see QgsFieldModel to combine in with a field selector.
  * @note added in 2.3
  */
+// TODO QGIS3: move to core
 class GUI_EXPORT QgsMapLayerModel : public QAbstractItemModel
 {
     Q_OBJECT
   public:
-    static const int LayerIdRole;
+    enum
+    {
+      LayerIdRole = Qt::UserRole + 1,
+      LayerRole
+    };
 
     /**
      * @brief QgsMapLayerModel creates a model to display layers in widgets.
@@ -81,6 +86,16 @@ class GUI_EXPORT QgsMapLayerModel : public QAbstractItemModel
     int rowCount( const QModelIndex &parent ) const override;
     int columnCount( const QModelIndex &parent ) const override;
     QVariant data( const QModelIndex &index, int role ) const override;
+///@cond PRIVATE
+#if QT_VERSION >= 0x050000
+    /**
+     * Returns strings for all roles supported by this model.
+     *
+     * @note Available only with Qt5 (python and c++)
+     */
+    QHash<int, QByteArray> roleNames() const override;
+#endif
+///@endcond
     bool setData( const QModelIndex &index, const QVariant &value, int role ) override;
     Qt::ItemFlags flags( const QModelIndex &index ) const override;
 };