[api] Make QgsLayerTreeView proxy handling more flexible

Allow use of custom QgsLayerTreeProxyModel subclasses

python/PyQt6/gui/auto_additions/qgslayertreeview.py

@@ -7,12 +7,13 @@ try:
 except (NameError, AttributeError):
     pass
 try:
-    QgsLayerTreeViewMenuProvider.__abstract_methods__ = ['createContextMenu']
-    QgsLayerTreeViewMenuProvider.__group__ = ['layertree']
-except (NameError, AttributeError):
-    pass
-try:
+    QgsLayerTreeProxyModel.__virtual_methods__ = ['nodeShown']
     QgsLayerTreeProxyModel.__overridden_methods__ = ['filterAcceptsRow']
     QgsLayerTreeProxyModel.__group__ = ['layertree']
 except (NameError, AttributeError):
     pass
+try:
+    QgsLayerTreeViewMenuProvider.__abstract_methods__ = ['createContextMenu']
+    QgsLayerTreeViewMenuProvider.__group__ = ['layertree']
+except (NameError, AttributeError):
+    pass

python/PyQt6/gui/auto_generated/layertree/qgslayertreeview.sip.in

@@ -75,6 +75,13 @@ shown).
     virtual bool filterAcceptsRow( int sourceRow, const QModelIndex &sourceParent ) const;
 
 
+    virtual bool nodeShown( QgsLayerTreeNode *node ) const;
+%Docstring
+Returns ``True`` if the specified ``node`` should be shown.
+
+.. versionadded:: 4.0
+%End
+
 };
 
 
@@ -118,6 +125,19 @@ Constructor for QgsLayerTreeView
 %Docstring
 Overridden :py:func:`~QgsLayerTreeView.setModel` from base class. Only
 :py:class:`QgsLayerTreeModel` is an acceptable model.
+
+.. note::
+
+   This method automatically creates a :py:class:`QgsLayerTreeProxyModel` to use as a proxy.
+%End
+
+    void setModel( QgsLayerTreeModel *model, QgsLayerTreeProxyModel *proxyModel );
+%Docstring
+Sets the ``model`` and ``proxyModel`` for the view.
+
+Use this method when a custom proxy model is required.
+
+.. versionadded:: 4.0
 %End
 
     QgsLayerTreeModel *layerTreeModel() const;

python/gui/auto_additions/qgslayertreeview.py

@@ -7,12 +7,13 @@ try:
 except (NameError, AttributeError):
     pass
 try:
-    QgsLayerTreeViewMenuProvider.__abstract_methods__ = ['createContextMenu']
-    QgsLayerTreeViewMenuProvider.__group__ = ['layertree']
-except (NameError, AttributeError):
-    pass
-try:
+    QgsLayerTreeProxyModel.__virtual_methods__ = ['nodeShown']
     QgsLayerTreeProxyModel.__overridden_methods__ = ['filterAcceptsRow']
     QgsLayerTreeProxyModel.__group__ = ['layertree']
 except (NameError, AttributeError):
     pass
+try:
+    QgsLayerTreeViewMenuProvider.__abstract_methods__ = ['createContextMenu']
+    QgsLayerTreeViewMenuProvider.__group__ = ['layertree']
+except (NameError, AttributeError):
+    pass

python/gui/auto_generated/layertree/qgslayertreeview.sip.in

@@ -75,6 +75,13 @@ shown).
     virtual bool filterAcceptsRow( int sourceRow, const QModelIndex &sourceParent ) const;
 
 
+    virtual bool nodeShown( QgsLayerTreeNode *node ) const;
+%Docstring
+Returns ``True`` if the specified ``node`` should be shown.
+
+.. versionadded:: 4.0
+%End
+
 };
 
 
@@ -118,6 +125,19 @@ Constructor for QgsLayerTreeView
 %Docstring
 Overridden :py:func:`~QgsLayerTreeView.setModel` from base class. Only
 :py:class:`QgsLayerTreeModel` is an acceptable model.
+
+.. note::
+
+   This method automatically creates a :py:class:`QgsLayerTreeProxyModel` to use as a proxy.
+%End
+
+    void setModel( QgsLayerTreeModel *model, QgsLayerTreeProxyModel *proxyModel );
+%Docstring
+Sets the ``model`` and ``proxyModel`` for the view.
+
+Use this method when a custom proxy model is required.
+
+.. versionadded:: 4.0
 %End
 
     QgsLayerTreeModel *layerTreeModel() const;

src/gui/layertree/qgslayertreeview.cpp

@@ -91,6 +91,15 @@ void QgsLayerTreeView::setModel( QAbstractItemModel *model )
   if ( !treeModel )
     return;
 
+  auto proxyModel = new QgsLayerTreeProxyModel( treeModel, this );
+  proxyModel->setShowPrivateLayers( mShowPrivateLayers );
+  proxyModel->setHideValidLayers( mHideValidLayers );
+
+  setModel( treeModel, proxyModel );
+}
+
+void QgsLayerTreeView::setModel( QgsLayerTreeModel *treeModel, QgsLayerTreeProxyModel *proxyModel )
+{
   if ( mMessageBar )
     connect( treeModel, &QgsLayerTreeModel::messageEmitted, this, [this]( const QString &message, Qgis::MessageLevel level = Qgis::MessageLevel::Info, int duration = 5 ) {
       Q_UNUSED( duration )
@@ -99,8 +108,7 @@ void QgsLayerTreeView::setModel( QAbstractItemModel *model )
 
   treeModel->addTargetScreenProperties( QgsScreenProperties( screen() ) );
 
-  mProxyModel = new QgsLayerTreeProxyModel( treeModel, this );
-
+  mProxyModel = proxyModel;
   connect( mProxyModel, &QAbstractItemModel::rowsInserted, this, &QgsLayerTreeView::modelRowsInserted );
   connect( mProxyModel, &QAbstractItemModel::rowsRemoved, this, &QgsLayerTreeView::modelRowsRemoved );
 
@@ -108,8 +116,6 @@ void QgsLayerTreeView::setModel( QAbstractItemModel *model )
   new ModelTest( mProxyModel, this );
 #endif
 
-  mProxyModel->setShowPrivateLayers( mShowPrivateLayers );
-  mProxyModel->setHideValidLayers( mHideValidLayers );
   QTreeView::setModel( mProxyModel );
 
   connect( treeModel->rootGroup(), &QgsLayerTreeNode::expandedChanged, this, &QgsLayerTreeView::onExpandedChanged );

src/gui/layertree/qgslayertreeview.h

@@ -96,9 +96,14 @@ class GUI_EXPORT QgsLayerTreeProxyModel : public QSortFilterProxyModel
   protected:
     bool filterAcceptsRow( int sourceRow, const QModelIndex &sourceParent ) const override;
 
-  private:
-    bool nodeShown( QgsLayerTreeNode *node ) const;
+    /**
+     * Returns TRUE if the specified \a node should be shown.
+     *
+     * \since QGIS 4.0
+     */
+    virtual bool nodeShown( QgsLayerTreeNode *node ) const;
 
+  private:
     QgsLayerTreeModel *mLayerTreeModel = nullptr;
     QString mFilterText;
     bool mShowPrivateLayers = false;
@@ -138,9 +143,22 @@ class GUI_EXPORT QgsLayerTreeView : public QTreeView
     explicit QgsLayerTreeView( QWidget *parent SIP_TRANSFERTHIS = nullptr );
     ~QgsLayerTreeView() override;
 
-    //! Overridden setModel() from base class. Only QgsLayerTreeModel is an acceptable model.
+    /**
+     * Overridden setModel() from base class. Only QgsLayerTreeModel is an acceptable model.
+     *
+     * \note This method automatically creates a QgsLayerTreeProxyModel to use as a proxy.
+     */
     void setModel( QAbstractItemModel *model ) override;
 
+    /**
+     * Sets the \a model and \a proxyModel for the view.
+     *
+     * Use this method when a custom proxy model is required.
+     *
+     * \since QGIS 4.0
+     */
+    void setModel( QgsLayerTreeModel *model, QgsLayerTreeProxyModel *proxyModel );
+
     //! Gets access to the model casted to QgsLayerTreeModel
     QgsLayerTreeModel *layerTreeModel() const;
 

tests/src/python/test_qgslayertreeview.py

@@ -22,7 +22,11 @@ from qgis.core import (
     QgsMarkerSymbol,
     QgsMapLayerLegend,
 )
-from qgis.gui import QgsLayerTreeView, QgsLayerTreeViewDefaultActions
+from qgis.gui import (
+    QgsLayerTreeView,
+    QgsLayerTreeViewDefaultActions,
+    QgsLayerTreeProxyModel,
+)
 import unittest
 from qgis.testing import start_app, QgisTestCase
 
@@ -814,6 +818,24 @@ class TestQgsLayerTreeView(QgisTestCase):
             view.selectedLegendNodes(), [legend_nodes[0], legend_nodes[2]]
         )
 
+    def test_set_model_and_proxy(self):
+        root = QgsLayerTree()
+        model = QgsLayerTreeModel(root)
+        view = QgsLayerTreeView()
+
+        view.setModel(model)
+        self.assertEqual(view.layerTreeModel(), model)
+        # a proxy should have been auto-created
+        self.assertIsInstance(view.model(), QgsLayerTreeProxyModel)
+
+        # set an explicit proxy
+        root2 = QgsLayerTree()
+        model2 = QgsLayerTreeModel(root2)
+        my_proxy = QgsLayerTreeProxyModel(model2, None)
+        view.setModel(model2, my_proxy)
+        self.assertEqual(view.layerTreeModel(), model2)
+        self.assertEqual(view.model(), my_proxy)
+
 
 if __name__ == "__main__":
     unittest.main()