Allow QgsMapLayerProxyModel to be filtered by string

python/core/auto_generated/qgsmaplayerproxymodel.sip.in

@@ -93,6 +93,15 @@ Returns the list of data providers which are excluded from the model.
 .. seealso:: :py:func:`setExcludedProviders`
 
 .. versionadded:: 3.0
+%End
+
+    QString filterString() const;
+%Docstring
+Returns the current filter string, if set.
+
+.. seealso:: :py:func:`setFilterString`
+
+.. versionadded:: 3.4
 %End
 
     virtual bool filterAcceptsRow( int source_row, const QModelIndex &source_parent ) const;
@@ -100,6 +109,18 @@ Returns the list of data providers which are excluded from the model.
     virtual bool lessThan( const QModelIndex &left, const QModelIndex &right ) const;
 
 
+  public slots:
+
+    void setFilterString( const QString &filter );
+%Docstring
+Sets a ``filter`` string, such that only layers with names matching the
+specified string will be shown.
+
+.. seealso:: :py:func:`filterString`
+
+.. versionadded:: 3.4
+%End
+
 };
 
 QFlags<QgsMapLayerProxyModel::Filter> operator|(QgsMapLayerProxyModel::Filter f1, QFlags<QgsMapLayerProxyModel::Filter> f2);

src/core/qgsmaplayerproxymodel.cpp

@@ -80,9 +80,15 @@ void QgsMapLayerProxyModel::setExcludedProviders( const QStringList &providers )
   invalidateFilter();
 }
 
+void QgsMapLayerProxyModel::setFilterString( const QString &filter )
+{
+  mFilterString = filter;
+  invalidateFilter();
+}
+
 bool QgsMapLayerProxyModel::filterAcceptsRow( int source_row, const QModelIndex &source_parent ) const
 {
-  if ( mFilters.testFlag( All ) && mExceptList.isEmpty() && mExcludedProviders.isEmpty() )
+  if ( mFilters.testFlag( All ) && mExceptList.isEmpty() && mExcludedProviders.isEmpty() && mFilterString.isEmpty() )
     return true;
 
   QModelIndex index = sourceModel()->index( source_row, 0, source_parent );
@@ -104,6 +110,9 @@ bool QgsMapLayerProxyModel::filterAcceptsRow( int source_row, const QModelIndex
   if ( mFilters.testFlag( WritableLayer ) && layer->readOnly() )
     return false;
 
+  if ( !layer->name().contains( mFilterString, Qt::CaseInsensitive ) )
+    return false;
+
   // layer type
   if ( ( mFilters.testFlag( RasterLayer ) && layer->type() == QgsMapLayer::RasterLayer ) ||
        ( mFilters.testFlag( VectorLayer ) && layer->type() == QgsMapLayer::VectorLayer ) ||

src/core/qgsmaplayerproxymodel.h

@@ -98,14 +98,34 @@ class CORE_EXPORT QgsMapLayerProxyModel : public QSortFilterProxyModel
      */
     QStringList excludedProviders() const { return mExcludedProviders; }
 
+    /**
+     * Returns the current filter string, if set.
+     *
+     * \see setFilterString()
+     * \since QGIS 3.4
+     */
+    QString filterString() const { return mFilterString; }
+
     bool filterAcceptsRow( int source_row, const QModelIndex &source_parent ) const override;
     bool lessThan( const QModelIndex &left, const QModelIndex &right ) const override;
 
+  public slots:
+
+    /**
+     * Sets a \a filter string, such that only layers with names matching the
+     * specified string will be shown.
+     *
+     * \see filterString()
+     * \since QGIS 3.4
+    */
+    void setFilterString( const QString &filter );
+
   private:
     Filters mFilters;
     QList<QgsMapLayer *> mExceptList;
     QgsMapLayerModel *mModel = nullptr;
     QStringList mExcludedProviders;
+    QString mFilterString;
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS( QgsMapLayerProxyModel::Filters )