Better way to mark styles as read only

python/core/auto_generated/symbology/qgsstyle.sip.in

@@ -114,6 +114,34 @@ Sets the ``name`` of the style.
 
 .. seealso:: :py:func:`name`
 
+.. versionadded:: 3.26
+%End
+
+    bool isReadOnly() const;
+%Docstring
+Returns ``True`` if the style is considered a read-only library.
+
+.. note::
+
+   This flag is used to control GUI operations, and does not prevent calling functions
+   which mutate the style directly via the API.
+
+.. seealso:: :py:func:`setReadOnly`
+
+.. versionadded:: 3.26
+%End
+
+    void setReadOnly( bool readOnly );
+%Docstring
+Sets whether the style is considered a read-only library.
+
+.. note::
+
+   This flag is used to control GUI operations, and does not prevent calling functions
+   which mutate the style directly via the API.
+
+.. seealso:: :py:func:`isReadOnly`
+
 .. versionadded:: 3.26
 %End
 

src/core/project/qgsprojectstylesettings.cpp

@@ -312,6 +312,7 @@ void QgsProjectStyleSettings::loadStyleAtPath( const QString &path )
     style->createMemoryDatabase();
     style->importXml( path );
     style->setFileName( path );
+    style->setReadOnly( true );
   }
   else
   {
@@ -519,11 +520,9 @@ bool QgsProjectStyleDatabaseProxyModel::filterAcceptsRow( int sourceRow, const Q
 {
   if ( mFilters & Filter::FilterHideReadOnly )
   {
-    const QString path = sourceModel()->data( sourceModel()->index( sourceRow, 0, sourceParent ), QgsProjectStyleDatabaseModel::Role::PathRole ).toString();
-    if ( !path.isEmpty() )
+    if ( const QgsStyle *style = qobject_cast< QgsStyle * >( sourceModel()->data( sourceModel()->index( sourceRow, 0, sourceParent ), QgsProjectStyleDatabaseModel::Role::StyleRole ).value< QObject * >() ) )
     {
-      const QFileInfo fi( path );
-      if ( fi.suffix().compare( QLatin1String( "xml" ), Qt::CaseInsensitive ) == 0 )
+      if ( style->isReadOnly() )
         return false;
     }
   }

src/core/symbology/qgsstyle.cpp

@@ -3043,6 +3043,16 @@ bool QgsStyle::isXmlStyleFile( const QString &path )
   return line == QLatin1String( "<!DOCTYPE qgis_style>" );
 }
 
+bool QgsStyle::isReadOnly() const
+{
+  return mReadOnly;
+}
+
+void QgsStyle::setReadOnly( bool readOnly )
+{
+  mReadOnly = readOnly;
+}
+
 bool QgsStyle::updateSymbol( StyleEntity type, const QString &name )
 {
   QDomDocument doc( QStringLiteral( "dummy" ) );

src/core/symbology/qgsstyle.h

@@ -203,6 +203,28 @@ class CORE_EXPORT QgsStyle : public QObject
      */
     void setName( const QString &name );
 
+    /**
+     * Returns TRUE if the style is considered a read-only library.
+     *
+     * \note This flag is used to control GUI operations, and does not prevent calling functions
+     * which mutate the style directly via the API.
+     *
+     * \see setReadOnly()
+     * \since QGIS 3.26
+     */
+    bool isReadOnly() const;
+
+    /**
+     * Sets whether the style is considered a read-only library.
+     *
+     * \note This flag is used to control GUI operations, and does not prevent calling functions
+     * which mutate the style directly via the API.
+     *
+     * \see isReadOnly()
+     * \since QGIS 3.26
+     */
+    void setReadOnly( bool readOnly );
+
     /**
      * Adds an \a entity to the style, with the specified \a name. Ownership is not transferred.
      *
@@ -1147,6 +1169,7 @@ class CORE_EXPORT QgsStyle : public QObject
   private:
 
     QString mName;
+    bool mReadOnly = false;
 
     QgsSymbolMap mSymbols;
     QgsVectorColorRampMap mColorRamps;

tests/src/core/testqgsstyle.cpp

@@ -204,6 +204,10 @@ void TestStyle::testProperties()
 
   s.setFileName( QStringLiteral( "file name" ) );
   QCOMPARE( s.fileName(), QStringLiteral( "file name" ) );
+
+  QVERIFY( !s.isReadOnly() );
+  s.setReadOnly( true );
+  QVERIFY( s.isReadOnly() );
 }
 
 void TestStyle::testCreateSymbols()