Sort variables in variable editor

Author: nyalldawson

python/core/qgsexpressioncontext.sip

@@ -125,9 +125,17 @@ class QgsExpressionContextScope
 
     /** Returns a list of variable names contained within the scope.
      * @see functionNames()
+     * @see filteredVariableNames()
      */
     QStringList variableNames() const;
 
+    /** Returns a fitlered and sorted list of variable names contained within the scope.
+     * Hidden variable names will be excluded, and the list will be sorted so that
+     * read only variables are listed first.
+     * @see variableNames()
+     */
+    QStringList filteredVariableNames() const;
+
     /** Tests whether the specified variable is read only and should not be editable
      * by users.
      * @param name variable name

src/core/qgsexpressioncontext.cpp

@@ -112,6 +112,51 @@ QStringList QgsExpressionContextScope::variableNames() const
   return names;
 }
 
+bool QgsExpressionContextScope::variableNameSort( const QString& a, const QString& b )
+{
+  return QString::localeAwareCompare( a, b ) < 0;
+}
+
+// not public API
+/// @cond
+class QgsExpressionContextVariableCompare
+{
+  public:
+    explicit QgsExpressionContextVariableCompare( const QgsExpressionContextScope& scope )
+        : mScope( scope )
+    {  }
+
+    bool operator()( const QString& a, const QString& b ) const
+    {
+      bool aReadOnly = mScope.isReadOnly( a );
+      bool bReadOnly = mScope.isReadOnly( b );
+      if ( aReadOnly != bReadOnly )
+        return aReadOnly;
+      return QString::localeAwareCompare( a, b ) < 0;
+    }
+
+  private:
+    const QgsExpressionContextScope& mScope;
+};
+/// @endcond
+
+QStringList QgsExpressionContextScope::filteredVariableNames() const
+{
+  QStringList allVariables = mVariables.keys();
+  QStringList filtered;
+  Q_FOREACH ( const QString& variable, allVariables )
+  {
+    if ( variable.startsWith( "_" ) )
+      continue;
+
+    filtered << variable;
+  }
+  QgsExpressionContextVariableCompare cmp( *this );
+  qSort( filtered.begin(), filtered.end(), cmp );
+
+  return filtered;
+}
+
 bool QgsExpressionContextScope::isReadOnly( const QString &name ) const
 {
   return hasVariable( name ) ? mVariables.value( name ).readOnly : false;

src/core/qgsexpressioncontext.h

@@ -155,9 +155,17 @@ class CORE_EXPORT QgsExpressionContextScope
 
     /** Returns a list of variable names contained within the scope.
      * @see functionNames()
+     * @see filteredVariableNames()
      */
     QStringList variableNames() const;
 
+    /** Returns a fitlered and sorted list of variable names contained within the scope.
+     * Hidden variable names will be excluded, and the list will be sorted so that
+     * read only variables are listed first.
+     * @see variableNames()
+     */
+    QStringList filteredVariableNames() const;
+
     /** Tests whether the specified variable is read only and should not be editable
      * by users.
      * @param name variable name
@@ -216,6 +224,7 @@ class CORE_EXPORT QgsExpressionContextScope
     QHash<QString, StaticVariable> mVariables;
     QHash<QString, QgsScopedExpressionFunction* > mFunctions;
 
+    bool variableNameSort( const QString &a, const QString &b );
 };
 
 /** \ingroup core

src/gui/qgsvariableeditorwidget.cpp

@@ -366,11 +366,8 @@ void QgsVariableEditorTree::refreshScopeVariables( QgsExpressionContextScope* sc
   bool isCurrent = scopeIndex == mEditableScopeIndex;
   QTreeWidgetItem* scopeItem = mScopeToItem.value( scopeIndex );
 
-  Q_FOREACH ( const QString& name, scope->variableNames() )
+  Q_FOREACH ( const QString& name, scope->filteredVariableNames() )
   {
-    if ( name.startsWith( QChar( '_' ) ) )
-      continue;
-
     QTreeWidgetItem* item;
     if ( mVariableToItem.contains( qMakePair( scopeIndex, name ) ) )
     {

tests/src/core/testqgsexpressioncontext.cpp

@@ -165,6 +165,10 @@ void TestQgsExpressionContext::contextScope()
   scope.setVariable( "readonly", "newvalue" );
   QVERIFY( scope.isReadOnly( "readonly" ) );
 
+  //test retrieving filtered variable names
+  scope.setVariable( "_hidden_", "hidden" );
+  QCOMPARE( scope.filteredVariableNames(), QStringList() << "readonly" << "notreadonly" << "test" );
+
   //removal
   scope.setVariable( "toremove", 5 );
   QVERIFY( scope.hasVariable( "toremove" ) );