Add KExtraColumnsProxyModel::removeColumn, will be needed by StatisticsProxyModel

autotests/kextracolumnsproxymodeltest.cpp

@@ -52,7 +52,9 @@ private:
         TwoExtraColumnsProxyModel() : KExtraColumnsProxyModel(), m_extraColumnData('Z')
         {
             appendColumn(QStringLiteral("H5"));
+            appendColumn(QStringLiteral("WRONG")); // removed two lines below, just to test removeColumn
             appendColumn(QStringLiteral("H6"));
+            removeColumn(1);
         }
         QVariant extraColumnData(const QModelIndex &, int row, int extraColumn, int role) const Q_DECL_OVERRIDE
         {

src/kextracolumnsproxymodel.cpp

@@ -61,6 +61,12 @@ void KExtraColumnsProxyModel::appendColumn(const QString &header)
     d->m_extraHeaders.append(header);
 }
 
+void KExtraColumnsProxyModel::removeColumn(int idx)
+{
+    Q_D(KExtraColumnsProxyModel);
+    d->m_extraHeaders.remove(idx);
+}
+
 bool KExtraColumnsProxyModel::setExtraColumnData(const QModelIndex &parent, int row, int extraColumn, const QVariant &data, int role)
 {
     Q_UNUSED(parent);

src/kextracolumnsproxymodel.h

@@ -65,9 +65,18 @@ public:
     /**
      * Appends an extra column.
      * @param header an optional text for the horizontal header
+     * This does not emit any signals - do it in the initial setup phase
      */
     void appendColumn(const QString &header = QString());
 
+    /**
+     * Removes an extra column.
+     * @param idx index of the extra column (starting from 0).
+     * This does not emit any signals - do it in the initial setup phase
+     * @since 5.24
+     */
+    void removeColumn(int idx);
+
     /**
      * This method is called by data() for extra columns.
      * Reimplement this method to return the data for the extra columns.