Add a 'filterCallback' property to SortFilterModel.

Allows setting a callback function from QML to replace the
default filter implementation.

src/declarativeimports/core/datamodel.cpp

@@ -20,6 +20,8 @@
 #include "datamodel.h"
 #include "datasource.h"
 
+#include <QQmlContext>
+#include <QQmlEngine>
 #include <QTimer>
 
 #include <QDebug>
@@ -90,6 +92,22 @@ void SortFilterModel::setModel(QAbstractItemModel *model)
     emit sourceModelChanged(model);
 }
 
+bool SortFilterModel::filterAcceptsRow(int source_row, const QModelIndex& source_parent) const
+{
+    if (m_filterCallback.isCallable()) {
+        QJSValueList args;
+        args << QJSValue(source_row);
+
+        const QModelIndex idx = sourceModel()->index(source_row, filterKeyColumn(), source_parent);
+        QQmlEngine *engine = QQmlEngine::contextForObject(this)->engine();
+        args << engine->toScriptValue<QVariant>(idx.data(m_roleIds.value(m_filterRole)));
+
+        return const_cast<SortFilterModel *>(this)->m_filterCallback.call(args).toBool();
+    }
+
+    return QSortFilterProxyModel::filterAcceptsRow(source_row, source_parent);
+}
+
 void SortFilterModel::setFilterRegExp(const QString &exp)
 {
     if (exp == filterRegExp()) {
@@ -119,6 +137,26 @@ QString SortFilterModel::filterString() const
     return m_filterString;
 }
 
+QJSValue SortFilterModel::filterCallback() const
+{
+    return m_filterCallback;
+}
+
+void SortFilterModel::setFilterCallback(const QJSValue& callback)
+{
+    if (m_filterCallback.strictlyEquals(callback)) {
+        return;
+    }
+
+    if (!callback.isNull() && !callback.isCallable()) {
+        return;
+    }
+
+    m_filterCallback = callback;
+
+    emit filterCallbackChanged(callback);
+}
+
 void SortFilterModel::setFilterRole(const QString &role)
 {
     QSortFilterProxyModel::setFilterRole(roleNameToId(role));

src/declarativeimports/core/datamodel.h

@@ -21,6 +21,7 @@
 #define DATAMODEL_H
 
 #include <QAbstractItemModel>
+#include <QJSValue>
 #include <QSortFilterProxyModel>
 #include <QVector>
 
@@ -56,6 +57,16 @@ class SortFilterModel : public QSortFilterProxyModel
      */
     Q_PROPERTY(QString filterString READ filterString WRITE setFilterString NOTIFY filterStringChanged REVISION 1)
 
+    /**
+     * A JavaScript callable that is passed the source model row index as first argument and the value
+     * of filterRole as second argument. The callable's return value is evaluated as boolean to determine
+     * whether the row is accepted (true) or filtered out (false). It overrides the default implementation
+     * that uses filterRegExp or filterString; while filterCallable is set those two properties are
+     * ignored. Attempts to write a non-callable to this property are silently ignored, but you can set
+     * it to null.
+     */
+    Q_PROPERTY(QJSValue filterCallback READ filterCallback WRITE setFilterCallback NOTIFY filterCallbackChanged REVISION 1)
+
     /**
      * The role of the sourceModel on which filterRegExp must be applied.
      */
@@ -90,6 +101,9 @@ public:
     void setFilterString(const QString &filterString);
     QString filterString() const;
 
+    void setFilterCallback(const QJSValue &callback);
+    QJSValue filterCallback() const;
+
     void setFilterRole(const QString &role);
     QString filterRole() const;
 
@@ -121,9 +135,11 @@ Q_SIGNALS:
     void sourceModelChanged(QObject *);
     void filterRegExpChanged(const QString &);
     Q_REVISION(1) void filterStringChanged(const QString &);
+    Q_REVISION(1) void filterCallbackChanged(const QJSValue &);
 
 protected:
     int roleNameToId(const QString &name);
+    virtual bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const;
 
 protected Q_SLOTS:
     void syncRoleNames();
@@ -132,6 +148,7 @@ private:
     QString m_filterRole;
     QString m_sortRole;
     QString m_filterString;
+    QJSValue m_filterCallback;
     QHash<QString, int> m_roleIds;
 };