Remove proxy code duplication

models/proxymodel.cpp

@@ -0,0 +1,61 @@
+/*
+ * Cantata
+ *
+ * Copyright (c) 2011-2012 Craig Drummond <craig.p.drummond@gmail.com>
+ *
+ * ----
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "proxymodel.h"
+
+void ProxyModel::update(const QString &text, const QString &genre)
+{
+    if (text.length()<2 && genre.isEmpty()) {
+        bool wasEmpty=isEmpty();
+        filterEnabled=false;
+        filterGenre=genre;
+        if (!filterRegExp().isEmpty()) {
+             setFilterRegExp(QString());
+        } else if (!wasEmpty) {
+            invalidate();
+        }
+    } else {
+        filterEnabled=true;
+        filterGenre=genre;
+        if (text!=filterRegExp().pattern()) {
+            setFilterRegExp(text);
+        } else {
+            invalidate();
+        }
+    }
+}
+
+bool ProxyModel::isChildOfRoot(const QModelIndex &idx) const {
+    if (!rootIndex.isValid()) {
+        return true;
+    }
+
+    QModelIndex i=idx;
+    while(i.isValid()) {
+        if (i==rootIndex) {
+            return true;
+        }
+        i=i.parent();
+    }
+    return false;
+}