Rewrite collection model and search

Fixes #392

src/collection/collectionfilter.h

@@ -0,0 +1,69 @@
+/*
+ * Strawberry Music Player
+ * Copyright 2021-2024, Jonas Kvinge <jonas@jkvinge.net>
+ *
+ * Strawberry 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry 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 Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef COLLECTIONFILTER_H
+#define COLLECTIONFILTER_H
+
+#include "config.h"
+
+#include <QtGlobal>
+#include <QObject>
+#include <QSortFilterProxyModel>
+#include <QVariant>
+#include <QString>
+#include <QStringList>
+
+#include "core/song.h"
+
+class CollectionItem;
+
+class CollectionFilter : public QSortFilterProxyModel {
+  Q_OBJECT
+
+ public:
+  explicit CollectionFilter(QObject *parent = nullptr);
+
+ protected:
+  bool filterAcceptsRow(const int source_row, const QModelIndex &source_parent) const override;
+
+ private:
+  static const QStringList Operators;
+  struct Filter {
+   public:
+    Filter(const QString &_field = QString(), const QVariant &_value = QVariant(), const QString &_foperator = QString()) : field(_field), value(_value), foperator(_foperator) {}
+    QString field;
+    QVariant value;
+    QString foperator;
+  };
+  using FilterList = QMap<QString, Filter>;
+  static bool ItemMatchesFilters(CollectionItem *item, const FilterList &filters, const QString &filter_text);
+  static bool ItemMetadataMatchesFilters(const Song &metadata, const FilterList &filters, const QString &filter_text);
+  static bool ItemMetadataMatchesFilterText(const Song &metadata, const QString &filter_text);
+  static QVariant DataFromField(const QString &field, const Song &metadata);
+  static bool FieldValueMatchesData(const QVariant &value, const QVariant &data, const QString &foperator);
+  template<typename T>
+  static bool FieldNumericalValueMatchesData(const T value, const QString &foperator, const T data);
+  static bool FieldIntValueMatchesData(const int value, const QString &foperator, const int data);
+  static bool FieldUIntValueMatchesData(const uint value, const QString &foperator, const uint data);
+  static bool FieldLongLongValueMatchesData(const qint64 value, const QString &foperator, const qint64 data);
+  static bool FieldFloatValueMatchesData(const float value, const QString &foperator, const float data);
+  static bool ContainsOperators(const QString &token);
+};
+
+#endif  // COLLECTIONFILTER_H