101 lines
3.1 KiB
C++
101 lines
3.1 KiB
C++
/*
|
||
* Strawberry Music Player
|
||
* This file was part of Clementine.
|
||
* Copyright 2012, David Sansome <me@davidsansome.com>
|
||
*
|
||
* 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 PLAYLISTFILTERPARSER_H
|
||
#define PLAYLISTFILTERPARSER_H
|
||
|
||
#include "config.h"
|
||
|
||
#include <QSet>
|
||
#include <QMap>
|
||
#include <QString>
|
||
|
||
class QAbstractItemModel;
|
||
class QModelIndex;
|
||
|
||
// Structure for filter parse tree
|
||
class FilterTree {
|
||
public:
|
||
FilterTree() = default;
|
||
virtual ~FilterTree() {}
|
||
virtual bool accept(int row, const QModelIndex &parent, const QAbstractItemModel *const model) const = 0;
|
||
enum class FilterType {
|
||
Nop = 0,
|
||
Or,
|
||
And,
|
||
Not,
|
||
Column,
|
||
Term
|
||
};
|
||
virtual FilterType type() = 0;
|
||
private:
|
||
Q_DISABLE_COPY(FilterTree)
|
||
};
|
||
|
||
// Trivial filter that accepts *anything*
|
||
class NopFilter : public FilterTree {
|
||
public:
|
||
bool accept(int row, const QModelIndex &parent, const QAbstractItemModel *const model) const override { Q_UNUSED(row); Q_UNUSED(parent); Q_UNUSED(model); return true; }
|
||
FilterType type() override { return FilterType::Nop; }
|
||
};
|
||
|
||
|
||
// A utility class to parse search filter strings into a decision tree
|
||
// that can decide whether a playlist entry matches the filter.
|
||
//
|
||
// Here's a grammar describing the filters we expect:
|
||
// expr ::= or-group
|
||
// or-group ::= and-group ('OR' and-group)*
|
||
// and-group ::= sexpr ('AND' sexpr)*
|
||
// sexpr ::= sterm | '-' sexpr | '(' or-group ')'
|
||
// sterm ::= col ':' sstring | sstring
|
||
// sstring ::= prefix? string
|
||
// string ::= [^:-()" ]+ | '"' [^"]+ '"'
|
||
// prefix ::= '=' | '<' | '>' | '<=' | '>='
|
||
// col ::= "title" | "artist" | ...
|
||
class FilterParser {
|
||
public:
|
||
explicit FilterParser(const QString &filter, const QMap<QString, int> &columns, const QSet<int> &numerical_cols);
|
||
|
||
FilterTree *parse();
|
||
|
||
private:
|
||
void advance();
|
||
FilterTree *parseOrGroup();
|
||
FilterTree *parseAndGroup();
|
||
// Check if iter is at the start of 'AND' if so, step over it and return true if not, return false and leave iter where it was
|
||
bool checkAnd();
|
||
// Check if iter is at the start of 'OR'
|
||
bool checkOr(bool step_over = true);
|
||
FilterTree *parseSearchExpression();
|
||
FilterTree *parseSearchTerm();
|
||
|
||
FilterTree *createSearchTermTreeNode(const QString &col, const QString &prefix, const QString &search) const;
|
||
|
||
QString::const_iterator iter_;
|
||
QString::const_iterator end_;
|
||
QString buf_;
|
||
const QString filterstring_;
|
||
const QMap<QString, int> columns_;
|
||
const QSet<int> numerical_columns_;
|
||
};
|
||
|
||
#endif // PLAYLISTFILTERPARSER_H
|