1 files changed, 117 insertions, 0 deletions
diff --git a/xbmc/interfaces/info/InfoExpression.h b/xbmc/interfaces/info/InfoExpression.h
new file mode 100644
index 0000000..1a0877c
--- /dev/null
+++ b/xbmc/interfaces/info/InfoExpression.h
@@ -0,0 +1,117 @@
+/*
+ *  Copyright (C) 2005-2018 Team Kodi
+ *  This file is part of Kodi - https://kodi.tv
+ *
+ *  SPDX-License-Identifier: GPL-2.0-or-later
+ *  See LICENSES/README.md for more information.
+ */
+
+#pragma once
+
+#include "InfoBool.h"
+
+#include <list>
+#include <stack>
+#include <utility>
+#include <vector>
+
+class CGUIListItem;
+
+namespace INFO
+{
+/*! \brief Class to wrap active boolean conditions
+ */
+class InfoSingle : public InfoBool
+{
+public:
+  InfoSingle(const std::string& expression, int context, unsigned int& refreshCounter)
+    : InfoBool(expression, context, refreshCounter)
+  {
+  }
+  void Initialize() override;
+
+  void Update(int contextWindow, const CGUIListItem* item) override;
+
+private:
+  int m_condition;             ///< actual condition this represents
+};
+
+/*! \brief Class to wrap active boolean expressions
+ */
+class InfoExpression : public InfoBool
+{
+public:
+  InfoExpression(const std::string& expression, int context, unsigned int& refreshCounter)
+    : InfoBool(expression, context, refreshCounter)
+  {
+  }
+  ~InfoExpression() override = default;
+
+  void Initialize() override;
+
+  void Update(int contextWindow, const CGUIListItem* item) override;
+
+private:
+  typedef enum
+  {
+    OPERATOR_NONE  = 0,
+    OPERATOR_LB,  // 1
+    OPERATOR_RB,  // 2
+    OPERATOR_OR,  // 3
+    OPERATOR_AND, // 4
+    OPERATOR_NOT, // 5
+  } operator_t;
+
+  typedef enum
+  {
+    NODE_LEAF,
+    NODE_AND,
+    NODE_OR,
+  } node_type_t;
+
+  // An abstract base class for nodes in the expression tree
+  class InfoSubexpression
+  {
+  public:
+    virtual ~InfoSubexpression(void) = default; // so we can destruct derived classes using a pointer to their base class
+    virtual bool Evaluate(int contextWindow, const CGUIListItem* item) = 0;
+    virtual node_type_t Type() const=0;
+  };
+
+  typedef std::shared_ptr<InfoSubexpression> InfoSubexpressionPtr;
+
+  // A leaf node in the expression tree
+  class InfoLeaf : public InfoSubexpression
+  {
+  public:
+    InfoLeaf(InfoPtr info, bool invert) : m_info(std::move(info)), m_invert(invert) {}
+    bool Evaluate(int contextWindow, const CGUIListItem* item) override;
+    node_type_t Type() const override { return NODE_LEAF; }
+
+  private:
+    InfoPtr m_info;
+    bool m_invert;
+  };
+
+  // A branch node in the expression tree
+  class InfoAssociativeGroup : public InfoSubexpression
+  {
+  public:
+    InfoAssociativeGroup(node_type_t type, const InfoSubexpressionPtr &left, const InfoSubexpressionPtr &right);
+    void AddChild(const InfoSubexpressionPtr &child);
+    void Merge(const std::shared_ptr<InfoAssociativeGroup>& other);
+    bool Evaluate(int contextWindow, const CGUIListItem* item) override;
+    node_type_t Type() const override { return m_type; }
+
+  private:
+    node_type_t m_type;
+    std::list<InfoSubexpressionPtr> m_children;
+  };
+
+  static operator_t GetOperator(char ch);
+  static void OperatorPop(std::stack<operator_t> &operator_stack, bool &invert, std::stack<InfoSubexpressionPtr> &nodes);
+  bool Parse(const std::string &expression);
+  InfoSubexpressionPtr m_expression_tree;
+};
+
+};