File indexing completed on 2024-06-16 04:59:04

 /*
   SPDX-FileCopyrightText: 2021 Intevation GmbH
   SPDX-FileContributor: Ingo Klöcker <dev@ingo-kloecker.de>
 
   SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #pragma once
 
 #include <Qt>
 
 #include <vector>
 
 class QAbstractItemModel;
 class QModelIndex;
 class QRegularExpression;
 class QString;
 
 namespace MailCommon
 {
 /* This class allows filtering a hierarchical item model with path-like
  * patterns like "parent/sub" similar to file path globbing.
  *
  * The matching works as follows:
  * * The pattern is split into sub-patterns wherever "/" occurs.
  * * The sub-patterns are matched against each item and its ancestors.
  * * The pattern matches for an item if all sub-patterns match the item and
  *   its ancestors.
  * * The sub-pattern matching uses wildcard matching with implied "*" before
  *   and after each sub-pattern. For details see
  *   QRegularExpression::wildcardToRegularExpression().
  *
  * Examples:
  * * "foo" matches all items that contain "foo".
  * * "foo/bar" matches all items matching "bar" with parent items matching "foo".
  * * "foo/" matches all child items of items matching "foo".
  * * "/bar" matches all items matching "bar" which have a parent item.
  * * "foo//bar" matches all items matching "bar" with grandparents matching "foo".
  *
  * For more examples have a look at the tests in foldertreewidgettest.cpp.
  *
  * Design decisions:
  * * The original request was that "foo" should match items that contain "foo"
  *   *and* their (direct?) child items, so that one can easily narrow down the
  *   list of folders to the folders belonging to a subfolder tree, e.g. the
  *   subfolder tree for "project foo".
  *   I decided against this for the following reasons:
  *   * The requested result can be achieved with "foo/".
  *   * If there are multiple folders matching "foo" with a larger number of
  *     subfolders, then it would not have been easy to select the wanted
  *     folder matching "foo" because of all the subfolders that are also listed.
  *   * I also think that the behavior of the original request isn't really
  *     intuitive, at least for people who know file path globbing.
  */
 class HierarchicalFolderMatcher
 {
 public:
     HierarchicalFolderMatcher();
 
     [[nodiscard]] bool isNull() const;
 
     void setFilter(const QString &filter, Qt::CaseSensitivity caseSensitivity);
 
     [[nodiscard]] bool matches(const QAbstractItemModel *model, const QModelIndex &start, int role = Qt::DisplayRole);
 
     [[nodiscard]] QModelIndex findFirstMatch(const QAbstractItemModel *model, const QModelIndex &start, int role = Qt::DisplayRole);
 
 private:
     std::vector<QRegularExpression> filterRegExps;
 };
 }