sd/source/ui/slidesorter/inc/model/SlsPageEnumeration.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
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   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #pragma once
  21
  22 #include <model/SlsEnumeration.hxx>
  23 #include <model/SlsSharedPageDescriptor.hxx>
  24
  25 #include <functional>
  26 #include <memory>
  27
  28 namespace sd::slidesorter::model
  29 {
  30 class SlideSorterModel;
  31
  32 /** Public class of page enumerations that delegates its calls to an
  33     implementation object that can filter pages by using a given predicate.
  34
  35     @see PageEnumerationProvider
  36         The PageEnumerationProvider has methods for creating different types
  37         of page enumerations.
  38 */
  39 class PageEnumeration final : public Enumeration<SharedPageDescriptor>
  40 {
  41 public:
  42     /** Create a new page enumeration that enumerates a subset of the pages
  43         of the given model.
  44         @param rModel
  45             The new page enumeration enumerates the pages of this model.
  46         @param rPredicate
  47             This predicate determines which pages to include in the
  48             enumeration.  Pages for which rPredicate returns <FALSE/> are
  49             exclude.
  50     */
  51     typedef ::std::function<bool(const SharedPageDescriptor&)> PagePredicate;
  52     static PageEnumeration Create(const SlideSorterModel& rModel, const PagePredicate& rPredicate);
  53
  54     /** This copy constructor creates a copy of the given enumeration.
  55     */
  56     PageEnumeration(const PageEnumeration& rEnumeration);
  57
  58     virtual ~PageEnumeration() override;
  59
  60     /** Create and return an exact copy of the called object.
  61     */
  62     virtual ::std::unique_ptr<Enumeration<SharedPageDescriptor>> Clone() override;
  63
  64     PageEnumeration& operator=(const PageEnumeration& rEnumeration);
  65
  66     /** Return <TRUE/> when the enumeration has more elements, i.e. it is
  67         save to call GetNextElement() at least one more time.
  68     */
  69     virtual bool HasMoreElements() const override;
  70
  71     /** Return the next element of the enumeration.  Call the
  72         HasMoreElements() before to make sure that there exists at least one
  73         more element.  Calling this method with HasMoreElements() returning
  74         <FALSE/> is an error.
  75     */
  76     virtual SharedPageDescriptor GetNextElement() override;
  77
  78     /** Rewind the enumeration so that the next call to GetNextElement()
  79         will return its first element.
  80     */
  81     virtual void Rewind() override;
  82
  83 private:
  84     /// Implementation object.
  85     ::std::unique_ptr<Enumeration<SharedPageDescriptor>> mpImpl;
  86
  87     /** This constructor expects an implementation object that holds
  88         the predicate that filters the pages.
  89     */
  90     PageEnumeration(::std::unique_ptr<Enumeration<SharedPageDescriptor>>&& pImpl);
  91 };
  92
  93 } // end of namespace ::sd::slidesorter::model
  94
  95 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */