widget/src/beos/nsCList.h

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  37
  38 #ifndef CLIST_H
  39 #define CLIST_H
  40
  41 #include <stddef.h>
  42
  43 // -----------------------------------------------------------------------
  44 //
  45 // Simple circular linked-list implementation...
  46 //
  47 // -----------------------------------------------------------------------
  48
  49 // Foreward declarations...
  50 struct CList;
  51
  52 #define OBJECT_PTR_FROM_CLIST(className, listElement) \
  53             ((char*)listElement - offsetof(className, m_link))
  54
  55
  56 struct CList {
  57     CList *next;
  58     CList *prev;
  59
  60     CList() {
  61         next = prev = this;
  62     }
  63
  64     ~CList() {
  65         Remove();
  66     }
  67
  68     //
  69     // Append an element to the end of this list
  70     //
  71     void Append(CList &element) {
  72         element.next = this;
  73         element.prev = prev;
  74         prev->next = &element;
  75         prev = &element;
  76     }
  77
  78     //
  79     // Add an element to the beginning of this list
  80     //
  81     void Add(CList &element) {
  82         element.next = next;
  83         element.prev = this;
  84         next->prev = &element;
  85         next = &element;
  86     }
  87
  88     //
  89     // Append this element to the end of a list
  90     //
  91     void AppendToList(CList &list) {
  92         list.Append(*this);
  93     }
  94
  95     //
  96     // Add this element to the beginning of a list
  97     //
  98     void AddToList(CList &list) {
  99         list.Add(*this);
 100     }
 101
 102     //
 103     // Remove this element from the list and re-initialize
 104     //
 105     void Remove(void) {
 106         prev->next = next;
 107         next->prev = prev;
 108
 109         next = prev = this;
 110     }
 111
 112     //
 113     // Is this list empty ?
 114     //
 115     bool IsEmpty(void) {
 116         return (next == this);
 117     }
 118 };
 119
 120 #endif // CLIST_H
 121