widget/cocoa/nsChangeObserver.h

   1 /* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  *
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef nsChangeObserver_h_
   8 #define nsChangeObserver_h_
   9
  10 class nsIContent;
  11 class nsAtom;
  12 namespace mozilla {
  13 namespace dom {
  14 class Document;
  15 }
  16 }  // namespace mozilla
  17
  18 #define NS_DECL_CHANGEOBSERVER                                            \
  19   void ObserveAttributeChanged(mozilla::dom::Document* aDocument,         \
  20                                nsIContent* aContent, nsAtom* aAttribute)  \
  21       override;                                                           \
  22   void ObserveContentRemoved(mozilla::dom::Document* aDocument,           \
  23                              nsIContent* aContainer, nsIContent* aChild,  \
  24                              nsIContent* aPreviousChild) override;        \
  25   void ObserveContentInserted(mozilla::dom::Document* aDocument,          \
  26                               nsIContent* aContainer, nsIContent* aChild) \
  27       override;
  28
  29 // Something that wants to be alerted to changes in attributes or changes in
  30 // its corresponding content object.
  31 //
  32 // This interface is used by our menu code so we only have to have one
  33 // nsIMutationObserver per menu subtree root (e.g. per menubar).
  34 //
  35 // Any class that implements this interface must take care to unregister itself
  36 // on deletion.
  37 //
  38 // XXXmstange The methods below use nsIContent*. Eventually, the should be
  39 // converted to use mozilla::dom::Element* instead.
  40 class nsChangeObserver {
  41  public:
  42   // Called when the attribute aAttribute on the element aContent has changed.
  43   // Only if aContent is being observed by this nsChangeObserver.
  44   virtual void ObserveAttributeChanged(mozilla::dom::Document* aDocument,
  45                                        nsIContent* aContent,
  46                                        nsAtom* aAttribute) = 0;
  47
  48   // Called when aChild has been removed from its parent aContainer.
  49   // aPreviousSibling is the old previous sibling of aChild.
  50   // aContainer is always the old parent node of aChild and of aPreviousSibling.
  51   // Only called if aContainer or aContainer's parent node are being observed
  52   // by this nsChangeObserver.
  53   // In other words: If you observe an element, ObserveContentRemoved is called
  54   // if that element's children and grandchildren are removed. NOT if the
  55   // observed element itself is removed.
  56   virtual void ObserveContentRemoved(mozilla::dom::Document* aDocument,
  57                                      nsIContent* aContainer, nsIContent* aChild,
  58                                      nsIContent* aPreviousSibling) = 0;
  59
  60   // Called when aChild has been inserted into its new parent aContainer.
  61   // Only called if aContainer or aContainer's parent node are being observed
  62   // by this nsChangeObserver.
  63   // In other words: If you observe an element, ObserveContentInserted is called
  64   // if that element receives a new child or grandchild. NOT if the observed
  65   // element itself is inserted anywhere.
  66   virtual void ObserveContentInserted(mozilla::dom::Document* aDocument,
  67                                       nsIContent* aContainer,
  68                                       nsIContent* aChild) = 0;
  69 };
  70
  71 #endif  // nsChangeObserver_h_