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/*
* DO NOT EDIT. THIS FILE IS GENERATED FROM c:/mozilla/modules/libpref/public/nsIPrefBranch2.idl
*/
#ifndef __gen_nsIPrefBranch2_h__
#define __gen_nsIPrefBranch2_h__
#ifndef __gen_nsIPrefBranch_h__
#include "nsIPrefBranch.h"
#endif
/* For IDL files that don't want to include root IDL files. */
#ifndef NS_NO_VTABLE
#define NS_NO_VTABLE
#endif
class nsIObserver; /* forward declaration */
/* starting interface: nsIPrefBranch2 */
#define NS_IPREFBRANCH2_IID_STR "74567534-eb94-4b1c-8f45-389643bfc555"
#define NS_IPREFBRANCH2_IID \
{0x74567534, 0xeb94, 0x4b1c, \
{ 0x8f, 0x45, 0x38, 0x96, 0x43, 0xbf, 0xc5, 0x55 }}
/**
* nsIPrefBranch2 allows clients to observe changes to pref values.
*
* @status FROZEN
* @see nsIPrefBranch
*/
class NS_NO_VTABLE nsIPrefBranch2 : public nsIPrefBranch {
public:
NS_DEFINE_STATIC_IID_ACCESSOR(NS_IPREFBRANCH2_IID)
/**
* Add a preference change observer. On preference changes, the following
* arguments will be passed to the nsIObserver.observe() method:
* aSubject - The nsIPrefBranch object (this)
* aTopic - The string defined by NS_PREFBRANCH_PREFCHANGE_TOPIC_ID
* aData - The preference which has changed
*
* @param aDomain The preference on which to listen for changes. This can
* be the name of an entire branch to observe.
* e.g. Holding the "root" prefbranch and calling
* addObserver("foo.bar.", ...) will observe changes to
* foo.bar.baz and foo.bar.bzip
* @param aObserver The object to be notified if the preference changes.
* @param aHoldWeak true Hold a weak reference to |aObserver|. The object
* must implement the nsISupportsWeakReference
* interface or this will fail.
* false Hold a strong reference to |aObserver|.
*
* @note
* Registering as a preference observer can open an object to potential
* cyclical references which will cause memory leaks. These cycles generally
* occur because an object both registers itself as an observer (causing the
* branch to hold a reference to the observer) and holds a reference to the
* branch object for the purpose of getting/setting preference values. There
* are 3 approaches which have been implemented in an attempt to avoid these
* situations.
* 1) The nsPrefBranch object supports nsISupportsWeakReference. Any consumer
* may hold a weak reference to it instead of a strong one.
* 2) The nsPrefBranch object listens for xpcom-shutdown and frees all of the
* objects currently in its observer list. This insures that long lived
* objects (services for example) will be freed correctly.
* 3) The observer can request to be held as a weak reference when it is
* registered. This insures that shorter lived objects (say one tied to an
* open window) will not fall into the cyclical reference trap.
*
* @see nsIObserver
* @see removeObserver
*/
/* void addObserver (in string aDomain, in nsIObserver aObserver, in boolean aHoldWeak); */
NS_IMETHOD AddObserver(const char *aDomain, nsIObserver *aObserver, PRBool aHoldWeak) = 0;
/**
* Remove a preference change observer.
*
* @param aDomain The preference which is being observed for changes.
* @param aObserver An observer previously registered with addObserver().
*
* @see nsIObserver
* @see addObserver
*/
/* void removeObserver (in string aDomain, in nsIObserver aObserver); */
NS_IMETHOD RemoveObserver(const char *aDomain, nsIObserver *aObserver) = 0;
};
/* Use this macro when declaring classes that implement this interface. */
#define NS_DECL_NSIPREFBRANCH2 \
NS_IMETHOD AddObserver(const char *aDomain, nsIObserver *aObserver, PRBool aHoldWeak); \
NS_IMETHOD RemoveObserver(const char *aDomain, nsIObserver *aObserver);
/* Use this macro to declare functions that forward the behavior of this interface to another object. */
#define NS_FORWARD_NSIPREFBRANCH2(_to) \
NS_IMETHOD AddObserver(const char *aDomain, nsIObserver *aObserver, PRBool aHoldWeak) { return _to AddObserver(aDomain, aObserver, aHoldWeak); } \
NS_IMETHOD RemoveObserver(const char *aDomain, nsIObserver *aObserver) { return _to RemoveObserver(aDomain, aObserver); }
/* Use this macro to declare functions that forward the behavior of this interface to another object in a safe way. */
#define NS_FORWARD_SAFE_NSIPREFBRANCH2(_to) \
NS_IMETHOD AddObserver(const char *aDomain, nsIObserver *aObserver, PRBool aHoldWeak) { return !_to ? NS_ERROR_NULL_POINTER : _to->AddObserver(aDomain, aObserver, aHoldWeak); } \
NS_IMETHOD RemoveObserver(const char *aDomain, nsIObserver *aObserver) { return !_to ? NS_ERROR_NULL_POINTER : _to->RemoveObserver(aDomain, aObserver); }
#if 0
/* Use the code below as a template for the implementation class for this interface. */
/* Header file */
class nsPrefBranch2 : public nsIPrefBranch2
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIPREFBRANCH2
nsPrefBranch2();
private:
~nsPrefBranch2();
protected:
/* additional members */
};
/* Implementation file */
NS_IMPL_ISUPPORTS1(nsPrefBranch2, nsIPrefBranch2)
nsPrefBranch2::nsPrefBranch2()
{
/* member initializers and constructor code */
}
nsPrefBranch2::~nsPrefBranch2()
{
/* destructor code */
}
/* void addObserver (in string aDomain, in nsIObserver aObserver, in boolean aHoldWeak); */
NS_IMETHODIMP nsPrefBranch2::AddObserver(const char *aDomain, nsIObserver *aObserver, PRBool aHoldWeak)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
/* void removeObserver (in string aDomain, in nsIObserver aObserver); */
NS_IMETHODIMP nsPrefBranch2::RemoveObserver(const char *aDomain, nsIObserver *aObserver)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
/* End of implementation class template. */
#endif
/**
* Notification sent when a preference changes.
*/
#define NS_PREFBRANCH_PREFCHANGE_TOPIC_ID "nsPref:changed"
#endif /* __gen_nsIPrefBranch2_h__ */
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