gecko-dev/xpcom/glue/nsCOMArray.h

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is a COM aware array class.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corp.
* Portions created by the Initial Developer are Copyright (C) 2002
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Alec Flett <alecf@netscape.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef nsCOMArray_h__
#define nsCOMArray_h__
#include "nsVoidArray.h"
#include "nsISupports.h"
// See below for the definition of nsCOMArray<T>
// a class that's nsISupports-specific, so that we can contain the
// work of this class in the XPCOM dll
class NS_COM_GLUE nsCOMArray_base
{
friend class nsArray;
protected:
nsCOMArray_base() {}
nsCOMArray_base(PRInt32 aCount) : mArray(aCount) {}
nsCOMArray_base(const nsCOMArray_base& other);
~nsCOMArray_base();
PRInt32 IndexOf(nsISupports* aObject) const {
return mArray.IndexOf(aObject);
}
PRInt32 IndexOfObject(nsISupports* aObject) const;
PRBool EnumerateForwards(nsVoidArrayEnumFunc aFunc, void* aData) {
return mArray.EnumerateForwards(aFunc, aData);
}
PRBool EnumerateBackwards(nsVoidArrayEnumFunc aFunc, void* aData) {
return mArray.EnumerateBackwards(aFunc, aData);
}
void Sort(nsVoidArrayComparatorFunc aFunc, void* aData) {
mArray.Sort(aFunc, aData);
}
// any method which is not a direct forward to mArray should
// avoid inline bodies, so that the compiler doesn't inline them
// all over the place
void Clear();
PRBool InsertObjectAt(nsISupports* aObject, PRInt32 aIndex);
PRBool InsertObjectsAt(const nsCOMArray_base& aObjects, PRInt32 aIndex);
PRBool ReplaceObjectAt(nsISupports* aObject, PRInt32 aIndex);
PRBool AppendObject(nsISupports *aObject) {
return InsertObjectAt(aObject, Count());
}
PRBool AppendObjects(const nsCOMArray_base& aObjects) {
return InsertObjectsAt(aObjects, Count());
}
PRBool RemoveObject(nsISupports *aObject);
PRBool RemoveObjectAt(PRInt32 aIndex);
public:
// override nsVoidArray stuff so that they can be accessed by
// consumers of nsCOMArray
PRInt32 Count() const {
return mArray.Count();
}
// If the array grows, the newly created entries will all be null;
// if the array shrinks, the excess entries will all be released.
PRBool SetCount(PRInt32 aNewCount);
nsISupports* ObjectAt(PRInt32 aIndex) const {
return static_cast<nsISupports*>(mArray.FastElementAt(aIndex));
}
nsISupports* SafeObjectAt(PRInt32 aIndex) const {
return static_cast<nsISupports*>(mArray.SafeElementAt(aIndex));
}
nsISupports* operator[](PRInt32 aIndex) const {
return ObjectAt(aIndex);
}
// Ensures there is enough space to store a total of aCapacity objects.
// This method never deletes any objects.
PRBool SetCapacity(PRUint32 aCapacity) {
return aCapacity > 0 ? mArray.SizeTo(static_cast<PRInt32>(aCapacity))
: PR_TRUE;
}
private:
// the actual storage
nsVoidArray mArray;
// don't implement these, defaults will muck with refcounts!
nsCOMArray_base& operator=(const nsCOMArray_base& other);
};
// a non-XPCOM, refcounting array of XPCOM objects
// used as a member variable or stack variable - this object is NOT
// refcounted, but the objects that it holds are
//
// most of the read-only accessors like ObjectAt()/etc do NOT refcount
// on the way out. This means that you can do one of two things:
//
// * does an addref, but holds onto a reference
// nsCOMPtr<T> foo = array[i];
//
// * avoids the refcount, but foo might go stale if array[i] is ever
// * modified/removed. Be careful not to NS_RELEASE(foo)!
// T* foo = array[i];
//
// This array will accept null as an argument for any object, and will
// store null in the array, just like nsVoidArray. But that also means
// that methods like ObjectAt() may return null when referring to an
// existing, but null entry in the array.
template <class T>
class nsCOMArray : public nsCOMArray_base
{
public:
nsCOMArray() {}
nsCOMArray(PRInt32 aCount) : nsCOMArray_base(aCount) {}
// only to be used by trusted classes who are going to pass us the
// right type!
nsCOMArray(const nsCOMArray<T>& aOther) : nsCOMArray_base(aOther) { }
~nsCOMArray() {}
// these do NOT refcount on the way out, for speed
T* ObjectAt(PRInt32 aIndex) const {
return static_cast<T*>(nsCOMArray_base::ObjectAt(aIndex));
}
// these do NOT refcount on the way out, for speed
T* SafeObjectAt(PRInt32 aIndex) const {
return static_cast<T*>(nsCOMArray_base::SafeObjectAt(aIndex));
}
// indexing operator for syntactic sugar
T* operator[](PRInt32 aIndex) const {
return ObjectAt(aIndex);
}
// index of the element in question.. does NOT refcount
// note: this does not check COM object identity. Use
// IndexOfObject() for that purpose
PRInt32 IndexOf(T* aObject) const {
return nsCOMArray_base::IndexOf(static_cast<nsISupports*>(aObject));
}
// index of the element in question.. be careful!
// this is much slower than IndexOf() because it uses
// QueryInterface to determine actual COM identity of the object
// if you need to do this frequently then consider enforcing
// COM object identity before adding/comparing elements
PRInt32 IndexOfObject(T* aObject) const {
return nsCOMArray_base::IndexOfObject(static_cast<nsISupports*>(aObject));
}
// inserts aObject at aIndex, shifting the objects at aIndex and
// later to make space
PRBool InsertObjectAt(T* aObject, PRInt32 aIndex) {
return nsCOMArray_base::InsertObjectAt(static_cast<nsISupports*>(aObject), aIndex);
}
// inserts the objects from aObject at aIndex, shifting the
// objects at aIndex and later to make space
PRBool InsertObjectsAt(const nsCOMArray<T>& aObjects, PRInt32 aIndex) {
return nsCOMArray_base::InsertObjectsAt(aObjects, aIndex);
}
// replaces an existing element. Warning: if the array grows,
// the newly created entries will all be null
PRBool ReplaceObjectAt(T* aObject, PRInt32 aIndex) {
return nsCOMArray_base::ReplaceObjectAt(static_cast<nsISupports*>(aObject), aIndex);
}
// override nsVoidArray stuff so that they can be accessed by
// other methods
// elements in the array (including null elements!)
PRInt32 Count() const {
return nsCOMArray_base::Count();
}
// remove all elements in the array, and call NS_RELEASE on each one
void Clear() {
nsCOMArray_base::Clear();
}
// Enumerator callback function. Return PR_FALSE to stop
// Here's a more readable form:
// PRBool enumerate(T* aElement, void* aData)
typedef PRBool (* nsCOMArrayEnumFunc)
(T* aElement, void *aData);
// enumerate through the array with a callback.
PRBool EnumerateForwards(nsCOMArrayEnumFunc aFunc, void* aData) {
return nsCOMArray_base::EnumerateForwards(nsVoidArrayEnumFunc(aFunc),
aData);
}
PRBool EnumerateBackwards(nsCOMArrayEnumFunc aFunc, void* aData) {
return nsCOMArray_base::EnumerateBackwards(nsVoidArrayEnumFunc(aFunc),
aData);
}
typedef int (* nsCOMArrayComparatorFunc)
(T* aElement1, T* aElement2, void* aData);
void Sort(nsCOMArrayComparatorFunc aFunc, void* aData) {
nsCOMArray_base::Sort(nsVoidArrayComparatorFunc(aFunc), aData);
}
// append an object, growing the array as necessary
PRBool AppendObject(T *aObject) {
return nsCOMArray_base::AppendObject(static_cast<nsISupports*>(aObject));
}
// append objects, growing the array as necessary
PRBool AppendObjects(const nsCOMArray<T>& aObjects) {
return nsCOMArray_base::AppendObjects(aObjects);
}
// remove the first instance of the given object and shrink the
// array as necessary
// Warning: if you pass null here, it will remove the first null element
PRBool RemoveObject(T *aObject) {
return nsCOMArray_base::RemoveObject(static_cast<nsISupports*>(aObject));
}
// remove an element at a specific position, shrinking the array
// as necessary
PRBool RemoveObjectAt(PRInt32 aIndex) {
return nsCOMArray_base::RemoveObjectAt(aIndex);
}
private:
// don't implement these!
nsCOMArray<T>& operator=(const nsCOMArray<T>& other);
};
#endif