gecko-dev/xpcom/glue/nsCOMArray.h

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#ifndef nsCOMArray_h__
#define nsCOMArray_h__

#include "nsVoidArray.h"
#include "nsISupports.h"

// 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
template <class T>
class NS_COM nsCOMArray
{
 public:
    nsCOMArray() {}
    nsCOMArray(PRInt32 aCount) : mArray(aCount) {}

    ~nsCOMArray() {}

    // these do NOT refcount on the way out, for speed
    T* ObjectAt(PRInt32 aIndex) const {
        return NS_STATIC_CAST(T*,mArray.ElementAt(aIndex));
    }
    
    T* operator[](PRInt32 aIndex) const {
        return ObjectAt(aIndex);
    }

    PRInt32 IndexOf(T* aObject) {
        return mArray.IndexOf(aObject);
    }
    
    PRBool InsertObjectAt(T* aObject, PRInt32 aIndex) {
        PRBool result = mArray.InsertElementAt(aObject, aIndex);
        if (result)
            NS_ADDREF(aObject);
        return result;
    }
    
    PRBool ReplaceObjectAt(T* aObject, PRInt32 aIndex) {
        T *oldObject = ObjectAt(aIndex);
        NS_IF_RELEASE(oldObject);
        PRBool result = mArray.ReplaceElementAt(aObject, aIndex);
        if (result)
            NS_ADDREF(aObject);
        return result;
    }

    // override nsVoidArray stuff so that they can be accessed by
    // other methods
    PRInt32 Count() const {
        return mArray.Count();
    }

    void Clear() {
        mArray.EnumerateForwards(ClearObjectsCallback, nsnull);
        mArray.Clear();
    }

    PRBool EnumerateForwards(nsVoidArrayEnumFunc aFunc, void* aData) {
        return mArray.EnumerateForwards(aFunc, aData);
    }
    
    PRBool AppendObject(T *aObject) {
        PRBool result = InsertObjectAt(aObject, Count());
        if (result)
            NS_ADDREF(aObject);
        return result;
    }

    PRBool RemoveObject(T *aObject) {
        PRBool result = mArray.RemoveElement(aObject);
        if (result)
            NS_RELEASE(aObject);
        return result;
    }
    
    PRBool RemoveObjectAt(PRInt32 aIndex) {
        T* element = ObjectAt(aIndex);
        if (element) {
            PRBool result = mArray.RemoveElementAt(aIndex);
            if (result)
                NS_RELEASE(element);
            return result;
        }
        return PR_FALSE;
    }


 private:
    
    static PRBool ClearObjectsCallback(void *aElement, void*) {
        T* element = NS_STATIC_CAST(nsISupports*, aElement);
        NS_RELEASE(element);
        return PR_TRUE;
    }

    nsCOMArray(const nsCOMArray& other);
    nsCOMArray& operator=(const nsCOMArray& other);
    nsVoidArray mArray;
};


#endif