gecko-dev/layout/base/nsLayoutHistoryState.cpp

140 строки
3.8 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#include "nsILayoutHistoryState.h"
#include "nsHashtable.h"
#include "nsIStatefulFrame.h" // Get StateType enum
class HistoryKey: public nsHashKey {
private:
PRUint32 itsHash;
public:
HistoryKey(PRUint32 aContentID, nsIStatefulFrame::StateType aStateType) {
itsHash = aContentID * nsIStatefulFrame::eNumStateTypes + aStateType;
}
HistoryKey(PRUint32 aKey) {
itsHash = aKey;
}
PRUint32 HashValue(void) const {
return itsHash;
}
PRBool Equals(const nsHashKey *aKey) const {
return (itsHash == (((const HistoryKey *) aKey)->HashValue())) ? PR_TRUE : PR_FALSE;
}
nsHashKey *Clone(void) const {
return new HistoryKey(itsHash);
}
};
class nsLayoutHistoryState : public nsILayoutHistoryState
{
public:
nsLayoutHistoryState();
virtual ~nsLayoutHistoryState();
NS_DECL_ISUPPORTS
// nsILayoutHistoryState
NS_IMETHOD AddState(PRUint32 aContentID,
nsISupports* aState,
nsIStatefulFrame::StateType aStateType = nsIStatefulFrame::eNoType);
NS_IMETHOD GetState(PRUint32 aContentID,
nsISupports** aState,
nsIStatefulFrame::StateType aStateType = nsIStatefulFrame::eNoType);
private:
nsSupportsHashtable mStates;
};
nsresult
NS_NewLayoutHistoryState(nsILayoutHistoryState** aState)
{
NS_PRECONDITION(aState != nsnull, "null ptr");
if (! aState)
return NS_ERROR_NULL_POINTER;
*aState = new nsLayoutHistoryState();
if (! *aState)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(*aState);
return NS_OK;
}
nsLayoutHistoryState::nsLayoutHistoryState()
{
NS_INIT_REFCNT();
}
nsLayoutHistoryState::~nsLayoutHistoryState()
{
}
NS_IMPL_ISUPPORTS(nsLayoutHistoryState,
nsILayoutHistoryState::GetIID());
NS_IMETHODIMP
nsLayoutHistoryState::AddState(PRUint32 aContentID,
nsISupports* aState,
nsIStatefulFrame::StateType aStateType)
{
nsresult rv = NS_OK;
HistoryKey key(aContentID, aStateType);
void * res = mStates.Put(&key, (void *) aState);
/* nsHashTable seems to return null when it actually added
* the element in to the table. If another element was already
* present in the table for the key, it seems to return the
* element that was already present. Not sure if that was
* the intended behavior
*/
if (res) {
printf("nsLayoutHistoryState::AddState OOPS!. There was already a state in the hash table for the key\n");
rv = NS_ERROR_UNEXPECTED;
}
return rv;
}
NS_IMETHODIMP
nsLayoutHistoryState::GetState(PRUint32 aContentID,
nsISupports** aState,
nsIStatefulFrame::StateType aStateType)
{
nsresult rv = NS_OK;
HistoryKey key(aContentID, aStateType);
void * state = nsnull;
state = mStates.Get(&key);
if (state) {
*aState = (nsISupports *)state;
}
else {
printf("nsLayoutHistoryState::GetState, ERROR getting History state for the key\n");
*aState = nsnull;
rv = NS_ERROR_NULL_POINTER;
}
return rv;
}