1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/xul/templates/src/nsContentSupportMap.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,70 @@
1.4 +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef nsContentSupportMap_h__
1.10 +#define nsContentSupportMap_h__
1.11 +
1.12 +#include "pldhash.h"
1.13 +#include "nsTemplateMatch.h"
1.14 +
1.15 +/**
1.16 + * The nsContentSupportMap maintains a mapping from a "resource element"
1.17 + * in the content tree to the nsTemplateMatch that was used to instantiate it. This
1.18 + * is necessary to allow the XUL content to be built lazily. Specifically,
1.19 + * when building "resumes" on a partially-built content element, the builder
1.20 + * will walk upwards in the content tree to find the first element with an
1.21 + * 'id' attribute. This element is assumed to be the "resource element",
1.22 + * and allows the content builder to access the nsTemplateMatch (variable assignments
1.23 + * and rule information).
1.24 + */
1.25 +class nsContentSupportMap {
1.26 +public:
1.27 + nsContentSupportMap() { Init(); }
1.28 + ~nsContentSupportMap() { Finish(); }
1.29 +
1.30 + nsresult Put(nsIContent* aElement, nsTemplateMatch* aMatch) {
1.31 + if (!mMap.ops)
1.32 + return NS_ERROR_NOT_INITIALIZED;
1.33 +
1.34 + PLDHashEntryHdr* hdr = PL_DHashTableOperate(&mMap, aElement, PL_DHASH_ADD);
1.35 + if (!hdr)
1.36 + return NS_ERROR_OUT_OF_MEMORY;
1.37 +
1.38 + Entry* entry = reinterpret_cast<Entry*>(hdr);
1.39 + NS_ASSERTION(entry->mMatch == nullptr, "over-writing entry");
1.40 + entry->mContent = aElement;
1.41 + entry->mMatch = aMatch;
1.42 + return NS_OK; }
1.43 +
1.44 + bool Get(nsIContent* aElement, nsTemplateMatch** aMatch) {
1.45 + if (!mMap.ops)
1.46 + return false;
1.47 +
1.48 + PLDHashEntryHdr* hdr = PL_DHashTableOperate(&mMap, aElement, PL_DHASH_LOOKUP);
1.49 + if (PL_DHASH_ENTRY_IS_FREE(hdr))
1.50 + return false;
1.51 +
1.52 + Entry* entry = reinterpret_cast<Entry*>(hdr);
1.53 + *aMatch = entry->mMatch;
1.54 + return true; }
1.55 +
1.56 + nsresult Remove(nsIContent* aElement);
1.57 +
1.58 + void Clear() { Finish(); Init(); }
1.59 +
1.60 +protected:
1.61 + PLDHashTable mMap;
1.62 +
1.63 + void Init();
1.64 + void Finish();
1.65 +
1.66 + struct Entry {
1.67 + PLDHashEntryHdr mHdr;
1.68 + nsIContent* mContent;
1.69 + nsTemplateMatch* mMatch;
1.70 + };
1.71 +};
1.72 +
1.73 +#endif
