1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/xpconnect/src/xpcObjectHelper.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,134 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
1.5 +/* vim: set ts=8 sts=4 et sw=4 tw=99: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef xpcObjectHelper_h
1.11 +#define xpcObjectHelper_h
1.12 +
1.13 +// Including 'windows.h' will #define GetClassInfo to something else.
1.14 +#ifdef XP_WIN
1.15 +#ifdef GetClassInfo
1.16 +#undef GetClassInfo
1.17 +#endif
1.18 +#endif
1.19 +
1.20 +#include "mozilla/Attributes.h"
1.21 +#include <stdint.h>
1.22 +#include "nsAutoPtr.h"
1.23 +#include "nsCOMPtr.h"
1.24 +#include "nsIClassInfo.h"
1.25 +#include "nsISupports.h"
1.26 +#include "nsIXPCScriptable.h"
1.27 +#include "nsWrapperCache.h"
1.28 +
1.29 +class xpcObjectHelper
1.30 +{
1.31 +public:
1.32 + xpcObjectHelper(nsISupports *aObject, nsWrapperCache *aCache = nullptr)
1.33 + : mCanonical(nullptr)
1.34 + , mObject(aObject)
1.35 + , mCache(aCache)
1.36 + {
1.37 + if (!mCache) {
1.38 + if (aObject)
1.39 + CallQueryInterface(aObject, &mCache);
1.40 + else
1.41 + mCache = nullptr;
1.42 + }
1.43 + }
1.44 +
1.45 + nsISupports *Object()
1.46 + {
1.47 + return mObject;
1.48 + }
1.49 +
1.50 + nsISupports *GetCanonical()
1.51 + {
1.52 + if (!mCanonical) {
1.53 + mCanonicalStrong = do_QueryInterface(mObject);
1.54 + mCanonical = mCanonicalStrong;
1.55 + }
1.56 + return mCanonical;
1.57 + }
1.58 +
1.59 + already_AddRefed<nsISupports> forgetCanonical()
1.60 + {
1.61 + MOZ_ASSERT(mCanonical, "Huh, no canonical to forget?");
1.62 +
1.63 + if (!mCanonicalStrong)
1.64 + mCanonicalStrong = mCanonical;
1.65 + mCanonical = nullptr;
1.66 + return mCanonicalStrong.forget();
1.67 + }
1.68 +
1.69 + nsIClassInfo *GetClassInfo()
1.70 + {
1.71 + if (mXPCClassInfo)
1.72 + return mXPCClassInfo;
1.73 + if (!mClassInfo)
1.74 + mClassInfo = do_QueryInterface(mObject);
1.75 + return mClassInfo;
1.76 + }
1.77 + nsXPCClassInfo *GetXPCClassInfo()
1.78 + {
1.79 + if (!mXPCClassInfo) {
1.80 + CallQueryInterface(mObject, getter_AddRefs(mXPCClassInfo));
1.81 + }
1.82 + return mXPCClassInfo;
1.83 + }
1.84 +
1.85 + already_AddRefed<nsXPCClassInfo> forgetXPCClassInfo()
1.86 + {
1.87 + GetXPCClassInfo();
1.88 +
1.89 + return mXPCClassInfo.forget();
1.90 + }
1.91 +
1.92 + // We assert that we can reach an nsIXPCScriptable somehow.
1.93 + uint32_t GetScriptableFlags()
1.94 + {
1.95 + // Try getting an nsXPCClassInfo - this handles DOM scriptable helpers.
1.96 + nsCOMPtr<nsIXPCScriptable> sinfo = GetXPCClassInfo();
1.97 +
1.98 + // If that didn't work, try just QI-ing. This handles BackstagePass.
1.99 + if (!sinfo)
1.100 + sinfo = do_QueryInterface(GetCanonical());
1.101 +
1.102 + // We should have something by now.
1.103 + MOZ_ASSERT(sinfo);
1.104 +
1.105 + // Grab the flags.
1.106 + return sinfo->GetScriptableFlags();
1.107 + }
1.108 +
1.109 + nsWrapperCache *GetWrapperCache()
1.110 + {
1.111 + return mCache;
1.112 + }
1.113 +
1.114 +protected:
1.115 + xpcObjectHelper(nsISupports *aObject, nsISupports *aCanonical,
1.116 + nsWrapperCache *aCache)
1.117 + : mCanonical(aCanonical)
1.118 + , mObject(aObject)
1.119 + , mCache(aCache)
1.120 + {
1.121 + if (!mCache && aObject)
1.122 + CallQueryInterface(aObject, &mCache);
1.123 + }
1.124 +
1.125 + nsCOMPtr<nsISupports> mCanonicalStrong;
1.126 + nsISupports* mCanonical;
1.127 +
1.128 +private:
1.129 + xpcObjectHelper(xpcObjectHelper& aOther) MOZ_DELETE;
1.130 +
1.131 + nsISupports* mObject;
1.132 + nsWrapperCache* mCache;
1.133 + nsCOMPtr<nsIClassInfo> mClassInfo;
1.134 + nsRefPtr<nsXPCClassInfo> mXPCClassInfo;
1.135 +};
1.136 +
1.137 +#endif
