1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/style/MediaQueryList.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,187 @@
1.4 +/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
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 +/* implements DOM interface for querying and observing media queries */
1.10 +
1.11 +#include "mozilla/dom/MediaQueryList.h"
1.12 +#include "nsPresContext.h"
1.13 +#include "nsIMediaList.h"
1.14 +#include "nsCSSParser.h"
1.15 +#include "nsIDocument.h"
1.16 +
1.17 +namespace mozilla {
1.18 +namespace dom {
1.19 +
1.20 +MediaQueryList::MediaQueryList(nsPresContext *aPresContext,
1.21 + const nsAString &aMediaQueryList)
1.22 + : mPresContext(aPresContext),
1.23 + mMediaList(new nsMediaList),
1.24 + mMatchesValid(false)
1.25 +{
1.26 + PR_INIT_CLIST(this);
1.27 +
1.28 + SetIsDOMBinding();
1.29 +
1.30 + nsCSSParser parser;
1.31 + parser.ParseMediaList(aMediaQueryList, nullptr, 0, mMediaList, false);
1.32 +}
1.33 +
1.34 +MediaQueryList::~MediaQueryList()
1.35 +{
1.36 + if (mPresContext) {
1.37 + PR_REMOVE_LINK(this);
1.38 + }
1.39 +}
1.40 +
1.41 +NS_IMPL_CYCLE_COLLECTION_CLASS(MediaQueryList)
1.42 +
1.43 +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(MediaQueryList)
1.44 + NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPresContext)
1.45 + NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCallbacks)
1.46 + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
1.47 +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
1.48 +
1.49 +NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(MediaQueryList)
1.50 + if (tmp->mPresContext) {
1.51 + PR_REMOVE_LINK(tmp);
1.52 + NS_IMPL_CYCLE_COLLECTION_UNLINK(mPresContext)
1.53 + }
1.54 + tmp->RemoveAllListeners();
1.55 + NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
1.56 +NS_IMPL_CYCLE_COLLECTION_UNLINK_END
1.57 +
1.58 +NS_IMPL_CYCLE_COLLECTION_TRACE_WRAPPERCACHE(MediaQueryList)
1.59 +
1.60 +NS_INTERFACE_MAP_BEGIN(MediaQueryList)
1.61 + NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
1.62 + NS_INTERFACE_MAP_ENTRY(nsISupports)
1.63 + NS_INTERFACE_MAP_ENTRIES_CYCLE_COLLECTION(MediaQueryList)
1.64 +NS_INTERFACE_MAP_END
1.65 +
1.66 +NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaQueryList)
1.67 +NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaQueryList)
1.68 +
1.69 +void
1.70 +MediaQueryList::GetMedia(nsAString &aMedia)
1.71 +{
1.72 + mMediaList->GetText(aMedia);
1.73 +}
1.74 +
1.75 +bool
1.76 +MediaQueryList::Matches()
1.77 +{
1.78 + if (!mMatchesValid) {
1.79 + NS_ABORT_IF_FALSE(!HasListeners(),
1.80 + "when listeners present, must keep mMatches current");
1.81 + RecomputeMatches();
1.82 + }
1.83 +
1.84 + return mMatches;
1.85 +}
1.86 +
1.87 +void
1.88 +MediaQueryList::AddListener(MediaQueryListListener& aListener)
1.89 +{
1.90 + if (!HasListeners()) {
1.91 + // When we have listeners, the pres context owns a reference to
1.92 + // this. This is a cyclic reference that can only be broken by
1.93 + // cycle collection.
1.94 + NS_ADDREF_THIS();
1.95 + }
1.96 +
1.97 + if (!mMatchesValid) {
1.98 + NS_ABORT_IF_FALSE(!HasListeners(),
1.99 + "when listeners present, must keep mMatches current");
1.100 + RecomputeMatches();
1.101 + }
1.102 +
1.103 + for (uint32_t i = 0; i < mCallbacks.Length(); ++i) {
1.104 + if (aListener == *mCallbacks[i]) {
1.105 + // Already registered
1.106 + return;
1.107 + }
1.108 + }
1.109 +
1.110 + mCallbacks.AppendElement(&aListener);
1.111 + if (!HasListeners()) {
1.112 + // Append failed; undo the AddRef above.
1.113 + NS_RELEASE_THIS();
1.114 + }
1.115 +}
1.116 +
1.117 +void
1.118 +MediaQueryList::RemoveListener(MediaQueryListListener& aListener)
1.119 +{
1.120 + for (uint32_t i = 0; i < mCallbacks.Length(); ++i) {
1.121 + if (aListener == *mCallbacks[i]) {
1.122 + mCallbacks.RemoveElementAt(i);
1.123 + if (!HasListeners()) {
1.124 + // See NS_ADDREF_THIS() in AddListener.
1.125 + NS_RELEASE_THIS();
1.126 + }
1.127 + break;
1.128 + }
1.129 + }
1.130 +}
1.131 +
1.132 +void
1.133 +MediaQueryList::RemoveAllListeners()
1.134 +{
1.135 + bool hadListeners = HasListeners();
1.136 + mCallbacks.Clear();
1.137 + if (hadListeners) {
1.138 + // See NS_ADDREF_THIS() in AddListener.
1.139 + NS_RELEASE_THIS();
1.140 + }
1.141 +}
1.142 +
1.143 +void
1.144 +MediaQueryList::RecomputeMatches()
1.145 +{
1.146 + if (!mPresContext) {
1.147 + return;
1.148 + }
1.149 +
1.150 + mMatches = mMediaList->Matches(mPresContext, nullptr);
1.151 + mMatchesValid = true;
1.152 +}
1.153 +
1.154 +void
1.155 +MediaQueryList::MediumFeaturesChanged(NotifyList &aListenersToNotify)
1.156 +{
1.157 + mMatchesValid = false;
1.158 +
1.159 + if (HasListeners()) {
1.160 + bool oldMatches = mMatches;
1.161 + RecomputeMatches();
1.162 + if (mMatches != oldMatches) {
1.163 + for (uint32_t i = 0, i_end = mCallbacks.Length(); i != i_end; ++i) {
1.164 + HandleChangeData *d = aListenersToNotify.AppendElement();
1.165 + if (d) {
1.166 + d->mql = this;
1.167 + d->callback = mCallbacks[i];
1.168 + }
1.169 + }
1.170 + }
1.171 + }
1.172 +}
1.173 +
1.174 +nsISupports*
1.175 +MediaQueryList::GetParentObject() const
1.176 +{
1.177 + if (!mPresContext) {
1.178 + return nullptr;
1.179 + }
1.180 + return mPresContext->Document();
1.181 +}
1.182 +
1.183 +JSObject*
1.184 +MediaQueryList::WrapObject(JSContext* aCx)
1.185 +{
1.186 + return MediaQueryListBinding::Wrap(aCx, this);
1.187 +}
1.188 +
1.189 +} // namespace dom
1.190 +} // namespace mozilla
