diff options
Diffstat (limited to 'layout/style/MediaQueryList.cpp')
| -rw-r--r-- | layout/style/MediaQueryList.cpp | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/layout/style/MediaQueryList.cpp b/layout/style/MediaQueryList.cpp new file mode 100644 index 0000000000..5b36bf09ad --- /dev/null +++ b/layout/style/MediaQueryList.cpp @@ -0,0 +1,174 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* implements DOM interface for querying and observing media queries */ + +#include "mozilla/dom/MediaQueryList.h" +#include "mozilla/dom/MediaQueryListEvent.h" +#include "mozilla/dom/MediaList.h" +#include "mozilla/dom/EventTarget.h" +#include "mozilla/dom/EventTargetBinding.h" +#include "nsPresContext.h" +#include "mozilla/dom/Document.h" + +#define ONCHANGE_STRING u"change"_ns + +namespace mozilla::dom { + +MediaQueryList::MediaQueryList(Document* aDocument, + const nsACString& aMediaQueryList, + CallerType aCallerType) + : DOMEventTargetHelper(aDocument->GetInnerWindow()), + mDocument(aDocument), + mMediaList(MediaList::Create(aMediaQueryList, aCallerType)), + mViewportDependent(mMediaList->IsViewportDependent()) { + KeepAliveIfHasListenersFor(nsGkAtoms::onchange); +} + +MediaQueryList::~MediaQueryList() = default; + +NS_IMPL_CYCLE_COLLECTION_CLASS(MediaQueryList) + +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(MediaQueryList, + DOMEventTargetHelper) + NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDocument) +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END + +NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(MediaQueryList, + DOMEventTargetHelper) + if (tmp->mDocument) { + static_cast<LinkedListElement<MediaQueryList>*>(tmp)->remove(); + NS_IMPL_CYCLE_COLLECTION_UNLINK(mDocument) + } + tmp->Disconnect(); + NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER +NS_IMPL_CYCLE_COLLECTION_UNLINK_END + +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaQueryList) +NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper) + +NS_IMPL_ADDREF_INHERITED(MediaQueryList, DOMEventTargetHelper) +NS_IMPL_RELEASE_INHERITED(MediaQueryList, DOMEventTargetHelper) + +void MediaQueryList::GetMedia(nsACString& aMedia) const { + mMediaList->GetText(aMedia); +} + +bool MediaQueryList::Matches() { + if (mViewportDependent && + mDocument->StyleOrLayoutObservablyDependsOnParentDocumentLayout()) { + RefPtr<Document> doc = mDocument; + // This is enough to trigger media query updates in the current doc, and + // will flush the parent document layout if appropriate. + doc->FlushPendingNotifications(FlushType::Layout); + } + if (!mMatchesValid) { + MOZ_ASSERT(!HasListeners(), + "when listeners present, must keep mMatches current"); + RecomputeMatches(); + } + return mMatches; +} + +void MediaQueryList::AddListener(EventListener* aListener, ErrorResult& aRv) { + if (!aListener) { + return; + } + + AddEventListenerOptionsOrBoolean options; + options.SetAsBoolean() = false; + + AddEventListener(ONCHANGE_STRING, aListener, options, Nullable<bool>(), aRv); +} + +void MediaQueryList::EventListenerAdded(nsAtom* aType) { + // HasListeners() might still be false if the added thing wasn't a + // listener we care about. + if (!mMatchesValid && HasListeners()) { + RecomputeMatches(); + } + + DOMEventTargetHelper::EventListenerAdded(aType); +} + +void MediaQueryList::RemoveListener(EventListener* aListener, + ErrorResult& aRv) { + if (!aListener) { + return; + } + + EventListenerOptionsOrBoolean options; + options.SetAsBoolean() = false; + + RemoveEventListener(ONCHANGE_STRING, aListener, options, aRv); +} + +bool MediaQueryList::HasListeners() const { + return HasListenersFor(ONCHANGE_STRING); +} + +void MediaQueryList::Disconnect() { + DisconnectFromOwner(); + + IgnoreKeepAliveIfHasListenersFor(nsGkAtoms::onchange); +} + +void MediaQueryList::RecomputeMatches() { + mMatches = false; + + if (!mDocument) { + return; + } + + mMatches = mMediaList->Matches(*mDocument); + mMatchesValid = true; +} + +nsISupports* MediaQueryList::GetParentObject() const { + return ToSupports(mDocument); +} + +JSObject* MediaQueryList::WrapObject(JSContext* aCx, + JS::Handle<JSObject*> aGivenProto) { + return MediaQueryList_Binding::Wrap(aCx, this, aGivenProto); +} + +bool MediaQueryList::MediaFeatureValuesChanged() { + mMatchesValid = false; + + if (!HasListeners()) { + return false; // No need to recompute or notify if we have no listeners. + } + + bool oldMatches = mMatches; + RecomputeMatches(); + + return mMatches != oldMatches; +} + +void MediaQueryList::FireChangeEvent() { + MediaQueryListEventInit init; + init.mBubbles = false; + init.mCancelable = false; + init.mMatches = mMatches; + mMediaList->GetText(init.mMedia); + + RefPtr<MediaQueryListEvent> event = + MediaQueryListEvent::Constructor(this, ONCHANGE_STRING, init); + event->SetTrusted(true); + + DispatchEvent(*event); +} + +size_t MediaQueryList::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const { + size_t n = 0; + // mMediaList is reference counted, but it's created and primarily owned + // by this MediaQueryList object. + n += mMediaList->SizeOfIncludingThis(aMallocSizeOf); + return n; +} + +} // namespace mozilla::dom |