/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */ /* 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 "nsPresContext.h" #include "nsIMediaList.h" #include "nsCSSParser.h" #include "nsIDocument.h" namespace mozilla { namespace dom { MediaQueryList::MediaQueryList(nsIDocument *aDocument, const nsAString &aMediaQueryList) : mDocument(aDocument), mMediaList(new nsMediaList), mMatchesValid(false) { PR_INIT_CLIST(this); nsCSSParser parser; parser.ParseMediaList(aMediaQueryList, nullptr, 0, mMediaList, false); } MediaQueryList::~MediaQueryList() { if (mDocument) { PR_REMOVE_LINK(this); } } NS_IMPL_CYCLE_COLLECTION_CLASS(MediaQueryList) NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(MediaQueryList) NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDocument) NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCallbacks) NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(MediaQueryList) if (tmp->mDocument) { PR_REMOVE_LINK(tmp); NS_IMPL_CYCLE_COLLECTION_UNLINK(mDocument) } tmp->RemoveAllListeners(); NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER NS_IMPL_CYCLE_COLLECTION_UNLINK_END NS_IMPL_CYCLE_COLLECTION_TRACE_WRAPPERCACHE(MediaQueryList) NS_INTERFACE_MAP_BEGIN(MediaQueryList) NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY NS_INTERFACE_MAP_ENTRY(nsISupports) NS_INTERFACE_MAP_ENTRIES_CYCLE_COLLECTION(MediaQueryList) NS_INTERFACE_MAP_END NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaQueryList) NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaQueryList) void MediaQueryList::GetMedia(nsAString &aMedia) { mMediaList->GetText(aMedia); } bool MediaQueryList::Matches() { if (!mMatchesValid) { MOZ_ASSERT(!HasListeners(), "when listeners present, must keep mMatches current"); RecomputeMatches(); } return mMatches; } void MediaQueryList::AddListener(MediaQueryListListener& aListener) { if (!HasListeners()) { // When we have listeners, the pres context owns a reference to // this. This is a cyclic reference that can only be broken by // cycle collection. NS_ADDREF_THIS(); } if (!mMatchesValid) { MOZ_ASSERT(!HasListeners(), "when listeners present, must keep mMatches current"); RecomputeMatches(); } for (uint32_t i = 0; i < mCallbacks.Length(); ++i) { if (aListener == *mCallbacks[i]) { // Already registered return; } } if (!mCallbacks.AppendElement(&aListener, fallible)) { if (!HasListeners()) { // Append failed; undo the AddRef above. NS_RELEASE_THIS(); } } } void MediaQueryList::RemoveListener(MediaQueryListListener& aListener) { for (uint32_t i = 0; i < mCallbacks.Length(); ++i) { if (aListener == *mCallbacks[i]) { mCallbacks.RemoveElementAt(i); if (!HasListeners()) { // See NS_ADDREF_THIS() in AddListener. NS_RELEASE_THIS(); } break; } } } void MediaQueryList::RemoveAllListeners() { bool hadListeners = HasListeners(); mCallbacks.Clear(); if (hadListeners) { // See NS_ADDREF_THIS() in AddListener. NS_RELEASE_THIS(); } } void MediaQueryList::RecomputeMatches() { if (!mDocument) { return; } if (mDocument->GetParentDocument()) { // Flush frames on the parent so our prescontext will get // recreated as needed. mDocument->GetParentDocument()->FlushPendingNotifications(Flush_Frames); // That might have killed our document, so recheck that. if (!mDocument) { return; } } nsIPresShell* shell = mDocument->GetShell(); if (!shell) { // XXXbz What's the right behavior here? Spec doesn't say. return; } nsPresContext* presContext = shell->GetPresContext(); if (!presContext) { // XXXbz What's the right behavior here? Spec doesn't say. return; } mMatches = mMediaList->Matches(presContext, nullptr); mMatchesValid = true; } void MediaQueryList::MediumFeaturesChanged( nsTArray<HandleChangeData>& aListenersToNotify) { mMatchesValid = false; if (HasListeners()) { bool oldMatches = mMatches; RecomputeMatches(); if (mMatches != oldMatches) { for (uint32_t i = 0, i_end = mCallbacks.Length(); i != i_end; ++i) { HandleChangeData *d = aListenersToNotify.AppendElement(fallible); if (d) { d->mql = this; d->callback = mCallbacks[i]; } } } } } nsISupports* MediaQueryList::GetParentObject() const { return mDocument; } JSObject* MediaQueryList::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) { return MediaQueryListBinding::Wrap(aCx, this, aGivenProto); } } // namespace dom } // namespace mozilla