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/* -*- 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_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
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