gecko-dev/layout/style/MediaQueryList.cpp

216 строки
5.2 KiB
C++

/* -*- 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 "nsCSSParser.h"
#include "nsIDocument.h"
#define ONCHANGE_STRING NS_LITERAL_STRING("change")
namespace mozilla {
namespace dom {
MediaQueryList::MediaQueryList(nsIDocument* aDocument,
const nsAString& aMediaQueryList,
CallerType aCallerType)
: mDocument(aDocument)
, mMatchesValid(false)
{
mMediaList =
MediaList::Create(aDocument->GetStyleBackendType(),
aMediaQueryList,
aCallerType);
KeepAliveIfHasListenersFor(ONCHANGE_STRING);
}
MediaQueryList::~MediaQueryList()
{}
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) {
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(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(EventListener* aListener, ErrorResult& aRv)
{
if (!aListener) {
return;
}
AddEventListenerOptionsOrBoolean options;
options.SetAsBoolean() = false;
AddEventListener(ONCHANGE_STRING, aListener, options, false, aRv);
}
void
MediaQueryList::AddEventListener(const nsAString& aType,
EventListener* aCallback,
const AddEventListenerOptionsOrBoolean& aOptions,
const dom::Nullable<bool>& aWantsUntrusted,
ErrorResult& aRv)
{
if (!mMatchesValid) {
MOZ_ASSERT(!HasListeners(),
"when listeners present, must keep mMatches current");
RecomputeMatches();
}
DOMEventTargetHelper::AddEventListener(aType, aCallback, aOptions,
aWantsUntrusted, aRv);
}
void
MediaQueryList::RemoveListener(EventListener* aListener, ErrorResult& aRv)
{
if (!aListener) {
return;
}
EventListenerOptionsOrBoolean options;
options.SetAsBoolean() = false;
RemoveEventListener(ONCHANGE_STRING, aListener, options, aRv);
}
bool
MediaQueryList::HasListeners()
{
return HasListenersFor(ONCHANGE_STRING);
}
void
MediaQueryList::Disconnect()
{
DisconnectFromOwner();
IgnoreKeepAliveIfHasListenersFor(ONCHANGE_STRING);
}
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(FlushType::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);
mMatchesValid = true;
}
nsISupports*
MediaQueryList::GetParentObject() const
{
return mDocument;
}
JSObject*
MediaQueryList::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
return MediaQueryListBinding::Wrap(aCx, this, aGivenProto);
}
void
MediaQueryList::MaybeNotify()
{
mMatchesValid = false;
if (!HasListeners()) {
return;
}
bool oldMatches = mMatches;
RecomputeMatches();
// No need to notify the change.
if (mMatches == oldMatches) {
return;
}
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);
bool dummy;
DispatchEvent(event, &dummy);
}
} // namespace dom
} // namespace mozilla