michael@0: /* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /* implements DOM interface for querying and observing media queries */
michael@0: 
michael@0: #include "mozilla/dom/MediaQueryList.h"
michael@0: #include "nsPresContext.h"
michael@0: #include "nsIMediaList.h"
michael@0: #include "nsCSSParser.h"
michael@0: #include "nsIDocument.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace dom {
michael@0: 
michael@0: MediaQueryList::MediaQueryList(nsPresContext *aPresContext,
michael@0:                                const nsAString &aMediaQueryList)
michael@0:   : mPresContext(aPresContext),
michael@0:     mMediaList(new nsMediaList),
michael@0:     mMatchesValid(false)
michael@0: {
michael@0:   PR_INIT_CLIST(this);
michael@0: 
michael@0:   SetIsDOMBinding();
michael@0: 
michael@0:   nsCSSParser parser;
michael@0:   parser.ParseMediaList(aMediaQueryList, nullptr, 0, mMediaList, false);
michael@0: }
michael@0: 
michael@0: MediaQueryList::~MediaQueryList()
michael@0: {
michael@0:   if (mPresContext) {
michael@0:     PR_REMOVE_LINK(this);
michael@0:   }
michael@0: }
michael@0: 
michael@0: NS_IMPL_CYCLE_COLLECTION_CLASS(MediaQueryList)
michael@0: 
michael@0: NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(MediaQueryList)
michael@0:   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPresContext)
michael@0:   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCallbacks)
michael@0:   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
michael@0: NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
michael@0: 
michael@0: NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(MediaQueryList)
michael@0:   if (tmp->mPresContext) {
michael@0:     PR_REMOVE_LINK(tmp);
michael@0:     NS_IMPL_CYCLE_COLLECTION_UNLINK(mPresContext)
michael@0:   }
michael@0:   tmp->RemoveAllListeners();
michael@0:   NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
michael@0: NS_IMPL_CYCLE_COLLECTION_UNLINK_END
michael@0: 
michael@0: NS_IMPL_CYCLE_COLLECTION_TRACE_WRAPPERCACHE(MediaQueryList)
michael@0: 
michael@0: NS_INTERFACE_MAP_BEGIN(MediaQueryList)
michael@0:   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
michael@0:   NS_INTERFACE_MAP_ENTRY(nsISupports)
michael@0:   NS_INTERFACE_MAP_ENTRIES_CYCLE_COLLECTION(MediaQueryList)
michael@0: NS_INTERFACE_MAP_END
michael@0: 
michael@0: NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaQueryList)
michael@0: NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaQueryList)
michael@0: 
michael@0: void
michael@0: MediaQueryList::GetMedia(nsAString &aMedia)
michael@0: {
michael@0:   mMediaList->GetText(aMedia);
michael@0: }
michael@0: 
michael@0: bool
michael@0: MediaQueryList::Matches()
michael@0: {
michael@0:   if (!mMatchesValid) {
michael@0:     NS_ABORT_IF_FALSE(!HasListeners(),
michael@0:                       "when listeners present, must keep mMatches current");
michael@0:     RecomputeMatches();
michael@0:   }
michael@0: 
michael@0:   return mMatches;
michael@0: }
michael@0: 
michael@0: void
michael@0: MediaQueryList::AddListener(MediaQueryListListener& aListener)
michael@0: {
michael@0:   if (!HasListeners()) {
michael@0:     // When we have listeners, the pres context owns a reference to
michael@0:     // this.  This is a cyclic reference that can only be broken by
michael@0:     // cycle collection.
michael@0:     NS_ADDREF_THIS();
michael@0:   }
michael@0: 
michael@0:   if (!mMatchesValid) {
michael@0:     NS_ABORT_IF_FALSE(!HasListeners(),
michael@0:                       "when listeners present, must keep mMatches current");
michael@0:     RecomputeMatches();
michael@0:   }
michael@0: 
michael@0:   for (uint32_t i = 0; i < mCallbacks.Length(); ++i) {
michael@0:     if (aListener == *mCallbacks[i]) {
michael@0:       // Already registered
michael@0:       return;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   mCallbacks.AppendElement(&aListener);
michael@0:   if (!HasListeners()) {
michael@0:     // Append failed; undo the AddRef above.
michael@0:     NS_RELEASE_THIS();
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: MediaQueryList::RemoveListener(MediaQueryListListener& aListener)
michael@0: {
michael@0:   for (uint32_t i = 0; i < mCallbacks.Length(); ++i) {
michael@0:     if (aListener == *mCallbacks[i]) {
michael@0:       mCallbacks.RemoveElementAt(i);
michael@0:       if (!HasListeners()) {
michael@0:         // See NS_ADDREF_THIS() in AddListener.
michael@0:         NS_RELEASE_THIS();
michael@0:       }
michael@0:       break;
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: MediaQueryList::RemoveAllListeners()
michael@0: {
michael@0:   bool hadListeners = HasListeners();
michael@0:   mCallbacks.Clear();
michael@0:   if (hadListeners) {
michael@0:     // See NS_ADDREF_THIS() in AddListener.
michael@0:     NS_RELEASE_THIS();
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: MediaQueryList::RecomputeMatches()
michael@0: {
michael@0:   if (!mPresContext) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   mMatches = mMediaList->Matches(mPresContext, nullptr);
michael@0:   mMatchesValid = true;
michael@0: }
michael@0: 
michael@0: void
michael@0: MediaQueryList::MediumFeaturesChanged(NotifyList &aListenersToNotify)
michael@0: {
michael@0:   mMatchesValid = false;
michael@0: 
michael@0:   if (HasListeners()) {
michael@0:     bool oldMatches = mMatches;
michael@0:     RecomputeMatches();
michael@0:     if (mMatches != oldMatches) {
michael@0:       for (uint32_t i = 0, i_end = mCallbacks.Length(); i != i_end; ++i) {
michael@0:         HandleChangeData *d = aListenersToNotify.AppendElement();
michael@0:         if (d) {
michael@0:           d->mql = this;
michael@0:           d->callback = mCallbacks[i];
michael@0:         }
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: nsISupports*
michael@0: MediaQueryList::GetParentObject() const
michael@0: {
michael@0:   if (!mPresContext) {
michael@0:     return nullptr;
michael@0:   }
michael@0:   return mPresContext->Document();
michael@0: }
michael@0: 
michael@0: JSObject*
michael@0: MediaQueryList::WrapObject(JSContext* aCx)
michael@0: {
michael@0:   return MediaQueryListBinding::Wrap(aCx, this);
michael@0: }
michael@0: 
michael@0: } // namespace dom
michael@0: } // namespace mozilla