gecko-dev/dom/base/nsReferencedElement.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 sw=2 et tw=78: */
2012-05-21 11:12:37 +00:00
/* 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/. */
#include "nsReferencedElement.h"
#include "nsContentUtils.h"
#include "nsIURI.h"
#include "nsBindingManager.h"
#include "nsEscape.h"
#include "nsXBLPrototypeBinding.h"
#include "nsIDOMNode.h"
#include "nsIDOMElement.h"
#include "nsCycleCollectionParticipant.h"
void
nsReferencedElement::Reset(nsIContent* aFromContent, nsIURI* aURI,
bool aWatch, bool aReferenceImage)
{
NS_ABORT_IF_FALSE(aFromContent, "Reset() expects non-null content pointer");
Unlink();
if (!aURI)
return;
nsAutoCString refPart;
aURI->GetRef(refPart);
// Unescape %-escapes in the reference. The result will be in the
// origin charset of the URL, hopefully...
NS_UnescapeURL(refPart);
nsAutoCString charset;
aURI->GetOriginCharset(charset);
nsAutoString ref;
nsresult rv = nsContentUtils::ConvertStringFromEncoding(charset,
refPart,
ref);
if (NS_FAILED(rv)) {
// XXX Eww. If fallible malloc failed, using a conversion method that
// assumes UTF-8 and doesn't handle UTF-8 errors.
// https://bugzilla.mozilla.org/show_bug.cgi?id=951082
CopyUTF8toUTF16(refPart, ref);
}
if (ref.IsEmpty())
return;
// Get the current document
nsIDocument *doc = aFromContent->GetComposedDoc();
if (!doc)
return;
nsIContent* bindingParent = aFromContent->GetBindingParent();
if (bindingParent) {
nsXBLBinding* binding = bindingParent->GetXBLBinding();
if (binding) {
bool isEqualExceptRef;
rv = aURI->EqualsExceptRef(binding->PrototypeBinding()->DocURI(),
&isEqualExceptRef);
if (NS_SUCCEEDED(rv) && isEqualExceptRef) {
// XXX sXBL/XBL2 issue
// Our content is an anonymous XBL element from a binding inside the
// same document that the referenced URI points to. In order to avoid
// the risk of ID collisions we restrict ourselves to anonymous
// elements from this binding; specifically, URIs that are relative to
// the binding document should resolve to the copy of the target
// element that has been inserted into the bound document.
// If the URI points to a different document we don't need this
// restriction.
nsINodeList* anonymousChildren =
doc->BindingManager()->GetAnonymousNodesFor(bindingParent);
if (anonymousChildren) {
uint32_t length;
anonymousChildren->GetLength(&length);
for (uint32_t i = 0; i < length && !mElement; ++i) {
mElement =
nsContentUtils::MatchElementId(anonymousChildren->Item(i), ref);
}
}
// We don't have watching working yet for XBL, so bail out here.
return;
}
}
}
bool isEqualExceptRef;
rv = aURI->EqualsExceptRef(doc->GetDocumentURI(), &isEqualExceptRef);
if (NS_FAILED(rv) || !isEqualExceptRef) {
nsRefPtr<nsIDocument::ExternalResourceLoad> load;
doc = doc->RequestExternalResource(aURI, aFromContent,
getter_AddRefs(load));
if (!doc) {
if (!load || !aWatch) {
// Nothing will ever happen here
return;
}
DocumentLoadNotification* observer =
new DocumentLoadNotification(this, ref);
mPendingNotification = observer;
if (observer) {
load->AddObserver(observer);
}
// Keep going so we set up our watching stuff a bit
}
}
if (aWatch) {
nsCOMPtr<nsIAtom> atom = do_GetAtom(ref);
if (!atom)
return;
atom.swap(mWatchID);
}
mReferencingImage = aReferenceImage;
HaveNewDocument(doc, aWatch, ref);
}
void
nsReferencedElement::ResetWithID(nsIContent* aFromContent, const nsString& aID,
bool aWatch)
{
nsIDocument *doc = aFromContent->GetComposedDoc();
if (!doc)
return;
// XXX Need to take care of XBL/XBL2
if (aWatch) {
nsCOMPtr<nsIAtom> atom = do_GetAtom(aID);
if (!atom)
return;
atom.swap(mWatchID);
}
mReferencingImage = false;
HaveNewDocument(doc, aWatch, aID);
}
void
nsReferencedElement::HaveNewDocument(nsIDocument* aDocument, bool aWatch,
const nsString& aRef)
{
if (aWatch) {
mWatchDocument = aDocument;
if (mWatchDocument) {
mElement = mWatchDocument->AddIDTargetObserver(mWatchID, Observe, this,
mReferencingImage);
}
return;
}
if (!aDocument) {
return;
}
Element *e = mReferencingImage ? aDocument->LookupImageElement(aRef) :
aDocument->GetElementById(aRef);
if (e) {
mElement = e;
}
}
void
nsReferencedElement::Traverse(nsCycleCollectionTraversalCallback* aCB)
{
NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCB, "mWatchDocument");
aCB->NoteXPCOMChild(mWatchDocument);
NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCB, "mContent");
aCB->NoteXPCOMChild(mElement);
}
void
nsReferencedElement::Unlink()
{
if (mWatchDocument && mWatchID) {
mWatchDocument->RemoveIDTargetObserver(mWatchID, Observe, this,
mReferencingImage);
}
if (mPendingNotification) {
mPendingNotification->Clear();
mPendingNotification = nullptr;
}
mWatchDocument = nullptr;
mWatchID = nullptr;
mElement = nullptr;
mReferencingImage = false;
}
bool
nsReferencedElement::Observe(Element* aOldElement,
Element* aNewElement, void* aData)
{
nsReferencedElement* p = static_cast<nsReferencedElement*>(aData);
if (p->mPendingNotification) {
p->mPendingNotification->SetTo(aNewElement);
} else {
NS_ASSERTION(aOldElement == p->mElement, "Failed to track content!");
ChangeNotification* watcher =
new ChangeNotification(p, aOldElement, aNewElement);
p->mPendingNotification = watcher;
nsContentUtils::AddScriptRunner(watcher);
}
bool keepTracking = p->IsPersistent();
if (!keepTracking) {
p->mWatchDocument = nullptr;
p->mWatchID = nullptr;
}
return keepTracking;
}
NS_IMPL_ISUPPORTS_INHERITED0(nsReferencedElement::ChangeNotification,
nsRunnable)
NS_IMPL_ISUPPORTS(nsReferencedElement::DocumentLoadNotification,
nsIObserver)
NS_IMETHODIMP
nsReferencedElement::DocumentLoadNotification::Observe(nsISupports* aSubject,
const char* aTopic,
const char16_t* aData)
{
NS_ASSERTION(PL_strcmp(aTopic, "external-resource-document-created") == 0,
"Unexpected topic");
if (mTarget) {
nsCOMPtr<nsIDocument> doc = do_QueryInterface(aSubject);
mTarget->mPendingNotification = nullptr;
NS_ASSERTION(!mTarget->mElement, "Why do we have content here?");
// If we got here, that means we had Reset() called with aWatch ==
// true. So keep watching if IsPersistent().
mTarget->HaveNewDocument(doc, mTarget->IsPersistent(), mRef);
mTarget->ElementChanged(nullptr, mTarget->mElement);
}
return NS_OK;
}