dom/xml/nsXMLPrettyPrinter.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsXMLPrettyPrinter.h"
   7 #include "nsContentUtils.h"
   8 #include "nsICSSDeclaration.h"
   9 #include "nsSyncLoadService.h"
  10 #include "nsPIDOMWindow.h"
  11 #include "nsNetUtil.h"
  12 #include "mozilla/dom/Element.h"
  13 #include "mozilla/dom/ShadowRoot.h"
  14 #include "mozilla/Preferences.h"
  15 #include "mozilla/dom/Document.h"
  16 #include "nsVariant.h"
  17 #include "mozilla/dom/CustomEvent.h"
  18 #include "mozilla/dom/DocumentFragment.h"
  19 #include "mozilla/dom/DocumentL10n.h"
  20 #include "mozilla/dom/ScriptSettings.h"
  21 #include "mozilla/dom/ToJSValue.h"
  22 #include "mozilla/dom/txMozillaXSLTProcessor.h"
  23
  24 using namespace mozilla;
  25 using namespace mozilla::dom;
  26
  27 NS_IMPL_ISUPPORTS(nsXMLPrettyPrinter, nsIDocumentObserver, nsIMutationObserver)
  28
  29 nsXMLPrettyPrinter::nsXMLPrettyPrinter()
  30     : mDocument(nullptr), mUnhookPending(false) {}
  31
  32 nsXMLPrettyPrinter::~nsXMLPrettyPrinter() {
  33   NS_ASSERTION(!mDocument, "we shouldn't be referencing the document still");
  34 }
  35
  36 nsresult nsXMLPrettyPrinter::PrettyPrint(Document* aDocument,
  37                                          bool* aDidPrettyPrint) {
  38   *aDidPrettyPrint = false;
  39
  40   // check the pref
  41   if (!Preferences::GetBool("layout.xml.prettyprint", true)) {
  42     return NS_OK;
  43   }
  44
  45   // Find the root element
  46   RefPtr<Element> rootElement = aDocument->GetRootElement();
  47   NS_ENSURE_TRUE(rootElement, NS_ERROR_UNEXPECTED);
  48
  49   // nsXMLContentSink should not ask us to pretty print an XML doc that comes
  50   // with a CanAttachShadowDOM() == true root element, but just in case:
  51   if (rootElement->CanAttachShadowDOM()) {
  52     MOZ_DIAGNOSTIC_ASSERT(false, "We shouldn't be getting this root element");
  53     return NS_ERROR_UNEXPECTED;
  54   }
  55
  56   // Ok, we should prettyprint. Let's do it!
  57   *aDidPrettyPrint = true;
  58   nsresult rv = NS_OK;
  59
  60   // Load the XSLT
  61   nsCOMPtr<nsIURI> xslUri;
  62   rv = NS_NewURI(getter_AddRefs(xslUri),
  63                  "chrome://global/content/xml/XMLPrettyPrint.xsl"_ns);
  64   NS_ENSURE_SUCCESS(rv, rv);
  65
  66   nsCOMPtr<Document> xslDocument;
  67   rv = nsSyncLoadService::LoadDocument(
  68       xslUri, nsIContentPolicy::TYPE_XSLT, nsContentUtils::GetSystemPrincipal(),
  69       nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL, nullptr,
  70       aDocument->CookieJarSettings(), true, ReferrerPolicy::_empty,
  71       getter_AddRefs(xslDocument));
  72   NS_ENSURE_SUCCESS(rv, rv);
  73
  74   // Transform the document
  75   RefPtr<txMozillaXSLTProcessor> transformer = new txMozillaXSLTProcessor();
  76   ErrorResult err;
  77   transformer->ImportStylesheet(*xslDocument, err);
  78   if (NS_WARN_IF(err.Failed())) {
  79     return err.StealNSResult();
  80   }
  81
  82   RefPtr<DocumentFragment> resultFragment =
  83       transformer->TransformToFragment(*aDocument, *aDocument, err);
  84   if (NS_WARN_IF(err.Failed())) {
  85     return err.StealNSResult();
  86   }
  87
  88   // Attach an UA Widget Shadow Root on it.
  89   rootElement->AttachAndSetUAShadowRoot(Element::NotifyUAWidgetSetup::No);
  90   RefPtr<ShadowRoot> shadowRoot = rootElement->GetShadowRoot();
  91   MOZ_RELEASE_ASSERT(shadowRoot && shadowRoot->IsUAWidget(),
  92                      "There should be a UA Shadow Root here.");
  93
  94   // Append the document fragment to the shadow dom.
  95   shadowRoot->AppendChild(*resultFragment, err);
  96   if (NS_WARN_IF(err.Failed())) {
  97     return err.StealNSResult();
  98   }
  99
 100   // Create a DocumentL10n, as the XML document is not allowed to have one.
 101   // Make it sync so that the test for bug 590812 does not require a setTimeout.
 102   RefPtr<DocumentL10n> l10n = DocumentL10n::Create(aDocument, true);
 103   NS_ENSURE_TRUE(l10n, NS_ERROR_UNEXPECTED);
 104   l10n->AddResourceId("dom/XMLPrettyPrint.ftl"_ns);
 105
 106   // Localize the shadow DOM header
 107   Element* l10nRoot = shadowRoot->GetElementById(u"header"_ns);
 108   NS_ENSURE_TRUE(l10nRoot, NS_ERROR_UNEXPECTED);
 109   l10n->SetRootInfo(l10nRoot);
 110   l10n->ConnectRoot(*l10nRoot, true, err);
 111   if (NS_WARN_IF(err.Failed())) {
 112     return err.StealNSResult();
 113   }
 114   RefPtr<Promise> promise = l10n->TranslateRoots(err);
 115   if (NS_WARN_IF(err.Failed())) {
 116     return err.StealNSResult();
 117   }
 118
 119   // Observe the document so we know when to switch to "normal" view
 120   aDocument->AddObserver(this);
 121   mDocument = aDocument;
 122
 123   NS_ADDREF_THIS();
 124
 125   return NS_OK;
 126 }
 127
 128 void nsXMLPrettyPrinter::MaybeUnhook(nsIContent* aContent) {
 129   // If aContent is null, the document-node was modified.
 130   // If it is not null but in the shadow tree or the <scrollbar> NACs,
 131   // the change was in the generated content, and it should be ignored.
 132   bool isGeneratedContent =
 133       aContent &&
 134       (aContent->IsInNativeAnonymousSubtree() || aContent->IsInShadowTree());
 135
 136   if (!isGeneratedContent && !mUnhookPending) {
 137     // Can't blindly to mUnhookPending after AddScriptRunner,
 138     // since AddScriptRunner _could_ in theory run us
 139     // synchronously
 140     mUnhookPending = true;
 141     nsContentUtils::AddScriptRunner(NewRunnableMethod(
 142         "nsXMLPrettyPrinter::Unhook", this, &nsXMLPrettyPrinter::Unhook));
 143   }
 144 }
 145
 146 void nsXMLPrettyPrinter::Unhook() {
 147   mDocument->RemoveObserver(this);
 148   nsCOMPtr<Element> element = mDocument->GetDocumentElement();
 149
 150   if (element) {
 151     // Remove the shadow root
 152     element->UnattachShadow();
 153   }
 154
 155   mDocument = nullptr;
 156
 157   NS_RELEASE_THIS();
 158 }
 159
 160 void nsXMLPrettyPrinter::AttributeChanged(Element* aElement,
 161                                           int32_t aNameSpaceID,
 162                                           nsAtom* aAttribute, int32_t aModType,
 163                                           const nsAttrValue* aOldValue) {
 164   MaybeUnhook(aElement);
 165 }
 166
 167 void nsXMLPrettyPrinter::ContentAppended(nsIContent* aFirstNewContent) {
 168   MaybeUnhook(aFirstNewContent->GetParent());
 169 }
 170
 171 void nsXMLPrettyPrinter::ContentInserted(nsIContent* aChild) {
 172   MaybeUnhook(aChild->GetParent());
 173 }
 174
 175 void nsXMLPrettyPrinter::ContentRemoved(nsIContent* aChild,
 176                                         nsIContent* aPreviousSibling) {
 177   MaybeUnhook(aChild->GetParent());
 178 }
 179
 180 void nsXMLPrettyPrinter::NodeWillBeDestroyed(nsINode* aNode) {
 181   mDocument = nullptr;
 182   NS_RELEASE_THIS();
 183 }
 184
 185 nsresult NS_NewXMLPrettyPrinter(nsXMLPrettyPrinter** aPrinter) {
 186   *aPrinter = new nsXMLPrettyPrinter;
 187   NS_ADDREF(*aPrinter);
 188   return NS_OK;
 189 }