Bug 1831649 - Parse interactive-widget. r=botond,emilio

It's defined in the CSS viewport spec.
https://drafts.csswg.org/css-viewport/#interactive-widget-section

Differential Revision: https://phabricator.services.mozilla.com/D204163

dom/base/Document.cpp

@@ -194,6 +194,7 @@
 #include "mozilla/dom/HTMLTextAreaElement.h"
 #include "mozilla/dom/ImageTracker.h"
 #include "mozilla/dom/InspectorUtils.h"
+#include "mozilla/dom/InteractiveWidget.h"
 #include "mozilla/dom/Link.h"
 #include "mozilla/dom/MediaQueryList.h"
 #include "mozilla/dom/MediaSource.h"
@@ -1432,6 +1433,7 @@ Document::Document(const char* aContentType)
       mHttpsOnlyStatus(nsILoadInfo::HTTPS_ONLY_UNINITIALIZED),
       mViewportType(Unknown),
       mViewportFit(ViewportFitType::Auto),
+      mInteractiveWidgetMode(InteractiveWidget::ResizesContent),
       mHeaderData(nullptr),
       mServoRestyleRootDirtyBits(0),
       mThrowOnDynamicMarkupInsertionCounter(0),
@@ -10953,11 +10955,47 @@ ViewportMetaData Document::GetViewportMetaData() const {
                                        : ViewportMetaData();
 }
 
+static InteractiveWidget ParseInteractiveWidget(
+    const ViewportMetaData& aViewportMetaData) {
+  if (aViewportMetaData.mInteractiveWidgetMode.IsEmpty()) {
+    // The spec defines "use `resizes-visual` if no value specified", but here
+    // we use `resizes-content` for the backward compatibility now.
+    // We will change it in bug 1884807.
+    return InteractiveWidget::ResizesContent;
+  }
+
+  if (aViewportMetaData.mInteractiveWidgetMode.EqualsIgnoreCase(
+          "resizes-visual")) {
+    return InteractiveWidget::ResizesVisual;
+  }
+  if (aViewportMetaData.mInteractiveWidgetMode.EqualsIgnoreCase(
+          "resizes-content")) {
+    return InteractiveWidget::ResizesContent;
+  }
+  if (aViewportMetaData.mInteractiveWidgetMode.EqualsIgnoreCase(
+          "overlays-content")) {
+    return InteractiveWidget::OverlaysContent;
+  }
+  // For the same reason above empty case, we use `resizes-content` here.
+  return InteractiveWidget::ResizesContent;
+}
+
 void Document::SetMetaViewportData(UniquePtr<ViewportMetaData> aData) {
   mLastModifiedViewportMetaData = std::move(aData);
   // Trigger recomputation of the nsViewportInfo the next time it's queried.
   mViewportType = Unknown;
 
+  // Parse interactive-widget here anyway. Normally we parse any data in the
+  // meta viewport tag in GetViewportInfo(), but GetViewportInfo() depends on
+  // the document state (e.g. display size, fullscreen, desktop-mode etc.)
+  // whereas interactive-widget is independent from the document state, it's
+  // necessary whatever the document state is.
+  dom::InteractiveWidget interactiveWidget =
+      ParseInteractiveWidget(*mLastModifiedViewportMetaData);
+  if (mInteractiveWidgetMode != interactiveWidget) {
+    mInteractiveWidgetMode = interactiveWidget;
+  }
+
   AsyncEventDispatcher::RunDOMEventWhenSafe(
       *this, u"DOMMetaViewportFitChanged"_ns, CanBubble::eYes,
       ChromeOnlyDispatch::eYes);

dom/base/Document.h

@@ -246,7 +246,6 @@ class FeaturePolicy;
 class FontFaceSet;
 class FragmentDirective;
 class FrameRequestCallback;
-class ImageTracker;
 class HighlightRegistry;
 class HTMLAllCollection;
 class HTMLBodyElement;
@@ -256,6 +255,8 @@ class HTMLDialogElement;
 class HTMLSharedElement;
 class HTMLVideoElement;
 class HTMLImageElement;
+class ImageTracker;
+enum class InteractiveWidget : uint8_t;
 struct LifecycleCallbackArgs;
 class Link;
 class Location;
@@ -3958,6 +3959,10 @@ class Document : public nsINode,
  public:
   const OriginTrials& Trials() const { return mTrials; }
 
+  dom::InteractiveWidget InteractiveWidget() const {
+    return mInteractiveWidgetMode;
+  }
+
  private:
   void DoCacheAllKnownLangPrefs();
   void RecomputeLanguageFromCharset();
@@ -5173,6 +5178,9 @@ class Document : public nsINode,
   // https://drafts.csswg.org/css-round-display/#viewport-fit-descriptor
   ViewportFitType mViewportFit;
 
+  // https://drafts.csswg.org/css-viewport/#interactive-widget-section
+  dom::InteractiveWidget mInteractiveWidgetMode;
+
   // XXXdholbert This should really be modernized to a nsTHashMap or similar,
   // though note that the modernization will need to take care to also convert
   // the special hash_table_ops logic (e.g. how SubDocClearEntry clears the

dom/base/InteractiveWidget.h

@@ -0,0 +1,19 @@
+/* -*- 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/. */
+
+#ifndef DOM_INTERACTIVE_WIDGET_H_
+#define DOM_INTERACTIVE_WIDGET_H_
+
+namespace mozilla::dom {
+// https://drafts.csswg.org/css-viewport/#interactive-widget-section
+enum class InteractiveWidget : uint8_t {
+  OverlaysContent,
+  ResizesContent,
+  ResizesVisual,
+};
+}  // namespace mozilla::dom
+
+#endif  // DOM_INTERACTIVE_WIDGET_H_

dom/base/ViewportMetaData.cpp

@@ -59,6 +59,8 @@ static void ProcessViewportToken(ViewportMetaData& aData,
     aData.mUserScalable.Assign(value);
   } else if (key_atom == nsGkAtoms::viewport_fit) {
     aData.mViewportFit.Assign(value);
+  } else if (key_atom == nsGkAtoms::interactive_widget) {
+    aData.mInteractiveWidgetMode.Assign(value);
   }
 }
 

dom/base/ViewportMetaData.h

@@ -20,6 +20,7 @@ struct ViewportMetaData {
   nsString mMaximumScale;
   nsString mUserScalable;
   nsString mViewportFit;
+  nsString mInteractiveWidgetMode;
 
   bool operator==(const ViewportMetaData& aOther) const {
     return mWidth == aOther.mWidth && mHeight == aOther.mHeight &&
@@ -27,7 +28,8 @@ struct ViewportMetaData {
            mMinimumScale == aOther.mMinimumScale &&
            mMaximumScale == aOther.mMaximumScale &&
            mUserScalable == aOther.mUserScalable &&
-           mViewportFit == aOther.mViewportFit;
+           mViewportFit == aOther.mViewportFit &&
+           mInteractiveWidgetMode == aOther.mInteractiveWidgetMode;
   }
   bool operator!=(const ViewportMetaData& aOther) const {
     return !(*this == aOther);

dom/base/moz.build

@@ -210,6 +210,7 @@ EXPORTS.mozilla.dom += [
     "IDTracker.h",
     "ImageEncoder.h",
     "ImageTracker.h",
+    "InteractiveWidget.h",
     "IntlUtils.h",
     "JSExecutionContext.h",
     "Link.h",

xpcom/ds/StaticAtoms.py

@@ -568,6 +568,7 @@ STATIC_ATOMS = [
     Atom("insertion", "insertion"),
     Atom("integer", "integer"),
     Atom("integrity", "integrity"),
+    Atom("interactive_widget", "interactive-widget"),
     Atom("internal", "internal"),
     Atom("internals", "internals"),
     Atom("intersection", "intersection"),