Bug 1570721 - Simplify emulated medium setup in nsPresContext. r=heycam (e288006e) · Commits · clairehurst / Tor Browser

layout/base/nsDocumentViewer.cpp

+18 −35

Original line number	Diff line number	Diff line
		@@ -318,6 +318,8 @@ class nsDocumentViewer final : public nsIContentViewer,
		// nsIDocumentViewerPrint Printing Methods
		NS_DECL_NSIDOCUMENTVIEWERPRINT

		void EmulateMediumInternal(nsAtom*);

		protected:
		virtual ~nsDocumentViewer();

		@@ -2957,61 +2959,42 @@ nsDocumentViewer::GetAuthorStyleDisabled(bool* aStyleDisabled) {
		}

		static bool ExtResourceEmulateMedium(Document* aDocument, void* aClosure) {
		nsPresContext* ctxt = aDocument->GetPresContext();
		if (ctxt) {
		const nsAString* mediaType = static_cast<nsAString*>(aClosure);
		ctxt->EmulateMedium(*mediaType);
		if (nsPresContext* pc = aDocument->GetPresContext()) {
		pc->EmulateMedium(static_cast<nsAtom*>(aClosure));
		}

		return true;
		}

		static void ChildEmulateMedium(nsDocumentViewer* aChild, void* aClosure) {
		const nsAString* mediaType = static_cast<nsAString*>(aClosure);
		aChild->EmulateMedium(*mediaType);
		aChild->EmulateMediumInternal(static_cast<nsAtom*>(aClosure));
		}

		NS_IMETHODIMP
		nsDocumentViewer::EmulateMedium(const nsAString& aMediaType) {
		void nsDocumentViewer::EmulateMediumInternal(nsAtom* aMedia) {
		if (mPresContext) {
		mPresContext->EmulateMedium(aMediaType);
		mPresContext->EmulateMedium(aMedia);
		}
		CallChildren(ChildEmulateMedium, const_cast<nsAString*>(&aMediaType));

		if (mDocument) {
		mDocument->EnumerateExternalResources(ExtResourceEmulateMedium,
		const_cast<nsAString*>(&aMediaType));
		}
		CallChildren(ChildEmulateMedium, aMedia);

		return NS_OK;
		if (mDocument) {
		mDocument->EnumerateExternalResources(ExtResourceEmulateMedium, aMedia);
		}

		static bool ExtResourceStopEmulatingMedium(Document* aDocument,
		void* aClosure) {
		nsPresContext* ctxt = aDocument->GetPresContext();
		if (ctxt) {
		ctxt->StopEmulatingMedium();
		}

		return true;
		}
		NS_IMETHODIMP
		nsDocumentViewer::EmulateMedium(const nsAString& aMediaType) {
		nsAutoString mediaType;
		nsContentUtils::ASCIIToLower(aMediaType, mediaType);
		RefPtr<nsAtom> media = NS_Atomize(mediaType);

		static void ChildStopEmulatingMedium(nsIContentViewer* aChild, void* aClosure) {
		aChild->StopEmulatingMedium();
		EmulateMediumInternal(media);
		return NS_OK;
		}

		NS_IMETHODIMP
		nsDocumentViewer::StopEmulatingMedium() {
		if (mPresContext) {
		mPresContext->StopEmulatingMedium();
		}
		CallChildren(ChildStopEmulatingMedium, nullptr);

		if (mDocument) {
		mDocument->EnumerateExternalResources(ExtResourceStopEmulatingMedium,
		nullptr);
		}

		EmulateMediumInternal(nullptr);
		return NS_OK;
		}

layout/base/nsPresContext.cpp

+4 −18

Original line number	Diff line number	Diff line
		@@ -144,7 +144,6 @@ nsPresContext::nsPresContext(dom::Document* aDocument, nsPresContextType aType)
		mPresShell(nullptr),
		mDocument(aDocument),
		mMedium(aType == eContext_Galley ? nsGkAtoms::screen : nsGkAtoms::print),
		mMediaEmulated(mMedium),
		mInflationDisabledForShrinkWrap(false),
		mSystemFontScale(1.0),
		mTextZoom(1.0),
		@@ -186,7 +185,6 @@ nsPresContext::nsPresContext(dom::Document* aDocument, nsPresContextType aType)
		mPendingUIResolutionChanged(false),
		mPrefChangePendingNeedsReflow(false),
		mPostedPrefChangedRunnable(false),
		mIsEmulatingMedia(false),
		mIsGlyph(false),
		mUsesRootEMUnits(false),
		mUsesExChUnits(false),
		@@ -1423,27 +1421,15 @@ void nsPresContext::UIResolutionChangedInternalScale(double aScale) {
		&aScale);
		}

		void nsPresContext::EmulateMedium(const nsAString& aMediaType) {
		nsAtom* previousMedium = Medium();
		mIsEmulatingMedia = true;

		nsAutoString mediaType;
		nsContentUtils::ASCIIToLower(aMediaType, mediaType);

		mMediaEmulated = NS_Atomize(mediaType);
		void nsPresContext::EmulateMedium(nsAtom* aMediaType) {
		MOZ_ASSERT(!aMediaType \|\| aMediaType->IsAsciiLowercase());
		RefPtr<const nsAtom> previousMedium = Medium();
		mMediaEmulated = aMediaType;
		if (mMediaEmulated != previousMedium && mPresShell) {
		MediaFeatureValuesChanged({MediaFeatureChangeReason::MediumChange});
		}
		}

		void nsPresContext::StopEmulatingMedium() {
		nsAtom* previousMedium = Medium();
		mIsEmulatingMedia = false;
		if (Medium() != previousMedium) {
		MediaFeatureValuesChanged({MediaFeatureChangeReason::MediumChange});
		}
		}

		void nsPresContext::ContentLanguageChanged() {
		PostRebuildAllStyleDataEvent(nsChangeHint(0),
		RestyleHint::RecascadeSubtree());

layout/base/nsPresContext.h

+7 −12

Original line number	Diff line number	Diff line
		@@ -303,21 +303,18 @@ class nsPresContext : public nsISupports,
		/**
		* Get medium of presentation
		*/
		nsAtom* Medium() {
		if (!mIsEmulatingMedia) return mMedium;
		return mMediaEmulated;
		const nsAtom* Medium() {
		MOZ_ASSERT(mMedium);
		return mMediaEmulated ? mMediaEmulated.get() : mMedium;
		}

		/*
		* Render the document as if being viewed on a device with the specified
		* media type.
		*
		* If passed null, it stops emulating.
		*/
		void EmulateMedium(const nsAString& aMediaType);

		/*
		* Restore the viewer's natural medium
		*/
		void StopEmulatingMedium();
		void EmulateMedium(nsAtom* aMediaType);

		/** Get a cached integer pref, by its type */
		// * - initially created for bugs 30910, 61883, 74186, 84398
		@@ -1119,8 +1116,7 @@ class nsPresContext : public nsISupports,
		mozilla::UniquePtr<nsAnimationManager> mAnimationManager;
		mozilla::UniquePtr<mozilla::RestyleManager> mRestyleManager;
		RefPtr<mozilla::CounterStyleManager> mCounterStyleManager;
		nsAtom* MOZ_UNSAFE_REF(
		"always a static atom") mMedium; // initialized by subclass ctors
		const nsStaticAtom* mMedium;
		RefPtr<nsAtom> mMediaEmulated;
		RefPtr<gfxFontFeatureValueSet> mFontFeatureValuesLookup;

		@@ -1221,7 +1217,6 @@ class nsPresContext : public nsISupports,
		unsigned mPendingUIResolutionChanged : 1;
		unsigned mPrefChangePendingNeedsReflow : 1;
		unsigned mPostedPrefChangedRunnable : 1;
		unsigned mIsEmulatingMedia : 1;

		// Are we currently drawing an SVG glyph?
		unsigned mIsGlyph : 1;

servo/components/style/gecko/media_queries.rs

+3 −4

Original line number	Diff line number	Diff line
		@@ -213,12 +213,11 @@ impl Device {
		None => return MediaType::screen(),
		};

		// Gecko allows emulating random media with mIsEmulatingMedia and
		// mMediaEmulated.
		let medium_to_use = if pc.mIsEmulatingMedia() != 0 {
		// Gecko allows emulating random media with mMediaEmulated.
		let medium_to_use = if !pc.mMediaEmulated.mRawPtr.is_null() {
		pc.mMediaEmulated.mRawPtr
		} else {
		pc.mMedium
		pc.mMedium as const bindings::nsAtom as mut _
		};

		MediaType(CustomIdent(unsafe { Atom::from_raw(medium_to_use) }))