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-rw-r--r--layout/svg/SVGContextPaint.cpp370
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diff --git a/layout/svg/SVGContextPaint.cpp b/layout/svg/SVGContextPaint.cpp
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+/* -*- 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/. */
+
+#include "SVGContextPaint.h"
+
+#include "gfxContext.h"
+#include "gfxUtils.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/BasePrincipal.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/extensions/WebExtensionPolicy.h"
+#include "mozilla/StaticPrefs_svg.h"
+#include "mozilla/SVGObserverUtils.h"
+#include "mozilla/SVGUtils.h"
+#include "SVGPaintServerFrame.h"
+
+using namespace mozilla::gfx;
+using namespace mozilla::image;
+
+namespace mozilla {
+
+using image::imgDrawingParams;
+
+/* static */
+bool SVGContextPaint::IsAllowedForImageFromURI(nsIURI* aURI) {
+ if (StaticPrefs::svg_context_properties_content_enabled()) {
+ return true;
+ }
+
+ // Context paint is pref'ed off for Web content. Ideally we'd have some
+ // easy means to determine whether the frame that has linked to the image
+ // is a frame for a content node that originated from Web content.
+ // Unfortunately different types of anonymous content, about: documents
+ // such as about:reader, etc. that are "our" code that we ship are
+ // sometimes hard to distinguish from real Web content. As a result,
+ // instead of trying to figure out what content is "ours" we instead let
+ // any content provide image context paint, but only if the image is
+ // chrome:// or resource:// do we return true. This should be sufficient
+ // to stop the image context paint feature being useful to (and therefore
+ // used by and relied upon by) Web content. (We don't want Web content to
+ // use this feature because we're not sure that image context paint is a
+ // good mechanism for wider use, or suitable for specification.)
+ //
+ // Because the default favicon used in the browser UI needs context paint, we
+ // also allow it for:
+ // - page-icon:<page-url> (used in history and bookmark items)
+ // - cached-favicon:<page-url> (used in the awesomebar)
+ // This allowance does also inadvertently expose context-paint to 3rd-party
+ // favicons, which is not great, but that hasn't caused trouble as far as we
+ // know. Also: other places such as the tab bar don't use these protocols to
+ // load favicons, so they help to ensure that 3rd-party favicons don't grow
+ // to depend on this feature.
+ //
+ // One case that is not covered by chrome:// or resource:// are WebExtensions,
+ // specifically ones that are "ours". WebExtensions are moz-extension://
+ // regardless if the extension is in-tree or not. Since we don't want
+ // extension developers coming to rely on image context paint either, we only
+ // enable context-paint for extensions that are owned by Mozilla
+ // (based on the extension permission "internal:svgContextPropertiesAllowed").
+ //
+ // We also allow this for browser UI icons that are served up from
+ // Mozilla-controlled domains listed in the
+ // svg.context-properties.content.allowed-domains pref.
+ //
+ nsAutoCString scheme;
+ if (NS_SUCCEEDED(aURI->GetScheme(scheme)) &&
+ (scheme.EqualsLiteral("chrome") || scheme.EqualsLiteral("resource") ||
+ scheme.EqualsLiteral("page-icon") ||
+ scheme.EqualsLiteral("cached-favicon"))) {
+ return true;
+ }
+ RefPtr<BasePrincipal> principal =
+ BasePrincipal::CreateContentPrincipal(aURI, OriginAttributes());
+
+ RefPtr<extensions::WebExtensionPolicy> addonPolicy = principal->AddonPolicy();
+ if (addonPolicy) {
+ // Only allowed for extensions that have the
+ // internal:svgContextPropertiesAllowed permission (added internally from
+ // to Mozilla-owned extensions, see `isMozillaExtension` function
+ // defined in Extension.jsm for the exact criteria).
+ return addonPolicy->HasPermission(
+ nsGkAtoms::svgContextPropertiesAllowedPermission);
+ }
+
+ bool isInAllowList = false;
+ principal->IsURIInPrefList("svg.context-properties.content.allowed-domains",
+ &isInAllowList);
+ return isInAllowList;
+}
+
+/**
+ * Stores in |aTargetPaint| information on how to reconstruct the current
+ * fill or stroke pattern. Will also set the paint opacity to transparent if
+ * the paint is set to "none".
+ * @param aOuterContextPaint pattern information from the outer text context
+ * @param aTargetPaint where to store the current pattern information
+ * @param aFillOrStroke member pointer to the paint we are setting up
+ */
+static void SetupInheritablePaint(const DrawTarget* aDrawTarget,
+ const gfxMatrix& aContextMatrix,
+ nsIFrame* aFrame, float& aOpacity,
+ SVGContextPaint* aOuterContextPaint,
+ SVGContextPaintImpl::Paint& aTargetPaint,
+ StyleSVGPaint nsStyleSVG::*aFillOrStroke,
+ nscolor aDefaultFallbackColor,
+ imgDrawingParams& aImgParams) {
+ const nsStyleSVG* style = aFrame->StyleSVG();
+ SVGPaintServerFrame* ps =
+ SVGObserverUtils::GetAndObservePaintServer(aFrame, aFillOrStroke);
+
+ if (ps) {
+ RefPtr<gfxPattern> pattern =
+ ps->GetPaintServerPattern(aFrame, aDrawTarget, aContextMatrix,
+ aFillOrStroke, aOpacity, aImgParams);
+
+ if (pattern) {
+ aTargetPaint.SetPaintServer(aFrame, aContextMatrix, ps);
+ return;
+ }
+ }
+
+ if (aOuterContextPaint) {
+ RefPtr<gfxPattern> pattern;
+ auto tag = SVGContextPaintImpl::Paint::Tag::None;
+ switch ((style->*aFillOrStroke).kind.tag) {
+ case StyleSVGPaintKind::Tag::ContextFill:
+ tag = SVGContextPaintImpl::Paint::Tag::ContextFill;
+ pattern = aOuterContextPaint->GetFillPattern(
+ aDrawTarget, aOpacity, aContextMatrix, aImgParams);
+ break;
+ case StyleSVGPaintKind::Tag::ContextStroke:
+ tag = SVGContextPaintImpl::Paint::Tag::ContextStroke;
+ pattern = aOuterContextPaint->GetStrokePattern(
+ aDrawTarget, aOpacity, aContextMatrix, aImgParams);
+ break;
+ default:;
+ }
+ if (pattern) {
+ aTargetPaint.SetContextPaint(aOuterContextPaint, tag);
+ return;
+ }
+ }
+
+ nscolor color = SVGUtils::GetFallbackOrPaintColor(
+ *aFrame->Style(), aFillOrStroke, aDefaultFallbackColor);
+ aTargetPaint.SetColor(color);
+}
+
+DrawMode SVGContextPaintImpl::Init(const DrawTarget* aDrawTarget,
+ const gfxMatrix& aContextMatrix,
+ nsIFrame* aFrame,
+ SVGContextPaint* aOuterContextPaint,
+ imgDrawingParams& aImgParams) {
+ DrawMode toDraw = DrawMode(0);
+
+ const nsStyleSVG* style = aFrame->StyleSVG();
+
+ // fill:
+ if (style->mFill.kind.IsNone()) {
+ SetFillOpacity(0.0f);
+ } else {
+ float opacity =
+ SVGUtils::GetOpacity(style->mFillOpacity, aOuterContextPaint);
+
+ SetupInheritablePaint(aDrawTarget, aContextMatrix, aFrame, opacity,
+ aOuterContextPaint, mFillPaint, &nsStyleSVG::mFill,
+ NS_RGB(0, 0, 0), aImgParams);
+
+ SetFillOpacity(opacity);
+
+ toDraw |= DrawMode::GLYPH_FILL;
+ }
+
+ // stroke:
+ if (style->mStroke.kind.IsNone()) {
+ SetStrokeOpacity(0.0f);
+ } else {
+ float opacity =
+ SVGUtils::GetOpacity(style->mStrokeOpacity, aOuterContextPaint);
+
+ SetupInheritablePaint(
+ aDrawTarget, aContextMatrix, aFrame, opacity, aOuterContextPaint,
+ mStrokePaint, &nsStyleSVG::mStroke, NS_RGBA(0, 0, 0, 0), aImgParams);
+
+ SetStrokeOpacity(opacity);
+
+ toDraw |= DrawMode::GLYPH_STROKE;
+ }
+
+ return toDraw;
+}
+
+void SVGContextPaint::InitStrokeGeometry(gfxContext* aContext,
+ float devUnitsPerSVGUnit) {
+ mStrokeWidth = aContext->CurrentLineWidth() / devUnitsPerSVGUnit;
+ aContext->CurrentDash(mDashes, &mDashOffset);
+ for (uint32_t i = 0; i < mDashes.Length(); i++) {
+ mDashes[i] /= devUnitsPerSVGUnit;
+ }
+ mDashOffset /= devUnitsPerSVGUnit;
+}
+
+SVGContextPaint* SVGContextPaint::GetContextPaint(nsIContent* aContent) {
+ dom::Document* ownerDoc = aContent->OwnerDoc();
+
+ const auto* contextPaint = ownerDoc->GetCurrentContextPaint();
+
+ // XXX The SVGContextPaint that Document keeps around is const. We could
+ // and should keep that constness to the SVGContextPaint that we get here
+ // (SVGImageContext is never changed after it is initialized).
+ //
+ // Unfortunately lazy initialization of SVGContextPaint (which is a member of
+ // SVGImageContext, and also conceptually never changes after construction)
+ // prevents some of SVGContextPaint's conceptually const methods from being
+ // const. Trying to fix SVGContextPaint (perhaps by using |mutable|) is a
+ // bit of a headache so for now we punt on that, don't reapply the constness
+ // to the SVGContextPaint here, and trust that no one will add code that
+ // actually modifies the object.
+ return const_cast<SVGContextPaint*>(contextPaint);
+}
+
+already_AddRefed<gfxPattern> SVGContextPaintImpl::GetFillPattern(
+ const DrawTarget* aDrawTarget, float aOpacity, const gfxMatrix& aCTM,
+ imgDrawingParams& aImgParams) {
+ return mFillPaint.GetPattern(aDrawTarget, aOpacity, &nsStyleSVG::mFill, aCTM,
+ aImgParams);
+}
+
+already_AddRefed<gfxPattern> SVGContextPaintImpl::GetStrokePattern(
+ const DrawTarget* aDrawTarget, float aOpacity, const gfxMatrix& aCTM,
+ imgDrawingParams& aImgParams) {
+ return mStrokePaint.GetPattern(aDrawTarget, aOpacity, &nsStyleSVG::mStroke,
+ aCTM, aImgParams);
+}
+
+already_AddRefed<gfxPattern> SVGContextPaintImpl::Paint::GetPattern(
+ const DrawTarget* aDrawTarget, float aOpacity,
+ StyleSVGPaint nsStyleSVG::*aFillOrStroke, const gfxMatrix& aCTM,
+ imgDrawingParams& aImgParams) {
+ RefPtr<gfxPattern> pattern;
+ if (mPatternCache.Get(aOpacity, getter_AddRefs(pattern))) {
+ // Set the pattern matrix just in case it was messed with by a previous
+ // caller. We should get the same matrix each time a pattern is constructed
+ // so this should be fine.
+ pattern->SetMatrix(aCTM * mPatternMatrix);
+ return pattern.forget();
+ }
+
+ switch (mPaintType) {
+ case Tag::None:
+ pattern = new gfxPattern(DeviceColor());
+ mPatternMatrix = gfxMatrix();
+ break;
+ case Tag::Color: {
+ DeviceColor color = ToDeviceColor(mPaintDefinition.mColor);
+ color.a *= aOpacity;
+ pattern = new gfxPattern(color);
+ mPatternMatrix = gfxMatrix();
+ break;
+ }
+ case Tag::PaintServer:
+ pattern = mPaintDefinition.mPaintServerFrame->GetPaintServerPattern(
+ mFrame, aDrawTarget, mContextMatrix, aFillOrStroke, aOpacity,
+ aImgParams);
+ if (!pattern) {
+ return nullptr;
+ }
+ {
+ // m maps original-user-space to pattern space
+ gfxMatrix m = pattern->GetMatrix();
+ gfxMatrix deviceToOriginalUserSpace = mContextMatrix;
+ if (!deviceToOriginalUserSpace.Invert()) {
+ return nullptr;
+ }
+ // mPatternMatrix maps device space to pattern space via original user
+ // space
+ mPatternMatrix = deviceToOriginalUserSpace * m;
+ }
+ pattern->SetMatrix(aCTM * mPatternMatrix);
+ break;
+ case Tag::ContextFill:
+ pattern = mPaintDefinition.mContextPaint->GetFillPattern(
+ aDrawTarget, aOpacity, aCTM, aImgParams);
+ // Don't cache this. mContextPaint will have cached it anyway. If we
+ // cache it, we'll have to compute mPatternMatrix, which is annoying.
+ return pattern.forget();
+ case Tag::ContextStroke:
+ pattern = mPaintDefinition.mContextPaint->GetStrokePattern(
+ aDrawTarget, aOpacity, aCTM, aImgParams);
+ // Don't cache this. mContextPaint will have cached it anyway. If we
+ // cache it, we'll have to compute mPatternMatrix, which is annoying.
+ return pattern.forget();
+ default:
+ MOZ_ASSERT(false, "invalid paint type");
+ return nullptr;
+ }
+
+ mPatternCache.InsertOrUpdate(aOpacity, RefPtr{pattern});
+ return pattern.forget();
+}
+
+AutoSetRestoreSVGContextPaint::AutoSetRestoreSVGContextPaint(
+ const SVGContextPaint* aContextPaint, dom::Document* aDocument)
+ : mDocument(aDocument),
+ mOuterContextPaint(aDocument->GetCurrentContextPaint()) {
+ mDocument->SetCurrentContextPaint(aContextPaint);
+}
+
+AutoSetRestoreSVGContextPaint::~AutoSetRestoreSVGContextPaint() {
+ mDocument->SetCurrentContextPaint(mOuterContextPaint);
+}
+
+// SVGEmbeddingContextPaint
+
+already_AddRefed<gfxPattern> SVGEmbeddingContextPaint::GetFillPattern(
+ const DrawTarget* aDrawTarget, float aFillOpacity, const gfxMatrix& aCTM,
+ imgDrawingParams& aImgParams) {
+ if (!mFill) {
+ return nullptr;
+ }
+ // The gfxPattern that we create below depends on aFillOpacity, and since
+ // different elements in the SVG image may pass in different values for
+ // fill opacities we don't try to cache the gfxPattern that we create.
+ DeviceColor fill = *mFill;
+ fill.a *= aFillOpacity;
+ return do_AddRef(new gfxPattern(fill));
+}
+
+already_AddRefed<gfxPattern> SVGEmbeddingContextPaint::GetStrokePattern(
+ const DrawTarget* aDrawTarget, float aStrokeOpacity, const gfxMatrix& aCTM,
+ imgDrawingParams& aImgParams) {
+ if (!mStroke) {
+ return nullptr;
+ }
+ DeviceColor stroke = *mStroke;
+ stroke.a *= aStrokeOpacity;
+ return do_AddRef(new gfxPattern(stroke));
+}
+
+uint32_t SVGEmbeddingContextPaint::Hash() const {
+ uint32_t hash = 0;
+
+ if (mFill) {
+ hash = HashGeneric(hash, mFill->ToABGR());
+ } else {
+ // Arbitrary number, just to avoid trivial hash collisions between pairs of
+ // instances where one embedding context has fill set to the same value as
+ // another context has stroke set to.
+ hash = 1;
+ }
+
+ if (mStroke) {
+ hash = HashGeneric(hash, mStroke->ToABGR());
+ }
+
+ if (mFillOpacity != 1.0f) {
+ hash = HashGeneric(hash, mFillOpacity);
+ }
+
+ if (mStrokeOpacity != 1.0f) {
+ hash = HashGeneric(hash, mStrokeOpacity);
+ }
+
+ return hash;
+}
+
+} // namespace mozilla