1 files changed, 72 insertions, 0 deletions
diff --git a/image/AutoRestoreSVGState.h b/image/AutoRestoreSVGState.h
new file mode 100644
index 0000000000..73fb127989
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+++ b/image/AutoRestoreSVGState.h
@@ -0,0 +1,72 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 mozilla_image_AutoRestoreSVGState_h
+#define mozilla_image_AutoRestoreSVGState_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/AutoRestore.h"
+#include "mozilla/SVGContextPaint.h"
+#include "mozilla/dom/SVGSVGElement.h"
+#include "nsPresContext.h"
+#include "SVGDrawingParameters.h"
+#include "SVGDocumentWrapper.h"
+#include "mozilla/dom/DocumentInlines.h"
+#include "mozilla/dom/SVGDocument.h"
+#include "mozilla/dom/BrowsingContextBinding.h"
+
+namespace mozilla::image {
+
+class MOZ_STACK_CLASS AutoRestoreSVGState final {
+ public:
+  AutoRestoreSVGState(const SVGDrawingParameters& aParams,
+                      SVGDocumentWrapper* aSVGDocumentWrapper,
+                      bool aContextPaint)
+      : AutoRestoreSVGState(aParams.svgContext, aParams.animationTime,
+                            aSVGDocumentWrapper, aContextPaint) {}
+
+  AutoRestoreSVGState(const SVGImageContext& aSVGContext, float aAnimationTime,
+                      SVGDocumentWrapper* aSVGDocumentWrapper,
+                      bool aContextPaint)
+      : mIsDrawing(aSVGDocumentWrapper->mIsDrawing),
+        // Apply any 'preserveAspectRatio' override (if specified) to the root
+        // element:
+        mPAR(aSVGContext, aSVGDocumentWrapper->GetRootSVGElem()),
+        // Set the animation time:
+        mTime(aSVGDocumentWrapper->GetRootSVGElem(), aAnimationTime) {
+    MOZ_ASSERT(!mIsDrawing.SavedValue());
+    MOZ_ASSERT(aSVGDocumentWrapper->GetDocument());
+
+    if (auto* pc = aSVGDocumentWrapper->GetDocument()->GetPresContext()) {
+      pc->SetColorSchemeOverride([&] {
+        if (auto scheme = aSVGContext.GetColorScheme()) {
+          return *scheme == ColorScheme::Light
+                     ? dom::PrefersColorSchemeOverride::Light
+                     : dom::PrefersColorSchemeOverride::Dark;
+        }
+        return dom::PrefersColorSchemeOverride::None;
+      }());
+    }
+
+    aSVGDocumentWrapper->mIsDrawing = true;
+
+    // Set context paint (if specified) on the document:
+    if (aContextPaint) {
+      MOZ_ASSERT(aSVGContext.GetContextPaint());
+      mContextPaint.emplace(*aSVGContext.GetContextPaint(),
+                            *aSVGDocumentWrapper->GetDocument());
+    }
+  }
+
+ private:
+  AutoRestore<bool> mIsDrawing;
+  AutoPreserveAspectRatioOverride mPAR;
+  AutoSVGTimeSetRestore mTime;
+  Maybe<AutoSetRestoreSVGContextPaint> mContextPaint;
+};
+
+}  // namespace mozilla::image
+
+#endif  // mozilla_image_AutoRestoreSVGState_h