1 files changed, 88 insertions, 0 deletions
diff --git a/layout/svg/SVGImageContext.h b/layout/svg/SVGImageContext.h
new file mode 100644
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+++ b/layout/svg/SVGImageContext.h
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+/* -*- 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_SVGCONTEXT_H_
+#define MOZILLA_SVGCONTEXT_H_
+
+#include "mozilla/Maybe.h"
+#include "SVGPreserveAspectRatio.h"
+#include "Units.h"
+
+namespace mozilla {
+
+// SVG image-specific rendering context. For imgIContainer::Draw.
+// Used to pass information such as
+//  - viewport information from CSS, and
+//  - overridden attributes from an SVG <image> element
+// to the image's internal SVG document when it's drawn.
+class SVGImageContext
+{
+public:
+  SVGImageContext()
+    : mGlobalOpacity(1.0)
+  { }
+
+  // Note: 'aIsPaintingSVGImageElement' should be used to indicate whether
+  // the SVG image in question is being painted for an SVG <image> element.
+  SVGImageContext(CSSIntSize aViewportSize,
+                  Maybe<SVGPreserveAspectRatio> aPreserveAspectRatio,
+                  gfxFloat aOpacity = 1.0,
+                  bool aIsPaintingSVGImageElement = false)
+    : mViewportSize(aViewportSize)
+    , mPreserveAspectRatio(aPreserveAspectRatio)
+    , mGlobalOpacity(aOpacity)
+    , mIsPaintingSVGImageElement(aIsPaintingSVGImageElement)
+  { }
+
+  const CSSIntSize& GetViewportSize() const {
+    return mViewportSize;
+  }
+
+  const Maybe<SVGPreserveAspectRatio>& GetPreserveAspectRatio() const {
+    return mPreserveAspectRatio;
+  }
+
+  gfxFloat GetGlobalOpacity() const {
+    return mGlobalOpacity;
+  }
+
+  bool IsPaintingForSVGImageElement() const {
+    return mIsPaintingSVGImageElement;
+  }
+
+  bool operator==(const SVGImageContext& aOther) const {
+    return mViewportSize == aOther.mViewportSize &&
+           mPreserveAspectRatio == aOther.mPreserveAspectRatio &&
+           mGlobalOpacity == aOther.mGlobalOpacity &&
+           mIsPaintingSVGImageElement == aOther.mIsPaintingSVGImageElement;
+  }
+
+  bool operator!=(const SVGImageContext& aOther) const {
+    return !(*this == aOther);
+  }
+
+  uint32_t Hash() const {
+    return HashGeneric(mViewportSize.width,
+                       mViewportSize.height,
+                       mPreserveAspectRatio.map(HashPAR).valueOr(0),
+                       HashBytes(&mGlobalOpacity, sizeof(gfxFloat)),
+                       mIsPaintingSVGImageElement);
+  }
+
+private:
+  static uint32_t HashPAR(const SVGPreserveAspectRatio& aPAR) {
+    return aPAR.Hash();
+  }
+
+  // NOTE: When adding new member-vars, remember to update Hash() & operator==.
+  CSSIntSize                    mViewportSize;
+  Maybe<SVGPreserveAspectRatio> mPreserveAspectRatio;
+  gfxFloat                      mGlobalOpacity;
+  bool                          mIsPaintingSVGImageElement;
+};
+
+} // namespace mozilla
+
+#endif // MOZILLA_SVGCONTEXT_H_