import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

dom/svg/nsSVGAnimatedTransformList.h

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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/. */
+
+#ifndef MOZILLA_SVGANIMATEDTRANSFORMLIST_H__
+#define MOZILLA_SVGANIMATEDTRANSFORMLIST_H__
+
+#include "mozilla/Attributes.h"
+#include "nsAutoPtr.h"
+#include "nsISMILAttr.h"
+#include "SVGTransformList.h"
+
+class nsIAtom;
+class nsSMILValue;
+class nsSVGElement;
+
+namespace mozilla {
+
+namespace dom {
+class SVGAnimationElement;
+class SVGTransform;
+} // namespace dom
+
+/**
+ * Class nsSVGAnimatedTransformList
+ *
+ * This class is very different to the SVG DOM interface of the same name found
+ * in the SVG specification. This is a lightweight internal class - see
+ * SVGAnimatedTransformList for the heavier DOM class that wraps instances of
+ * this class and implements the SVG specification's SVGAnimatedTransformList
+ * DOM interface.
+ *
+ * Except where noted otherwise, this class' methods take care of keeping the
+ * appropriate DOM wrappers in sync (see the comment in
+ * SVGAnimatedTransformList::InternalBaseValListWillChangeTo) so that their
+ * consumers don't need to concern themselves with that.
+ */
+class nsSVGAnimatedTransformList
+{
+  // friends so that they can get write access to mBaseVal
+  friend class dom::SVGTransform;
+  friend class DOMSVGTransformList;
+
+public:
+  nsSVGAnimatedTransformList()
+    : mIsAttrSet(false),
+      mHadTransformBeforeLastBaseValChange(false) { }
+
+  /**
+   * Because it's so important that mBaseVal and its DOMSVGTransformList wrapper
+   * (if any) be kept in sync (see the comment in
+   * SVGAnimatedTransformList::InternalBaseValListWillChangeTo), this method
+   * returns a const reference. Only our friend classes may get mutable
+   * references to mBaseVal.
+   */
+  const SVGTransformList& GetBaseValue() const {
+    return mBaseVal;
+  }
+
+  nsresult SetBaseValue(const SVGTransformList& aValue);
+
+  nsresult SetBaseValueString(const nsAString& aValue);
+
+  void ClearBaseValue();
+
+  const SVGTransformList& GetAnimValue() const {
+    return mAnimVal ? *mAnimVal : mBaseVal;
+  }
+
+  nsresult SetAnimValue(const SVGTransformList& aNewAnimValue,
+                        nsSVGElement *aElement);
+
+  void ClearAnimValue(nsSVGElement *aElement);
+
+  /**
+   * Returns true if the corresponding transform attribute is set (or animated)
+   * to a valid value. Unlike HasTransform it will return true for an empty
+   * transform.
+   */
+  bool IsExplicitlySet() const;
+
+  /**
+   * Returns true if the corresponding transform attribute is set (or animated)
+   * to a valid value, such that we have at least one transform in our list.
+   * Returns false otherwise (e.g. if the transform attribute is missing or empty
+   * or invalid).
+   */
+  bool HasTransform() const
+    { return (mAnimVal && !mAnimVal->IsEmpty()) || !mBaseVal.IsEmpty(); }
+
+  bool IsAnimating() const {
+    return !!mAnimVal;
+  }
+
+  /**
+   * Returns true iff "HasTransform" returned true just before our most recent
+   * SetBaseValue/SetBaseValueString/ClearBaseValue change.
+   *
+   * (This is used as part of an optimization in
+   * SVGTransformableElement::GetAttributeChangeHint. That function reports an
+   * inexpensive nsChangeHint when a transform has just modified -- but this
+   * accessor lets it detect cases where the "modification" is actually adding
+   * a transform where we previously had none. These cases require a more
+   * thorough nsChangeHint.)
+   */
+  bool HadTransformBeforeLastBaseValChange() const {
+    return mHadTransformBeforeLastBaseValChange;
+  }
+
+  /// Callers own the returned nsISMILAttr
+  nsISMILAttr* ToSMILAttr(nsSVGElement* aSVGElement);
+
+private:
+
+  // mAnimVal is a pointer to allow us to determine if we're being animated or
+  // not. Making it a non-pointer member and using mAnimVal.IsEmpty() to check
+  // if we're animating is not an option, since that would break animation *to*
+  // the empty string (<set to="">).
+
+  SVGTransformList mBaseVal;
+  nsAutoPtr<SVGTransformList> mAnimVal;
+  bool mIsAttrSet;
+   // (See documentation for accessor, HadTransformBeforeLastBaseValChange.)
+  bool mHadTransformBeforeLastBaseValChange;
+
+  struct SMILAnimatedTransformList : public nsISMILAttr
+  {
+  public:
+    SMILAnimatedTransformList(nsSVGAnimatedTransformList* aVal,
+                              nsSVGElement* aSVGElement)
+      : mVal(aVal)
+      , mElement(aSVGElement)
+    {}
+
+    // nsISMILAttr methods
+    virtual nsresult ValueFromString(const nsAString& aStr,
+                                     const dom::SVGAnimationElement* aSrcElement,
+                                     nsSMILValue& aValue,
+                                     bool& aPreventCachingOfSandwich) const override;
+    virtual nsSMILValue GetBaseValue() const override;
+    virtual void ClearAnimValue() override;
+    virtual nsresult SetAnimValue(const nsSMILValue& aValue) override;
+
+  protected:
+    static void ParseValue(const nsAString& aSpec,
+                           const nsIAtom* aTransformType,
+                           nsSMILValue& aResult);
+    static int32_t ParseParameterList(const nsAString& aSpec, float* aVars,
+                                      int32_t aNVars);
+
+    // These will stay alive because a nsISMILAttr only lives as long
+    // as the Compositing step, and DOM elements don't get a chance to
+    // die during that.
+    nsSVGAnimatedTransformList* mVal;
+    nsSVGElement* mElement;
+  };
+};
+
+} // namespace mozilla
+
+#endif // MOZILLA_SVGANIMATEDTRANSFORMLIST_H__