dom/smil/nsSMILMappedAttribute.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /* representation of a SMIL-animatable mapped attribute on an element */
   7 #include "nsSMILMappedAttribute.h"
   8 #include "nsContentUtils.h"
   9 #include "nsError.h" // For NS_PROPTABLE_PROP_OVERWRITTEN
  10 #include "nsSMILValue.h"
  11 #include "nsSMILCSSValueType.h"
  12 #include "nsIDocument.h"
  13 #include "nsIPresShell.h"
  14 #include "nsCSSProps.h"
  15 #include "mozilla/dom/Element.h"
  16
  17 // Callback function, for freeing string buffers stored in property table
  18 static void
  19 ReleaseStringBufferPropertyValue(void*    aObject,       /* unused */
  20                                  nsIAtom* aPropertyName, /* unused */
  21                                  void*    aPropertyValue,
  22                                  void*    aData          /* unused */)
  23 {
  24   nsStringBuffer* buf = static_cast<nsStringBuffer*>(aPropertyValue);
  25   buf->Release();
  26 }
  27
  28
  29 nsresult
  30 nsSMILMappedAttribute::ValueFromString(const nsAString& aStr,
  31                                        const mozilla::dom::SVGAnimationElement* aSrcElement,
  32                                        nsSMILValue& aValue,
  33                                        bool& aPreventCachingOfSandwich) const
  34 {
  35   NS_ENSURE_TRUE(IsPropertyAnimatable(mPropID), NS_ERROR_FAILURE);
  36
  37   nsSMILCSSValueType::ValueFromString(mPropID, mElement, aStr, aValue,
  38                                       &aPreventCachingOfSandwich);
  39   return aValue.IsNull() ? NS_ERROR_FAILURE : NS_OK;
  40 }
  41
  42 nsSMILValue
  43 nsSMILMappedAttribute::GetBaseValue() const
  44 {
  45   nsAutoString baseStringValue;
  46   nsRefPtr<nsIAtom> attrName = GetAttrNameAtom();
  47   bool success = mElement->GetAttr(kNameSpaceID_None, attrName,
  48                                      baseStringValue);
  49   nsSMILValue baseValue;
  50   if (success) {
  51     // For base values, we don't need to worry whether the value returned is
  52     // context-sensitive or not since the compositor will take care of comparing
  53     // the returned (computed) base value and its cached value and determining
  54     // if an update is required or not.
  55     nsSMILCSSValueType::ValueFromString(mPropID, mElement,
  56                                         baseStringValue, baseValue, nullptr);
  57   } else {
  58     // Attribute is unset -- use computed value.
  59     // FIRST: Temporarily clear animated value, to make sure it doesn't pollute
  60     // the computed value. (We want base value, _without_ animations applied.)
  61     void* buf = mElement->UnsetProperty(SMIL_MAPPED_ATTR_ANIMVAL,
  62                                         attrName, nullptr);
  63     FlushChangesToTargetAttr();
  64
  65     // SECOND: we use nsSMILCSSProperty::GetBaseValue to look up the property's
  66     // computed value.  NOTE: This call will temporarily clear the SMIL
  67     // override-style for the corresponding CSS property on our target element.
  68     // This prevents any animations that target the CSS property from affecting
  69     // animations that target the mapped attribute.
  70     baseValue = nsSMILCSSProperty::GetBaseValue();
  71
  72     // FINALLY: If we originally had an animated value set, then set it again.
  73     if (buf) {
  74       mElement->SetProperty(SMIL_MAPPED_ATTR_ANIMVAL, attrName, buf,
  75                             ReleaseStringBufferPropertyValue);
  76       FlushChangesToTargetAttr();
  77     }
  78   }
  79   return baseValue;
  80 }
  81
  82 nsresult
  83 nsSMILMappedAttribute::SetAnimValue(const nsSMILValue& aValue)
  84 {
  85   NS_ENSURE_TRUE(IsPropertyAnimatable(mPropID), NS_ERROR_FAILURE);
  86
  87   // Convert nsSMILValue to string
  88   nsAutoString valStr;
  89   if (!nsSMILCSSValueType::ValueToString(aValue, valStr)) {
  90     NS_WARNING("Failed to convert nsSMILValue for mapped attr into a string");
  91     return NS_ERROR_FAILURE;
  92   }
  93
  94   nsRefPtr<nsIAtom> attrName = GetAttrNameAtom();
  95   nsStringBuffer* oldValStrBuf = static_cast<nsStringBuffer*>
  96     (mElement->GetProperty(SMIL_MAPPED_ATTR_ANIMVAL, attrName));
  97   if (oldValStrBuf) {
  98     nsString oldValStr;
  99     nsContentUtils::PopulateStringFromStringBuffer(oldValStrBuf, oldValStr);
 100     if (valStr.Equals(oldValStr)) {
 101       // New animated value is the same as the old; nothing to do.
 102       return NS_OK;
 103     }
 104   }
 105
 106   // Set the string as this mapped attribute's animated value.
 107   nsStringBuffer* valStrBuf =
 108     nsCSSValue::BufferFromString(nsString(valStr)).take();
 109   nsresult rv = mElement->SetProperty(SMIL_MAPPED_ATTR_ANIMVAL,
 110                                       attrName, valStrBuf,
 111                                       ReleaseStringBufferPropertyValue);
 112   if (rv == NS_PROPTABLE_PROP_OVERWRITTEN) {
 113     rv = NS_OK;
 114   }
 115   FlushChangesToTargetAttr();
 116
 117   return rv;
 118 }
 119
 120 void
 121 nsSMILMappedAttribute::ClearAnimValue()
 122 {
 123   nsRefPtr<nsIAtom> attrName = GetAttrNameAtom();
 124   mElement->DeleteProperty(SMIL_MAPPED_ATTR_ANIMVAL, attrName);
 125   FlushChangesToTargetAttr();
 126 }
 127
 128 void
 129 nsSMILMappedAttribute::FlushChangesToTargetAttr() const
 130 {
 131   // Clear animated content-style-rule
 132   mElement->DeleteProperty(SMIL_MAPPED_ATTR_ANIMVAL,
 133                            SMIL_MAPPED_ATTR_STYLERULE_ATOM);
 134   nsIDocument* doc = mElement->GetCurrentDoc();
 135
 136   // Request animation restyle
 137   if (doc) {
 138     nsIPresShell* shell = doc->GetShell();
 139     if (shell) {
 140       shell->RestyleForAnimation(mElement, eRestyle_Self);
 141     }
 142   }
 143 }
 144
 145 already_AddRefed<nsIAtom>
 146 nsSMILMappedAttribute::GetAttrNameAtom() const
 147 {
 148   return do_GetAtom(nsCSSProps::GetStringValue(mPropID));
 149 }