dom/smil/SMILCSSProperty.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /* representation of a SMIL-animatable CSS property on an element */
   8
   9 #include "SMILCSSProperty.h"
  10
  11 #include <utility>
  12
  13 #include "mozilla/AnimatedPropertyID.h"
  14 #include "mozilla/SMILCSSValueType.h"
  15 #include "mozilla/SMILValue.h"
  16 #include "mozilla/ServoBindings.h"
  17 #include "mozilla/StyleAnimationValue.h"
  18 #include "mozilla/dom/Element.h"
  19 #include "nsCSSProps.h"
  20 #include "nsDOMCSSAttrDeclaration.h"
  21
  22 namespace mozilla {
  23
  24 // Class Methods
  25 SMILCSSProperty::SMILCSSProperty(nsCSSPropertyID aPropID,
  26                                  dom::Element* aElement,
  27                                  const ComputedStyle* aBaseComputedStyle)
  28     : mPropID(aPropID),
  29       mElement(aElement),
  30       mBaseComputedStyle(aBaseComputedStyle) {
  31   MOZ_ASSERT(IsPropertyAnimatable(mPropID),
  32              "Creating a SMILCSSProperty for a property "
  33              "that's not supported for animation");
  34 }
  35
  36 SMILValue SMILCSSProperty::GetBaseValue() const {
  37   // To benefit from Return Value Optimization and avoid copy constructor calls
  38   // due to our use of return-by-value, we must return the exact same object
  39   // from ALL return points. This function must only return THIS variable:
  40   SMILValue baseValue;
  41
  42   // SPECIAL CASE: (a) Shorthands
  43   //               (b) 'display'
  44   //               (c) No base ComputedStyle
  45   if (nsCSSProps::IsShorthand(mPropID) || mPropID == eCSSProperty_display ||
  46       !mBaseComputedStyle) {
  47     // We can't look up the base (computed-style) value of shorthand
  48     // properties because they aren't guaranteed to have a consistent computed
  49     // value.
  50     //
  51     // Also, although we can look up the base value of the display property,
  52     // doing so involves clearing and resetting the property which can cause
  53     // frames to be recreated which we'd like to avoid.
  54     //
  55     // Furthermore, if we don't (yet) have a base ComputedStyle we obviously
  56     // can't resolve a base value.
  57     //
  58     // In any case, just return a dummy value (initialized with the right
  59     // type, so as not to indicate failure).
  60     SMILValue tmpVal(&SMILCSSValueType::sSingleton);
  61     std::swap(baseValue, tmpVal);
  62     return baseValue;
  63   }
  64
  65   AnimationValue computedValue;
  66   AnimatedPropertyID property(mPropID);
  67   MOZ_ASSERT(!property.IsCustom(),
  68              "Cannot animate custom properties with SMIL");
  69   computedValue.mServo =
  70       Servo_ComputedValues_ExtractAnimationValue(mBaseComputedStyle, &property)
  71           .Consume();
  72   if (!computedValue.mServo) {
  73     return baseValue;
  74   }
  75
  76   baseValue = SMILCSSValueType::ValueFromAnimationValue(mPropID, mElement,
  77                                                         computedValue);
  78   return baseValue;
  79 }
  80
  81 nsresult SMILCSSProperty::ValueFromString(
  82     const nsAString& aStr, const dom::SVGAnimationElement* aSrcElement,
  83     SMILValue& aValue, bool& aPreventCachingOfSandwich) const {
  84   NS_ENSURE_TRUE(IsPropertyAnimatable(mPropID), NS_ERROR_FAILURE);
  85
  86   SMILCSSValueType::ValueFromString(mPropID, mElement, aStr, aValue,
  87                                     &aPreventCachingOfSandwich);
  88
  89   if (aValue.IsNull()) {
  90     return NS_ERROR_FAILURE;
  91   }
  92
  93   // XXX Due to bug 536660 (or at least that seems to be the most likely
  94   // culprit), when we have animation setting display:none on a <use> element,
  95   // if we DON'T set the property every sample, chaos ensues.
  96   if (!aPreventCachingOfSandwich && mPropID == eCSSProperty_display) {
  97     aPreventCachingOfSandwich = true;
  98   }
  99   return NS_OK;
 100 }
 101
 102 nsresult SMILCSSProperty::SetAnimValue(const SMILValue& aValue) {
 103   NS_ENSURE_TRUE(IsPropertyAnimatable(mPropID), NS_ERROR_FAILURE);
 104   return mElement->SMILOverrideStyle()->SetSMILValue(mPropID, aValue);
 105 }
 106
 107 void SMILCSSProperty::ClearAnimValue() {
 108   mElement->SMILOverrideStyle()->ClearSMILValue(mPropID);
 109 }
 110
 111 // Based on http://www.w3.org/TR/SVG/propidx.html
 112 // static
 113 bool SMILCSSProperty::IsPropertyAnimatable(nsCSSPropertyID aPropID) {
 114   // NOTE: Right now, Gecko doesn't recognize the following properties from
 115   // the SVG Property Index:
 116   //   alignment-baseline
 117   //   baseline-shift
 118   //   color-profile
 119   //   glyph-orientation-horizontal
 120   //   glyph-orientation-vertical
 121   //   kerning
 122   //   writing-mode
 123
 124   switch (aPropID) {
 125     case eCSSProperty_clip:
 126     case eCSSProperty_clip_rule:
 127     case eCSSProperty_clip_path:
 128     case eCSSProperty_color:
 129     case eCSSProperty_color_interpolation:
 130     case eCSSProperty_color_interpolation_filters:
 131     case eCSSProperty_cursor:
 132     case eCSSProperty_display:
 133     case eCSSProperty_dominant_baseline:
 134     case eCSSProperty_fill:
 135     case eCSSProperty_fill_opacity:
 136     case eCSSProperty_fill_rule:
 137     case eCSSProperty_filter:
 138     case eCSSProperty_flood_color:
 139     case eCSSProperty_flood_opacity:
 140     case eCSSProperty_font:
 141     case eCSSProperty_font_family:
 142     case eCSSProperty_font_size:
 143     case eCSSProperty_font_size_adjust:
 144     case eCSSProperty_font_stretch:
 145     case eCSSProperty_font_style:
 146     case eCSSProperty_font_variant:
 147     case eCSSProperty_font_weight:
 148     case eCSSProperty_height:
 149     case eCSSProperty_image_rendering:
 150     case eCSSProperty_letter_spacing:
 151     case eCSSProperty_lighting_color:
 152     case eCSSProperty_marker:
 153     case eCSSProperty_marker_end:
 154     case eCSSProperty_marker_mid:
 155     case eCSSProperty_marker_start:
 156     case eCSSProperty_mask:
 157     case eCSSProperty_mask_type:
 158     case eCSSProperty_opacity:
 159     case eCSSProperty_overflow:
 160     case eCSSProperty_pointer_events:
 161     case eCSSProperty_shape_rendering:
 162     case eCSSProperty_stop_color:
 163     case eCSSProperty_stop_opacity:
 164     case eCSSProperty_stroke:
 165     case eCSSProperty_stroke_dasharray:
 166     case eCSSProperty_stroke_dashoffset:
 167     case eCSSProperty_stroke_linecap:
 168     case eCSSProperty_stroke_linejoin:
 169     case eCSSProperty_stroke_miterlimit:
 170     case eCSSProperty_stroke_opacity:
 171     case eCSSProperty_stroke_width:
 172     case eCSSProperty_text_anchor:
 173     case eCSSProperty_text_decoration:
 174     case eCSSProperty_text_decoration_line:
 175     case eCSSProperty_text_rendering:
 176     case eCSSProperty_vector_effect:
 177     case eCSSProperty_width:
 178     case eCSSProperty_visibility:
 179     case eCSSProperty_word_spacing:
 180       return true;
 181
 182     // EXPLICITLY NON-ANIMATABLE PROPERTIES:
 183     // (Some of these aren't supported at all in Gecko -- I've commented those
 184     // ones out. If/when we add support for them, uncomment their line here)
 185     // ----------------------------------------------------------------------
 186     // case eCSSProperty_enable_background:
 187     // case eCSSProperty_glyph_orientation_horizontal:
 188     // case eCSSProperty_glyph_orientation_vertical:
 189     // case eCSSProperty_writing_mode:
 190     case eCSSProperty_direction:
 191     case eCSSProperty_unicode_bidi:
 192       return false;
 193
 194     default:
 195       return false;
 196   }
 197 }
 198
 199 }  // namespace mozilla