tor-browser

SMILCSSProperty.cpp (7107B)

---

/* -*- 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/. */

/* representation of a SMIL-animatable CSS property on an element */

#include "SMILCSSProperty.h"

#include <utility>

#include "mozilla/CSSPropertyId.h"
#include "mozilla/SMILCSSValueType.h"
#include "mozilla/SMILValue.h"
#include "mozilla/ServoBindings.h"
#include "mozilla/StyleAnimationValue.h"
#include "mozilla/dom/Element.h"
#include "nsCSSProps.h"
#include "nsDOMCSSAttrDeclaration.h"

namespace mozilla {

// Class Methods
SMILCSSProperty::SMILCSSProperty(NonCustomCSSPropertyId aPropId,
                                dom::Element* aElement,
                                const ComputedStyle* aBaseComputedStyle)
   : mPropId(aPropId),
     mElement(aElement),
     mBaseComputedStyle(aBaseComputedStyle) {
 MOZ_ASSERT(IsPropertyAnimatable(mPropId),
            "Creating a SMILCSSProperty for a property "
            "that's not supported for animation");
}

SMILValue SMILCSSProperty::GetBaseValue() const {
 // To benefit from Return Value Optimization and avoid copy constructor calls
 // due to our use of return-by-value, we must return the exact same object
 // from ALL return points. This function must only return THIS variable:
 SMILValue baseValue;

 // SPECIAL CASE: (a) Shorthands
 //               (b) 'display'
 //               (c) No base ComputedStyle
 if (nsCSSProps::IsShorthand(mPropId) || mPropId == eCSSProperty_display ||
     !mBaseComputedStyle) {
   // We can't look up the base (computed-style) value of shorthand
   // properties because they aren't guaranteed to have a consistent computed
   // value.
   //
   // Also, although we can look up the base value of the display property,
   // doing so involves clearing and resetting the property which can cause
   // frames to be recreated which we'd like to avoid.
   //
   // Furthermore, if we don't (yet) have a base ComputedStyle we obviously
   // can't resolve a base value.
   //
   // In any case, just return a dummy value (initialized with the right
   // type, so as not to indicate failure).
   SMILValue tmpVal(&SMILCSSValueType::sSingleton);
   std::swap(baseValue, tmpVal);
   return baseValue;
 }

 AnimationValue computedValue;
 CSSPropertyId property(mPropId);
 MOZ_ASSERT(!property.IsCustom(),
            "Cannot animate custom properties with SMIL");
 computedValue.mServo =
     Servo_ComputedValues_ExtractAnimationValue(mBaseComputedStyle, &property)
         .Consume();
 if (!computedValue.mServo) {
   return baseValue;
 }

 baseValue = SMILCSSValueType::ValueFromAnimationValue(mPropId, mElement,
                                                       computedValue);
 return baseValue;
}

nsresult SMILCSSProperty::ValueFromString(
   const nsAString& aStr, const dom::SVGAnimationElement* aSrcElement,
   SMILValue& aValue, bool& aPreventCachingOfSandwich) const {
 NS_ENSURE_TRUE(IsPropertyAnimatable(mPropId), NS_ERROR_FAILURE);

 SMILCSSValueType::ValueFromString(mPropId, mElement, aStr, aValue,
                                   &aPreventCachingOfSandwich);

 if (aValue.IsNull()) {
   return NS_ERROR_FAILURE;
 }

 // XXX Due to bug 536660 (or at least that seems to be the most likely
 // culprit), when we have animation setting display:none on a <use> element,
 // if we DON'T set the property every sample, chaos ensues.
 if (!aPreventCachingOfSandwich && mPropId == eCSSProperty_display) {
   aPreventCachingOfSandwich = true;
 }
 return NS_OK;
}

nsresult SMILCSSProperty::SetAnimValue(const SMILValue& aValue) {
 NS_ENSURE_TRUE(IsPropertyAnimatable(mPropId), NS_ERROR_FAILURE);
 return mElement->SMILOverrideStyle()->SetSMILValue(mPropId, aValue);
}

void SMILCSSProperty::ClearAnimValue() {
 mElement->SMILOverrideStyle()->ClearSMILValue(mPropId);
}

// Based on http://www.w3.org/TR/SVG/propidx.html
// static
bool SMILCSSProperty::IsPropertyAnimatable(NonCustomCSSPropertyId aPropId) {
 // NOTE: Right now, Gecko doesn't recognize the following properties from
 // the SVG Property Index:
 //   alignment-baseline
 //   baseline-shift
 //   color-profile
 //   glyph-orientation-horizontal
 //   glyph-orientation-vertical
 //   kerning
 //   writing-mode

 switch (aPropId) {
   case eCSSProperty_clip:
   case eCSSProperty_clip_rule:
   case eCSSProperty_clip_path:
   case eCSSProperty_color:
   case eCSSProperty_color_interpolation:
   case eCSSProperty_color_interpolation_filters:
   case eCSSProperty_cursor:
   case eCSSProperty_display:
   case eCSSProperty_dominant_baseline:
   case eCSSProperty_fill:
   case eCSSProperty_fill_opacity:
   case eCSSProperty_fill_rule:
   case eCSSProperty_filter:
   case eCSSProperty_flood_color:
   case eCSSProperty_flood_opacity:
   case eCSSProperty_font:
   case eCSSProperty_font_family:
   case eCSSProperty_font_size:
   case eCSSProperty_font_size_adjust:
   case eCSSProperty_font_stretch:
   case eCSSProperty_font_style:
   case eCSSProperty_font_variant:
   case eCSSProperty_font_weight:
   case eCSSProperty_height:
   case eCSSProperty_image_rendering:
   case eCSSProperty_letter_spacing:
   case eCSSProperty_lighting_color:
   case eCSSProperty_marker:
   case eCSSProperty_marker_end:
   case eCSSProperty_marker_mid:
   case eCSSProperty_marker_start:
   case eCSSProperty_mask:
   case eCSSProperty_mask_type:
   case eCSSProperty_opacity:
   case eCSSProperty_overflow:
   case eCSSProperty_pointer_events:
   case eCSSProperty_shape_rendering:
   case eCSSProperty_stop_color:
   case eCSSProperty_stop_opacity:
   case eCSSProperty_stroke:
   case eCSSProperty_stroke_dasharray:
   case eCSSProperty_stroke_dashoffset:
   case eCSSProperty_stroke_linecap:
   case eCSSProperty_stroke_linejoin:
   case eCSSProperty_stroke_miterlimit:
   case eCSSProperty_stroke_opacity:
   case eCSSProperty_stroke_width:
   case eCSSProperty_text_anchor:
   case eCSSProperty_text_decoration:
   case eCSSProperty_text_decoration_line:
   case eCSSProperty_text_rendering:
   case eCSSProperty_vector_effect:
   case eCSSProperty_width:
   case eCSSProperty_visibility:
   case eCSSProperty_word_spacing:
     return true;

   // EXPLICITLY NON-ANIMATABLE PROPERTIES:
   // (Some of these aren't supported at all in Gecko -- I've commented those
   // ones out. If/when we add support for them, uncomment their line here)
   // ----------------------------------------------------------------------
   // case eCSSProperty_enable_background:
   // case eCSSProperty_glyph_orientation_horizontal:
   // case eCSSProperty_glyph_orientation_vertical:
   // case eCSSProperty_writing_mode:
   case eCSSProperty_direction:
   case eCSSProperty_unicode_bidi:
     return false;

   default:
     return false;
 }
}

}  // namespace mozilla