gecko-dev/dom/smil/nsSMILCSSProperty.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2012-05-21 11:12:37 +00:00
/* 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 "nsSMILCSSProperty.h"
#include "nsSMILCSSValueType.h"
#include "nsSMILValue.h"
#include "nsComputedDOMStyle.h"
#include "nsCSSProps.h"
#include "nsStyleAnimation.h"
#include "mozilla/dom/Element.h"
#include "nsIDOMElement.h"
#include "nsIDocument.h"
using namespace mozilla::dom;
// Helper function
static bool
GetCSSComputedValue(Element* aElem,
nsCSSProperty aPropID,
nsAString& aResult)
{
NS_ABORT_IF_FALSE(!nsCSSProps::IsShorthand(aPropID),
"Can't look up computed value of shorthand property");
NS_ABORT_IF_FALSE(nsSMILCSSProperty::IsPropertyAnimatable(aPropID),
"Shouldn't get here for non-animatable properties");
nsIDocument* doc = aElem->GetCurrentDoc();
if (!doc) {
// This can happen if we process certain types of restyles mid-sample
// and remove anonymous animated content from the document as a result.
// See bug 534975.
return false;
}
nsIPresShell* shell = doc->GetShell();
if (!shell) {
NS_WARNING("Unable to look up computed style -- no pres shell");
return false;
}
nsRefPtr<nsComputedDOMStyle> computedStyle =
NS_NewComputedDOMStyle(aElem, EmptyString(), shell);
computedStyle->GetPropertyValue(aPropID, aResult);
return true;
}
// Class Methods
nsSMILCSSProperty::nsSMILCSSProperty(nsCSSProperty aPropID,
Element* aElement)
: mPropID(aPropID), mElement(aElement)
{
NS_ABORT_IF_FALSE(IsPropertyAnimatable(mPropID),
"Creating a nsSMILCSSProperty for a property "
"that's not supported for animation");
}
nsSMILValue
nsSMILCSSProperty::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:
nsSMILValue baseValue;
// SPECIAL CASE: (a) Shorthands
// (b) 'display'
if (nsCSSProps::IsShorthand(mPropID) || mPropID == eCSSProperty_display) {
// 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.
//
// In either case, just return a dummy value (initialized with the right
// type, so as not to indicate failure).
nsSMILValue tmpVal(&nsSMILCSSValueType::sSingleton);
baseValue.Swap(tmpVal);
return baseValue;
}
// GENERAL CASE: Non-Shorthands
// (1) Put empty string in override style for property mPropID
// (saving old override style value, so we can set it again when we're done)
nsICSSDeclaration* overrideDecl = mElement->GetSMILOverrideStyle();
nsAutoString cachedOverrideStyleVal;
if (overrideDecl) {
overrideDecl->GetPropertyValue(mPropID, cachedOverrideStyleVal);
// (Don't bother clearing override style if it's already empty)
if (!cachedOverrideStyleVal.IsEmpty()) {
overrideDecl->SetPropertyValue(mPropID, EmptyString());
}
}
// (2) Get Computed Style
nsAutoString computedStyleVal;
bool didGetComputedVal = GetCSSComputedValue(mElement, mPropID,
computedStyleVal);
// (3) Put cached override style back (if it's non-empty)
if (overrideDecl && !cachedOverrideStyleVal.IsEmpty()) {
overrideDecl->SetPropertyValue(mPropID, cachedOverrideStyleVal);
}
// (4) Populate our nsSMILValue from the computed style
if (didGetComputedVal) {
// When we parse animation values we check if they are context-sensitive or
// not so that we don't cache animation values whose meaning may change.
// For base values however this is unnecessary since on each sample the
// compositor will fetch the (computed) base value and compare it against
// the cached (computed) value and detect changes for us.
nsSMILCSSValueType::ValueFromString(mPropID, mElement,
computedStyleVal, baseValue,
nullptr);
}
return baseValue;
}
nsresult
nsSMILCSSProperty::ValueFromString(const nsAString& aStr,
const SVGAnimationElement* aSrcElement,
nsSMILValue& aValue,
bool& aPreventCachingOfSandwich) const
{
NS_ENSURE_TRUE(IsPropertyAnimatable(mPropID), NS_ERROR_FAILURE);
nsSMILCSSValueType::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
nsSMILCSSProperty::SetAnimValue(const nsSMILValue& aValue)
{
NS_ENSURE_TRUE(IsPropertyAnimatable(mPropID), NS_ERROR_FAILURE);
// Convert nsSMILValue to string
nsAutoString valStr;
if (!nsSMILCSSValueType::ValueToString(aValue, valStr)) {
NS_WARNING("Failed to convert nsSMILValue for CSS property into a string");
return NS_ERROR_FAILURE;
}
// Use string value to style the target element
nsICSSDeclaration* overrideDecl = mElement->GetSMILOverrideStyle();
if (overrideDecl) {
nsAutoString oldValStr;
overrideDecl->GetPropertyValue(mPropID, oldValStr);
if (valStr.Equals(oldValStr)) {
return NS_OK;
}
overrideDecl->SetPropertyValue(mPropID, valStr);
}
return NS_OK;
}
void
nsSMILCSSProperty::ClearAnimValue()
{
// Put empty string in override style for our property
nsICSSDeclaration* overrideDecl = mElement->GetSMILOverrideStyle();
if (overrideDecl) {
overrideDecl->SetPropertyValue(mPropID, EmptyString());
}
}
// Based on http://www.w3.org/TR/SVG/propidx.html
// static
bool
nsSMILCSSProperty::IsPropertyAnimatable(nsCSSProperty aPropID)
{
// NOTE: Right now, Gecko doesn't recognize the following properties from
// the SVG Property Index:
// alignment-baseline
// baseline-shift
// color-profile
// color-rendering
// 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;
}
}