gecko/content/smil/nsSMILCSSValueType.cpp
2012-05-21 12:12:37 +01:00

418 lines
15 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 value for a SMIL-animated CSS property */
#include "nsSMILCSSValueType.h"
#include "nsString.h"
#include "nsStyleAnimation.h"
#include "nsSMILParserUtils.h"
#include "nsSMILValue.h"
#include "nsCSSValue.h"
#include "nsColor.h"
#include "nsPresContext.h"
#include "mozilla/dom/Element.h"
#include "nsDebug.h"
using namespace mozilla::dom;
/*static*/ nsSMILCSSValueType nsSMILCSSValueType::sSingleton;
struct ValueWrapper {
ValueWrapper(nsCSSProperty aPropID, const nsStyleAnimation::Value& aValue,
nsPresContext* aPresContext) :
mPropID(aPropID), mCSSValue(aValue), mPresContext(aPresContext) {}
nsCSSProperty mPropID;
nsStyleAnimation::Value mCSSValue;
nsPresContext* mPresContext;
};
// Helper "zero" values of various types
// -------------------------------------
static const nsStyleAnimation::Value
sZeroCoord(0, nsStyleAnimation::Value::CoordConstructor);
static const nsStyleAnimation::Value
sZeroPercent(0.0f, nsStyleAnimation::Value::PercentConstructor);
static const nsStyleAnimation::Value
sZeroFloat(0.0f, nsStyleAnimation::Value::FloatConstructor);
static const nsStyleAnimation::Value
sZeroColor(NS_RGB(0,0,0), nsStyleAnimation::Value::ColorConstructor);
// Helper Methods
// --------------
static const nsStyleAnimation::Value*
GetZeroValueForUnit(nsStyleAnimation::Unit aUnit)
{
NS_ABORT_IF_FALSE(aUnit != nsStyleAnimation::eUnit_Null,
"Need non-null unit for a zero value");
switch (aUnit) {
case nsStyleAnimation::eUnit_Coord:
return &sZeroCoord;
case nsStyleAnimation::eUnit_Percent:
return &sZeroPercent;
case nsStyleAnimation::eUnit_Float:
return &sZeroFloat;
case nsStyleAnimation::eUnit_Color:
return &sZeroColor;
default:
return nsnull;
}
}
// This method requires at least one of its arguments to be non-null.
//
// If one argument is null, this method updates it to point to "zero"
// for the other argument's Unit (if applicable; otherwise, we return false).
//
// If neither argument is null, this method generally does nothing, though it
// may apply a workaround for the special case where a 0 length-value is mixed
// with a eUnit_Float value. (See comment below.)
//
// Returns true on success, or false.
static const bool
FinalizeStyleAnimationValues(const nsStyleAnimation::Value*& aValue1,
const nsStyleAnimation::Value*& aValue2)
{
NS_ABORT_IF_FALSE(aValue1 || aValue2,
"expecting at least one non-null value");
// Are we missing either val? (If so, it's an implied 0 in other val's units)
if (!aValue1) {
aValue1 = GetZeroValueForUnit(aValue2->GetUnit());
return !!aValue1; // Fail if we have no zero value for this unit.
}
if (!aValue2) {
aValue2 = GetZeroValueForUnit(aValue1->GetUnit());
return !!aValue2; // Fail if we have no zero value for this unit.
}
// Ok, both values were specified.
// Need to handle a special-case, though: unitless nonzero length (parsed as
// eUnit_Float) mixed with unitless 0 length (parsed as eUnit_Coord). These
// won't interoperate in nsStyleAnimation, since their Units don't match.
// In this case, we replace the eUnit_Coord 0 value with eUnit_Float 0 value.
if (*aValue1 == sZeroCoord &&
aValue2->GetUnit() == nsStyleAnimation::eUnit_Float) {
aValue1 = &sZeroFloat;
} else if (*aValue2 == sZeroCoord &&
aValue1->GetUnit() == nsStyleAnimation::eUnit_Float) {
aValue2 = &sZeroFloat;
}
return true;
}
static void
InvertSign(nsStyleAnimation::Value& aValue)
{
switch (aValue.GetUnit()) {
case nsStyleAnimation::eUnit_Coord:
aValue.SetCoordValue(-aValue.GetCoordValue());
break;
case nsStyleAnimation::eUnit_Percent:
aValue.SetPercentValue(-aValue.GetPercentValue());
break;
case nsStyleAnimation::eUnit_Float:
aValue.SetFloatValue(-aValue.GetFloatValue());
break;
default:
NS_NOTREACHED("Calling InvertSign with an unsupported unit");
break;
}
}
static ValueWrapper*
ExtractValueWrapper(nsSMILValue& aValue)
{
return static_cast<ValueWrapper*>(aValue.mU.mPtr);
}
static const ValueWrapper*
ExtractValueWrapper(const nsSMILValue& aValue)
{
return static_cast<const ValueWrapper*>(aValue.mU.mPtr);
}
// Class methods
// -------------
void
nsSMILCSSValueType::Init(nsSMILValue& aValue) const
{
NS_ABORT_IF_FALSE(aValue.IsNull(), "Unexpected SMIL value type");
aValue.mU.mPtr = nsnull;
aValue.mType = this;
}
void
nsSMILCSSValueType::Destroy(nsSMILValue& aValue) const
{
NS_ABORT_IF_FALSE(aValue.mType == this, "Unexpected SMIL value type");
delete static_cast<ValueWrapper*>(aValue.mU.mPtr);
aValue.mType = &nsSMILNullType::sSingleton;
}
nsresult
nsSMILCSSValueType::Assign(nsSMILValue& aDest, const nsSMILValue& aSrc) const
{
NS_ABORT_IF_FALSE(aDest.mType == aSrc.mType, "Incompatible SMIL types");
NS_ABORT_IF_FALSE(aDest.mType == this, "Unexpected SMIL value type");
const ValueWrapper* srcWrapper = ExtractValueWrapper(aSrc);
ValueWrapper* destWrapper = ExtractValueWrapper(aDest);
if (srcWrapper) {
if (!destWrapper) {
// barely-initialized dest -- need to alloc & copy
aDest.mU.mPtr = new ValueWrapper(*srcWrapper);
} else {
// both already fully-initialized -- just copy straight across
*destWrapper = *srcWrapper;
}
} else if (destWrapper) {
// fully-initialized dest, barely-initialized src -- clear dest
delete destWrapper;
aDest.mU.mPtr = destWrapper = nsnull;
} // else, both are barely-initialized -- nothing to do.
return NS_OK;
}
bool
nsSMILCSSValueType::IsEqual(const nsSMILValue& aLeft,
const nsSMILValue& aRight) const
{
NS_ABORT_IF_FALSE(aLeft.mType == aRight.mType, "Incompatible SMIL types");
NS_ABORT_IF_FALSE(aLeft.mType == this, "Unexpected SMIL value");
const ValueWrapper* leftWrapper = ExtractValueWrapper(aLeft);
const ValueWrapper* rightWrapper = ExtractValueWrapper(aRight);
if (leftWrapper) {
if (rightWrapper) {
// Both non-null
NS_WARN_IF_FALSE(leftWrapper != rightWrapper,
"Two nsSMILValues with matching ValueWrapper ptr");
// mPresContext doesn't really matter for equality comparison
return (leftWrapper->mPropID == rightWrapper->mPropID &&
leftWrapper->mCSSValue == rightWrapper->mCSSValue);
}
// Left non-null, right null
return false;
}
if (rightWrapper) {
// Left null, right non-null
return false;
}
// Both null
return true;
}
nsresult
nsSMILCSSValueType::Add(nsSMILValue& aDest, const nsSMILValue& aValueToAdd,
PRUint32 aCount) const
{
NS_ABORT_IF_FALSE(aValueToAdd.mType == aDest.mType,
"Trying to add invalid types");
NS_ABORT_IF_FALSE(aValueToAdd.mType == this, "Unexpected source type");
ValueWrapper* destWrapper = ExtractValueWrapper(aDest);
const ValueWrapper* valueToAddWrapper = ExtractValueWrapper(aValueToAdd);
NS_ABORT_IF_FALSE(destWrapper || valueToAddWrapper,
"need at least one fully-initialized value");
nsCSSProperty property = (valueToAddWrapper ? valueToAddWrapper->mPropID :
destWrapper->mPropID);
// Special case: font-size-adjust and stroke-dasharray are explicitly
// non-additive (even though nsStyleAnimation *could* support adding them)
if (property == eCSSProperty_font_size_adjust ||
property == eCSSProperty_stroke_dasharray) {
return NS_ERROR_FAILURE;
}
const nsStyleAnimation::Value* valueToAdd = valueToAddWrapper ?
&valueToAddWrapper->mCSSValue : nsnull;
const nsStyleAnimation::Value* destValue = destWrapper ?
&destWrapper->mCSSValue : nsnull;
if (!FinalizeStyleAnimationValues(valueToAdd, destValue)) {
return NS_ERROR_FAILURE;
}
// Did FinalizeStyleAnimationValues change destValue?
// If so, update outparam to use the new value.
if (destWrapper && &destWrapper->mCSSValue != destValue) {
destWrapper->mCSSValue = *destValue;
}
// Handle barely-initialized "zero" destination.
if (!destWrapper) {
aDest.mU.mPtr = destWrapper =
new ValueWrapper(property, *destValue, valueToAddWrapper->mPresContext);
}
return nsStyleAnimation::Add(property,
destWrapper->mCSSValue, *valueToAdd, aCount) ?
NS_OK : NS_ERROR_FAILURE;
}
nsresult
nsSMILCSSValueType::ComputeDistance(const nsSMILValue& aFrom,
const nsSMILValue& aTo,
double& aDistance) const
{
NS_ABORT_IF_FALSE(aFrom.mType == aTo.mType,
"Trying to compare different types");
NS_ABORT_IF_FALSE(aFrom.mType == this, "Unexpected source type");
const ValueWrapper* fromWrapper = ExtractValueWrapper(aFrom);
const ValueWrapper* toWrapper = ExtractValueWrapper(aTo);
NS_ABORT_IF_FALSE(toWrapper, "expecting non-null endpoint");
const nsStyleAnimation::Value* fromCSSValue = fromWrapper ?
&fromWrapper->mCSSValue : nsnull;
const nsStyleAnimation::Value* toCSSValue = &toWrapper->mCSSValue;
if (!FinalizeStyleAnimationValues(fromCSSValue, toCSSValue)) {
return NS_ERROR_FAILURE;
}
return nsStyleAnimation::ComputeDistance(toWrapper->mPropID,
*fromCSSValue, *toCSSValue,
aDistance) ?
NS_OK : NS_ERROR_FAILURE;
}
nsresult
nsSMILCSSValueType::Interpolate(const nsSMILValue& aStartVal,
const nsSMILValue& aEndVal,
double aUnitDistance,
nsSMILValue& aResult) const
{
NS_ABORT_IF_FALSE(aStartVal.mType == aEndVal.mType,
"Trying to interpolate different types");
NS_ABORT_IF_FALSE(aStartVal.mType == this,
"Unexpected types for interpolation");
NS_ABORT_IF_FALSE(aResult.mType == this, "Unexpected result type");
NS_ABORT_IF_FALSE(aUnitDistance >= 0.0 && aUnitDistance <= 1.0,
"unit distance value out of bounds");
NS_ABORT_IF_FALSE(!aResult.mU.mPtr, "expecting barely-initialized outparam");
const ValueWrapper* startWrapper = ExtractValueWrapper(aStartVal);
const ValueWrapper* endWrapper = ExtractValueWrapper(aEndVal);
NS_ABORT_IF_FALSE(endWrapper, "expecting non-null endpoint");
const nsStyleAnimation::Value* startCSSValue = startWrapper ?
&startWrapper->mCSSValue : nsnull;
const nsStyleAnimation::Value* endCSSValue = &endWrapper->mCSSValue;
if (!FinalizeStyleAnimationValues(startCSSValue, endCSSValue)) {
return NS_ERROR_FAILURE;
}
nsStyleAnimation::Value resultValue;
if (nsStyleAnimation::Interpolate(endWrapper->mPropID,
*startCSSValue, *endCSSValue,
aUnitDistance, resultValue)) {
aResult.mU.mPtr = new ValueWrapper(endWrapper->mPropID, resultValue,
endWrapper->mPresContext);
return NS_OK;
}
return NS_ERROR_FAILURE;
}
// Helper function to extract presContext
static nsPresContext*
GetPresContextForElement(Element* aElem)
{
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 nsnull;
}
nsIPresShell* shell = doc->GetShell();
return shell ? shell->GetPresContext() : nsnull;
}
// Helper function to parse a string into a nsStyleAnimation::Value
static bool
ValueFromStringHelper(nsCSSProperty aPropID,
Element* aTargetElement,
nsPresContext* aPresContext,
const nsAString& aString,
nsStyleAnimation::Value& aStyleAnimValue,
bool* aIsContextSensitive)
{
// If value is negative, we'll strip off the "-" so the CSS parser won't
// barf, and then manually make the parsed value negative.
// (This is a partial solution to let us accept some otherwise out-of-bounds
// CSS values. Bug 501188 will provide a more complete fix.)
bool isNegative = false;
PRUint32 subStringBegin = 0;
// NOTE: We need to opt-out 'stroke-dasharray' from the negative-number
// check. Its values might look negative (e.g. by starting with "-1"), but
// they're more complicated than our simple negation logic here can handle.
if (aPropID != eCSSProperty_stroke_dasharray) {
PRInt32 absValuePos = nsSMILParserUtils::CheckForNegativeNumber(aString);
if (absValuePos > 0) {
isNegative = true;
subStringBegin = (PRUint32)absValuePos; // Start parsing after '-' sign
}
}
nsDependentSubstring subString(aString, subStringBegin);
if (!nsStyleAnimation::ComputeValue(aPropID, aTargetElement, subString,
true, aStyleAnimValue,
aIsContextSensitive)) {
return false;
}
if (isNegative) {
InvertSign(aStyleAnimValue);
}
if (aPropID == eCSSProperty_font_size) {
// Divide out text-zoom, since SVG is supposed to ignore it
NS_ABORT_IF_FALSE(aStyleAnimValue.GetUnit() ==
nsStyleAnimation::eUnit_Coord,
"'font-size' value with unexpected style unit");
aStyleAnimValue.SetCoordValue(aStyleAnimValue.GetCoordValue() /
aPresContext->TextZoom());
}
return true;
}
// static
void
nsSMILCSSValueType::ValueFromString(nsCSSProperty aPropID,
Element* aTargetElement,
const nsAString& aString,
nsSMILValue& aValue,
bool* aIsContextSensitive)
{
NS_ABORT_IF_FALSE(aValue.IsNull(), "Outparam should be null-typed");
nsPresContext* presContext = GetPresContextForElement(aTargetElement);
if (!presContext) {
NS_WARNING("Not parsing animation value; unable to get PresContext");
return;
}
nsStyleAnimation::Value parsedValue;
if (ValueFromStringHelper(aPropID, aTargetElement, presContext,
aString, parsedValue, aIsContextSensitive)) {
sSingleton.Init(aValue);
aValue.mU.mPtr = new ValueWrapper(aPropID, parsedValue, presContext);
}
}
// static
bool
nsSMILCSSValueType::ValueToString(const nsSMILValue& aValue,
nsAString& aString)
{
NS_ABORT_IF_FALSE(aValue.mType == &nsSMILCSSValueType::sSingleton,
"Unexpected SMIL value type");
const ValueWrapper* wrapper = ExtractValueWrapper(aValue);
return !wrapper ||
nsStyleAnimation::UncomputeValue(wrapper->mPropID, wrapper->mPresContext,
wrapper->mCSSValue, aString);
}