gecko-dev/layout/style/nsStyleAnimation.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is nsStyleAnimation.
*
* The Initial Developer of the Original Code is
* The Mozilla Corporation.
* Portions created by the Initial Developer are Copyright (C) 2009
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Daniel Holbert <dholbert@mozilla.com>, Mozilla Corporation
* L. David Baron <dbaron@dbaron.org>, Mozilla Corporation
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/* Utilities for animation of computed style values */
#include "nsStyleAnimation.h"
#include "nsCOMArray.h"
#include "nsIStyleRule.h"
#include "nsICSSStyleRule.h"
#include "nsString.h"
#include "nsStyleCoord.h"
#include "nsStyleContext.h"
#include "nsStyleSet.h"
#include "nsComputedDOMStyle.h"
#include "nsICSSParser.h"
#include "nsICSSLoader.h"
#include "nsCSSDataBlock.h"
#include "nsCSSDeclaration.h"
#include "prlog.h"
#include <math.h>
// HELPER METHODS
// --------------
/*
* Given two units, this method returns a common unit that they can both be
* converted into, if possible. This is intended to facilitate
* interpolation, distance-computation, and addition between "similar" units.
*
* The ordering of the arguments should not affect the output of this method.
*
* If there's no sensible common unit, this method returns eStyleUnit_Null.
*
* @param aFirstUnit One unit to resolve.
* @param aFirstUnit The other unit to resolve.
* @return A "common" unit that both source units can be converted into, or
* eStyleUnit_Null if that's not possible.
*/
static
nsStyleUnit
GetCommonUnit(nsStyleUnit aFirstUnit,
nsStyleUnit aSecondUnit)
{
// XXXdholbert Naive implementation for now: simply require that the input
// units match.
if (aFirstUnit != aSecondUnit) {
// XXXdholbert Fail on mismatches for now.
// Eventually we'll need to be able to resolve conflicts here, e.g. for
// rgb() colors vs. named colors. Some conflicts can't be resolved,
// e.g. percent vs coord, which we'll hopefully handle using CSS calc()
// once that's implemented.
NS_WARNING("start unit & end unit don't match -- need to resolve this "
"and pick which one we want to use");
return eStyleUnit_Null;
}
return aFirstUnit;
}
// CLASS METHODS
// -------------
#define MAX_PACKED_COLOR_COMPONENT 255
inline PRUint8 ClampColor(PRUint32 aColor)
{
if (aColor >= MAX_PACKED_COLOR_COMPONENT)
return MAX_PACKED_COLOR_COMPONENT;
return aColor;
}
PRBool
nsStyleAnimation::Add(nsStyleCoord& aDest, const nsStyleCoord& aValueToAdd,
PRUint32 aCount)
{
nsStyleUnit commonUnit = GetCommonUnit(aDest.GetUnit(),
aValueToAdd.GetUnit());
PRBool success = PR_TRUE;
switch (commonUnit) {
case eStyleUnit_Coord: {
nscoord destCoord = aDest.GetCoordValue();
nscoord valueToAddCoord = aValueToAdd.GetCoordValue();
destCoord += aCount * valueToAddCoord;
aDest.SetCoordValue(destCoord);
break;
}
case eStyleUnit_Percent: {
float destPct = aDest.GetPercentValue();
float valueToAddPct = aValueToAdd.GetPercentValue();
destPct += aCount * valueToAddPct;
aDest.SetPercentValue(destPct);
break;
}
case eStyleUnit_Color: {
// Since nscolor doesn't allow out-of-sRGB values, by-animations
// of colors don't make much sense in our implementation.
// FIXME (bug 515919): Animation of colors should really use
// floating point colors (and when it does, ClampColor and the
// clamping of aCount should go away).
// Also, given RGBA colors, it's not clear whether we want
// premultiplication. Probably we don't, given that's hard to
// premultiply aValueToAdd since it's a difference rather than a
// value.
nscolor destColor = aDest.GetColorValue();
nscolor colorToAdd = aValueToAdd.GetColorValue();
if (aCount > MAX_PACKED_COLOR_COMPONENT) {
// Given that we're using integers and clamping at 255, we can
// clamp aCount to 255 since that's enough to saturate if we're
// multiplying it by anything nonzero.
aCount = MAX_PACKED_COLOR_COMPONENT;
}
PRUint8 resultR =
ClampColor(NS_GET_R(destColor) + aCount * NS_GET_R(colorToAdd));
PRUint8 resultG =
ClampColor(NS_GET_G(destColor) + aCount * NS_GET_G(colorToAdd));
PRUint8 resultB =
ClampColor(NS_GET_B(destColor) + aCount * NS_GET_B(colorToAdd));
PRUint8 resultA =
ClampColor(NS_GET_A(destColor) + aCount * NS_GET_A(colorToAdd));
aDest.SetColorValue(NS_RGBA(resultR, resultG, resultB, resultA));
break;
}
case eStyleUnit_Null:
NS_WARNING("Unable to find a common unit for given values");
success = PR_FALSE;
break;
default:
NS_NOTREACHED("Can't add nsStyleCoords using the given common unit");
success = PR_FALSE;
break;
}
return success;
}
PRBool
nsStyleAnimation::ComputeDistance(const nsStyleCoord& aStartValue,
const nsStyleCoord& aEndValue,
double& aDistance)
{
nsStyleUnit commonUnit = GetCommonUnit(aStartValue.GetUnit(),
aEndValue.GetUnit());
PRBool success = PR_TRUE;
switch (commonUnit) {
case eStyleUnit_Coord: {
nscoord startCoord = aStartValue.GetCoordValue();
nscoord endCoord = aEndValue.GetCoordValue();
aDistance = fabs(double(endCoord - startCoord));
break;
}
case eStyleUnit_Percent: {
float startPct = aStartValue.GetPercentValue();
float endPct = aEndValue.GetPercentValue();
aDistance = fabs(double(endPct - startPct));
break;
}
case eStyleUnit_Color: {
// http://www.w3.org/TR/smil-animation/#animateColorElement says
// that we should use Euclidean RGB cube distance. However, we
// have to extend that to RGBA. For now, we'll just use the
// Euclidean distance in the (part of the) 4-cube of premultiplied
// colors.
// FIXME (spec): The CSS transitions spec doesn't say whether
// colors are premultiplied, but things work better when they are,
// so use premultiplication. Spec issue is still open per
// http://lists.w3.org/Archives/Public/www-style/2009Jul/0050.html
nscolor startColor = aStartValue.GetColorValue();
nscolor endColor = aEndValue.GetColorValue();
// Get a color component on a 0-1 scale, which is much easier to
// deal with when working with alpha.
#define GET_COMPONENT(component_, color_) \
(NS_GET_##component_(color_) * (1.0 / 255.0))
double startA = GET_COMPONENT(A, startColor);
double startR = GET_COMPONENT(R, startColor) * startA;
double startG = GET_COMPONENT(G, startColor) * startA;
double startB = GET_COMPONENT(B, startColor) * startA;
double endA = GET_COMPONENT(A, endColor);
double endR = GET_COMPONENT(R, endColor) * endA;
double endG = GET_COMPONENT(G, endColor) * endA;
double endB = GET_COMPONENT(B, endColor) * endA;
#undef GET_COMPONENT
double diffA = startA - endA;
double diffR = startR - endR;
double diffG = startG - endG;
double diffB = startB - endB;
aDistance = sqrt(diffA * diffA + diffR * diffR +
diffG * diffG + diffB * diffB);
break;
}
case eStyleUnit_Null:
NS_WARNING("Unable to find a common unit for given values");
success = PR_FALSE;
break;
default:
NS_NOTREACHED("Can't compute distance using the given common unit");
success = PR_FALSE;
break;
}
return success;
}
PRBool
nsStyleAnimation::Interpolate(const nsStyleCoord& aStartValue,
const nsStyleCoord& aEndValue,
double aPortion,
nsStyleCoord& aResultValue)
{
NS_ABORT_IF_FALSE(aPortion >= 0.0 && aPortion <= 1.0,
"aPortion out of bounds");
nsStyleUnit commonUnit = GetCommonUnit(aStartValue.GetUnit(),
aEndValue.GetUnit());
// Maybe need a followup method to convert the inputs into the common
// unit-type, if they don't already match it. (Or would it make sense to do
// that in GetCommonUnit? in which case maybe ConvertToCommonUnit would be
// better.)
PRBool success = PR_TRUE;
switch (commonUnit) {
case eStyleUnit_Coord: {
nscoord startCoord = aStartValue.GetCoordValue();
nscoord endCoord = aEndValue.GetCoordValue();
nscoord resultCoord = startCoord +
NSToCoordRound(aPortion * (endCoord - startCoord));
aResultValue.SetCoordValue(resultCoord);
break;
}
case eStyleUnit_Percent: {
float startPct = aStartValue.GetPercentValue();
float endPct = aEndValue.GetPercentValue();
float resultPct = startPct + aPortion * (endPct - startPct);
aResultValue.SetPercentValue(resultPct);
break;
}
case eStyleUnit_Color: {
double inv = 1.0 - aPortion;
nscolor startColor = aStartValue.GetColorValue();
nscolor endColor = aEndValue.GetColorValue();
// FIXME (spec): The CSS transitions spec doesn't say whether
// colors are premultiplied, but things work better when they are,
// so use premultiplication. Spec issue is still open per
// http://lists.w3.org/Archives/Public/www-style/2009Jul/0050.html
// To save some math, scale the alpha down to a 0-1 scale, but
// leave the color components on a 0-255 scale.
double startA = NS_GET_A(startColor) * (1.0 / 255.0);
double startR = NS_GET_R(startColor) * startA;
double startG = NS_GET_G(startColor) * startA;
double startB = NS_GET_B(startColor) * startA;
double endA = NS_GET_A(endColor) * (1.0 / 255.0);
double endR = NS_GET_R(endColor) * endA;
double endG = NS_GET_G(endColor) * endA;
double endB = NS_GET_B(endColor) * endA;
double resAf = (startA * inv + endA * aPortion);
nscolor resultColor;
if (resAf == 0.0) {
resultColor = NS_RGBA(0, 0, 0, 0);
} else {
double factor = 1.0 / resAf;
PRUint8 resA = NSToIntRound(resAf * 255.0);
PRUint8 resR = NSToIntRound((startR * inv + endR * aPortion) * factor);
PRUint8 resG = NSToIntRound((startG * inv + endG * aPortion) * factor);
PRUint8 resB = NSToIntRound((startB * inv + endB * aPortion) * factor);
resultColor = NS_RGBA(resR, resG, resB, resA);
}
aResultValue.SetColorValue(resultColor);
break;
}
case eStyleUnit_Null:
NS_WARNING("Unable to find a common unit for given values");
success = PR_FALSE;
break;
default:
NS_NOTREACHED("Can't interpolate using the given common unit");
success = PR_FALSE;
break;
}
return success;
}
already_AddRefed<nsICSSStyleRule>
BuildStyleRule(nsCSSProperty aProperty,
nsIContent* aTargetElement,
const nsAString& aSpecifiedValue)
{
// Set up an empty CSS Declaration
nsCSSDeclaration* declaration = new nsCSSDeclaration();
if (!declaration) {
NS_WARNING("Failed to allocate nsCSSDeclaration");
return nsnull;
}
PRBool changed; // ignored, but needed as outparam for ParseProperty
nsIDocument* doc = aTargetElement->GetOwnerDoc();
nsCOMPtr<nsIURI> baseURI = aTargetElement->GetBaseURI();
nsCOMPtr<nsICSSParser> parser;
nsCOMPtr<nsICSSStyleRule> styleRule;
// The next statement performs the following, in sequence: Get parser, use
// parser to parse property, check that parsing succeeded, and build a rule
// for the resulting declaration. If any of these steps fails, we bail out
// and delete the declaration.
if (!declaration->InitializeEmpty() ||
NS_FAILED(doc->CSSLoader()->GetParserFor(nsnull,
getter_AddRefs(parser))) ||
NS_FAILED(parser->ParseProperty(aProperty, aSpecifiedValue,
doc->GetDocumentURI(), baseURI,
aTargetElement->NodePrincipal(),
declaration, &changed)) ||
// SlotForValue checks whether property parsed w/out CSS parsing errors
!declaration->SlotForValue(aProperty) ||
NS_FAILED(NS_NewCSSStyleRule(getter_AddRefs(styleRule), nsnull,
declaration))) {
NS_WARNING("failure in BuildStyleRule");
declaration->RuleAbort(); // deletes declaration
return nsnull;
}
return styleRule.forget();
}
inline
already_AddRefed<nsStyleContext>
LookupStyleContext(nsIContent* aElement)
{
nsIDocument* doc = aElement->GetCurrentDoc();
nsIPresShell* shell = doc->GetPrimaryShell();
if (!shell) {
return nsnull;
}
return nsComputedDOMStyle::GetStyleContextForContent(aElement, nsnull, shell);
}
PRBool
nsStyleAnimation::ComputeValue(nsCSSProperty aProperty,
nsIContent* aTargetElement,
const nsAString& aSpecifiedValue,
nsStyleCoord& aComputedValue)
{
NS_ABORT_IF_FALSE(aTargetElement, "null target element");
NS_ABORT_IF_FALSE(aTargetElement->GetCurrentDoc(),
"we should only be able to actively animate nodes that "
"are in a document");
// Look up style context for our target element
nsRefPtr<nsStyleContext> styleContext = LookupStyleContext(aTargetElement);
if (!styleContext) {
return PR_FALSE;
}
// Parse specified value into a temporary nsICSSStyleRule
nsCOMPtr<nsICSSStyleRule> styleRule =
BuildStyleRule(aProperty, aTargetElement, aSpecifiedValue);
if (!styleRule) {
return PR_FALSE;
}
// Create a temporary nsStyleContext for the style rule
nsCOMArray<nsIStyleRule> ruleArray;
ruleArray.AppendObject(styleRule);
nsStyleSet* styleSet = styleContext->PresContext()->StyleSet();
nsRefPtr<nsStyleContext> tmpStyleContext =
styleSet->ResolveStyleForRules(styleContext->GetParent(),
styleContext->GetPseudoType(),
styleContext->GetRuleNode(), ruleArray);
// Extract computed value of our property from the temporary style rule
return ExtractComputedValue(aProperty, tmpStyleContext, aComputedValue);
}
PRBool
nsStyleAnimation::UncomputeValue(nsCSSProperty aProperty,
nsPresContext* aPresContext,
const nsStyleCoord& aComputedValue,
nsAString& aSpecifiedValue)
{
NS_ABORT_IF_FALSE(aPresContext, "null pres context");
aSpecifiedValue.Truncate(); // Clear outparam, if it's not already empty
nsCSSValue value;
switch (aComputedValue.GetUnit()) {
case eStyleUnit_Coord: {
float pxVal = aPresContext->AppUnitsToFloatCSSPixels(
aComputedValue.GetCoordValue());
value.SetFloatValue(pxVal, eCSSUnit_Pixel);
break;
}
case eStyleUnit_Percent:
value.SetPercentValue(aComputedValue.GetPercentValue());
break;
case eStyleUnit_Color:
value.SetColorValue(aComputedValue.GetColorValue());
break;
default:
return PR_FALSE;
}
return nsCSSDeclaration::AppendCSSValueToString(aProperty, value,
aSpecifiedValue);
}
inline const void*
StyleDataAtOffset(const void* aStyleStruct, ptrdiff_t aOffset)
{
return reinterpret_cast<const char*>(aStyleStruct) + aOffset;
}
inline void*
StyleDataAtOffset(void* aStyleStruct, ptrdiff_t aOffset)
{
return reinterpret_cast<char*>(aStyleStruct) + aOffset;
}
PRBool
nsStyleAnimation::ExtractComputedValue(nsCSSProperty aProperty,
nsStyleContext* aStyleContext,
nsStyleCoord& aComputedValue)
{
NS_ABORT_IF_FALSE(0 <= aProperty &&
aProperty < eCSSProperty_COUNT_no_shorthands,
"bad property");
const void* styleStruct =
aStyleContext->GetStyleData(nsCSSProps::kSIDTable[aProperty]);
ptrdiff_t ssOffset = nsCSSProps::kStyleStructOffsetTable[aProperty];
NS_ABORT_IF_FALSE(0 <= ssOffset, "must be dealing with animatable property");
nsStyleAnimType animType = nsCSSProps::kAnimTypeTable[aProperty];
switch (animType) {
case eStyleAnimType_Coord:
aComputedValue = *static_cast<const nsStyleCoord*>(
StyleDataAtOffset(styleStruct, ssOffset));
return PR_TRUE;
case eStyleAnimType_Sides_Top:
case eStyleAnimType_Sides_Right:
case eStyleAnimType_Sides_Bottom:
case eStyleAnimType_Sides_Left:
PR_STATIC_ASSERT(0 == NS_SIDE_TOP);
PR_STATIC_ASSERT(eStyleAnimType_Sides_Right - eStyleAnimType_Sides_Top
== NS_SIDE_RIGHT);
PR_STATIC_ASSERT(eStyleAnimType_Sides_Bottom - eStyleAnimType_Sides_Top
== NS_SIDE_BOTTOM);
PR_STATIC_ASSERT(eStyleAnimType_Sides_Left - eStyleAnimType_Sides_Top
== NS_SIDE_LEFT);
aComputedValue = static_cast<const nsStyleSides*>(
StyleDataAtOffset(styleStruct, ssOffset))->
Get(animType - eStyleAnimType_Sides_Top);
return PR_TRUE;
case eStyleAnimType_nscoord:
aComputedValue.SetCoordValue(*static_cast<const nscoord*>(
StyleDataAtOffset(styleStruct, ssOffset)));
return PR_TRUE;
case eStyleAnimType_Color:
aComputedValue.SetColorValue(*static_cast<const nscolor*>(
StyleDataAtOffset(styleStruct, ssOffset)));
return PR_TRUE;
case eStyleAnimType_PaintServer: {
const nsStyleSVGPaint &paint = *static_cast<const nsStyleSVGPaint*>(
StyleDataAtOffset(styleStruct, ssOffset));
// We *could* animate 'none' by treating it as rgba(0, 0, 0, 0),
// but since SVG doesn't have (or really get along with) rgba()
// colors, I think we're not supposed to.
// FIXME: However, at some point in the future, we should animate
// gradients.
if (paint.mType == eStyleSVGPaintType_Color) {
aComputedValue.SetColorValue(paint.mPaint.mColor);
return PR_TRUE;
}
return PR_FALSE;
}
case eStyleAnimType_None:
NS_NOTREACHED("shouldn't use on non-animatable properties");
}
return PR_FALSE;
}
PRBool
nsStyleAnimation::StoreComputedValue(nsCSSProperty aProperty,
nsPresContext* aPresContext,
void* aStyleStruct,
const nsStyleCoord& aComputedValue)
{
NS_ABORT_IF_FALSE(0 <= aProperty &&
aProperty < eCSSProperty_COUNT_no_shorthands,
"bad property");
ptrdiff_t ssOffset = nsCSSProps::kStyleStructOffsetTable[aProperty];
NS_ABORT_IF_FALSE(0 <= ssOffset, "must be dealing with animatable property");
nsStyleAnimType animType = nsCSSProps::kAnimTypeTable[aProperty];
switch (animType) {
case eStyleAnimType_Coord:
*static_cast<nsStyleCoord*>(StyleDataAtOffset(aStyleStruct, ssOffset)) =
aComputedValue;
return PR_TRUE;
case eStyleAnimType_Sides_Top:
case eStyleAnimType_Sides_Right:
case eStyleAnimType_Sides_Bottom:
case eStyleAnimType_Sides_Left: {
PR_STATIC_ASSERT(0 == NS_SIDE_TOP);
PR_STATIC_ASSERT(eStyleAnimType_Sides_Right - eStyleAnimType_Sides_Top
== NS_SIDE_RIGHT);
PR_STATIC_ASSERT(eStyleAnimType_Sides_Bottom - eStyleAnimType_Sides_Top
== NS_SIDE_BOTTOM);
PR_STATIC_ASSERT(eStyleAnimType_Sides_Left - eStyleAnimType_Sides_Top
== NS_SIDE_LEFT);
static_cast<nsStyleSides*>(StyleDataAtOffset(aStyleStruct, ssOffset))->
Set(animType - eStyleAnimType_Sides_Top, aComputedValue);
nsStyleStructID sid = nsCSSProps::kSIDTable[aProperty];
if (sid == eStyleStruct_Margin) {
static_cast<nsStyleMargin*>(aStyleStruct)->RecalcData();
} else if (sid == eStyleStruct_Padding) {
static_cast<nsStylePadding*>(aStyleStruct)->RecalcData();
}
return PR_TRUE;
}
case eStyleAnimType_nscoord:
*static_cast<nscoord*>(StyleDataAtOffset(aStyleStruct, ssOffset)) =
aComputedValue.GetCoordValue();
if (aProperty == eCSSProperty_font) {
nsStyleFont *font = static_cast<nsStyleFont*>(aStyleStruct);
if (!aPresContext->IsChrome()) {
nscoord minimumFontSize =
aPresContext->GetCachedIntPref(kPresContext_MinimumFontSize);
font->mFont.size = NS_MAX(font->mSize, minimumFontSize);
} else {
font->mFont.size = font->mSize;
}
}
return PR_TRUE;
case eStyleAnimType_Color:
*static_cast<nscolor*>(StyleDataAtOffset(aStyleStruct, ssOffset)) =
aComputedValue.GetColorValue();
return PR_TRUE;
case eStyleAnimType_PaintServer: {
nsStyleSVGPaint &paint = *static_cast<nsStyleSVGPaint*>(
StyleDataAtOffset(aStyleStruct, ssOffset));
paint.mType = eStyleSVGPaintType_Color;
paint.mPaint.mColor = aComputedValue.GetColorValue();
return PR_TRUE;
}
case eStyleAnimType_None:
NS_NOTREACHED("shouldn't use on non-animatable properties");
}
return PR_FALSE;
}