gecko-dev/layout/style/nsStyleAnimation.h

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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/. */
/* Utilities for animation of computed style values */
#ifndef nsStyleAnimation_h_
#define nsStyleAnimation_h_
#include "prtypes.h"
#include "nsAString.h"
#include "nsCRTGlue.h"
#include "nsStringBuffer.h"
#include "nsCSSProperty.h"
#include "nsCoord.h"
#include "nsColor.h"
class nsPresContext;
class nsStyleContext;
class nsCSSValue;
struct nsCSSValueList;
struct nsCSSValuePair;
struct nsCSSValueTriplet;
struct nsCSSValuePairList;
struct nsCSSRect;
class gfx3DMatrix;
namespace mozilla {
namespace dom {
class Element;
} // namespace dom
} // namespace mozilla
/**
* Utility class to handle animated style values
*/
class nsStyleAnimation {
public:
class Value;
// Mathematical methods
// --------------------
/**
* Adds |aCount| copies of |aValueToAdd| to |aDest|. The result of this
* addition is stored in aDest.
*
* Note that if |aCount| is 0, then |aDest| will be unchanged. Also, if
* this method fails, then |aDest| will be unchanged.
*
* @param aDest The value to add to.
* @param aValueToAdd The value to add.
* @param aCount The number of times to add aValueToAdd.
* @return true on success, false on failure.
*/
static bool Add(nsCSSProperty aProperty, Value& aDest,
const Value& aValueToAdd, PRUint32 aCount) {
return AddWeighted(aProperty, 1.0, aDest, aCount, aValueToAdd, aDest);
}
/**
* Calculates a measure of 'distance' between two values.
*
* This measure of Distance is guaranteed to be proportional to
* portions passed to Interpolate, Add, or AddWeighted. However, for
* some types of Value it may not produce sensible results for paced
* animation.
*
* If this method succeeds, the returned distance value is guaranteed to be
* non-negative.
*
* @param aStartValue The start of the interval for which the distance
* should be calculated.
* @param aEndValue The end of the interval for which the distance
* should be calculated.
* @param aDistance The result of the calculation.
* @return true on success, false on failure.
*/
static bool ComputeDistance(nsCSSProperty aProperty,
const Value& aStartValue,
const Value& aEndValue,
double& aDistance);
/**
* Calculates an interpolated value that is the specified |aPortion| between
* the two given values.
*
* This really just does the following calculation:
* aResultValue = (1.0 - aPortion) * aStartValue + aPortion * aEndValue
*
* @param aStartValue The value defining the start of the interval of
* interpolation.
* @param aEndValue The value defining the end of the interval of
* interpolation.
* @param aPortion A number in the range [0.0, 1.0] defining the
* distance of the interpolated value in the interval.
* @param [out] aResultValue The resulting interpolated value.
* @return true on success, false on failure.
*/
static bool Interpolate(nsCSSProperty aProperty,
const Value& aStartValue,
const Value& aEndValue,
double aPortion,
Value& aResultValue) {
return AddWeighted(aProperty, 1.0 - aPortion, aStartValue,
aPortion, aEndValue, aResultValue);
}
/**
* Does the calculation:
* aResultValue = aCoeff1 * aValue1 + aCoeff2 * aValue2
*
* @param [out] aResultValue The resulting interpolated value. May be
* the same as aValue1 or aValue2.
* @return true on success, false on failure.
*
* NOTE: Current callers always pass aCoeff1 and aCoeff2 >= 0. They
* are currently permitted to be negative; however, if, as we add
* support more value types types, we find that this causes
* difficulty, we might change this to restrict them to being
* positive.
*/
static bool AddWeighted(nsCSSProperty aProperty,
double aCoeff1, const Value& aValue1,
double aCoeff2, const Value& aValue2,
Value& aResultValue);
// Type-conversion methods
// -----------------------
/**
* Creates a computed value for the given specified value
* (property ID + string). A style context is needed in case the
* specified value depends on inherited style or on the values of other
* properties.
*
* @param aProperty The property whose value we're computing.
* @param aTargetElement The content node to which our computed value is
* applicable.
* @param aSpecifiedValue The specified value, from which we'll build our
* computed value.
* @param aUseSVGMode A flag to indicate whether we should parse
* |aSpecifiedValue| in SVG mode.
* @param [out] aComputedValue The resulting computed value.
* @param [out] aIsContextSensitive
* Set to true if |aSpecifiedValue| may produce
* a different |aComputedValue| depending on other CSS
* properties on |aTargetElement| or its ancestors.
* false otherwise.
* Note that the operation of this method is
* significantly faster when |aIsContextSensitive| is
* nsnull.
* @return true on success, false on failure.
*/
static bool ComputeValue(nsCSSProperty aProperty,
mozilla::dom::Element* aTargetElement,
const nsAString& aSpecifiedValue,
bool aUseSVGMode,
Value& aComputedValue,
bool* aIsContextSensitive = nsnull);
/**
* Creates a specified value for the given computed value.
*
* The first overload fills in an nsCSSValue object; the second
* produces a string. The nsCSSValue result may depend on objects
* owned by the |aComputedValue| object, so users of that variant
* must keep |aComputedValue| alive longer than |aSpecifiedValue|.
*
* @param aProperty The property whose value we're uncomputing.
* @param aPresContext The presentation context for the document in
* which we're working.
* @param aComputedValue The computed value to be converted.
* @param [out] aSpecifiedValue The resulting specified value.
* @return true on success, false on failure.
*/
static bool UncomputeValue(nsCSSProperty aProperty,
nsPresContext* aPresContext,
const Value& aComputedValue,
nsCSSValue& aSpecifiedValue);
static bool UncomputeValue(nsCSSProperty aProperty,
nsPresContext* aPresContext,
const Value& aComputedValue,
nsAString& aSpecifiedValue);
/**
* Gets the computed value for the given property from the given style
* context.
*
* @param aProperty The property whose value we're looking up.
* @param aStyleContext The style context to check for the computed value.
* @param [out] aComputedValue The resulting computed value.
* @return true on success, false on failure.
*/
static bool ExtractComputedValue(nsCSSProperty aProperty,
nsStyleContext* aStyleContext,
Value& aComputedValue);
/**
* Interpolates between 2 matrices by decomposing them.
*
* @param aMatrix1 First matrix, using CSS pixel units.
* @param aMatrix2 Second matrix, using CSS pixel units.
* @param aProgress Interpolation value in the range [0.0, 1.0]
*/
static gfx3DMatrix InterpolateTransformMatrix(const gfx3DMatrix &aMatrix1,
const gfx3DMatrix &aMatrix2,
double aProgress);
/**
* The types and values for the values that we extract and animate.
*/
enum Unit {
eUnit_Null, // not initialized
eUnit_Normal,
eUnit_Auto,
eUnit_None,
eUnit_Enumerated,
eUnit_Visibility, // special case for transitions (which converts
// Enumerated to Visibility as needed)
eUnit_Integer,
eUnit_Coord,
eUnit_Percent,
eUnit_Float,
eUnit_Color,
eUnit_Calc, // nsCSSValue* (never null), always with a single
// calc() expression that's either length or length+percent
eUnit_CSSValuePair, // nsCSSValuePair* (never null)
eUnit_CSSValueTriplet, // nsCSSValueTriplet* (never null)
eUnit_CSSRect, // nsCSSRect* (never null)
eUnit_Dasharray, // nsCSSValueList* (never null)
eUnit_Shadow, // nsCSSValueList* (may be null)
eUnit_Transform, // nsCSSValueList* (never null)
eUnit_BackgroundPosition, // nsCSSValueList* (never null)
eUnit_CSSValuePairList, // nsCSSValuePairList* (never null)
eUnit_UnparsedString // nsStringBuffer* (never null)
};
class Value {
private:
Unit mUnit;
union {
PRInt32 mInt;
nscoord mCoord;
float mFloat;
nscolor mColor;
nsCSSValue* mCSSValue;
nsCSSValuePair* mCSSValuePair;
nsCSSValueTriplet* mCSSValueTriplet;
nsCSSRect* mCSSRect;
nsCSSValueList* mCSSValueList;
nsCSSValuePairList* mCSSValuePairList;
nsStringBuffer* mString;
} mValue;
public:
Unit GetUnit() const {
NS_ASSERTION(mUnit != eUnit_Null, "uninitialized");
return mUnit;
}
// Accessor to let us verify assumptions about presence of null unit,
// without tripping the assertion in GetUnit().
bool IsNull() const {
return mUnit == eUnit_Null;
}
PRInt32 GetIntValue() const {
NS_ASSERTION(IsIntUnit(mUnit), "unit mismatch");
return mValue.mInt;
}
nscoord GetCoordValue() const {
NS_ASSERTION(mUnit == eUnit_Coord, "unit mismatch");
return mValue.mCoord;
}
float GetPercentValue() const {
NS_ASSERTION(mUnit == eUnit_Percent, "unit mismatch");
return mValue.mFloat;
}
float GetFloatValue() const {
NS_ASSERTION(mUnit == eUnit_Float, "unit mismatch");
return mValue.mFloat;
}
nscolor GetColorValue() const {
NS_ASSERTION(mUnit == eUnit_Color, "unit mismatch");
return mValue.mColor;
}
nsCSSValue* GetCSSValueValue() const {
NS_ASSERTION(IsCSSValueUnit(mUnit), "unit mismatch");
return mValue.mCSSValue;
}
nsCSSValuePair* GetCSSValuePairValue() const {
NS_ASSERTION(IsCSSValuePairUnit(mUnit), "unit mismatch");
return mValue.mCSSValuePair;
}
nsCSSValueTriplet* GetCSSValueTripletValue() const {
NS_ASSERTION(IsCSSValueTripletUnit(mUnit), "unit mismatch");
return mValue.mCSSValueTriplet;
}
nsCSSRect* GetCSSRectValue() const {
NS_ASSERTION(IsCSSRectUnit(mUnit), "unit mismatch");
return mValue.mCSSRect;
}
nsCSSValueList* GetCSSValueListValue() const {
NS_ASSERTION(IsCSSValueListUnit(mUnit), "unit mismatch");
return mValue.mCSSValueList;
}
nsCSSValuePairList* GetCSSValuePairListValue() const {
NS_ASSERTION(IsCSSValuePairListUnit(mUnit), "unit mismatch");
return mValue.mCSSValuePairList;
}
const PRUnichar* GetStringBufferValue() const {
NS_ASSERTION(IsStringUnit(mUnit), "unit mismatch");
return GetBufferValue(mValue.mString);
}
void GetStringValue(nsAString& aBuffer) const {
NS_ASSERTION(IsStringUnit(mUnit), "unit mismatch");
aBuffer.Truncate();
PRUint32 len = NS_strlen(GetBufferValue(mValue.mString));
mValue.mString->ToString(len, aBuffer);
}
explicit Value(Unit aUnit = eUnit_Null) : mUnit(aUnit) {
NS_ASSERTION(aUnit == eUnit_Null || aUnit == eUnit_Normal ||
aUnit == eUnit_Auto || aUnit == eUnit_None,
"must be valueless unit");
}
Value(const Value& aOther) : mUnit(eUnit_Null) { *this = aOther; }
enum IntegerConstructorType { IntegerConstructor };
Value(PRInt32 aInt, Unit aUnit, IntegerConstructorType);
enum CoordConstructorType { CoordConstructor };
Value(nscoord aLength, CoordConstructorType);
enum PercentConstructorType { PercentConstructor };
Value(float aPercent, PercentConstructorType);
enum FloatConstructorType { FloatConstructor };
Value(float aFloat, FloatConstructorType);
enum ColorConstructorType { ColorConstructor };
Value(nscolor aColor, ColorConstructorType);
~Value() { FreeValue(); }
void SetNormalValue();
void SetAutoValue();
void SetNoneValue();
void SetIntValue(PRInt32 aInt, Unit aUnit);
void SetCoordValue(nscoord aCoord);
void SetPercentValue(float aPercent);
void SetFloatValue(float aFloat);
void SetColorValue(nscolor aColor);
void SetUnparsedStringValue(const nsString& aString);
// These setters take ownership of |aValue|, and are therefore named
// "SetAndAdopt*".
void SetAndAdoptCSSValueValue(nsCSSValue *aValue, Unit aUnit);
void SetAndAdoptCSSValuePairValue(nsCSSValuePair *aValue, Unit aUnit);
void SetAndAdoptCSSValueTripletValue(nsCSSValueTriplet *aValue, Unit aUnit);
void SetAndAdoptCSSRectValue(nsCSSRect *aValue, Unit aUnit);
void SetAndAdoptCSSValueListValue(nsCSSValueList *aValue, Unit aUnit);
void SetAndAdoptCSSValuePairListValue(nsCSSValuePairList *aValue);
Value& operator=(const Value& aOther);
bool operator==(const Value& aOther) const;
bool operator!=(const Value& aOther) const
{ return !(*this == aOther); }
private:
void FreeValue();
static const PRUnichar* GetBufferValue(nsStringBuffer* aBuffer) {
return static_cast<PRUnichar*>(aBuffer->Data());
}
static bool IsIntUnit(Unit aUnit) {
return aUnit == eUnit_Enumerated || aUnit == eUnit_Visibility ||
aUnit == eUnit_Integer;
}
static bool IsCSSValueUnit(Unit aUnit) {
return aUnit == eUnit_Calc;
}
static bool IsCSSValuePairUnit(Unit aUnit) {
return aUnit == eUnit_CSSValuePair;
}
static bool IsCSSValueTripletUnit(Unit aUnit) {
return aUnit == eUnit_CSSValueTriplet;
}
static bool IsCSSRectUnit(Unit aUnit) {
return aUnit == eUnit_CSSRect;
}
static bool IsCSSValueListUnit(Unit aUnit) {
return aUnit == eUnit_Dasharray || aUnit == eUnit_Shadow ||
aUnit == eUnit_Transform || aUnit == eUnit_BackgroundPosition;
}
static bool IsCSSValuePairListUnit(Unit aUnit) {
return aUnit == eUnit_CSSValuePairList;
}
static bool IsStringUnit(Unit aUnit) {
return aUnit == eUnit_UnparsedString;
}
};
};
#endif