gecko-dev/content/shared/public/nsHTMLValue.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: NPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Netscape 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/NPL/
*
* 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 mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
*
* 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 NPL, 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 NPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef nsHTMLValue_h___
#define nsHTMLValue_h___
#include "nscore.h"
#include "nsColor.h"
#include "nsString.h"
#include "nsISupports.h"
#include "nsCOMPtr.h"
#include "nsReadableUtils.h"
#include "nsCRT.h"
class nsIDocument;
class nsCheapStringBufferUtils {
public:
/**
* Get the string pointer
* @param aBuf the buffer
* @return a pointer to the string
*/
static const PRUnichar* StrPtr(const PRUnichar* aBuf) {
NS_ASSERTION(aBuf, "Cannot work on null buffer!");
return (const PRUnichar*)( ((const char*)aBuf) + sizeof(PRUint32) );
}
static PRUnichar* StrPtr(PRUnichar* aBuf) {
NS_ASSERTION(aBuf, "Cannot work on null buffer!");
return (PRUnichar*)( ((char*)aBuf) + sizeof(PRUint32) );
}
/**
* Get the string length
* @param aBuf the buffer
* @return the string length
*/
static PRUint32 Length(const PRUnichar* aBuf) {
NS_ASSERTION(aBuf, "Cannot work on null buffer!");
return *((PRUint32*)aBuf);
}
/**
* Get a DependentString from a buffer
*
* @param aBuf the buffer to get string from
* @return a DependentString representing this string
*/
static nsDependentSingleFragmentSubstring GetDependentString(const PRUnichar* aBuf) {
NS_ASSERTION(aBuf, "Cannot work on null buffer!");
const PRUnichar* buf = StrPtr(aBuf);
return Substring(buf, buf + Length(aBuf));
}
/**
* Construct from an AString
* @param aBuf the buffer to copy to
* @param aStr the string to construct from
*/
static void CopyToBuffer(PRUnichar*& aBuf, const nsAString& aStr) {
PRUint32 len = aStr.Length();
aBuf = (PRUnichar*)nsMemory::Alloc(sizeof(PRUint32) +
len * sizeof(PRUnichar));
*((PRUint32*)aBuf) = len;
CopyUnicodeTo(aStr, 0, StrPtr(aBuf), len);
}
/**
* Construct from another nsCheapStringBuffer
* @param aBuf the buffer to put into
* @param aSrc the buffer to construct from
*/
static void Clone(PRUnichar*& aBuf, const PRUnichar* aSrc) {
NS_ASSERTION(aSrc, "Cannot work on null buffer!");
aBuf = (PRUnichar*)nsMemory::Clone(aSrc, sizeof(PRUint32) +
Length(aSrc) * sizeof(PRUnichar));
}
/**
* Free the memory for the buf
* @param aBuf the buffer to free
*/
static void Free(PRUnichar* aBuf) {
NS_ASSERTION(aBuf, "Cannot work on null buffer!");
nsMemory::Free(aBuf);
}
/**
* Get a hashcode for the buffer
* @param aBuf the buffer
* @return the hashcode
*/
static PRUint32 HashCode(const PRUnichar* aBuf) {
NS_ASSERTION(aBuf, "Cannot work on null buffer!");
return nsCRT::BufferHashCode((char*)StrPtr(aBuf),
Length(aBuf)*sizeof(PRUnichar));
}
};
//
// nsHTMLUnit is two bytes: the class of type, and a specifier to distinguish
// between different things stored as the same type. Doing
// mUnit & HTMLUNIT_CLASS_MASK should give you the class of type.
//
#define HTMLUNIT_NOSTORE 0x0000
#define HTMLUNIT_STRING 0x0100
#define HTMLUNIT_INTEGER 0x0200
#define HTMLUNIT_PIXEL 0x0400
#define HTMLUNIT_COLOR 0x0800
#define HTMLUNIT_ISUPPORTS 0x1000
#define HTMLUNIT_PERCENT 0x2000
#define HTMLUNIT_CLASS_MASK 0xff00
enum nsHTMLUnit {
// null, value is not specified: 0x0000
eHTMLUnit_Null = HTMLUNIT_NOSTORE,
// empty, value is not specified: 0x0001
eHTMLUnit_Empty = HTMLUNIT_NOSTORE | 1,
// a string value
eHTMLUnit_String = HTMLUNIT_STRING,
// a color name value
eHTMLUnit_ColorName = HTMLUNIT_STRING | 1,
// a simple int value
eHTMLUnit_Integer = HTMLUNIT_INTEGER,
// value has enumerated meaning
eHTMLUnit_Enumerated = HTMLUNIT_INTEGER | 1,
// value is a relative proportion of some whole
eHTMLUnit_Proportional = HTMLUNIT_INTEGER | 2,
// screen pixels (screen relative measure)
eHTMLUnit_Pixel = HTMLUNIT_PIXEL,
// an RGBA value
eHTMLUnit_Color = HTMLUNIT_COLOR,
// (nsISupports*) a ref counted interface
eHTMLUnit_ISupports = HTMLUNIT_ISUPPORTS,
// (1.0 == 100%) value is percentage of something
eHTMLUnit_Percent = HTMLUNIT_PERCENT
};
/**
* Class which is used to represent the value of an attribute of an
* HTML element. The value has a unit which is an nsHTMLUnit;
* checking the unit is a must before asking for the value in any
* particular form.
*/
class nsHTMLValue {
public:
nsHTMLValue(nsHTMLUnit aUnit = eHTMLUnit_Null);
nsHTMLValue(PRInt32 aValue, nsHTMLUnit aUnit);
nsHTMLValue(float aValue);
nsHTMLValue(const nsAString& aValue, nsHTMLUnit aUnit = eHTMLUnit_String);
nsHTMLValue(nsISupports* aValue);
nsHTMLValue(nscolor aValue);
nsHTMLValue(const nsHTMLValue& aCopy);
~nsHTMLValue(void);
nsHTMLValue& operator=(const nsHTMLValue& aCopy);
PRBool operator==(const nsHTMLValue& aOther) const;
PRBool operator!=(const nsHTMLValue& aOther) const;
PRUint32 HashValue(void) const;
/**
* Get the unit of this HTMLValue
* @return the unit of this HTMLValue
*/
nsHTMLUnit GetUnit(void) const { return (nsHTMLUnit)mUnit; }
PRInt32 GetIntValue(void) const;
PRInt32 GetPixelValue(void) const;
float GetPercentValue(void) const;
nsAString& GetStringValue(nsAString& aBuffer) const;
already_AddRefed<nsISupports> GetISupportsValue(void) const;
nscolor GetColorValue(void) const;
/**
* Reset the string to null type, freeing things in the process if necessary.
*/
void Reset(void);
void SetIntValue(PRInt32 aValue, nsHTMLUnit aUnit);
void SetPixelValue(PRInt32 aValue);
void SetPercentValue(float aValue);
void SetStringValue(const nsAString& aValue, nsHTMLUnit aUnit = eHTMLUnit_String);
void SetISupportsValue(nsISupports* aValue);
void SetColorValue(nscolor aValue);
void SetEmptyValue(void);
/**
* Get this HTML value as a string (depends on the type)
* @param aResult the resulting string
* @return whether the value was successfully turned to a string
*/
PRBool ToString(nsAString& aResult) const;
#ifdef DEBUG
void AppendToString(nsAString& aBuffer) const;
#endif
/**
* Structure for a mapping from int (enum) values to strings. When you use
* it you generally create an array of them.
* Instantiate like this:
* EnumTable myTable[] = {
* { "string1", 1 },
* { "string2", 2 },
* { 0 }
* }
*/
struct EnumTable {
/** The string the value maps to */
const char* tag;
/** The enum value that maps to this string */
PRInt32 value;
};
/**
* Parse and output this HTMLValue in a variety of ways
*/
// Attribute parsing utilities
/**
* Map a string to its enum value and return result as HTMLValue
* (case-insensitive matching)
*
* @param aValue the string to find the value for
* @param aTable the enumeration to map with
* @param aResult the enum mapping [OUT]
* @return whether the enum value was found or not
*/
PRBool ParseEnumValue(const nsAString& aValue,
const EnumTable* aTable,
PRBool aCaseSensitive = PR_FALSE);
/**
* Map an enum HTMLValue to its string
*
* @param aValue the HTMLValue with the int in it
* @param aTable the enumeration to map with
* @param aResult the string the value maps to [OUT]
* @return whether the enum value was found or not
*/
PRBool EnumValueToString(const EnumTable* aTable,
nsAString& aResult) const;
/**
* Parse a string value into an int or pixel HTMLValue.
*
* @param aString the string to parse
* @param aDefaultUnit the unit to use (eHTMLUnit_Pixel or Integer)
* @return whether the value could be parsed
*/
PRBool ParseIntValue(const nsAString& aString, nsHTMLUnit aDefaultUnit) {
return ParseIntWithBounds(aString, aDefaultUnit, PR_INT32_MIN, PR_INT32_MAX);
}
/**
* Parse a string value into an int or pixel HTMLValue with minimum
* value and maximum value (can optionally parse percent (n%) and
* proportional (n%). This method explicitly sets a lower bound of zero on
* the element, whether it be proportional or percent or raw integer.
*
* @param aString the string to parse
* @param aDefaultUnit the unit to use (eHTMLUnit_Pixel or Integer)
* @param aCanBePercent true if it can be a percent value (%)
* @param aCanBeProportional true if it can be a proportional value (*)
* @return whether the value could be parsed
*/
PRBool ParseSpecialIntValue(const nsAString& aString, nsHTMLUnit aDefaultUnit,
PRBool aCanBePercent,
PRBool aCanBeProportional);
/**
* Parse a string value into an int or pixel HTMLValue with minimum
* value and maximum value
*
* @param aString the string to parse
* @param aMin the minimum value (if value is less it will be bumped up)
* @param aMax the maximum value (if value is greater it will be chopped down)
* @param aValueUnit the unit to use (eHTMLUnit_Pixel or Integer)
* @return whether the value could be parsed
*/
PRBool ParseIntWithBounds(const nsAString& aString, nsHTMLUnit aValueUnit,
PRInt32 aMin, PRInt32 aMax = PR_INT32_MAX);
/**
* Parse a string into a color HTMLValue (with hexes or color names)
*
* @param aString the string to parse
* @param aDocument the document (to find out whether we're in quirks mode)
* @param aResult the resulting HTMLValue [OUT]
* @return whether the value could be parsed
*/
PRBool ParseColor(const nsAString& aString, nsIDocument* aDocument);
protected:
/**
* The unit of the value
* @see nsHTMLUnit
*/
PRUint32 mUnit;
/**
* The actual value. Please to not be adding more-than-4-byte things to this
* union.
*/
union {
/** Int. */
PRInt32 mInt;
/** Float. */
float mFloat;
/** String. First 4 bytes are the length, non-null-terminated. */
PRUnichar* mString;
/** ISupports. Strong reference. */
nsISupports* mISupports;
/** Color. */
nscolor mColor;
} mValue;
private:
/**
* Copy into this HTMLValue from aCopy. Please be aware that if this is an
* existing HTMLValue and you do not call Reset(), this will leak.
* @param aCopy the value to copy
*/
void InitializeFrom(const nsHTMLValue& aCopy);
/**
* Helper to set string value (checks for embedded nulls or length); verifies
* that aUnit is a string type as well.
* @param aValue the value to set
* @param aUnit the unit to set
*/
void SetStringValueInternal(const nsAString& aValue, nsHTMLUnit aUnit);
/**
* Get a DependentString from mValue.mString (if the string is stored with
* length, passes that information to the DependentString). Do not call this
* if mValue.mString is null.
*
* @return a DependentString representing this string
*/
nsDependentSingleFragmentSubstring GetDependentString() const;
/**
* Get the unit class (HTMLUNIT_*)
* @return the unit class
*/
PRUint32 GetUnitClass() const { return mUnit & HTMLUNIT_CLASS_MASK; }
};
inline nsDependentSingleFragmentSubstring nsHTMLValue::GetDependentString() const
{
NS_ASSERTION(GetUnitClass() == HTMLUNIT_STRING,
"Some dork called GetDependentString() on a non-string!");
static const PRUnichar blankStr[] = { '\0' };
return mValue.mString
? nsCheapStringBufferUtils::GetDependentString(mValue.mString)
: Substring(blankStr, blankStr);
}
inline PRInt32 nsHTMLValue::GetIntValue(void) const
{
NS_ASSERTION(GetUnitClass() == HTMLUNIT_STRING ||
GetUnitClass() == HTMLUNIT_INTEGER,
"not an int value");
PRUint32 unitClass = GetUnitClass();
if (unitClass == HTMLUNIT_INTEGER) {
return mValue.mInt;
}
if (unitClass == HTMLUNIT_STRING) {
if (mValue.mString) {
PRInt32 err=0;
// XXX this copies. new string APIs will make this better, right?
nsAutoString str(GetDependentString());
return str.ToInteger(&err);
}
}
return 0;
}
inline PRInt32 nsHTMLValue::GetPixelValue(void) const
{
NS_ASSERTION((mUnit == eHTMLUnit_Pixel), "not a pixel value");
if (mUnit == eHTMLUnit_Pixel) {
return mValue.mInt;
}
return 0;
}
inline float nsHTMLValue::GetPercentValue(void) const
{
NS_ASSERTION(mUnit == eHTMLUnit_Percent, "not a percent value");
if (mUnit == eHTMLUnit_Percent) {
return mValue.mFloat;
}
return 0.0f;
}
inline nsAString& nsHTMLValue::GetStringValue(nsAString& aBuffer) const
{
NS_ASSERTION(GetUnitClass() == HTMLUNIT_STRING || mUnit == eHTMLUnit_Null,
"not a string value");
if (GetUnitClass() == HTMLUNIT_STRING && mValue.mString) {
aBuffer = GetDependentString();
} else {
aBuffer.Truncate();
}
return aBuffer;
}
inline already_AddRefed<nsISupports> nsHTMLValue::GetISupportsValue(void) const
{
NS_ASSERTION(mUnit == eHTMLUnit_ISupports, "not an ISupports value");
if (mUnit == eHTMLUnit_ISupports) {
nsISupports *result = mValue.mISupports;
NS_IF_ADDREF(result);
return result;
}
return nsnull;
}
inline nscolor nsHTMLValue::GetColorValue(void) const
{
NS_ASSERTION((mUnit == eHTMLUnit_Color) || (mUnit == eHTMLUnit_ColorName),
"not a color value");
if (mUnit == eHTMLUnit_Color) {
return mValue.mColor;
}
if (mUnit == eHTMLUnit_ColorName) {
nscolor color;
if (NS_ColorNameToRGB(GetDependentString(), &color)) {
return color;
}
}
return NS_RGB(0,0,0);
}
inline PRBool nsHTMLValue::operator!=(const nsHTMLValue& aOther) const
{
return PRBool(! ((*this) == aOther));
}
#endif /* nsHTMLValue_h___ */