/*
* Copyright 2011 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkFontMgr_android_parser_DEFINED
#define SkFontMgr_android_parser_DEFINED
#include "SkFontMgr.h"
#include "SkString.h"
#include "SkTArray.h"
#include "SkTDArray.h"
#include "SkTHash.h"
#include "SkTypes.h"
#include <climits>
#include <limits>
/** \class SkLanguage
The SkLanguage class represents a human written language, and is used by
text draw operations to determine which glyph to draw when drawing
characters with variants (ie Han-derived characters).
*/
class SkLanguage {
public:
SkLanguage() { }
SkLanguage(const SkString& tag) : fTag(tag) { }
SkLanguage(const char* tag) : fTag(tag) { }
SkLanguage(const char* tag, size_t len) : fTag(tag, len) { }
SkLanguage(const SkLanguage& b) : fTag(b.fTag) { }
/** Gets a BCP 47 language identifier for this SkLanguage.
@return a BCP 47 language identifier representing this language
*/
const SkString& getTag() const { return fTag; }
/** Performs BCP 47 fallback to return an SkLanguage one step more general.
@return an SkLanguage one step more general
*/
SkLanguage getParent() const;
bool operator==(const SkLanguage& b) const {
return fTag == b.fTag;
}
bool operator!=(const SkLanguage& b) const {
return fTag != b.fTag;
}
SkLanguage& operator=(const SkLanguage& b) {
fTag = b.fTag;
return *this;
}
private:
//! BCP 47 language identifier
SkString fTag;
};
enum FontVariants {
kDefault_FontVariant = 0x01,
kCompact_FontVariant = 0x02,
kElegant_FontVariant = 0x04,
kLast_FontVariant = kElegant_FontVariant,
};
typedef uint32_t FontVariant;
// Must remain trivially movable (can be memmoved).
struct FontFileInfo {
FontFileInfo() : fIndex(0), fWeight(0), fStyle(Style::kAuto) { }
SkString fFileName;
int fIndex;
int fWeight;
enum class Style { kAuto, kNormal, kItalic } fStyle;
SkTArray<SkFontArguments::VariationPosition::Coordinate, true> fVariationDesignPosition;
};
/**
* A font family provides one or more names for a collection of fonts, each of
* which has a different style (normal, italic) or weight (thin, light, bold,
* etc).
* Some fonts may occur in compact variants for use in the user interface.
* Android distinguishes "fallback" fonts to support non-ASCII character sets.
*/
struct FontFamily {
FontFamily(const SkString& basePath, bool isFallbackFont)
: fVariant(kDefault_FontVariant)
, fOrder(-1)
, fIsFallbackFont(isFallbackFont)
, fBasePath(basePath)
{ }
SkTArray<SkString, true> fNames;
SkTArray<FontFileInfo, true> fFonts;
SkTArray<SkLanguage, true> fLanguages;
SkTHashMap<SkString, std::unique_ptr<FontFamily>> fallbackFamilies;
FontVariant fVariant;
int fOrder; // internal to the parser, not useful to users.
bool fIsFallbackFont;
SkString fFallbackFor;
const SkString fBasePath;
};
namespace SkFontMgr_Android_Parser {
/** Parses system font configuration files and appends result to fontFamilies. */
void GetSystemFontFamilies(SkTDArray<FontFamily*>& fontFamilies);
/** Parses font configuration files and appends result to fontFamilies. */
void GetCustomFontFamilies(SkTDArray<FontFamily*>& fontFamilies,
const SkString& basePath,
const char* fontsXml,
const char* fallbackFontsXml,
const char* langFallbackFontsDir = nullptr);
} // SkFontMgr_Android_Parser namespace
/** Parses a null terminated string into an integer type, checking for overflow.
* http://www.w3.org/TR/html-markup/datatypes.html#common.data.integer.non-negative-def
*
* If the string cannot be parsed into 'value', returns false and does not change 'value'.
*/
template <typename T> static bool parse_non_negative_integer(const char* s, T* value) {
static_assert(std::numeric_limits<T>::is_integer, "T_must_be_integer");
if (*s == '\0') {
return false;
}
const T nMax = std::numeric_limits<T>::max() / 10;
const T dMax = std::numeric_limits<T>::max() - (nMax * 10);
T n = 0;
for (; *s; ++s) {
// Check if digit
if (*s < '0' || '9' < *s) {
return false;
}
T d = *s - '0';
// Check for overflow
if (n > nMax || (n == nMax && d > dMax)) {
return false;
}
n = (n * 10) + d;
}
*value = n;
return true;
}
/** Parses a null terminated string into a signed fixed point value with bias N.
*
* Like http://www.w3.org/TR/html-markup/datatypes.html#common.data.float-def ,
* but may start with '.' and does not support 'e'. '-?((:digit:+(.:digit:+)?)|(.:digit:+))'
*
* Checks for overflow.
* Low bit rounding is not defined (is currently truncate).
* Bias (N) required to allow for the sign bit and 4 bits of integer.
*
* If the string cannot be parsed into 'value', returns false and does not change 'value'.
*/
template <int N, typename T> static bool parse_fixed(const char* s, T* value) {
static_assert(std::numeric_limits<T>::is_integer, "T_must_be_integer");
static_assert(std::numeric_limits<T>::is_signed, "T_must_be_signed");
static_assert(sizeof(T) * CHAR_BIT - N >= 5, "N_must_leave_four_bits_plus_sign");
bool negate = false;
if (*s == '-') {
++s;
negate = true;
}
if (*s == '\0') {
return false;
}
const T nMax = (std::numeric_limits<T>::max() >> N) / 10;
const T dMax = (std::numeric_limits<T>::max() >> N) - (nMax * 10);
T n = 0;
T frac = 0;
for (; *s; ++s) {
// Check if digit
if (*s < '0' || '9' < *s) {
// If it wasn't a digit, check if it is a '.' followed by something.
if (*s != '.' || s[1] == '\0') {
return false;
}
// Find the end, verify digits.
for (++s; *s; ++s) {
if (*s < '0' || '9' < *s) {
return false;
}
}
// Read back toward the '.'.
for (--s; *s != '.'; --s) {
T d = *s - '0';
frac = (frac + (d << N)) / 10; // This requires four bits overhead.
}
break;
}
T d = *s - '0';
// Check for overflow
if (n > nMax || (n == nMax && d > dMax)) {
return false;
}
n = (n * 10) + d;
}
if (negate) {
n = -n;
frac = -frac;
}
*value = SkLeftShift(n, N) + frac;
return true;
}
#endif /* SkFontMgr_android_parser_DEFINED */