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// Copyright (c) 2010 LearnBoost <tj@learnboost.com>
#include "Canvas.h"
#include "InstanceData.h"
#include <algorithm> // std::min
#include <assert.h>
#include <cairo-pdf.h>
#include <cairo-svg.h>
#include "CanvasRenderingContext2d.h"
#include "closure.h"
#include <cstring>
#include <cctype>
#include <ctime>
#include <glib.h>
#include "PNG.h"
#include "register_font.h"
#include <sstream>
#include <stdlib.h>
#include <string>
#include <unordered_set>
#include "Util.h"
#include <vector>
#include "node_buffer.h"
#include "FontParser.h"
#ifdef HAVE_JPEG
#include "JPEGStream.h"
#endif
#include "backend/ImageBackend.h"
#include "backend/PdfBackend.h"
#include "backend/SvgBackend.h"
#define GENERIC_FACE_ERROR \
"The second argument to registerFont is required, and should be an object " \
"with at least a family (string) and optionally weight (string/number) " \
"and style (string)."
using namespace std;
std::vector<FontFace> Canvas::font_face_list;
// Increases each time a font is (de)registered
int Canvas::fontSerial = 1;
/*
* Initialize Canvas.
*/
void
Canvas::Initialize(Napi::Env& env, Napi::Object& exports) {
Napi::HandleScope scope(env);
InstanceData* data = env.GetInstanceData<InstanceData>();
// Constructor
Napi::Function ctor = DefineClass(env, "Canvas", {
InstanceMethod<&Canvas::ToBuffer>("toBuffer", napi_default_method),
InstanceMethod<&Canvas::StreamPNGSync>("streamPNGSync", napi_default_method),
InstanceMethod<&Canvas::StreamPDFSync>("streamPDFSync", napi_default_method),
#ifdef HAVE_JPEG
InstanceMethod<&Canvas::StreamJPEGSync>("streamJPEGSync", napi_default_method),
#endif
InstanceAccessor<&Canvas::GetType>("type", napi_default_jsproperty),
InstanceAccessor<&Canvas::GetStride>("stride", napi_default_jsproperty),
InstanceAccessor<&Canvas::GetWidth, &Canvas::SetWidth>("width", napi_default_jsproperty),
InstanceAccessor<&Canvas::GetHeight, &Canvas::SetHeight>("height", napi_default_jsproperty),
StaticValue("PNG_NO_FILTERS", Napi::Number::New(env, PNG_NO_FILTERS), napi_default_jsproperty),
StaticValue("PNG_FILTER_NONE", Napi::Number::New(env, PNG_FILTER_NONE), napi_default_jsproperty),
StaticValue("PNG_FILTER_SUB", Napi::Number::New(env, PNG_FILTER_SUB), napi_default_jsproperty),
StaticValue("PNG_FILTER_UP", Napi::Number::New(env, PNG_FILTER_UP), napi_default_jsproperty),
StaticValue("PNG_FILTER_AVG", Napi::Number::New(env, PNG_FILTER_AVG), napi_default_jsproperty),
StaticValue("PNG_FILTER_PAETH", Napi::Number::New(env, PNG_FILTER_PAETH), napi_default_jsproperty),
StaticValue("PNG_ALL_FILTERS", Napi::Number::New(env, PNG_ALL_FILTERS), napi_default_jsproperty),
StaticMethod<&Canvas::RegisterFont>("_registerFont", napi_default_method),
StaticMethod<&Canvas::DeregisterAllFonts>("_deregisterAllFonts", napi_default_method),
StaticMethod<&Canvas::ParseFont>("parseFont", napi_default_method)
});
data->CanvasCtor = Napi::Persistent(ctor);
exports.Set("Canvas", ctor);
}
/*
* Initialize a Canvas with the given width and height.
*/
Canvas::Canvas(const Napi::CallbackInfo& info) : Napi::ObjectWrap<Canvas>(info), env(info.Env()) {
InstanceData* data = env.GetInstanceData<InstanceData>();
ctor = Napi::Persistent(data->CanvasCtor.Value());
Backend* backend = NULL;
Napi::Object jsBackend;
if (info[0].IsNumber()) {
Napi::Number width = info[0].As<Napi::Number>();
Napi::Number height = Napi::Number::New(env, 0);
if (info[1].IsNumber()) height = info[1].As<Napi::Number>();
if (info[2].IsString()) {
std::string str = info[2].As<Napi::String>();
if (str == "pdf") {
Napi::Maybe<Napi::Object> instance = data->PdfBackendCtor.New({ width, height });
if (instance.IsJust()) backend = PdfBackend::Unwrap(jsBackend = instance.Unwrap());
} else if (str == "svg") {
Napi::Maybe<Napi::Object> instance = data->SvgBackendCtor.New({ width, height });
if (instance.IsJust()) backend = SvgBackend::Unwrap(jsBackend = instance.Unwrap());
} else {
Napi::Maybe<Napi::Object> instance = data->ImageBackendCtor.New({ width, height });
if (instance.IsJust()) backend = ImageBackend::Unwrap(jsBackend = instance.Unwrap());
}
} else {
Napi::Maybe<Napi::Object> instance = data->ImageBackendCtor.New({ width, height });
if (instance.IsJust()) backend = ImageBackend::Unwrap(jsBackend = instance.Unwrap());
}
} else if (info[0].IsObject()) {
jsBackend = info[0].As<Napi::Object>();
if (jsBackend.InstanceOf(data->ImageBackendCtor.Value()).UnwrapOr(false)) {
backend = ImageBackend::Unwrap(jsBackend);
} else if (jsBackend.InstanceOf(data->PdfBackendCtor.Value()).UnwrapOr(false)) {
backend = PdfBackend::Unwrap(jsBackend);
} else if (jsBackend.InstanceOf(data->SvgBackendCtor.Value()).UnwrapOr(false)) {
backend = SvgBackend::Unwrap(jsBackend);
} else {
Napi::TypeError::New(env, "Invalid arguments").ThrowAsJavaScriptException();
return;
}
} else {
Napi::Number width = Napi::Number::New(env, 0);
Napi::Number height = Napi::Number::New(env, 0);
Napi::Maybe<Napi::Object> instance = data->ImageBackendCtor.New({ width, height });
if (instance.IsJust()) backend = ImageBackend::Unwrap(jsBackend = instance.Unwrap());
}
backend->setCanvas(this);
if (!backend->isSurfaceValid()) {
Napi::Error::New(env, backend->getError()).ThrowAsJavaScriptException();
return;
}
// Note: the backend gets destroyed when the jsBackend is GC'd. The cleaner
// way would be to only store the jsBackend and unwrap it when the c++ ref is
// needed, but that's slower and a burden. The _backend might be null if we
// returned early, but since an exception was thrown it gets destroyed soon.
_backend = backend;
_jsBackend = Napi::Persistent(jsBackend);
}
/*
* Get type string.
*/
Napi::Value
Canvas::GetType(const Napi::CallbackInfo& info) {
return Napi::String::New(env, backend()->getName());
}
/*
* Get stride.
*/
Napi::Value
Canvas::GetStride(const Napi::CallbackInfo& info) {
return Napi::Number::New(env, stride());
}
/*
* Get width.
*/
Napi::Value
Canvas::GetWidth(const Napi::CallbackInfo& info) {
return Napi::Number::New(env, getWidth());
}
/*
* Set width.
*/
void
Canvas::SetWidth(const Napi::CallbackInfo& info, const Napi::Value& value) {
if (value.IsNumber()) {
backend()->setWidth(value.As<Napi::Number>().Uint32Value());
resurface(info.This().As<Napi::Object>());
}
}
/*
* Get height.
*/
Napi::Value
Canvas::GetHeight(const Napi::CallbackInfo& info) {
return Napi::Number::New(env, getHeight());
}
/*
* Set height.
*/
void
Canvas::SetHeight(const Napi::CallbackInfo& info, const Napi::Value& value) {
if (value.IsNumber()) {
backend()->setHeight(value.As<Napi::Number>().Uint32Value());
resurface(info.This().As<Napi::Object>());
}
}
/*
* EIO toBuffer callback.
*/
void
Canvas::ToPngBufferAsync(Closure* base) {
PngClosure* closure = static_cast<PngClosure*>(base);
closure->status = canvas_write_to_png_stream(
closure->canvas->surface(),
PngClosure::writeVec,
closure);
}
#ifdef HAVE_JPEG
void
Canvas::ToJpegBufferAsync(Closure* base) {
JpegClosure* closure = static_cast<JpegClosure*>(base);
write_to_jpeg_buffer(closure->canvas->surface(), closure);
}
#endif
static void
parsePNGArgs(Napi::Value arg, PngClosure& pngargs) {
if (arg.IsObject()) {
Napi::Object obj = arg.As<Napi::Object>();
Napi::Value cLevel;
if (obj.Get("compressionLevel").UnwrapTo(&cLevel) && cLevel.IsNumber()) {
uint32_t val = cLevel.As<Napi::Number>().Uint32Value();
// See quote below from spec section 4.12.5.5.
if (val <= 9) pngargs.compressionLevel = val;
}
Napi::Value rez;
if (obj.Get("resolution").UnwrapTo(&rez) && rez.IsNumber()) {
uint32_t val = rez.As<Napi::Number>().Uint32Value();
if (val > 0) pngargs.resolution = val;
}
Napi::Value filters;
if (obj.Get("filters").UnwrapTo(&filters) && filters.IsNumber()) {
pngargs.filters = filters.As<Napi::Number>().Uint32Value();
}
Napi::Value palette;
if (obj.Get("palette").UnwrapTo(&palette) && palette.IsTypedArray()) {
Napi::TypedArray palette_ta = palette.As<Napi::TypedArray>();
if (palette_ta.TypedArrayType() == napi_uint8_clamped_array) {
pngargs.nPaletteColors = palette_ta.ElementLength();
if (pngargs.nPaletteColors % 4 != 0) {
throw "Palette length must be a multiple of 4.";
}
pngargs.palette = palette_ta.As<Napi::Uint8Array>().Data();
pngargs.nPaletteColors /= 4;
// Optional background color index:
Napi::Value backgroundIndexVal;
if (obj.Get("backgroundIndex").UnwrapTo(&backgroundIndexVal) && backgroundIndexVal.IsNumber()) {
pngargs.backgroundIndex = backgroundIndexVal.As<Napi::Number>().Uint32Value();
}
}
}
}
}
#ifdef HAVE_JPEG
static void parseJPEGArgs(Napi::Value arg, JpegClosure& jpegargs) {
// "If Type(quality) is not Number, or if quality is outside that range, the
// user agent must use its default quality value, as if the quality argument
// had not been given." - 4.12.5.5
if (arg.IsObject()) {
Napi::Object obj = arg.As<Napi::Object>();
Napi::Value qual;
if (obj.Get("quality").UnwrapTo(&qual) && qual.IsNumber()) {
double quality = qual.As<Napi::Number>().DoubleValue();
if (quality >= 0.0 && quality <= 1.0) {
jpegargs.quality = static_cast<uint32_t>(100.0 * quality);
}
}
Napi::Value chroma;
if (obj.Get("chromaSubsampling").UnwrapTo(&chroma)) {
if (chroma.IsBoolean()) {
bool subsample = chroma.As<Napi::Boolean>().Value();
jpegargs.chromaSubsampling = subsample ? 2 : 1;
} else if (chroma.IsNumber()) {
jpegargs.chromaSubsampling = chroma.As<Napi::Number>().Uint32Value();
}
}
Napi::Value progressive;
if (obj.Get("progressive").UnwrapTo(&progressive) && progressive.IsBoolean()) {
jpegargs.progressive = progressive.As<Napi::Boolean>().Value();
}
}
}
#endif
#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 16, 0)
static inline void setPdfMetaStr(cairo_surface_t* surf, Napi::Object opts,
cairo_pdf_metadata_t t, const char* propName) {
Napi::Value propValue;
if (opts.Get(propName).UnwrapTo(&propValue) && propValue.IsString()) {
// (copies char data)
cairo_pdf_surface_set_metadata(surf, t, propValue.As<Napi::String>().Utf8Value().c_str());
}
}
static inline void setPdfMetaDate(cairo_surface_t* surf, Napi::Object opts,
cairo_pdf_metadata_t t, const char* propName) {
Napi::Value propValue;
if (opts.Get(propName).UnwrapTo(&propValue) && propValue.IsDate()) {
auto date = static_cast<time_t>(propValue.As<Napi::Date>().ValueOf() / 1000); // ms -> s
char buf[sizeof "2011-10-08T07:07:09Z"];
strftime(buf, sizeof buf, "%FT%TZ", gmtime(&date));
cairo_pdf_surface_set_metadata(surf, t, buf);
}
}
static void setPdfMetadata(Canvas* canvas, Napi::Object opts) {
cairo_surface_t* surf = canvas->surface();
setPdfMetaStr(surf, opts, CAIRO_PDF_METADATA_TITLE, "title");
setPdfMetaStr(surf, opts, CAIRO_PDF_METADATA_AUTHOR, "author");
setPdfMetaStr(surf, opts, CAIRO_PDF_METADATA_SUBJECT, "subject");
setPdfMetaStr(surf, opts, CAIRO_PDF_METADATA_KEYWORDS, "keywords");
setPdfMetaStr(surf, opts, CAIRO_PDF_METADATA_CREATOR, "creator");
setPdfMetaDate(surf, opts, CAIRO_PDF_METADATA_CREATE_DATE, "creationDate");
setPdfMetaDate(surf, opts, CAIRO_PDF_METADATA_MOD_DATE, "modDate");
}
#endif // CAIRO 16+
/*
* Converts/encodes data to a Buffer. Async when a callback function is passed.
* PDF canvases:
(any) => Buffer
("application/pdf", config) => Buffer
* SVG canvases:
(any) => Buffer
* ARGB data:
("raw") => Buffer
* PNG-encoded
() => Buffer
(undefined|"image/png", {compressionLevel?: number, filter?: number}) => Buffer
((err: null|Error, buffer) => any)
((err: null|Error, buffer) => any, undefined|"image/png", {compressionLevel?: number, filter?: number})
* JPEG-encoded
("image/jpeg") => Buffer
("image/jpeg", {quality?: number, progressive?: Boolean, chromaSubsampling?: Boolean|number}) => Buffer
((err: null|Error, buffer) => any, "image/jpeg")
((err: null|Error, buffer) => any, "image/jpeg", {quality?: number, progressive?: Boolean, chromaSubsampling?: Boolean|number})
*/
Napi::Value
Canvas::ToBuffer(const Napi::CallbackInfo& info) {
cairo_status_t status;
// Vector canvases, sync only
const std::string name = backend()->getName();
if (name == "pdf" || name == "svg") {
// mime type may be present, but it's not checked
PdfSvgClosure* closure;
if (name == "pdf") {
closure = static_cast<PdfBackend*>(backend())->closure();
#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 16, 0)
if (info[1].IsObject()) { // toBuffer("application/pdf", config)
setPdfMetadata(this, info[1].As<Napi::Object>());
}
#endif // CAIRO 16+
} else {
closure = static_cast<SvgBackend*>(backend())->closure();
}
cairo_surface_t *surf = surface();
cairo_surface_finish(surf);
cairo_status_t status = cairo_surface_status(surf);
if (status != CAIRO_STATUS_SUCCESS) {
Napi::Error::New(env, cairo_status_to_string(status)).ThrowAsJavaScriptException();
return env.Undefined();
}
return Napi::Buffer<uint8_t>::Copy(env, &closure->vec[0], closure->vec.size());
}
// Raw ARGB data -- just a memcpy()
if (info[0].StrictEquals(Napi::String::New(env, "raw"))) {
cairo_surface_t *surface = this->surface();
cairo_surface_flush(surface);
if (nBytes() > node::Buffer::kMaxLength) {
Napi::Error::New(env, "Data exceeds maximum buffer length.").ThrowAsJavaScriptException();
return env.Undefined();
}
return Napi::Buffer<uint8_t>::Copy(env, cairo_image_surface_get_data(surface), nBytes());
}
// Sync PNG, default
if (info[0].IsUndefined() || info[0].StrictEquals(Napi::String::New(env, "image/png"))) {
try {
PngClosure closure(this);
parsePNGArgs(info[1], closure);
if (closure.nPaletteColors == 0xFFFFFFFF) {
Napi::Error::New(env, "Palette length must be a multiple of 4.").ThrowAsJavaScriptException();
return env.Undefined();
}
status = canvas_write_to_png_stream(surface(), PngClosure::writeVec, &closure);
if (!env.IsExceptionPending()) {
if (status) {
throw status; // TODO: throw in js?
} else {
// TODO it's possible to avoid this copy
return Napi::Buffer<uint8_t>::Copy(env, &closure.vec[0], closure.vec.size());
}
}
} catch (cairo_status_t ex) {
CairoError(ex).ThrowAsJavaScriptException();
} catch (const char* ex) {
Napi::Error::New(env, ex).ThrowAsJavaScriptException();
}
return env.Undefined();
}
// Async PNG
if (info[0].IsFunction() &&
(info[1].IsUndefined() || info[1].StrictEquals(Napi::String::New(env, "image/png")))) {
PngClosure* closure;
try {
closure = new PngClosure(this);
parsePNGArgs(info[2], *closure);
} catch (cairo_status_t ex) {
CairoError(ex).ThrowAsJavaScriptException();
return env.Undefined();
} catch (const char* ex) {
Napi::Error::New(env, ex).ThrowAsJavaScriptException();
return env.Undefined();
}
Ref();
closure->cb = Napi::Persistent(info[0].As<Napi::Function>());
// Make sure the surface exists since we won't have an isolate context in the async block:
surface();
EncodingWorker* worker = new EncodingWorker(env);
worker->Init(&ToPngBufferAsync, closure);
worker->Queue();
return env.Undefined();
}
#ifdef HAVE_JPEG
// Sync JPEG
Napi::Value jpegStr = Napi::String::New(env, "image/jpeg");
if (info[0].StrictEquals(jpegStr)) {
try {
JpegClosure closure(this);
parseJPEGArgs(info[1], closure);
write_to_jpeg_buffer(surface(), &closure);
if (!env.IsExceptionPending()) {
// TODO it's possible to avoid this copy.
return Napi::Buffer<uint8_t>::Copy(env, &closure.vec[0], closure.vec.size());
}
} catch (cairo_status_t ex) {
CairoError(ex).ThrowAsJavaScriptException();
return env.Undefined();
}
return env.Undefined();
}
// Async JPEG
if (info[0].IsFunction() && info[1].StrictEquals(jpegStr)) {
JpegClosure* closure = new JpegClosure(this);
parseJPEGArgs(info[2], *closure);
Ref();
closure->cb = Napi::Persistent(info[0].As<Napi::Function>());
// Make sure the surface exists since we won't have an isolate context in the async block:
surface();
EncodingWorker* worker = new EncodingWorker(env);
worker->Init(&ToJpegBufferAsync, closure);
worker->Queue();
return env.Undefined();
}
#endif
return env.Undefined();
}
/*
* Canvas::StreamPNG callback.
*/
static cairo_status_t
streamPNG(void *c, const uint8_t *data, unsigned len) {
PngClosure* closure = (PngClosure*) c;
Napi::Env env = closure->canvas->env;
Napi::HandleScope scope(env);
Napi::AsyncContext async(env, "canvas:StreamPNG");
Napi::Value buf = Napi::Buffer<uint8_t>::Copy(env, data, len);
closure->cb.MakeCallback(env.Global(), { env.Null(), buf, Napi::Number::New(env, len) }, async);
return CAIRO_STATUS_SUCCESS;
}
/*
* Stream PNG data synchronously. TODO async
* StreamPngSync(this, options: {palette?: Uint8ClampedArray, backgroundIndex?: uint32, compressionLevel: uint32, filters: uint32})
*/
void
Canvas::StreamPNGSync(const Napi::CallbackInfo& info) {
if (!info[0].IsFunction()) {
Napi::TypeError::New(env, "callback function required").ThrowAsJavaScriptException();
return;
}
PngClosure closure(this);
parsePNGArgs(info[1], closure);
closure.cb = Napi::Persistent(info[0].As<Napi::Function>());
cairo_status_t status = canvas_write_to_png_stream(surface(), streamPNG, &closure);
if (!env.IsExceptionPending()) {
if (status) {
closure.cb.Call(env.Global(), { CairoError(status).Value() });
} else {
closure.cb.Call(env.Global(), { env.Null(), env.Null(), Napi::Number::New(env, 0) });
}
}
}
struct PdfStreamInfo {
Napi::Function fn;
uint32_t len;
uint8_t* data;
};
/*
* Canvas::StreamPDF callback.
*/
static cairo_status_t
streamPDF(void *c, const uint8_t *data, unsigned len) {
PdfStreamInfo* streaminfo = static_cast<PdfStreamInfo*>(c);
Napi::Env env = streaminfo->fn.Env();
Napi::HandleScope scope(env);
Napi::AsyncContext async(env, "canvas:StreamPDF");
// TODO this is technically wrong, we're returning a pointer to the data in a
// vector in a class with automatic storage duration. If the canvas goes out
// of scope while we're in the handler, a use-after-free could happen.
Napi::Value buf = Napi::Buffer<uint8_t>::New(env, (uint8_t *)(data), len);
streaminfo->fn.MakeCallback(env.Global(), { env.Null(), buf, Napi::Number::New(env, len) }, async);
return CAIRO_STATUS_SUCCESS;
}
cairo_status_t canvas_write_to_pdf_stream(cairo_surface_t *surface, cairo_write_func_t write_func, PdfStreamInfo* streaminfo) {
size_t whole_chunks = streaminfo->len / PAGE_SIZE;
size_t remainder = streaminfo->len - whole_chunks * PAGE_SIZE;
for (size_t i = 0; i < whole_chunks; ++i) {
write_func(streaminfo, &streaminfo->data[i * PAGE_SIZE], PAGE_SIZE);
}
if (remainder) {
write_func(streaminfo, &streaminfo->data[whole_chunks * PAGE_SIZE], remainder);
}
return CAIRO_STATUS_SUCCESS;
}
/*
* Stream PDF data synchronously.
*/
void
Canvas::StreamPDFSync(const Napi::CallbackInfo& info) {
if (!info[0].IsFunction()) {
Napi::TypeError::New(env, "callback function required").ThrowAsJavaScriptException();
return;
}
if (backend()->getName() != "pdf") {
Napi::TypeError::New(env, "wrong canvas type").ThrowAsJavaScriptException();
return;
}
#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 16, 0)
if (info[1].IsObject()) {
setPdfMetadata(this, info[1].As<Napi::Object>());
}
#endif
cairo_surface_finish(surface());
PdfSvgClosure* closure = static_cast<PdfBackend*>(backend())->closure();
Napi::Function fn = info[0].As<Napi::Function>();
PdfStreamInfo streaminfo;
streaminfo.fn = fn;
streaminfo.data = &closure->vec[0];
streaminfo.len = closure->vec.size();
cairo_status_t status = canvas_write_to_pdf_stream(surface(), streamPDF, &streaminfo);
if (!env.IsExceptionPending()) {
if (status) {
fn.Call(env.Global(), { CairoError(status).Value() });
} else {
fn.Call(env.Global(), { env.Null(), env.Null(), Napi::Number::New(env, 0) });
}
}
}
/*
* Stream JPEG data synchronously.
*/
#ifdef HAVE_JPEG
static uint32_t getSafeBufSize(Canvas* canvas) {
// Don't allow the buffer size to exceed the size of the canvas (#674)
// TODO not sure if this is really correct, but it fixed #674
return (std::min)(canvas->getWidth() * canvas->getHeight() * 4, static_cast<int>(PAGE_SIZE));
}
void
Canvas::StreamJPEGSync(const Napi::CallbackInfo& info) {
if (!info[1].IsFunction()) {
Napi::TypeError::New(env, "callback function required").ThrowAsJavaScriptException();
return;
}
JpegClosure closure(this);
parseJPEGArgs(info[0], closure);
closure.cb = Napi::Persistent(info[1].As<Napi::Function>());
uint32_t bufsize = getSafeBufSize(this);
write_to_jpeg_stream(surface(), bufsize, &closure);
}
#endif
char *
str_value(Napi::Maybe<Napi::Value> maybe, const char *fallback, bool can_be_number) {
Napi::Value val;
if (maybe.UnwrapTo(&val)) {
if (val.IsString() || (can_be_number && val.IsNumber())) {
Napi::String strVal;
if (val.ToString().UnwrapTo(&strVal)) return strdup(strVal.Utf8Value().c_str());
} else if (fallback) {
return strdup(fallback);
}
}
return NULL;
}
void
Canvas::RegisterFont(const Napi::CallbackInfo& info) {
Napi::Env env = info.Env();
if (!info[0].IsString()) {
Napi::Error::New(env, "Wrong argument type").ThrowAsJavaScriptException();
return;
} else if (!info[1].IsObject()) {
Napi::Error::New(env, GENERIC_FACE_ERROR).ThrowAsJavaScriptException();
return;
}
std::string filePath = info[0].As<Napi::String>();
PangoFontDescription *sys_desc = get_pango_font_description((unsigned char *)(filePath.c_str()));
if (!sys_desc) {
Napi::Error::New(env, "Could not parse font file").ThrowAsJavaScriptException();
return;
}
PangoFontDescription *user_desc = pango_font_description_new();
// now check the attrs, there are many ways to be wrong
Napi::Object js_user_desc = info[1].As<Napi::Object>();
// TODO: use FontParser on these values just like the FontFace API works
char *family = str_value(js_user_desc.Get("family"), NULL, false);
char *weight = str_value(js_user_desc.Get("weight"), "normal", true);
char *style = str_value(js_user_desc.Get("style"), "normal", false);
if (family && weight && style) {
pango_font_description_set_weight(user_desc, Canvas::GetWeightFromCSSString(weight));
pango_font_description_set_style(user_desc, Canvas::GetStyleFromCSSString(style));
pango_font_description_set_family(user_desc, family);
auto found = std::find_if(font_face_list.begin(), font_face_list.end(), [&](FontFace& f) {
return pango_font_description_equal(f.sys_desc, sys_desc);
});
if (found != font_face_list.end()) {
pango_font_description_free(found->user_desc);
found->user_desc = user_desc;
} else if (register_font((unsigned char *) filePath.c_str())) {
FontFace face;
face.user_desc = user_desc;
face.sys_desc = sys_desc;
strncpy((char *)face.file_path, (char *) filePath.c_str(), 1023);
font_face_list.push_back(face);
} else {
pango_font_description_free(user_desc);
Napi::Error::New(env, "Could not load font to the system's font host").ThrowAsJavaScriptException();
}
} else {
pango_font_description_free(user_desc);
if (!env.IsExceptionPending()) {
Napi::Error::New(env, GENERIC_FACE_ERROR).ThrowAsJavaScriptException();
}
}
free(family);
free(weight);
free(style);
fontSerial++;
}
void
Canvas::DeregisterAllFonts(const Napi::CallbackInfo& info) {
Napi::Env env = info.Env();
// Unload all fonts from pango to free up memory
bool success = true;
std::for_each(font_face_list.begin(), font_face_list.end(), [&](FontFace& f) {
if (!deregister_font( (unsigned char *)f.file_path )) success = false;
pango_font_description_free(f.user_desc);
pango_font_description_free(f.sys_desc);
});
font_face_list.clear();
fontSerial++;
if (!success) Napi::Error::New(env, "Could not deregister one or more fonts").ThrowAsJavaScriptException();
}
/*
* Do not use! This is only exported for testing
*/
Napi::Value
Canvas::ParseFont(const Napi::CallbackInfo& info) {
Napi::Env env = info.Env();
if (info.Length() != 1) return env.Undefined();
Napi::String str;
if (!info[0].ToString().UnwrapTo(&str)) return env.Undefined();
bool ok;
auto props = FontParser::parse(str, &ok);
if (!ok) return env.Undefined();
Napi::Object obj = Napi::Object::New(env);
obj.Set("size", Napi::Number::New(env, props.fontSize));
Napi::Array families = Napi::Array::New(env);
obj.Set("families", families);
unsigned int index = 0;
for (auto& family : props.fontFamily) {
families[index++] = Napi::String::New(env, family);
}
obj.Set("weight", Napi::Number::New(env, props.fontWeight));
obj.Set("variant", Napi::Number::New(env, static_cast<int>(props.fontVariant)));
obj.Set("style", Napi::Number::New(env, static_cast<int>(props.fontStyle)));
return obj;
}
/*
* Get a PangoStyle from a CSS string (like "italic")
*/
PangoStyle
Canvas::GetStyleFromCSSString(const char *style) {
PangoStyle s = PANGO_STYLE_NORMAL;
if (strlen(style) > 0) {
if (0 == strcmp("italic", style)) {
s = PANGO_STYLE_ITALIC;
} else if (0 == strcmp("oblique", style)) {
s = PANGO_STYLE_OBLIQUE;
}
}
return s;
}
/*
* Get a PangoWeight from a CSS string ("bold", "100", etc)
*/
PangoWeight
Canvas::GetWeightFromCSSString(const char *weight) {
PangoWeight w = PANGO_WEIGHT_NORMAL;
if (strlen(weight) > 0) {
if (0 == strcmp("bold", weight)) {
w = PANGO_WEIGHT_BOLD;
} else if (0 == strcmp("100", weight)) {
w = PANGO_WEIGHT_THIN;
} else if (0 == strcmp("200", weight)) {
w = PANGO_WEIGHT_ULTRALIGHT;
} else if (0 == strcmp("300", weight)) {
w = PANGO_WEIGHT_LIGHT;
} else if (0 == strcmp("400", weight)) {
w = PANGO_WEIGHT_NORMAL;
} else if (0 == strcmp("500", weight)) {
w = PANGO_WEIGHT_MEDIUM;
} else if (0 == strcmp("600", weight)) {
w = PANGO_WEIGHT_SEMIBOLD;
} else if (0 == strcmp("700", weight)) {
w = PANGO_WEIGHT_BOLD;
} else if (0 == strcmp("800", weight)) {
w = PANGO_WEIGHT_ULTRABOLD;
} else if (0 == strcmp("900", weight)) {
w = PANGO_WEIGHT_HEAVY;
}
}
return w;
}
/*
* Given a user description, return a description that will select the
* font either from the system or @font-face
*/
PangoFontDescription *
Canvas::ResolveFontDescription(const PangoFontDescription *desc) {
// One of the user-specified families could map to multiple SFNT family names
// if someone registered two different fonts under the same family name.
// https://drafts.csswg.org/css-fonts-3/#font-style-matching
FontFace best;
istringstream families(pango_font_description_get_family(desc));
unordered_set<string> seen_families;
string resolved_families;
bool first = true;
for (string family; getline(families, family, ','); ) {
string renamed_families;
for (auto& ff : font_face_list) {
string pangofamily = string(pango_font_description_get_family(ff.user_desc));
if (streq_casein(family, pangofamily)) {
const char* sys_desc_family_name = pango_font_description_get_family(ff.sys_desc);
bool unseen = seen_families.find(sys_desc_family_name) == seen_families.end();
bool better = best.user_desc == nullptr || pango_font_description_better_match(desc, best.user_desc, ff.user_desc);
// Avoid sending duplicate SFNT font names due to a bug in Pango for macOS:
// https://bugzilla.gnome.org/show_bug.cgi?id=762873
if (unseen) {
seen_families.insert(sys_desc_family_name);
if (better) {
renamed_families = string(sys_desc_family_name) + (renamed_families.size() ? "," : "") + renamed_families;
} else {
renamed_families = renamed_families + (renamed_families.size() ? "," : "") + sys_desc_family_name;
}
}
if (first && better) best = ff;
}
}
if (resolved_families.size()) resolved_families += ',';
resolved_families += renamed_families.size() ? renamed_families : family;
first = false;
}
PangoFontDescription* ret = pango_font_description_copy(best.sys_desc ? best.sys_desc : desc);
pango_font_description_set_family(ret, resolved_families.c_str());
return ret;
}
/*
* Re-alloc the surface, destroying the previous.
*/
void
Canvas::resurface(Napi::Object This) {
Napi::HandleScope scope(env);
Napi::Value context;
if (This.Get("context").UnwrapTo(&context) && context.IsObject()) {
backend()->destroySurface();
backend()->ensureSurface();
// Reset context
Context2d *context2d = Context2d::Unwrap(context.As<Napi::Object>());
cairo_t *prev = context2d->context();
context2d->setContext(createCairoContext());
context2d->resetState();
cairo_destroy(prev);
}
}
/**
* Wrapper around cairo_create()
* (do not call cairo_create directly, call this instead)
*/
cairo_t*
Canvas::createCairoContext() {
cairo_t* ret = cairo_create(surface());
cairo_set_line_width(ret, 1); // Cairo defaults to 2
return ret;
}
/*
* Construct an Error from the given cairo status.
*/
Napi::Error
Canvas::CairoError(cairo_status_t status) {
return Napi::Error::New(env, cairo_status_to_string(status));
}