// Copyright (c) 2010 LearnBoost <tj@learnboost.com>
#include "Canvas.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"
#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)."
#define CHECK_RECEIVER(prop) \
if (!Canvas::constructor.Get(info.GetIsolate())->HasInstance(info.This())) { \
Nan::ThrowTypeError("Method " #prop " called on incompatible receiver"); \
return; \
}
using namespace v8;
using namespace std;
Nan::Persistent<FunctionTemplate> Canvas::constructor;
std::vector<FontFace> font_face_list;
/*
* Initialize Canvas.
*/
void
Canvas::Initialize(Nan::ADDON_REGISTER_FUNCTION_ARGS_TYPE target) {
Nan::HandleScope scope;
// Constructor
Local<FunctionTemplate> ctor = Nan::New<FunctionTemplate>(Canvas::New);
constructor.Reset(ctor);
ctor->InstanceTemplate()->SetInternalFieldCount(1);
ctor->SetClassName(Nan::New("Canvas").ToLocalChecked());
// Prototype
Local<ObjectTemplate> proto = ctor->PrototypeTemplate();
Nan::SetPrototypeMethod(ctor, "toBuffer", ToBuffer);
Nan::SetPrototypeMethod(ctor, "streamPNGSync", StreamPNGSync);
Nan::SetPrototypeMethod(ctor, "streamPDFSync", StreamPDFSync);
#ifdef HAVE_JPEG
Nan::SetPrototypeMethod(ctor, "streamJPEGSync", StreamJPEGSync);
#endif
Nan::SetAccessor(proto, Nan::New("type").ToLocalChecked(), GetType);
Nan::SetAccessor(proto, Nan::New("stride").ToLocalChecked(), GetStride);
Nan::SetAccessor(proto, Nan::New("width").ToLocalChecked(), GetWidth, SetWidth);
Nan::SetAccessor(proto, Nan::New("height").ToLocalChecked(), GetHeight, SetHeight);
Nan::SetTemplate(proto, "PNG_NO_FILTERS", Nan::New<Uint32>(PNG_NO_FILTERS));
Nan::SetTemplate(proto, "PNG_FILTER_NONE", Nan::New<Uint32>(PNG_FILTER_NONE));
Nan::SetTemplate(proto, "PNG_FILTER_SUB", Nan::New<Uint32>(PNG_FILTER_SUB));
Nan::SetTemplate(proto, "PNG_FILTER_UP", Nan::New<Uint32>(PNG_FILTER_UP));
Nan::SetTemplate(proto, "PNG_FILTER_AVG", Nan::New<Uint32>(PNG_FILTER_AVG));
Nan::SetTemplate(proto, "PNG_FILTER_PAETH", Nan::New<Uint32>(PNG_FILTER_PAETH));
Nan::SetTemplate(proto, "PNG_ALL_FILTERS", Nan::New<Uint32>(PNG_ALL_FILTERS));
// Class methods
Nan::SetMethod(ctor, "_registerFont", RegisterFont);
Nan::SetMethod(ctor, "_deregisterAllFonts", DeregisterAllFonts);
Local<Context> ctx = Nan::GetCurrentContext();
Nan::Set(target,
Nan::New("Canvas").ToLocalChecked(),
ctor->GetFunction(ctx).ToLocalChecked());
}
/*
* Initialize a Canvas with the given width and height.
*/
NAN_METHOD(Canvas::New) {
if (!info.IsConstructCall()) {
return Nan::ThrowTypeError("Class constructors cannot be invoked without 'new'");
}
Backend* backend = NULL;
if (info[0]->IsNumber()) {
int width = Nan::To<uint32_t>(info[0]).FromMaybe(0), height = 0;
if (info[1]->IsNumber()) height = Nan::To<uint32_t>(info[1]).FromMaybe(0);
if (info[2]->IsString()) {
if (0 == strcmp("pdf", *Nan::Utf8String(info[2])))
backend = new PdfBackend(width, height);
else if (0 == strcmp("svg", *Nan::Utf8String(info[2])))
backend = new SvgBackend(width, height);
else
backend = new ImageBackend(width, height);
}
else
backend = new ImageBackend(width, height);
}
else if (info[0]->IsObject()) {
if (Nan::New(ImageBackend::constructor)->HasInstance(info[0]) ||
Nan::New(PdfBackend::constructor)->HasInstance(info[0]) ||
Nan::New(SvgBackend::constructor)->HasInstance(info[0])) {
backend = Nan::ObjectWrap::Unwrap<Backend>(Nan::To<Object>(info[0]).ToLocalChecked());
}else{
return Nan::ThrowTypeError("Invalid arguments");
}
}
else {
backend = new ImageBackend(0, 0);
}
if (!backend->isSurfaceValid()) {
delete backend;
return Nan::ThrowError(backend->getError());
}
Canvas* canvas = new Canvas(backend);
canvas->Wrap(info.This());
backend->setCanvas(canvas);
info.GetReturnValue().Set(info.This());
}
/*
* Get type string.
*/
NAN_GETTER(Canvas::GetType) {
CHECK_RECEIVER(Canvas.GetType);
Canvas *canvas = Nan::ObjectWrap::Unwrap<Canvas>(info.This());
info.GetReturnValue().Set(Nan::New<String>(canvas->backend()->getName()).ToLocalChecked());
}
/*
* Get stride.
*/
NAN_GETTER(Canvas::GetStride) {
CHECK_RECEIVER(Canvas.GetStride);
Canvas *canvas = Nan::ObjectWrap::Unwrap<Canvas>(info.This());
info.GetReturnValue().Set(Nan::New<Number>(canvas->stride()));
}
/*
* Get width.
*/
NAN_GETTER(Canvas::GetWidth) {
CHECK_RECEIVER(Canvas.GetWidth);
Canvas *canvas = Nan::ObjectWrap::Unwrap<Canvas>(info.This());
info.GetReturnValue().Set(Nan::New<Number>(canvas->getWidth()));
}
/*
* Set width.
*/
NAN_SETTER(Canvas::SetWidth) {
CHECK_RECEIVER(Canvas.SetWidth);
if (value->IsNumber()) {
Canvas *canvas = Nan::ObjectWrap::Unwrap<Canvas>(info.This());
canvas->backend()->setWidth(Nan::To<uint32_t>(value).FromMaybe(0));
canvas->resurface(info.This());
}
}
/*
* Get height.
*/
NAN_GETTER(Canvas::GetHeight) {
CHECK_RECEIVER(Canvas.GetHeight);
Canvas *canvas = Nan::ObjectWrap::Unwrap<Canvas>(info.This());
info.GetReturnValue().Set(Nan::New<Number>(canvas->getHeight()));
}
/*
* Set height.
*/
NAN_SETTER(Canvas::SetHeight) {
CHECK_RECEIVER(Canvas.SetHeight);
if (value->IsNumber()) {
Canvas *canvas = Nan::ObjectWrap::Unwrap<Canvas>(info.This());
canvas->backend()->setHeight(Nan::To<uint32_t>(value).FromMaybe(0));
canvas->resurface(info.This());
}
}
/*
* EIO toBuffer callback.
*/
void
Canvas::ToPngBufferAsync(uv_work_t *req) {
PngClosure* closure = static_cast<PngClosure*>(req->data);
closure->status = canvas_write_to_png_stream(
closure->canvas->surface(),
PngClosure::writeVec,
closure);
}
#ifdef HAVE_JPEG
void
Canvas::ToJpegBufferAsync(uv_work_t *req) {
JpegClosure* closure = static_cast<JpegClosure*>(req->data);
write_to_jpeg_buffer(closure->canvas->surface(), closure);
}
#endif
/*
* EIO after toBuffer callback.
*/
void
Canvas::ToBufferAsyncAfter(uv_work_t *req) {
Nan::HandleScope scope;
Nan::AsyncResource async("canvas:ToBufferAsyncAfter");
Closure* closure = static_cast<Closure*>(req->data);
delete req;
if (closure->status) {
Local<Value> argv[1] = { Canvas::Error(closure->status) };
closure->cb.Call(1, argv, &async);
} else {
Local<Object> buf = Nan::CopyBuffer((char*)&closure->vec[0], closure->vec.size()).ToLocalChecked();
Local<Value> argv[2] = { Nan::Null(), buf };
closure->cb.Call(sizeof argv / sizeof *argv, argv, &async);
}
closure->canvas->Unref();
delete closure;
}
static void parsePNGArgs(Local<Value> arg, PngClosure& pngargs) {
if (arg->IsObject()) {
Local<Object> obj = Nan::To<Object>(arg).ToLocalChecked();
Local<Value> cLevel = Nan::Get(obj, Nan::New("compressionLevel").ToLocalChecked()).ToLocalChecked();
if (cLevel->IsUint32()) {
uint32_t val = Nan::To<uint32_t>(cLevel).FromMaybe(0);
// See quote below from spec section 4.12.5.5.
if (val <= 9) pngargs.compressionLevel = val;
}
Local<Value> rez = Nan::Get(obj, Nan::New("resolution").ToLocalChecked()).ToLocalChecked();
if (rez->IsUint32()) {
uint32_t val = Nan::To<uint32_t>(rez).FromMaybe(0);
if (val > 0) pngargs.resolution = val;
}
Local<Value> filters = Nan::Get(obj, Nan::New("filters").ToLocalChecked()).ToLocalChecked();
if (filters->IsUint32()) pngargs.filters = Nan::To<uint32_t>(filters).FromMaybe(0);
Local<Value> palette = Nan::Get(obj, Nan::New("palette").ToLocalChecked()).ToLocalChecked();
if (palette->IsUint8ClampedArray()) {
Local<Uint8ClampedArray> palette_ta = palette.As<Uint8ClampedArray>();
pngargs.nPaletteColors = palette_ta->Length();
if (pngargs.nPaletteColors % 4 != 0) {
throw "Palette length must be a multiple of 4.";
}
pngargs.nPaletteColors /= 4;
Nan::TypedArrayContents<uint8_t> _paletteColors(palette_ta);
pngargs.palette = *_paletteColors;
// Optional background color index:
Local<Value> backgroundIndexVal = Nan::Get(obj, Nan::New("backgroundIndex").ToLocalChecked()).ToLocalChecked();
if (backgroundIndexVal->IsUint32()) {
pngargs.backgroundIndex = static_cast<uint8_t>(Nan::To<uint32_t>(backgroundIndexVal).FromMaybe(0));
}
}
}
}
#ifdef HAVE_JPEG
static void parseJPEGArgs(Local<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()) {
Local<Object> obj = Nan::To<Object>(arg).ToLocalChecked();
Local<Value> qual = Nan::Get(obj, Nan::New("quality").ToLocalChecked()).ToLocalChecked();
if (qual->IsNumber()) {
double quality = Nan::To<double>(qual).FromMaybe(0);
if (quality >= 0.0 && quality <= 1.0) {
jpegargs.quality = static_cast<uint32_t>(100.0 * quality);
}
}
Local<Value> chroma = Nan::Get(obj, Nan::New("chromaSubsampling").ToLocalChecked()).ToLocalChecked();
if (chroma->IsBoolean()) {
bool subsample = Nan::To<bool>(chroma).FromMaybe(0);
jpegargs.chromaSubsampling = subsample ? 2 : 1;
} else if (chroma->IsNumber()) {
jpegargs.chromaSubsampling = Nan::To<uint32_t>(chroma).FromMaybe(0);
}
Local<Value> progressive = Nan::Get(obj, Nan::New("progressive").ToLocalChecked()).ToLocalChecked();
if (!progressive->IsUndefined()) {
jpegargs.progressive = Nan::To<bool>(progressive).FromMaybe(0);
}
}
}
#endif
#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 16, 0)
static inline void setPdfMetaStr(cairo_surface_t* surf, Local<Object> opts,
cairo_pdf_metadata_t t, const char* pName) {
auto propName = Nan::New(pName).ToLocalChecked();
auto propValue = Nan::Get(opts, propName).ToLocalChecked();
if (propValue->IsString()) {
// (copies char data)
cairo_pdf_surface_set_metadata(surf, t, *Nan::Utf8String(propValue));
}
}
static inline void setPdfMetaDate(cairo_surface_t* surf, Local<Object> opts,
cairo_pdf_metadata_t t, const char* pName) {
auto propName = Nan::New(pName).ToLocalChecked();
auto propValue = Nan::Get(opts, propName).ToLocalChecked();
if (propValue->IsDate()) {
auto date = static_cast<time_t>(propValue.As<v8::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, Local<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})
*/
NAN_METHOD(Canvas::ToBuffer) {
cairo_status_t status;
Canvas *canvas = Nan::ObjectWrap::Unwrap<Canvas>(info.This());
// Vector canvases, sync only
const std::string name = canvas->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*>(canvas->backend())->closure();
#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 16, 0)
if (info[1]->IsObject()) { // toBuffer("application/pdf", config)
setPdfMetadata(canvas, Nan::To<Object>(info[1]).ToLocalChecked());
}
#endif // CAIRO 16+
} else {
closure = static_cast<SvgBackend*>(canvas->backend())->closure();
}
cairo_surface_finish(canvas->surface());
Local<Object> buf = Nan::CopyBuffer((char*)&closure->vec[0], closure->vec.size()).ToLocalChecked();
info.GetReturnValue().Set(buf);
return;
}
// Raw ARGB data -- just a memcpy()
if (info[0]->StrictEquals(Nan::New<String>("raw").ToLocalChecked())) {
cairo_surface_t *surface = canvas->surface();
cairo_surface_flush(surface);
if (canvas->nBytes() > node::Buffer::kMaxLength) {
Nan::ThrowError("Data exceeds maximum buffer length.");
return;
}
const unsigned char *data = cairo_image_surface_get_data(surface);
Isolate* iso = Nan::GetCurrentContext()->GetIsolate();
Local<Object> buf = node::Buffer::Copy(iso, reinterpret_cast<const char*>(data), canvas->nBytes()).ToLocalChecked();
info.GetReturnValue().Set(buf);
return;
}
// Sync PNG, default
if (info[0]->IsUndefined() || info[0]->StrictEquals(Nan::New<String>("image/png").ToLocalChecked())) {
try {
PngClosure closure(canvas);
parsePNGArgs(info[1], closure);
if (closure.nPaletteColors == 0xFFFFFFFF) {
Nan::ThrowError("Palette length must be a multiple of 4.");
return;
}
Nan::TryCatch try_catch;
status = canvas_write_to_png_stream(canvas->surface(), PngClosure::writeVec, &closure);
if (try_catch.HasCaught()) {
try_catch.ReThrow();
} else if (status) {
throw status;
} else {
// TODO it's possible to avoid this copy
Local<Object> buf = Nan::CopyBuffer((char *)&closure.vec[0], closure.vec.size()).ToLocalChecked();
info.GetReturnValue().Set(buf);
}
} catch (cairo_status_t ex) {
Nan::ThrowError(Canvas::Error(ex));
} catch (const char* ex) {
Nan::ThrowError(ex);
}
return;
}
// Async PNG
if (info[0]->IsFunction() &&
(info[1]->IsUndefined() || info[1]->StrictEquals(Nan::New<String>("image/png").ToLocalChecked()))) {
PngClosure* closure;
try {
closure = new PngClosure(canvas);
parsePNGArgs(info[2], *closure);
} catch (cairo_status_t ex) {
Nan::ThrowError(Canvas::Error(ex));
return;
} catch (const char* ex) {
Nan::ThrowError(ex);
return;
}
canvas->Ref();
closure->cb.Reset(info[0].As<Function>());
uv_work_t* req = new uv_work_t;
req->data = closure;
// Make sure the surface exists since we won't have an isolate context in the async block:
canvas->surface();
uv_queue_work(uv_default_loop(), req, ToPngBufferAsync, (uv_after_work_cb)ToBufferAsyncAfter);
return;
}
#ifdef HAVE_JPEG
// Sync JPEG
Local<Value> jpegStr = Nan::New<String>("image/jpeg").ToLocalChecked();
if (info[0]->StrictEquals(jpegStr)) {
try {
JpegClosure closure(canvas);
parseJPEGArgs(info[1], closure);
Nan::TryCatch try_catch;
write_to_jpeg_buffer(canvas->surface(), &closure);
if (try_catch.HasCaught()) {
try_catch.ReThrow();
} else {
// TODO it's possible to avoid this copy.
Local<Object> buf = Nan::CopyBuffer((char *)&closure.vec[0], closure.vec.size()).ToLocalChecked();
info.GetReturnValue().Set(buf);
}
} catch (cairo_status_t ex) {
Nan::ThrowError(Canvas::Error(ex));
}
return;
}
// Async JPEG
if (info[0]->IsFunction() && info[1]->StrictEquals(jpegStr)) {
JpegClosure* closure = new JpegClosure(canvas);
parseJPEGArgs(info[2], *closure);
canvas->Ref();
closure->cb.Reset(info[0].As<Function>());
uv_work_t* req = new uv_work_t;
req->data = closure;
// Make sure the surface exists since we won't have an isolate context in the async block:
canvas->surface();
uv_queue_work(uv_default_loop(), req, ToJpegBufferAsync, (uv_after_work_cb)ToBufferAsyncAfter);
return;
}
#endif
}
/*
* Canvas::StreamPNG callback.
*/
static cairo_status_t
streamPNG(void *c, const uint8_t *data, unsigned len) {
Nan::HandleScope scope;
Nan::AsyncResource async("canvas:StreamPNG");
PngClosure* closure = (PngClosure*) c;
Local<Object> buf = Nan::CopyBuffer((char *)data, len).ToLocalChecked();
Local<Value> argv[3] = {
Nan::Null()
, buf
, Nan::New<Number>(len) };
closure->cb.Call(sizeof argv / sizeof *argv, argv, &async);
return CAIRO_STATUS_SUCCESS;
}
/*
* Stream PNG data synchronously. TODO async
* StreamPngSync(this, options: {palette?: Uint8ClampedArray, backgroundIndex?: uint32, compressionLevel: uint32, filters: uint32})
*/
NAN_METHOD(Canvas::StreamPNGSync) {
if (!info[0]->IsFunction())
return Nan::ThrowTypeError("callback function required");
Canvas *canvas = Nan::ObjectWrap::Unwrap<Canvas>(info.This());
PngClosure closure(canvas);
parsePNGArgs(info[1], closure);
closure.cb.Reset(Local<Function>::Cast(info[0]));
Nan::TryCatch try_catch;
cairo_status_t status = canvas_write_to_png_stream(canvas->surface(), streamPNG, &closure);
if (try_catch.HasCaught()) {
try_catch.ReThrow();
return;
} else if (status) {
Local<Value> argv[1] = { Canvas::Error(status) };
Nan::Call(closure.cb, Nan::GetCurrentContext()->Global(), sizeof argv / sizeof *argv, argv);
} else {
Local<Value> argv[3] = {
Nan::Null()
, Nan::Null()
, Nan::New<Uint32>(0) };
Nan::Call(closure.cb, Nan::GetCurrentContext()->Global(), sizeof argv / sizeof *argv, argv);
}
return;
}
struct PdfStreamInfo {
Local<Function> fn;
uint32_t len;
uint8_t* data;
};
/*
* Canvas::StreamPDF FreeCallback
*/
void stream_pdf_free(char *, void *) {}
/*
* Canvas::StreamPDF callback.
*/
static cairo_status_t
streamPDF(void *c, const uint8_t *data, unsigned len) {
Nan::HandleScope scope;
Nan::AsyncResource async("canvas:StreamPDF");
PdfStreamInfo* streaminfo = static_cast<PdfStreamInfo*>(c);
// 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.
Local<Object> buf = Nan::NewBuffer(const_cast<char *>(reinterpret_cast<const char *>(data)), len, stream_pdf_free, 0).ToLocalChecked();
Local<Value> argv[3] = {
Nan::Null()
, buf
, Nan::New<Number>(len) };
async.runInAsyncScope(Nan::GetCurrentContext()->Global(), streaminfo->fn, sizeof argv / sizeof *argv, argv);
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.
*/
NAN_METHOD(Canvas::StreamPDFSync) {
if (!info[0]->IsFunction())
return Nan::ThrowTypeError("callback function required");
Canvas *canvas = Nan::ObjectWrap::Unwrap<Canvas>(info.Holder());
if (canvas->backend()->getName() != "pdf")
return Nan::ThrowTypeError("wrong canvas type");
#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 16, 0)
if (info[1]->IsObject()) {
setPdfMetadata(canvas, Nan::To<Object>(info[1]).ToLocalChecked());
}
#endif
cairo_surface_finish(canvas->surface());
PdfSvgClosure* closure = static_cast<PdfBackend*>(canvas->backend())->closure();
Local<Function> fn = info[0].As<Function>();
PdfStreamInfo streaminfo;
streaminfo.fn = fn;
streaminfo.data = &closure->vec[0];
streaminfo.len = closure->vec.size();
Nan::TryCatch try_catch;
cairo_status_t status = canvas_write_to_pdf_stream(canvas->surface(), streamPDF, &streaminfo);
if (try_catch.HasCaught()) {
try_catch.ReThrow();
} else if (status) {
Local<Value> error = Canvas::Error(status);
Nan::Call(fn, Nan::GetCurrentContext()->Global(), 1, &error);
} else {
Local<Value> argv[3] = {
Nan::Null()
, Nan::Null()
, Nan::New<Uint32>(0) };
Nan::Call(fn, Nan::GetCurrentContext()->Global(), sizeof argv / sizeof *argv, argv);
}
}
/*
* 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));
}
NAN_METHOD(Canvas::StreamJPEGSync) {
if (!info[1]->IsFunction())
return Nan::ThrowTypeError("callback function required");
Canvas *canvas = Nan::ObjectWrap::Unwrap<Canvas>(info.This());
JpegClosure closure(canvas);
parseJPEGArgs(info[0], closure);
closure.cb.Reset(Local<Function>::Cast(info[1]));
Nan::TryCatch try_catch;
uint32_t bufsize = getSafeBufSize(canvas);
write_to_jpeg_stream(canvas->surface(), bufsize, &closure);
if (try_catch.HasCaught()) {
try_catch.ReThrow();
}
return;
}
#endif
char *
str_value(Local<Value> val, const char *fallback, bool can_be_number) {
if (val->IsString() || (can_be_number && val->IsNumber())) {
return strdup(*Nan::Utf8String(val));
} else if (fallback) {
return strdup(fallback);
} else {
return NULL;
}
}
NAN_METHOD(Canvas::RegisterFont) {
if (!info[0]->IsString()) {
return Nan::ThrowError("Wrong argument type");
} else if (!info[1]->IsObject()) {
return Nan::ThrowError(GENERIC_FACE_ERROR);
}
Nan::Utf8String filePath(info[0]);
PangoFontDescription *sys_desc = get_pango_font_description((unsigned char *) *filePath);
if (!sys_desc) return Nan::ThrowError("Could not parse font file");
PangoFontDescription *user_desc = pango_font_description_new();
// now check the attrs, there are many ways to be wrong
Local<Object> js_user_desc = Nan::To<Object>(info[1]).ToLocalChecked();
Local<String> family_prop = Nan::New<String>("family").ToLocalChecked();
Local<String> weight_prop = Nan::New<String>("weight").ToLocalChecked();
Local<String> style_prop = Nan::New<String>("style").ToLocalChecked();
char *family = str_value(Nan::Get(js_user_desc, family_prop).ToLocalChecked(), NULL, false);
char *weight = str_value(Nan::Get(js_user_desc, weight_prop).ToLocalChecked(), "normal", true);
char *style = str_value(Nan::Get(js_user_desc, style_prop).ToLocalChecked(), "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)) {
FontFace face;
face.user_desc = user_desc;
face.sys_desc = sys_desc;
strncpy((char *)face.file_path, (char *) *filePath, 1023);
font_face_list.push_back(face);
} else {
pango_font_description_free(user_desc);
Nan::ThrowError("Could not load font to the system's font host");
}
} else {
pango_font_description_free(user_desc);
Nan::ThrowError(GENERIC_FACE_ERROR);
}
free(family);
free(weight);
free(style);
}
NAN_METHOD(Canvas::DeregisterAllFonts) {
// 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();
if (!success) Nan::ThrowError("Could not deregister one or more fonts");
}
/*
* Initialize cairo surface.
*/
Canvas::Canvas(Backend* backend) : ObjectWrap() {
_backend = backend;
}
/*
* Destroy cairo surface.
*/
Canvas::~Canvas() {
if (_backend != NULL) {
delete _backend;
}
}
/*
* 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(Local<Object> canvas) {
Nan::HandleScope scope;
Local<Value> context;
backend()->recreateSurface();
// Reset context
context = Nan::Get(canvas, Nan::New<String>("context").ToLocalChecked()).ToLocalChecked();
if (!context->IsUndefined()) {
Context2d *context2d = ObjectWrap::Unwrap<Context2d>(Nan::To<Object>(context).ToLocalChecked());
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.
*/
Local<Value>
Canvas::Error(cairo_status_t status) {
return Exception::Error(Nan::New<String>(cairo_status_to_string(status)).ToLocalChecked());
}
#undef CHECK_RECEIVER
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