support @font-face style attrs in registerFont

* registerFont is now implemented as a static member function of the Canvas class itself. there is a static list of fonts registered on the class, which are picked up by setting the font when necessary. * register_font, if compiled with FT, will fill in its second arg with a PangoFontDescription that should resolve to the file specified
Automattic · Apr 24, 2016 · 5f26917 · 5f26917
1 parent 297fb40
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Showing 7 changed files with 358 additions and 56 deletions.
diff --git a/lib/canvas.js b/lib/canvas.js
@@ -14,7 +14,6 @@ var canvas = require('./bindings')
   , Canvas = canvas.Canvas
   , Image = canvas.Image
   , cairoVersion = canvas.cairoVersion
-  , registerFont = canvas.registerFont
   , Context2d = require('./context2d')
   , PNGStream = require('./pngstream')
   , JPEGStream = require('./jpegstream')
@@ -38,7 +37,17 @@ exports.version = packageJson.version;
  * Register custom font
  */
 
-exports.registerFont = registerFont;
+exports.registerFont = function(src, fontFace) {
+  var weight, style, family;
+
+  if (typeof fontFace === 'object') {
+    weight = fontFace.weight;
+    style = fontFace.style;
+    family = fontFace.family;
+  }
+
+  this._registerFont(src, weight, style, family);
+};
 
 /**
  * Cairo version.

diff --git a/src/Canvas.cc b/src/Canvas.cc
@@ -9,13 +9,15 @@
 #include <string.h>
 #include <node_buffer.h>
 #include <node_version.h>
+#include <glib.h>
 #include <cairo-pdf.h>
 #include <cairo-svg.h>
 
 #include "Canvas.h"
 #include "PNG.h"
 #include "CanvasRenderingContext2d.h"
 #include "closure.h"
+#include "register_font.h"
 
 #ifdef HAVE_JPEG
 #include "JPEGStream.h"
@@ -56,6 +58,9 @@ Canvas::Initialize(Nan::ADDON_REGISTER_FUNCTION_ARGS_TYPE target) {
   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::Set(target, Nan::New("Canvas").ToLocalChecked(), ctor->GetFunction());
 }
 
@@ -467,6 +472,41 @@ NAN_METHOD(Canvas::StreamJPEGSync) {
 
 #endif
 
+NAN_METHOD(Canvas::RegisterFont) {
+  FontFace face;
+
+  if (!info[0]->IsString()) {
+    return Nan::ThrowError("Wrong argument type");
+  }
+
+  String::Utf8Value filePath(info[0]);
+
+  if (!register_font((unsigned char*) *filePath, &face.target_desc)) {
+    Nan::ThrowError("Could not load font to the system's font host");
+  } else if (face.target_desc) { // NULL if not compiled with FT
+    PangoFontDescription* d  = pango_font_description_copy(face.target_desc);
+
+    if (!info[1]->Equals(Nan::Null())) {
+      String::Utf8Value weight(info[1]->ToString());
+      pango_font_description_set_weight(d, Canvas::GetWeightFromCSSString(*weight));
+    }
+
+    if (!info[2]->Equals(Nan::Null())) {
+      String::Utf8Value style(info[2]->ToString());
+      pango_font_description_set_style(d, Canvas::GetStyleFromCSSString(*style));
+    }
+
+    if (!info[3]->Equals(Nan::Null())) {
+      String::Utf8Value family(info[3]->ToString());
+      pango_font_description_set_family(d, *family);
+    }
+
+    face.user_desc = d;
+
+    _font_face_list.push_back(face);
+  }
+}
+
 /*
  * Initialize cairo surface.
  */
@@ -517,6 +557,95 @@ Canvas::~Canvas() {
   }
 }
 
+std::vector<FontFace>
+_init_font_face_list() {
+  std::vector<FontFace> x;
+  return x;
+}
+
+std::vector<FontFace> Canvas::_font_face_list = _init_font_face_list();
+
+/*
+ * Get a PangoStyle from a CSS string (like "italic")
+ */
+
+PangoStyle
+Canvas::GetStyleFromCSSString(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(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;
+}
+
+/*
+ * Tries to find a matching font given to registerFont
+ */
+
+PangoFontDescription *
+Canvas::FindCustomFace(PangoFontDescription *desc) {
+  PangoFontDescription* best_match = NULL;
+  PangoFontDescription* best_match_target = NULL;
+  std::vector<FontFace>::iterator it = _font_face_list.begin();
+
+  while (it != _font_face_list.end()) {
+    FontFace f = *it;
+
+    if (g_ascii_strcasecmp(pango_font_description_get_family(desc),
+      pango_font_description_get_family(f.user_desc)) == 0
+      && pango_font_description_better_match(desc, best_match, f.user_desc)) {
+
+      best_match = f.user_desc;
+      best_match_target = f.target_desc;
+    }
+
+    ++it;
+  }
+
+  return best_match_target;
+}
+
 /*
  * Re-alloc the surface, destroying the previous.
  */

diff --git a/src/Canvas.h b/src/Canvas.h
@@ -13,9 +13,11 @@
 #include <node_object_wrap.h>
 #include <node_version.h>
 #include <pango/pangocairo.h>
+#include <vector>
 #include <cairo.h>
 #include <nan.h>
 
+
 using namespace node;
 using namespace v8;
 
@@ -38,6 +40,16 @@ typedef enum {
   CANVAS_TYPE_SVG
 } canvas_type_t;
 
+/**
+ * FontFace describes a font file in terms of one PangoFontDescription that
+ * will resolve to it and one that the user describes it as (like @font-face)
+ */
+class FontFace {
+  public:
+    PangoFontDescription *target_desc;
+    PangoFontDescription *user_desc;
+};
+
 /*
  * Canvas.
  */
@@ -58,6 +70,7 @@ class Canvas: public Nan::ObjectWrap {
     static NAN_SETTER(SetHeight);
     static NAN_METHOD(StreamPNGSync);
     static NAN_METHOD(StreamJPEGSync);
+    static NAN_METHOD(RegisterFont);
     static Local<Value> Error(cairo_status_t status);
 #if NODE_VERSION_AT_LEAST(0, 6, 0)
     static void ToBufferAsync(uv_work_t *req);
@@ -72,6 +85,9 @@ class Canvas: public Nan::ObjectWrap {
       EIO_ToBuffer(eio_req *req);
     static int EIO_AfterToBuffer(eio_req *req);
 #endif
+    static PangoWeight GetWeightFromCSSString(char *weight);
+    static PangoStyle GetStyleFromCSSString(char *style);
+    static PangoFontDescription* FindCustomFace(PangoFontDescription *desc);
 
     inline bool isPDF(){ return CANVAS_TYPE_PDF == type; }
     inline bool isSVG(){ return CANVAS_TYPE_SVG == type; }
@@ -86,6 +102,7 @@ class Canvas: public Nan::ObjectWrap {
     ~Canvas();
     cairo_surface_t *_surface;
     void *_closure;
+    static std::vector<FontFace> _font_face_list;
 };
 
 #endif
diff --git a/src/CanvasRenderingContext2d.cc b/src/CanvasRenderingContext2d.cc
@@ -1817,47 +1817,21 @@ NAN_METHOD(Context2d::SetFont) {
 
   PangoFontDescription *desc = pango_font_description_copy(context->state->fontDescription);
   pango_font_description_free(context->state->fontDescription);
-  context->state->fontDescription = desc;
 
-  if (strlen(*family) > 0) pango_font_description_set_family(desc, *family);
+  pango_font_description_set_style(desc, Canvas::GetStyleFromCSSString(*style));
+  pango_font_description_set_weight(desc, Canvas::GetWeightFromCSSString(*weight));
 
-  if (size > 0) pango_font_description_set_absolute_size(desc, size * PANGO_SCALE);
+  if (strlen(*family) > 0) pango_font_description_set_family(desc, *family);
 
-  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;
-    }
+  PangoFontDescription *target_desc;
+  if ((target_desc = Canvas::FindCustomFace(desc))) {
+    pango_font_description_free(desc);
+    desc = pango_font_description_copy(target_desc);
   }
 
-  pango_font_description_set_style(desc, s);
-
-  PangoWeight w = PANGO_WEIGHT_NORMAL;
-  if (strlen(*weight) > 0) {
-    if (0 == strcmp("bold", *weight)) {
-      w = PANGO_WEIGHT_BOLD;
-    } 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;
-    }
-  }
+  if (size > 0) pango_font_description_set_absolute_size(desc, size * PANGO_SCALE);
 
-  pango_font_description_set_weight(desc, w);
+  context->state->fontDescription = desc;
 
   pango_layout_set_font_description(context->_layout, desc);
 }

diff --git a/src/init.cc b/src/init.cc
@@ -6,31 +6,20 @@
 //
 
 #include <stdio.h>
+#include <pango/pango.h>
+#include <glib.h>
 #include "Canvas.h"
 #include "Image.h"
 #include "ImageData.h"
 #include "CanvasGradient.h"
 #include "CanvasPattern.h"
 #include "CanvasRenderingContext2d.h"
-#include "register_font.h"
 
 // Compatibility with Visual Studio versions prior to VS2015
 #if defined(_MSC_VER) && _MSC_VER < 1900
 #define snprintf _snprintf
 #endif
 
-NAN_METHOD(register_font_js) {
-  if (!info[0]->IsString()) {
-    return Nan::ThrowError("Wrong argument type");
-  }
-
-  String::Utf8Value filePath(info[0]);
-
-  if (!register_font((unsigned char*) *filePath)) {
-    Nan::ThrowError("Could not load font to the system's font host");
-  }
-}
-
 NAN_MODULE_INIT(init) {
   Canvas::Initialize(target);
   Image::Initialize(target);
@@ -39,8 +28,6 @@ NAN_MODULE_INIT(init) {
   Gradient::Initialize(target);
   Pattern::Initialize(target);
 
-  Nan::SetMethod(target, "registerFont", register_font_js);
-
   target->Set(Nan::New<String>("cairoVersion").ToLocalChecked(), Nan::New<String>(cairo_version_string()).ToLocalChecked());
 #ifdef HAVE_JPEG