fix(🍏): Add missing system apple fonts in listFontFamilies (#3600)

Author: wcandillon

apps/example/src/Examples/API/FontMgr.tsx

@@ -2,8 +2,8 @@ import React from "react";
 import { ScrollView, useWindowDimensions } from "react-native";
 import {
   Canvas,
-  Skia,
   Text,
+  listFontFamilies,
   matchFont,
   useFonts,
 } from "@shopify/react-native-skia";
@@ -16,11 +16,7 @@ const titleText = "Fonts from the System";
 const titleY = titleFontSize + PADDING;
 const subtitleY = titleY + 14 + PADDING;
 
-const fontMgr = Skia.FontMgr.System();
-const familyNames = new Array(fontMgr.countFamilies())
-  .fill(0)
-  .map((_, i) => fontMgr.getFamilyName(i));
-
+const familyNames = listFontFamilies();
 const title2Y = subtitleY + 16 * familyNames.length + PADDING + titleFontSize;
 
 export const FontMgr = () => {

packages/skia/android/cpp/jni/JniPlatformContext.cpp

@@ -207,7 +207,7 @@ void JniPlatformContext::notifyTaskReadyExternal() {
   jni::ThreadScope ts;
 
   static auto method =
-    javaPart_->getClass()->getMethod<void()>("notifyTaskReady");
+      javaPart_->getClass()->getMethod<void()>("notifyTaskReady");
   method(javaPart_.get());
 }
 

packages/skia/apple/RNSkApplePlatformContext.h

@@ -73,6 +73,8 @@ class RNSkApplePlatformContext : public RNSkPlatformContext {
 
   sk_sp<SkFontMgr> createFontMgr() override;
 
+  std::vector<std::string> getSystemFontFamilies() override;
+
 private:
   ViewScreenshotService *_screenshotService;
 

packages/skia/apple/RNSkApplePlatformContext.mm

@@ -3,6 +3,7 @@
 #import <CoreMedia/CMSampleBuffer.h>
 #include <Metal/Metal.h>
 #import <React/RCTUtils.h>
+#include <set>
 #include <thread>
 #include <utility>
 
@@ -300,6 +301,51 @@
   return SkFontMgr_New_CoreText(nullptr);
 }
 
+std::vector<std::string> RNSkApplePlatformContext::getSystemFontFamilies() {
+  std::vector<std::string> families;
+
+  // System UI fonts (e.g., .AppleSystemUIFont) are not enumerated by Skia's
+  // font manager. We retrieve them via Core Text's CTFontUIFontType constants.
+  // This list covers common system font types as of iOS 17 / macOS 14.
+  // Apple may add new CTFontUIFontType values in future OS versions,
+  // so this list may need to be updated periodically.
+  CTFontUIFontType fontTypes[] = {
+      kCTFontUIFontUser,        kCTFontUIFontUserFixedPitch,
+      kCTFontUIFontSystem,      kCTFontUIFontEmphasizedSystem,
+      kCTFontUIFontSmallSystem, kCTFontUIFontSmallEmphasizedSystem,
+      kCTFontUIFontMiniSystem,  kCTFontUIFontMiniEmphasizedSystem,
+      kCTFontUIFontLabel,       kCTFontUIFontMessage,
+      kCTFontUIFontToolTip,
+  };
+
+  std::set<std::string> uniqueFamilies;
+
+  for (CTFontUIFontType fontType : fontTypes) {
+    CTFontRef font = CTFontCreateUIFontForLanguage(fontType, 12.0, nullptr);
+    if (font) {
+      CFStringRef familyName = CTFontCopyFamilyName(font);
+      if (familyName) {
+        const char *cstr =
+            CFStringGetCStringPtr(familyName, kCFStringEncodingUTF8);
+        if (cstr) {
+          uniqueFamilies.insert(std::string(cstr));
+        } else {
+          char buffer[256];
+          if (CFStringGetCString(familyName, buffer, sizeof(buffer),
+                                 kCFStringEncodingUTF8)) {
+            uniqueFamilies.insert(std::string(buffer));
+          }
+        }
+        CFRelease(familyName);
+      }
+      CFRelease(font);
+    }
+  }
+
+  families.assign(uniqueFamilies.begin(), uniqueFamilies.end());
+  return families;
+}
+
 void RNSkApplePlatformContext::runOnMainThread(std::function<void()> func) {
   dispatch_async(dispatch_get_main_queue(), ^{
     func();

packages/skia/apple/SkiaCVPixelBufferUtils.mm

@@ -30,12 +30,16 @@
 #include <TargetConditionals.h>
 #if TARGET_RT_BIG_ENDIAN
 #define FourCC2Str(fourcc)                                                     \
-  (const char[]){*((char *)&fourcc), *(((char *)&fourcc) + 1),                 \
-                 *(((char *)&fourcc) + 2), *(((char *)&fourcc) + 3), 0}
+  (const char[]) {                                                             \
+    *((char *)&fourcc), *(((char *)&fourcc) + 1), *(((char *)&fourcc) + 2),    \
+        *(((char *)&fourcc) + 3), 0                                            \
+  }
 #else
 #define FourCC2Str(fourcc)                                                     \
-  (const char[]){*(((char *)&fourcc) + 3), *(((char *)&fourcc) + 2),           \
-                 *(((char *)&fourcc) + 1), *(((char *)&fourcc) + 0), 0}
+  (const char[]) {                                                             \
+    *(((char *)&fourcc) + 3), *(((char *)&fourcc) + 2),                        \
+        *(((char *)&fourcc) + 1), *(((char *)&fourcc) + 0), 0                  \
+  }
 #endif
 
 // pragma MARK: TextureHolder

packages/skia/cpp/api/JsiSkFontMgr.h

@@ -27,15 +27,32 @@ class JsiSkFontMgr : public JsiSkWrappingSkPtrHostObject<SkFontMgr> {
 
   JsiSkFontMgr(std::shared_ptr<RNSkPlatformContext> context,
                sk_sp<SkFontMgr> fontMgr)
-      : JsiSkWrappingSkPtrHostObject(std::move(context), fontMgr) {}
+      : JsiSkWrappingSkPtrHostObject(context, fontMgr),
+        _systemFontFamilies(context->getSystemFontFamilies()) {}
 
-  JSI_HOST_FUNCTION(countFamilies) { return getObject()->countFamilies(); }
+  JSI_HOST_FUNCTION(countFamilies) {
+    return static_cast<int>(getObject()->countFamilies() +
+                            _systemFontFamilies.size());
+  }
 
   JSI_HOST_FUNCTION(getFamilyName) {
     auto i = static_cast<int>(arguments[0].asNumber());
-    SkString name;
-    getObject()->getFamilyName(i, &name);
-    return jsi::String::createFromUtf8(runtime, name.c_str());
+    auto baseFamilyCount = getObject()->countFamilies();
+    if (i < baseFamilyCount) {
+      SkString name;
+      getObject()->getFamilyName(i, &name);
+      return jsi::String::createFromUtf8(runtime, name.c_str());
+    }
+    auto systemIndex = i - baseFamilyCount;
+    if (systemIndex < static_cast<int>(_systemFontFamilies.size())) {
+      return jsi::String::createFromUtf8(runtime,
+                                         _systemFontFamilies[systemIndex]);
+    }
+    throw jsi::JSError(runtime, "Font family index out of bounds: " +
+                                    std::to_string(i) + " (total families: " +
+                                    std::to_string(baseFamilyCount +
+                                                   _systemFontFamilies.size()) +
+                                    ")");
   }
 
   JSI_HOST_FUNCTION(matchFamilyStyle) {
@@ -55,6 +72,9 @@ class JsiSkFontMgr : public JsiSkWrappingSkPtrHostObject<SkFontMgr> {
   JSI_EXPORT_FUNCTIONS(JSI_EXPORT_FUNC(JsiSkFontMgr, countFamilies),
                        JSI_EXPORT_FUNC(JsiSkFontMgr, getFamilyName),
                        JSI_EXPORT_FUNC(JsiSkFontMgr, matchFamilyStyle))
+
+private:
+  std::vector<std::string> _systemFontFamilies;
 };
 
 } // namespace RNSkia

packages/skia/cpp/api/JsiSkPictureFactory.h

@@ -50,12 +50,15 @@ class JsiSkPictureFactory : public JsiSkHostObject {
       }
     }
 
-    // Get ArrayBuffer - try buffer property first (Uint8Array, etc.), then direct ArrayBuffer
-    jsi::ArrayBuffer buffer = obj.hasProperty(runtime, jsi::PropNameID::forAscii(runtime, "buffer"))
-        ? obj.getProperty(runtime, jsi::PropNameID::forAscii(runtime, "buffer"))
-              .asObject(runtime)
-              .getArrayBuffer(runtime)
-        : obj.getArrayBuffer(runtime);
+    // Get ArrayBuffer - try buffer property first (Uint8Array, etc.), then
+    // direct ArrayBuffer
+    jsi::ArrayBuffer buffer =
+        obj.hasProperty(runtime, jsi::PropNameID::forAscii(runtime, "buffer"))
+            ? obj.getProperty(runtime,
+                              jsi::PropNameID::forAscii(runtime, "buffer"))
+                  .asObject(runtime)
+                  .getArrayBuffer(runtime)
+            : obj.getArrayBuffer(runtime);
 
     sk_sp<SkData> data =
         SkData::MakeWithCopy(buffer.data(runtime), buffer.size(runtime));