core/jni/android/graphics/fonts/Font.cpp

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define LOG_TAG "Minikin"

#include <nativehelper/JNIHelp.h>
#include <core_jni_helpers.h>

#include "SkData.h"
#include "SkFontMgr.h"
#include "SkRefCnt.h"
#include "SkTypeface.h"
#include "GraphicsJNI.h"
#include <nativehelper/ScopedUtfChars.h>
#include <android_runtime/AndroidRuntime.h>
#include <android_runtime/android_util_AssetManager.h>
#include <androidfw/AssetManager2.h>
#include "Utils.h"
#include "FontUtils.h"

#include <hwui/MinikinSkia.h>
#include <hwui/Typeface.h>
#include <utils/FatVector.h>
#include <minikin/FontFamily.h>

#include <memory>

namespace android {

struct NativeFontBuilder {
    std::vector<minikin::FontVariation> axes;
};

static inline NativeFontBuilder* toBuilder(jlong ptr) {
    return reinterpret_cast<NativeFontBuilder*>(ptr);
}

static inline Asset* toAsset(jlong ptr) {
    return reinterpret_cast<Asset*>(ptr);
}

static void releaseAsset(jlong asset) {
    delete toAsset(asset);
}

static void releaseFont(jlong font) {
    delete reinterpret_cast<FontWrapper*>(font);
}

static void release_global_ref(const void* /*data*/, void* context) {
    JNIEnv* env = AndroidRuntime::getJNIEnv();
    if (env == nullptr) {
        JavaVMAttachArgs args;
        args.version = JNI_VERSION_1_4;
        args.name = "release_font_data";
        args.group = nullptr;
        jint result = AndroidRuntime::getJavaVM()->AttachCurrentThread(&env, &args);
        if (result != JNI_OK) {
            ALOGE("failed to attach to thread to release global ref.");
            return;
        }
    }

    jobject obj = reinterpret_cast<jobject>(context);
    env->DeleteGlobalRef(obj);
}

// Regular JNI
static jlong Font_Builder_getNativeAsset(
    JNIEnv* env, jobject clazz, jobject assetMgr, jstring path, jboolean isAsset, jint cookie) {
    NPE_CHECK_RETURN_ZERO(env, assetMgr);
    NPE_CHECK_RETURN_ZERO(env, path);

    Guarded<AssetManager2>* mgr = AssetManagerForJavaObject(env, assetMgr);
    if (mgr == nullptr) {
        return 0;
    }

    ScopedUtfChars str(env, path);
    if (str.c_str() == nullptr) {
        return 0;
    }

    std::unique_ptr<Asset> asset;
    {
      ScopedLock<AssetManager2> locked_mgr(*mgr);
      if (isAsset) {
          asset = locked_mgr->Open(str.c_str(), Asset::ACCESS_BUFFER);
      } else if (cookie > 0) {
          // Valid java cookies are 1-based, but AssetManager cookies are 0-based.
          asset = locked_mgr->OpenNonAsset(str.c_str(), static_cast<ApkAssetsCookie>(cookie - 1),
                  Asset::ACCESS_BUFFER);
      } else {
          asset = locked_mgr->OpenNonAsset(str.c_str(), Asset::ACCESS_BUFFER);
      }
    }

    return reinterpret_cast<jlong>(asset.release());
}

// Regular JNI
static jobject Font_Builder_getAssetBuffer(JNIEnv* env, jobject clazz, jlong nativeAsset) {
    Asset* asset = toAsset(nativeAsset);
    return env->NewDirectByteBuffer(const_cast<void*>(asset->getBuffer(false)), asset->getLength());
}

// CriticalNative
static jlong Font_Builder_getReleaseNativeAssetFunc() {
    return reinterpret_cast<jlong>(&releaseAsset);
}

// Regular JNI
static jlong Font_Builder_initBuilder(JNIEnv*, jobject) {
    return reinterpret_cast<jlong>(new NativeFontBuilder());
}

// Critical Native
static void Font_Builder_addAxis(jlong builderPtr, jint tag, jfloat value) {
    toBuilder(builderPtr)->axes.emplace_back(static_cast<minikin::AxisTag>(tag), value);
}

// Regular JNI
static jlong Font_Builder_build(JNIEnv* env, jobject clazz, jlong builderPtr, jobject buffer,
        jint weight, jboolean italic, jint ttcIndex) {
    NPE_CHECK_RETURN_ZERO(env, buffer);
    std::unique_ptr<NativeFontBuilder> builder(toBuilder(builderPtr));
    const void* fontPtr = env->GetDirectBufferAddress(buffer);
    if (fontPtr == nullptr) {
        jniThrowException(env, "java/lang/IllegalArgumentException", "Not a direct buffer");
        return 0;
    }
    jlong fontSize = env->GetDirectBufferCapacity(buffer);
    if (fontSize <= 0) {
        jniThrowException(env, "java/lang/IllegalArgumentException",
                          "buffer size must not be zero or negative");
        return 0;
    }
    jobject fontRef = MakeGlobalRefOrDie(env, buffer);
    sk_sp<SkData> data(SkData::MakeWithProc(fontPtr, fontSize,
            release_global_ref, reinterpret_cast<void*>(fontRef)));

    uirenderer::FatVector<SkFontArguments::Axis, 2> skiaAxes;
    for (const auto& axis : builder->axes) {
        skiaAxes.emplace_back(SkFontArguments::Axis{axis.axisTag, axis.value});
    }

    std::unique_ptr<SkStreamAsset> fontData(new SkMemoryStream(std::move(data)));

    SkFontArguments params;
    params.setCollectionIndex(ttcIndex);
    params.setAxes(skiaAxes.data(), skiaAxes.size());

    sk_sp<SkFontMgr> fm(SkFontMgr::RefDefault());
    sk_sp<SkTypeface> face(fm->makeFromStream(std::move(fontData), params));
    if (face == nullptr) {
        jniThrowException(env, "java/lang/IllegalArgumentException",
                          "Failed to create internal object. maybe invalid font data.");
        return 0;
    }
    std::shared_ptr<minikin::MinikinFont> minikinFont =
            std::make_shared<MinikinFontSkia>(std::move(face), fontPtr, fontSize, ttcIndex,
                    builder->axes);
    minikin::Font font = minikin::Font::Builder(minikinFont).setWeight(weight)
                    .setSlant(static_cast<minikin::FontStyle::Slant>(italic)).build();
    return reinterpret_cast<jlong>(new FontWrapper(std::move(font)));
}

// Critical Native
static jlong Font_Builder_getReleaseNativeFont() {
    return reinterpret_cast<jlong>(releaseFont);
}

///////////////////////////////////////////////////////////////////////////////

static const JNINativeMethod gFontBuilderMethods[] = {
    { "nInitBuilder", "()J", (void*) Font_Builder_initBuilder },
    { "nAddAxis", "(JIF)V", (void*) Font_Builder_addAxis },
    { "nBuild", "(JLjava/nio/ByteBuffer;IZI)J", (void*) Font_Builder_build },
    { "nGetReleaseNativeFont", "()J", (void*) Font_Builder_getReleaseNativeFont },

    { "nGetNativeAsset", "(Landroid/content/res/AssetManager;Ljava/lang/String;ZI)J",
      (void*) Font_Builder_getNativeAsset },
    { "nGetAssetBuffer", "(J)Ljava/nio/ByteBuffer;", (void*) Font_Builder_getAssetBuffer },
    { "nGetReleaseNativeAssetFunc", "()J", (void*) Font_Builder_getReleaseNativeAssetFunc },
};

int register_android_graphics_fonts_Font(JNIEnv* env) {
    return RegisterMethodsOrDie(env, "android/graphics/fonts/Font$Builder", gFontBuilderMethods,
            NELEM(gFontBuilderMethods));
}

}