1 /*
2  * Copyright 2021 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #include "experimental/sktext/include/Text.h"
9 #include "experimental/sktext/include/Types.h"
10 #include "include/core/SkCanvas.h"
11 #include "modules/androidkit/src/Utils.h"
12 
13 #include <jni.h>
14 
15 namespace {
16 static jmethodID gFontChain_countMethodID;
17 static jmethodID gFontChain_getAtMethodID;
18 static jmethodID gFontChain_fontSizeMethodID;
19 static jmethodID gFontChain_localeMethodID;
20 
21 class FontChainAdapter : public skia::text::FontChain {
22     public:
FontChainAdapter(JNIEnv* env, jobject jFontChain)23         FontChainAdapter(JNIEnv* env, jobject jFontChain)
24             : fEnv(env)
25             , fFontChainImpl(jFontChain)
26         { }
27 
28         size_t count() const override {
29             return fEnv->CallIntMethod(fFontChainImpl, gFontChain_countMethodID);
30         }
31 
32         sk_sp<SkTypeface> operator[](size_t index) const  override {
33             SkASSERT(index < this->count());
34             SkFont* font = reinterpret_cast<SkFont*>(fEnv->CallLongMethod(fFontChainImpl, gFontChain_getAtMethodID, index));
35             if (font) {
36                 return sk_ref_sp(font->getTypeface());
37             }
38             return nullptr;
39         }
40 
41         float fontSize() const override {
42             return fEnv->CallFloatMethod(fFontChainImpl, gFontChain_fontSizeMethodID);
43         }
44 
45         SkString locale() const override {
46             jstring jLocale = (jstring)fEnv->CallObjectMethod(fFontChainImpl, gFontChain_localeMethodID);
47 
48             const androidkit::utils::CString cstr(fEnv, jLocale);
49             SkString str(cstr);
50             return str;
51         }
52 
53     private:
54         // TODO: Check, can we hold on to env here or do we have to get it every time?
55         JNIEnv* fEnv;
56         jobject fFontChainImpl;
57 };
58 
FontChain_Create(JNIEnv* env, jobject, jobject jFontChain)59 static jlong FontChain_Create(JNIEnv* env, jobject, jobject jFontChain) {
60     return reinterpret_cast<jlong>(new FontChainAdapter(env, jFontChain));
61 }
62 
FontChain_Release(JNIEnv* env, jobject, jlong native_FontChain)63 static void FontChain_Release(JNIEnv* env, jobject, jlong native_FontChain) {
64     SkSafeUnref(reinterpret_cast<FontChainAdapter*>(native_FontChain));
65 }
66 
67 } // namespace
68 
register_androidkit_FontChain(JNIEnv* env)69 int register_androidkit_FontChain(JNIEnv* env) {
70     const auto clazz = env->FindClass("org/skia/androidkit/FontChain");
71 
72     gFontChain_countMethodID = env->GetMethodID(clazz, "count", "()I");
73     gFontChain_getAtMethodID = env->GetMethodID(clazz, "getAt", "(I)J");
74     gFontChain_fontSizeMethodID = env->GetMethodID(clazz, "fontSize", "()F");
75     gFontChain_localeMethodID = env->GetMethodID(clazz, "locale", "()Ljava/lang/String;");
76 
77     if (!gFontChain_countMethodID || !gFontChain_getAtMethodID ||
78         !gFontChain_fontSizeMethodID || !gFontChain_localeMethodID) {
79             return JNI_ERR;
80         }
81 
82     static const JNINativeMethod methods[] = {
83         {"nCreate" , "(Lorg/skia/androidkit/FontChain;)J", reinterpret_cast<void*>(FontChain_Create)},
84         {"nRelease", "(J)V",                               reinterpret_cast<void*>(FontChain_Release)},
85     };
86 
87     return clazz
88         ? env->RegisterNatives(clazz, methods, SK_ARRAY_COUNT(methods))
89         : JNI_ERR;
90 }
91