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 <jni.h>
9
10 #include "experimental/sktext/src/Paint.h"
11 #include "modules/androidkit/src/Utils.h"
12 #include <string>
13
14 using namespace skia::text;
15
16 namespace {
17
18 // conversion function for passing jstrings to SkText static calls
JStringToU16String(JNIEnv * env,const jstring & jstr)19 static std::u16string JStringToU16String(JNIEnv* env, const jstring& jstr) {
20 const jchar* u16 = env->GetStringChars(jstr, nullptr);
21 std::u16string str(reinterpret_cast<const char16_t*>(u16), env->GetStringLength(jstr));
22 env->ReleaseStringChars(jstr, u16);
23 return str;
24 }
25
Text_RenderText(JNIEnv * env,jobject,jstring jtext,jlong native_canvas,jlong native_fg_paint,jfloat x,jfloat y)26 static void Text_RenderText(JNIEnv* env, jobject, jstring jtext,
27 jlong native_canvas, jlong native_fg_paint,
28 jfloat x, jfloat y) {
29 auto* canvas = reinterpret_cast<SkCanvas*>(native_canvas);
30 auto foreground = reinterpret_cast<SkPaint*>(native_fg_paint);
31 std::u16string u16str = JStringToU16String(env, jtext);
32 if (canvas && foreground) {
33 SkPaint background(SkColors::kTransparent);
34 Paint::drawText(u16str, canvas,
35 skia::text::TextDirection::kLtr, skia::text::TextAlign::kLeft,
36 *foreground, background, SkString("arial"), 50, SkFontStyle::Bold(), x, y);
37 }
38 }
39
40 } //namespace
41
register_androidkit_Text(JNIEnv * env)42 int register_androidkit_Text(JNIEnv* env) {
43 static const JNINativeMethod methods[] = {
44 {"nRenderText", "(Ljava/lang/String;JJFF)V", reinterpret_cast<void*>(Text_RenderText)},
45 };
46
47 const auto clazz = env->FindClass("org/skia/androidkit/Text");
48 return clazz
49 ? env->RegisterNatives(clazz, methods, SK_ARRAY_COUNT(methods))
50 : JNI_ERR;
51 }
52