Android 언어 설정

안드로이드 앱에서 언어설정을 사용할 일이 거의 없어서 까먹고 있었다가 최근에 구현할 일이 있어서 생각난김에 정리해본다.

LocaleHelper클래스 작성

import android.annotation.TargetApi;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.os.Build;
import android.preference.PreferenceManager;

import java.util.Locale;

public class LocaleHelper {

    public static Context onAttach(Context context) {
        String locale = getPersistedLocale(context);
        LogUtils.e("", "onAttach: " + locale);
        return setLocale(context, locale);
    }

    public static String getPersistedLocale(Context context) {
        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
        return preferences.getString(SHARED_KEY_LANGUAGE, "");
    }

    public static Context setLocale(Context context, String localeSpec) {
        LogUtils.e("", "setLocale 111 : " + localeSpec);
        Locale locale;
        if (localeSpec.equals("system")) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                locale = Resources.getSystem().getConfiguration().getLocales().get(0);
            } else {
                //noinspection deprecation
                locale = Resources.getSystem().getConfiguration().locale;
            }
        } else {
            locale = new Locale(localeSpec);
            LogUtils.e("", "setLocale  222: " + locale);
        }
        Locale.setDefault(locale);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            LogUtils.e("", "setLocale 333 : " + locale);
            return updateResources(context, locale);
        } else {
            return updateResourcesLegacy(context, locale);
        }
    }

    @TargetApi(Build.VERSION_CODES.N)
    public static Context updateResources(Context context, Locale locale) {
        Configuration configuration = context.getResources().getConfiguration();
        configuration.setLocale(locale);
        configuration.setLayoutDirection(locale);

        return context.createConfigurationContext(configuration);
    }

    @SuppressWarnings("deprecation")
    public static Context updateResourcesLegacy(Context context, Locale locale) {
        Resources resources = context.getResources();

        Configuration configuration = resources.getConfiguration();
        configuration.locale = locale;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
            configuration.setLayoutDirection(locale);
        }

        resources.updateConfiguration(configuration, resources.getDisplayMetrics());

        return context;
    }

}
코드를 입력하세요

BaseActivity에 onSharedPreferenceChangeListener 추가

import android.Manifest;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import java.util.Locale;

public class BaseActivity extends AppCompatActivity implements SharedPreferences.OnSharedPreferenceChangeListener {
    public SharedPreferences mSharedPreferences;
    private String mInitLocale;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mInitLocale = LocaleHelper.getPersistedLocale(this);
        Log.e("", "onCreate : " + mInitLocale);

        mSharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
        
    }

    @Override
    public void onResume() {
        super.onResume();
        mSharedPreferences.registerOnSharedPreferenceChangeListener(this);

        Log.e("", "onResume mInitLocale : " + mInitLocale);
        Log.e("", "onResume LocaleHelper.getPersistedLocale(this) : " + LocaleHelper.getPersistedLocale(this));
        if (mInitLocale != null && !mInitLocale.equals(LocaleHelper.getPersistedLocale(this))) {
            recreate();
        }
    }

    @Override
    public void onPause() {
        super.onPause();
        mSharedPreferences.unregisterOnSharedPreferenceChangeListener(this);
    }

    @Override
    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
        LogUtils.e("", "onSharedPreferenceChanged : " + key);
        LocaleHelper.setLocale(BaseActivity.this, mSharedPreferences.getString(SHARED_KEY_LANGUAGE, ""));
        this.recreate();
    }


    public void setPersistedLocale(Context context, String newLocale) {
        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
        SharedPreferences.Editor editor = preferences.edit();
        LogUtils.e("", "setPersistedLocale : " + newLocale);
        editor.putString(SHARED_KEY_LANGUAGE, newLocale);
        editor.apply();
        editor.commit();
    }

    public void setLanguage(View view) {
        switch (view.getId()) {
            case R.id.ll_set_kor:
                LocaleHelper.setLocale(BaseActivity.this, Locale.KOREAN.getLanguage());
                setPersistedLocale(BaseActivity.this, Locale.KOREAN.getLanguage());
                break;
            case R.id.ll_set_eng:
                LocaleHelper.setLocale(BaseActivity.this, Locale.US.getLanguage());
                setPersistedLocale(BaseActivity.this, Locale.US.getLanguage());
                break;
            case R.id.ll_set_jpn:
                LocaleHelper.setLocale(BaseActivity.this, Locale.JAPANESE.getLanguage());
                setPersistedLocale(BaseActivity.this, Locale.JAPANESE.getLanguage());
                break;
            case R.id.ll_set_chz:
                LocaleHelper.setLocale(BaseActivity.this, Locale.CHINESE.getLanguage());
                setPersistedLocale(BaseActivity.this, Locale.CHINESE.getLanguage());
                break;
        }

    }

}
코드를 입력하세요

이제 적용될 화면 즉 액티비티에서 추가해야할 내용

@Override
    protected void attachBaseContext(Context newBase) {
        super.attachBaseContext(LocaleHelper.onAttach(newBase));
    }

BaseActivity를 상속받은 액티비티에서 attachBaseContext를 Override해준다.