Add app language option

app/src/main/java/com/hippo/content/ContextLocalWrapper.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2018 Hippo Seven
+ *
+ * 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.
+ */
+
+package com.hippo.content;
+
+/*
+ * Created by Hippo on 2018/3/27.
+ */
+
+import android.content.Context;
+import android.content.ContextWrapper;
+import android.content.res.Configuration;
+import android.content.res.Resources;
+import android.os.Build;
+import android.os.LocaleList;
+import java.util.Locale;
+
+public class ContextLocalWrapper extends ContextWrapper {
+
+  public ContextLocalWrapper(Context base) {
+    super(base);
+  }
+
+  public static ContextLocalWrapper wrap(Context context, Locale newLocale) {
+    Resources res = context.getResources();
+    Configuration configuration = res.getConfiguration();
+
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+      configuration.setLocale(newLocale);
+
+      LocaleList localeList = new LocaleList(newLocale);
+      LocaleList.setDefault(localeList);
+      configuration.setLocales(localeList);
+
+      context = context.createConfigurationContext(configuration);
+
+    } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
+      configuration.setLocale(newLocale);
+      context = context.createConfigurationContext(configuration);
+
+    } else {
+      configuration.locale = newLocale;
+      res.updateConfiguration(configuration, res.getDisplayMetrics());
+    }
+
+    return new ContextLocalWrapper(context);
+  }
+}

app/src/main/java/com/hippo/ehviewer/Settings.java

@@ -963,6 +963,17 @@ public class Settings {
         putBoolean(KEY_BUILT_IN_HOSTS, value);
     }
 
+    public static final String KEY_APP_LANGUAGE = "app_language";
+    private static final String DEFAULT_APP_LANGUAGE = "system";
+
+    public static String getAppLanguage() {
+        return getString(KEY_APP_LANGUAGE, DEFAULT_APP_LANGUAGE);
+    }
+
+    public static void putAppLanguage(String value) {
+        putString(KEY_APP_LANGUAGE, value);
+    }
+
     /********************
      ****** Guide
      ********************/

app/src/main/java/com/hippo/ehviewer/ui/EhActivity.java

@@ -16,15 +16,16 @@
 
 package com.hippo.ehviewer.ui;
 
+import android.content.Context;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
 import android.support.v7.app.AppCompatActivity;
-import android.util.Log;
 import android.view.WindowManager;
-
 import com.google.analytics.tracking.android.EasyTracker;
+import com.hippo.content.ContextLocalWrapper;
 import com.hippo.ehviewer.EhApplication;
 import com.hippo.ehviewer.Settings;
+import java.util.Locale;
 
 public abstract class EhActivity extends AppCompatActivity {
 
@@ -74,4 +75,26 @@ public abstract class EhActivity extends AppCompatActivity {
             getWindow().clearFlags(WindowManager.LayoutParams.FLAG_SECURE);
         }
     }
+
+    @Override
+    protected void attachBaseContext(Context newBase) {
+        Locale locale = null;
+        String language = Settings.getAppLanguage();
+        if (language != null && !language.equals("system")) {
+            String[] split = language.split("-");
+            if (split.length == 1) {
+                locale = new Locale(split[0]);
+            } else if (split.length == 2) {
+                locale = new Locale(split[0], split[0]);
+            } else if (split.length == 3) {
+                locale = new Locale(split[0], split[0], split[0]);
+            }
+        }
+
+        if (locale != null) {
+            newBase = ContextLocalWrapper.wrap(newBase, locale);
+        }
+
+        super.attachBaseContext(newBase);
+    }
 }

app/src/main/java/com/hippo/ehviewer/ui/EhPreferenceActivity.java

@@ -16,15 +16,17 @@
 
 package com.hippo.ehviewer.ui;
 
+import android.content.Context;
+import android.content.res.Resources;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
-import android.util.Log;
 import android.view.WindowManager;
-
 import com.google.analytics.tracking.android.EasyTracker;
 import com.hippo.app.AppCompatPreferenceActivity;
+import com.hippo.content.ContextLocalWrapper;
 import com.hippo.ehviewer.EhApplication;
 import com.hippo.ehviewer.Settings;
+import java.util.Locale;
 
 public abstract class EhPreferenceActivity extends AppCompatPreferenceActivity {
 
@@ -74,4 +76,27 @@ public abstract class EhPreferenceActivity extends AppCompatPreferenceActivity {
             getWindow().clearFlags(WindowManager.LayoutParams.FLAG_SECURE);
         }
     }
+
+    @Override
+    protected void attachBaseContext(Context newBase) {
+        Locale locale = null;
+        String language = Settings.getAppLanguage();
+        if (language != null && !language.equals("system")) {
+            String[] split = language.split("-");
+            if (split.length == 1) {
+                locale = new Locale(split[0]);
+            } else if (split.length == 2) {
+                locale = new Locale(split[0], split[0]);
+            } else if (split.length == 3) {
+                locale = new Locale(split[0], split[0], split[0]);
+            }
+        }
+
+        if (locale == null) {
+            locale = Resources.getSystem().getConfiguration().locale;
+        }
+
+        newBase = ContextLocalWrapper.wrap(newBase, locale);
+        super.attachBaseContext(newBase);
+    }
 }