Add support for guild locale (#1359)

src/main/java/net/dv8tion/jda/api/entities/Guild.java

@@ -414,6 +414,14 @@ default String getVanityUrl()
     @Nullable
     String getDescription();
 
+    /**
+     * The preferred locale for this guild.
+     *
+     * @return The preferred {@link Locale} for this guild
+     */
+    @Nonnull
+    Locale getLocale();
+
     /**
      * The guild banner id.
      * <br>This is shown in guilds below the guild name.

src/main/java/net/dv8tion/jda/api/events/guild/update/GuildUpdateLocaleEvent.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2015-2020 Austin Keener, Michael Ritter, Florian Spieß, and the JDA contributors
+ *
+ * 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 net.dv8tion.jda.api.events.guild.update;
+
+import net.dv8tion.jda.api.JDA;
+import net.dv8tion.jda.api.entities.Guild;
+
+import javax.annotation.Nonnull;
+import java.util.Locale;
+
+/**
+ * Indicates that the {@link Locale} of a {@link net.dv8tion.jda.api.entities.Guild Guild} changed.
+ *
+ * <p>Can be used to detect when a Locale changes and retrieve the old one
+ *
+ * <p>Identifier: {@code locale}
+ */
+@SuppressWarnings("ConstantConditions")
+public class GuildUpdateLocaleEvent extends GenericGuildUpdateEvent<Locale>
+{
+    public static final String IDENTIFIER = "locale";
+
+    public GuildUpdateLocaleEvent(@Nonnull JDA api, long responseNumber, @Nonnull Guild guild, @Nonnull Locale previous)
+    {
+        super(api, responseNumber, guild, previous, guild.getLocale(), IDENTIFIER);
+    }
+
+    @Nonnull
+    @Override
+    public Locale getOldValue()
+    {
+        return super.getOldValue();
+    }
+
+    @Nonnull
+    @Override
+    public Locale getNewValue()
+    {
+        return super.getNewValue();
+    }
+}

src/main/java/net/dv8tion/jda/api/hooks/ListenerAdapter.java

@@ -274,6 +274,7 @@ public void onGuildUpdateOwner(@Nonnull GuildUpdateOwnerEvent event) {}
     public void onGuildUpdateRegion(@Nonnull GuildUpdateRegionEvent event) {}
     public void onGuildUpdateSplash(@Nonnull GuildUpdateSplashEvent event) {}
     public void onGuildUpdateVerificationLevel(@Nonnull GuildUpdateVerificationLevelEvent event) {}
+    public void onGuildUpdateLocale(@Nonnull GuildUpdateLocaleEvent event) {}
     public void onGuildUpdateFeatures(@Nonnull GuildUpdateFeaturesEvent event) {}
     public void onGuildUpdateVanityCode(@Nonnull GuildUpdateVanityCodeEvent event) {}
     public void onGuildUpdateBanner(@Nonnull GuildUpdateBannerEvent event) {}
@@ -596,6 +597,8 @@ else if (event instanceof GuildUpdateSplashEvent)
             onGuildUpdateSplash((GuildUpdateSplashEvent) event);
         else if (event instanceof GuildUpdateVerificationLevelEvent)
             onGuildUpdateVerificationLevel((GuildUpdateVerificationLevelEvent) event);
+        else if (event instanceof GuildUpdateLocaleEvent)
+            onGuildUpdateLocale((GuildUpdateLocaleEvent) event);
         else if (event instanceof GuildUpdateFeaturesEvent)
             onGuildUpdateFeatures((GuildUpdateFeaturesEvent) event);
         else if (event instanceof GuildUpdateVanityCodeEvent)

src/main/java/net/dv8tion/jda/internal/entities/EntityBuilder.java

@@ -170,6 +170,7 @@ public GuildImpl createGuild(long guildId, DataObject guildJson, TLongObjectMap<
         final String description = guildJson.getString("description", null);
         final String vanityCode = guildJson.getString("vanity_url_code", null);
         final String bannerId = guildJson.getString("banner", null);
+        final String locale = guildJson.getString("preferred_locale", "en");
         final DataArray roleArray = guildJson.getArray("roles");
         final DataArray channelArray = guildJson.getArray("channels");
         final DataArray emotesArray = guildJson.getArray("emojis");
@@ -205,6 +206,7 @@ public GuildImpl createGuild(long guildId, DataObject guildJson, TLongObjectMap<
                 .setDefaultNotificationLevel(Guild.NotificationLevel.fromKey(notificationLevel))
                 .setExplicitContentLevel(Guild.ExplicitContentLevel.fromKey(explicitContentLevel))
                 .setRequiredMFALevel(Guild.MFALevel.fromKey(mfaLevel))
+                .setLocale(locale)
                 .setBoostCount(boostCount)
                 .setBoostTier(boostTier)
                 .setMemberCount(memberCount);

src/main/java/net/dv8tion/jda/internal/entities/GuildImpl.java

@@ -111,6 +111,7 @@ public class GuildImpl implements Guild
     private ExplicitContentLevel explicitContentLevel = ExplicitContentLevel.UNKNOWN;
     private Timeout afkTimeout;
     private BoostTier boostTier = BoostTier.NONE;
+    private Locale preferredLocale = Locale.ENGLISH;
     private boolean available;
     private boolean canSendVerification = false;
     private int memberCount;
@@ -249,6 +250,13 @@ public String getDescription()
         return description;
     }
 
+    @Nonnull
+    @Override
+    public Locale getLocale()
+    {
+        return preferredLocale;
+    }
+
     @Nullable
     @Override
     public String getBannerId()
@@ -1581,6 +1589,12 @@ public GuildImpl setAfkTimeout(Timeout afkTimeout)
         return this;
     }
 
+    public GuildImpl setLocale(String locale)
+    {
+        this.preferredLocale = Locale.forLanguageTag(locale);
+        return this;
+    }
+
     public GuildImpl setBoostTier(int tier)
     {
         this.boostTier = BoostTier.fromKey(tier);

src/main/java/net/dv8tion/jda/internal/handle/GuildUpdateHandler.java

@@ -27,6 +27,7 @@
 import net.dv8tion.jda.internal.requests.WebSocketClient;
 
 import java.util.Collections;
+import java.util.Locale;
 import java.util.Objects;
 import java.util.Set;
 import java.util.stream.Collectors;
@@ -80,6 +81,7 @@ protected Long handleInternally(DataObject content)
         Guild.MFALevel mfaLevel = Guild.MFALevel.fromKey(content.getInt("mfa_level"));
         Guild.ExplicitContentLevel explicitContentLevel = Guild.ExplicitContentLevel.fromKey(content.getInt("explicit_content_filter"));
         Guild.Timeout afkTimeout = Guild.Timeout.fromKey(content.getInt("afk_timeout"));
+        Locale locale = Locale.forLanguageTag(content.getString("preferred_locale"));
         VoiceChannel afkChannel = content.isNull("afk_channel_id")
                 ? null : guild.getVoiceChannelsView().get(content.getLong("afk_channel_id"));
         TextChannel systemChannel = content.isNull("system_channel_id")
@@ -263,6 +265,15 @@ protected Long handleInternally(DataObject content)
                             getJDA(), responseNumber,
                             guild, oldAfkTimeout));
         }
+        if (!Objects.equals(locale, guild.getLocale()))
+        {
+            Locale oldLocale = guild.getLocale();
+            guild.setLocale(locale.toLanguageTag());
+            getJDA().handleEvent(
+                new GuildUpdateLocaleEvent(
+                    getJDA(), responseNumber,
+                    guild, oldLocale));
+        }
         if (!Objects.equals(afkChannel, guild.getAfkChannel()))
         {
             VoiceChannel oldAfkChannel = guild.getAfkChannel();