Adds support for user's avatar decorations

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

@@ -89,6 +89,8 @@ public interface User extends UserSnowflake
     String DEFAULT_AVATAR_URL = "https://cdn.discordapp.com/embed/avatars/%s.png";
     /** Template for {@link Profile#getBannerUrl()} */
     String BANNER_URL = "https://cdn.discordapp.com/banners/%s/%s.%s";
+    /** Template for {@link AvatarDecoration#getDecorationAvatarUrl()} */
+    String DECORATION_AVATAR_URL = "https://cdn.discordapp.com/avatar-decoration-presets/%s.png";
 
     /** Used to keep consistency between color values used in the API */
     int DEFAULT_ACCENT_COLOR_RAW = 0x1FFFFFFF; // java.awt.Color fills the MSB with FF, we just use 1F to provide better consistency
@@ -361,6 +363,14 @@ default ImageProxy getEffectiveAvatar()
      */
     int getFlagsRaw();
 
+    /**
+     * Returns the possibly-null {@link AvatarDecoration} of this user. If the user has not set a decoration avatar, this will return null.
+     *
+     * @return The possibly-null avatar decoration of this user
+     */
+    @Nullable
+    AvatarDecoration getAvatarDecoration();
+
     /**
      * Represents the information contained in a {@link User User}'s profile.
      *
@@ -455,6 +465,70 @@ public String toString()
         }
     }
 
+    /**
+     * Represents the avatar decoration of a {@link User User}.
+     */
+    class AvatarDecoration
+    {
+
+        private final String decorationAvatarId;
+        private final String skuId;
+
+        public AvatarDecoration(String decorationAvatarId, String skuId)
+        {
+            this.decorationAvatarId = decorationAvatarId;
+            this.skuId = skuId;
+        }
+
+        /**
+         * The never-null SKU id of the {@link User User} decoration avatar.
+         *
+         * @return The never-null SKU id of the {@link User User} decoration avatar.
+         */
+        @Nonnull
+        public String getSkuId()
+        {
+            return skuId;
+        }
+
+        /**
+         * The never-null avatar ID for this user's decoration avatar image.
+         *
+         * @return The never-null avatar ID for this user's decoration avatar image.
+         */
+        @Nonnull
+        public String getDecorationAvatarId()
+        {
+            return decorationAvatarId;
+        }
+
+        /**
+         * The URL for the user's decoration avatar image.
+         *
+         * @return The never-null String containing the {@link User User} decoration avatar url.
+         *
+         * @see User#DECORATION_AVATAR_URL
+         */
+        @Nonnull
+        public String getDecorationAvatarUrl()
+        {
+            return String.format(DECORATION_AVATAR_URL, decorationAvatarId);
+        }
+
+        /**
+         * Returns an {@link ImageProxy} for this user's decoration avatar.
+         *
+         * @return Never-null {@link ImageProxy} of this user's decoration avatar
+         *
+         * @see    #getDecorationAvatarUrl()
+         */
+        @Nonnull
+        public ImageProxy getDecorationAvatar()
+        {
+            return new ImageProxy(getDecorationAvatarUrl());
+        }
+    }
+
     /**
      * Represents the bit offsets used by Discord for public flags
      */

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

@@ -450,13 +450,18 @@ public UserImpl createUser(DataObject user)
             ? new User.Profile(id, user.getString("banner", null), user.getInt("accent_color", User.DEFAULT_ACCENT_COLOR_RAW))
             : null;
 
+        User.AvatarDecoration avatarDecoration = user.optObject("avatar_decoration_data")
+                .map(o -> new User.AvatarDecoration(o.getString("asset"), o.getString("sku_id")))
+                .orElse(null);
+
         if (newUser)
         {
             // Initial creation
             userObj.setName(user.getString("username"))
                    .setGlobalName(user.getString("global_name", null))
                    .setDiscriminator(Short.parseShort(user.getString("discriminator", "0")))
                    .setAvatarId(user.getString("avatar", null))
+                   .setAvatarDecoration(avatarDecoration)
                    .setBot(user.getBoolean("bot"))
                    .setSystem(user.getBoolean("system"))
                    .setFlags(user.getInt("public_flags", 0))

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

@@ -45,6 +45,7 @@ public class UserImpl extends UserSnowflakeImpl implements User
     protected String name;
     protected String globalName;
     protected String avatarId;
+    protected AvatarDecoration avatarDecoration;
     protected Profile profile;
     protected long privateChannelId = 0L;
     protected boolean bot;
@@ -191,6 +192,13 @@ public int getFlagsRaw()
         return flags;
     }
 
+    @Nullable
+    @Override
+    public User.AvatarDecoration getAvatarDecoration()
+    {
+        return avatarDecoration;
+    }
+
     @Override
     public String toString()
     {
@@ -225,6 +233,12 @@ public UserImpl setAvatarId(String avatarId)
         return this;
     }
 
+    public UserImpl setAvatarDecoration(AvatarDecoration avatarDecoration)
+    {
+        this.avatarDecoration = avatarDecoration;
+        return this;
+    }
+
     public UserImpl setProfile(Profile profile)
     {
         this.profile = profile;