Implement user banner & banner color

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

@@ -28,6 +28,7 @@
 import javax.annotation.CheckReturnValue;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
+import java.awt.Color;
 import java.util.Collection;
 import java.util.EnumSet;
 import java.util.List;
@@ -84,6 +85,11 @@ public interface User extends IMentionable
     String AVATAR_URL = "https://cdn.discordapp.com/avatars/%s/%s.%s";
     /** Template for {@link #getDefaultAvatarUrl()} */
     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";
+
+    /** 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
 
     /**
      * Creates a User instance which only wraps an ID.
@@ -220,6 +226,21 @@ default String getEffectiveAvatarUrl()
         return avatarUrl == null ? getDefaultAvatarUrl() : avatarUrl;
     }
 
+    /**
+     * Loads the user's {@link User.Profile} data.
+     * Returns a completed RestAction if this User has been retrieved using {@link JDA#retrieveUserById(long)}.
+     *
+     * @throws UnsupportedOperationException
+     *         If this User was created with {@link #fromId(long)}
+     *
+     * @return {@link RestAction} - Type: {@link User.Profile}
+     *
+     * @since 4.3.0
+     */
+    @Nonnull
+    @CheckReturnValue
+    RestAction<Profile> retrieveProfile();
+
     /**
      * The "tag" for this user
      * <p>This is the equivalent of calling {@link java.lang.String#format(String, Object...) String.format}("%#s", user)
@@ -344,6 +365,86 @@ default String getEffectiveAvatarUrl()
      */
     int getFlagsRaw();
 
+    /**
+     * Represents the information contained in a {@link User User}'s profile.
+     *
+     * @since 4.3.0
+     */
+    class Profile
+    {
+        private final long userId;
+        private final String bannerId;
+        private final int accentColor;
+
+        public Profile(long userId, String bannerId, int accentColor)
+        {
+            this.userId = userId;
+            this.bannerId = bannerId;
+            this.accentColor = accentColor;
+        }
+
+        /**
+         * The Discord Id for this user's banner image.
+         * If the user has not set a banner, this will return null.
+         *
+         * @return Possibly-null String containing the {@link User User} banner id.
+         */
+        @Nullable
+        public String getBannerId()
+        {
+            return bannerId;
+        }
+
+        /**
+         * The URL for the user's banner image.
+         * If the user has not set a banner, this will return null.
+         *
+         * @return Possibly-null String containing the {@link User User} banner url.
+         *
+         * @see User#BANNER_URL
+         */
+        @Nullable
+        public String getBannerUrl()
+        {
+            return bannerId == null ? null : String.format(BANNER_URL, Long.toUnsignedString(userId), bannerId, bannerId.startsWith("a_") ? "gif" : "png");
+        }
+
+        /**
+         * The user's accent color.
+         * If the user has not set an accent color, this will return null.
+         * The automatically calculated color is not returned.
+         * The accent color is not shown in the client if the user has set a banner.
+         *
+         * @return Possibly-null {@link java.awt.Color} containing the {@link User User} accent color.
+         */
+        @Nullable
+        public Color getAccentColor()
+        {
+            return accentColor == DEFAULT_ACCENT_COLOR_RAW ? null : new Color(accentColor);
+        }
+
+        /**
+         * The raw RGB value of this user's accent color.
+         * <br>Defaults to {@link #DEFAULT_ACCENT_COLOR_RAW} if this user's banner color is not available.
+         *
+         * @return The raw RGB color value or {@link User#DEFAULT_ACCENT_COLOR_RAW}
+         */
+        public int getAccentColorRaw()
+        {
+            return accentColor;
+        }
+
+        @Override
+        public String toString()
+        {
+            return "UserProfile(" +
+                    "userId=" + userId +
+                    ", bannerId='" + bannerId + "'" +
+                    ", accentColor=" + accentColor +
+                    ')';
+        }
+    }
+
     /**
      * Represents the bit offsets used by Discord for public flags
      */

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

@@ -345,6 +345,10 @@ public UserImpl createUser(DataObject user)
             }
         }
 
+        User.Profile profile = user.hasKey("banner")
+            ? new User.Profile(id, user.getString("banner", null), user.getInt("accent_color", User.DEFAULT_ACCENT_COLOR_RAW))
+            : null;
+
         if (newUser)
         {
             // Initial creation
@@ -353,7 +357,8 @@ public UserImpl createUser(DataObject user)
                    .setAvatarId(user.getString("avatar", null))
                    .setBot(user.getBoolean("bot"))
                    .setSystem(user.getBoolean("system"))
-                   .setFlags(user.getInt("public_flags", 0));
+                   .setFlags(user.getInt("public_flags", 0))
+                   .setProfile(profile);
         }
         else
         {

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

@@ -102,6 +102,14 @@ public String getAvatarId()
         return null;
     }
 
+    @Nonnull
+    @Override
+    public RestAction<Profile> retrieveProfile()
+    {
+        unsupported();
+        return null;
+    }
+
     @Nonnull
     @Override
     public String getDefaultAvatarId()

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

@@ -41,6 +41,7 @@ public class UserImpl extends UserById implements User
     protected short discriminator;
     protected String name;
     protected String avatarId;
+    protected Profile profile;
     protected long privateChannel = 0L;
     protected boolean bot;
     protected boolean system;
@@ -73,6 +74,28 @@ public String getAvatarId()
         return avatarId;
     }
 
+    @Nonnull
+    @Override
+    public RestAction<Profile> retrieveProfile()
+    {
+        return new DeferredRestAction<>(getJDA(), Profile.class, this::getProfile, () -> {
+            Route.CompiledRoute route = Route.Users.GET_USER.compile(getId());
+            return new RestActionImpl<>(getJDA(), route, (response, request) -> {
+                DataObject json = response.getObject();
+
+                String bannerId = json.getString("banner", null);
+                int accentColor = json.getInt("accent_color", User.DEFAULT_ACCENT_COLOR_RAW);
+
+                return new Profile(getIdLong(), bannerId, accentColor);
+            });
+        });
+    }
+
+    public Profile getProfile()
+    {
+        return profile;
+    }
+
     @Nonnull
     @Override
     public String getDefaultAvatarId()
@@ -182,6 +205,12 @@ public UserImpl setAvatarId(String avatarId)
         return this;
     }
 
+    public UserImpl setProfile(Profile profile)
+    {
+        this.profile = profile;
+        return this;
+    }
+
     public UserImpl setPrivateChannel(PrivateChannel privateChannel)
     {
         if (privateChannel != null)