Feature: Add API to show/hide GUI elements (#4705)

* Add API to show/hide GUI elements
* Bump version to 2.3.2
---------

Co-authored-by: Konicai <71294714+Konicai@users.noreply.github.com>

api/src/main/java/org/geysermc/geyser/api/bedrock/camera/CameraData.java

@@ -145,4 +145,36 @@ public interface CameraData {
      * @return whether the camera is currently locked
      */
     boolean isCameraLocked();
-}
+
+    /**
+     * Hides a {@link GuiElement} on the client's side.
+     *
+     * @param element the {@link GuiElement} to hide
+     */
+    void hideElement(@NonNull GuiElement... element);
+
+    /**
+     * Resets a {@link GuiElement} on the client's side.
+     * This makes the client decide on its own - e.g. based on client settings -
+     * whether to show or hide the gui element.
+     * <p>
+     * If no elements are specified, this will reset all currently hidden elements
+     *
+     * @param element the {@link GuiElement} to reset
+     */
+    void resetElement(@NonNull GuiElement @Nullable... element);
+
+    /**
+     * Determines whether a {@link GuiElement} is currently hidden.
+     *
+     * @param element the {@link GuiElement} to check
+     */
+    boolean isHudElementHidden(@NonNull GuiElement element);
+
+    /**
+     * Returns the currently hidden {@link GuiElement}s.
+     *
+     * @return an unmodifiable view of all currently hidden {@link GuiElement}s
+     */
+    @NonNull Set<GuiElement> hiddenElements();
+}

api/src/main/java/org/geysermc/geyser/api/bedrock/camera/GuiElement.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2024 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.api.bedrock.camera;
+
+/**
+ * Represent GUI elements on the players HUD display.
+ * These can be hidden using {@link CameraData#hideElement(GuiElement...)},
+ * and one can reset their visibility using {@link CameraData#resetElement(GuiElement...)}.
+ */
+public class GuiElement {
+    public static final GuiElement PAPER_DOLL = new GuiElement(0);
+    public static final GuiElement ARMOR = new GuiElement(1);
+    public static final GuiElement TOOL_TIPS = new GuiElement(2);
+    public static final GuiElement TOUCH_CONTROLS = new GuiElement(3);
+    public static final GuiElement CROSSHAIR = new GuiElement(4);
+    public static final GuiElement HOTBAR = new GuiElement(5);
+    public static final GuiElement HEALTH = new GuiElement(6);
+    public static final GuiElement PROGRESS_BAR = new GuiElement(7);
+    public static final GuiElement FOOD_BAR = new GuiElement(8);
+    public static final GuiElement AIR_BUBBLES_BAR = new GuiElement(9);
+    public static final GuiElement VEHICLE_HEALTH = new GuiElement(10);
+    public static final GuiElement EFFECTS_BAR = new GuiElement(11);
+    public static final GuiElement ITEM_TEXT_POPUP = new GuiElement(12);
+
+    private GuiElement(int id) {
+        this.id = id;
+    }
+
+    private final int id;
+
+    /**
+     * Internal use only; don't depend on these values being consistent.
+     */
+    public int id() {
+        return this.id;
+    }
+}

core/src/main/java/org/geysermc/geyser/impl/camera/GeyserCameraData.java

@@ -32,24 +32,50 @@ import org.cloudburstmc.math.vector.Vector2f;
 import org.cloudburstmc.math.vector.Vector3f;
 import org.cloudburstmc.protocol.bedrock.data.CameraShakeAction;
 import org.cloudburstmc.protocol.bedrock.data.CameraShakeType;
+import org.cloudburstmc.protocol.bedrock.data.HudElement;
+import org.cloudburstmc.protocol.bedrock.data.HudVisibility;
 import org.cloudburstmc.protocol.bedrock.data.camera.CameraEase;
 import org.cloudburstmc.protocol.bedrock.data.camera.CameraFadeInstruction;
 import org.cloudburstmc.protocol.bedrock.data.camera.CameraSetInstruction;
 import org.cloudburstmc.protocol.bedrock.packet.CameraInstructionPacket;
 import org.cloudburstmc.protocol.bedrock.packet.CameraShakePacket;
 import org.cloudburstmc.protocol.bedrock.packet.PlayerFogPacket;
-import org.geysermc.geyser.api.bedrock.camera.*;
+import org.cloudburstmc.protocol.bedrock.packet.SetHudPacket;
+import org.geysermc.geyser.api.bedrock.camera.CameraData;
+import org.geysermc.geyser.api.bedrock.camera.CameraEaseType;
+import org.geysermc.geyser.api.bedrock.camera.CameraFade;
+import org.geysermc.geyser.api.bedrock.camera.CameraPerspective;
+import org.geysermc.geyser.api.bedrock.camera.CameraPosition;
+import org.geysermc.geyser.api.bedrock.camera.CameraShake;
+import org.geysermc.geyser.api.bedrock.camera.GuiElement;
 import org.geysermc.geyser.session.GeyserSession;
+import org.geysermc.mcprotocollib.protocol.data.game.entity.player.GameMode;
 
-import java.util.*;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Objects;
+import java.util.Set;
+import java.util.UUID;
 
 public class GeyserCameraData implements CameraData {
+    private static final HudElement[] HUD_ELEMENT_VALUES = HudElement.values();
+    private static final Set<HudElement> ALL_HUD_ELEMENTS = Set.of(HUD_ELEMENT_VALUES);
+
+    /**
+     * An array of elements to hide when the player is in spectator mode.
+     * Helps with tidying up the GUI; Java-style.
+     */
+    private static final GuiElement[] SPECTATOR_HIDDEN_ELEMENTS = {
+            GuiElement.AIR_BUBBLES_BAR,
+            GuiElement.ARMOR,
+            GuiElement.HEALTH,
+            GuiElement.FOOD_BAR,
+            GuiElement.PROGRESS_BAR,
+            GuiElement.TOOL_TIPS
+    };
 
     private final GeyserSession session;
 
-    @Getter
-    private CameraPerspective cameraPerspective;
-
     /**
      * All fog effects that are currently applied to the client.
      */
@@ -57,6 +83,14 @@ public class GeyserCameraData implements CameraData {
 
     private final Set<UUID> cameraLockOwners = new HashSet<>();
 
+    /**
+     * All currently hidden HUD elements
+     */
+    private final Set<GuiElement> hiddenHudElements = new HashSet<>();
+
+    @Getter
+    private CameraPerspective cameraPerspective;
+
     public GeyserCameraData(GeyserSession session) {
         this.session = session;
     }
@@ -223,4 +257,67 @@ public class GeyserCameraData implements CameraData {
     public boolean isCameraLocked() {
         return !this.cameraLockOwners.isEmpty();
     }
-}
+
+    @Override
+    public void hideElement(GuiElement... elements) {
+        Objects.requireNonNull(elements);
+        SetHudPacket packet = new SetHudPacket();
+        packet.setVisibility(HudVisibility.HIDE);
+        Set<HudElement> elementSet = packet.getElements();
+
+        for (GuiElement element : elements) {
+            this.hiddenHudElements.add(element);
+            elementSet.add(HUD_ELEMENT_VALUES[element.id()]);
+        }
+
+        session.sendUpstreamPacket(packet);
+    }
+
+    @Override
+    public void resetElement(GuiElement... elements) {
+        SetHudPacket packet = new SetHudPacket();
+        packet.setVisibility(HudVisibility.RESET);
+        Set<HudElement> elementSet = packet.getElements();
+
+        if (elements != null && elements.length != 0) {
+            for (GuiElement element : elements) {
+                this.hiddenHudElements.remove(element);
+                elementSet.add(HUD_ELEMENT_VALUES[element.id()]);
+            }
+        } else {
+            this.hiddenHudElements.clear();
+            elementSet.addAll(ALL_HUD_ELEMENTS);
+        }
+
+        session.sendUpstreamPacket(packet);
+    }
+
+    @Override
+    public boolean isHudElementHidden(@NonNull GuiElement element) {
+        Objects.requireNonNull(element);
+        return this.hiddenHudElements.contains(element);
+    }
+
+    @Override
+    public @NonNull Set<GuiElement> hiddenElements() {
+        return Collections.unmodifiableSet(hiddenHudElements);
+    }
+
+    /**
+     * Deals with hiding hud elements while in spectator.
+     *
+     * @param currentlySpectator whether the player is currently in spectator mode
+     * @param newGameMode the new GameMode to switch to
+     */
+    public void handleGameModeChange(boolean currentlySpectator, GameMode newGameMode) {
+        if (newGameMode == GameMode.SPECTATOR) {
+            if (!currentlySpectator) {
+                hideElement(SPECTATOR_HIDDEN_ELEMENTS);
+            }
+        } else {
+            if (currentlySpectator) {
+                resetElement(SPECTATOR_HIDDEN_ELEMENTS);
+            }
+        }
+    }
+}

core/src/main/java/org/geysermc/geyser/session/GeyserSession.java

@@ -284,7 +284,6 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
      */
     private volatile boolean closed;
 
-    @Setter
     private GameMode gameMode = GameMode.SURVIVAL;
 
     /**
@@ -1302,6 +1301,12 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
         }
     }
 
+    public void setGameMode(GameMode newGamemode) {
+        boolean currentlySpectator = this.gameMode == GameMode.SPECTATOR;
+        this.gameMode = newGamemode;
+        this.cameraData.handleGameModeChange(currentlySpectator, newGamemode);
+    }
+
     /**
      * Checks to see if a shield is in either hand to activate blocking. If so, it sets the Bedrock client to display
      * blocking and sends a packet to the Java server.

gradle.properties

@@ -7,5 +7,5 @@ org.gradle.vfs.watch=false
 
 group=org.geysermc
 id=geyser
-version=2.3.1-SNAPSHOT
+version=2.3.2-SNAPSHOT
 description=Allows for players from Minecraft: Bedrock Edition to join Minecraft: Java Edition servers.