New event for radio

Exiled.Events/EventArgs/Item/UsingRadioPickupBatteryEventArgs.cs

@@ -0,0 +1,45 @@
+// -----------------------------------------------------------------------
+// <copyright file="UsingRadioPickupBatteryEventArgs.cs" company="Exiled Team">
+// Copyright (c) Exiled Team. All rights reserved.
+// Licensed under the CC BY-SA 3.0 license.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Exiled.Events.EventArgs.Item
+{
+    using Exiled.API.Features.Pickups;
+    using Exiled.Events.EventArgs.Interfaces;
+
+    /// <summary>
+    /// Contains all information before radio pickup battery drains.
+    /// </summary>
+    public class UsingRadioPickupBatteryEventArgs : IDeniableEvent, IPickupEvent
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="UsingRadioPickupBatteryEventArgs"/> class.
+        /// </summary>
+        /// <param name="pickup"><inheritdoc cref="RadioPickup"/></param>
+        /// <param name="drain"><inheritdoc cref="Drain"/></param>
+        /// <param name="isAllowed"><inheritdoc cref="IsAllowed"/></param>
+        public UsingRadioPickupBatteryEventArgs(InventorySystem.Items.Radio.RadioPickup pickup, float drain, bool isAllowed = true)
+        {
+            RadioPickup = Pickup.Get(pickup).As<RadioPickup>();
+            Drain = drain;
+            IsAllowed = isAllowed;
+        }
+
+        /// <inheritdoc/>
+        public bool IsAllowed { get; set; }
+
+        /// <inheritdoc/>
+        public Pickup Pickup => RadioPickup;
+
+        /// <inheritdoc cref="Pickup"/>
+        public RadioPickup RadioPickup { get; }
+
+        /// <summary>
+        /// Gets or sets the radio percent drain.
+        /// </summary>
+        public float Drain { get; set; }
+    }
+}

Exiled.Events/Handlers/Item.cs

@@ -48,6 +48,11 @@ public static class Item
         /// </summary>
         public static Event<ChargingJailbirdEventArgs> ChargingJailbird { get; set; } = new();
 
+        /// <summary>
+        /// Invoked before a radio pickup is draining battery.
+        /// </summary>
+        public static Event<UsingRadioPickupBatteryEventArgs> UsingRadioPickupBattery { get; set; } = new();
+
         /// <summary>
         /// Called before the ammo of an firearm is changed.
         /// </summary>
@@ -83,5 +88,11 @@ public static class Item
         /// </summary>
         /// <param name="ev">The <see cref="ChargingJailbirdEventArgs"/> instance.</param>
         public static void OnChargingJailbird(ChargingJailbirdEventArgs ev) => ChargingJailbird.InvokeSafely(ev);
+
+        /// <summary>
+        /// Called before radio pickup is draining battery.
+        /// </summary>
+        /// <param name="ev">The <see cref="UsingRadioPickupBatteryEventArgs"/> instance.</param>
+        public static void OnUsingRadioPickupBattery(UsingRadioPickupBatteryEventArgs ev) => UsingRadioPickupBattery.InvokeSafely(ev);
     }
 }

Exiled.Events/Patches/Events/Item/UsingRadioPickupBattery.cs

@@ -0,0 +1,79 @@
+// -----------------------------------------------------------------------
+// <copyright file="UsingRadioPickupBattery.cs" company="Exiled Team">
+// Copyright (c) Exiled Team. All rights reserved.
+// Licensed under the CC BY-SA 3.0 license.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Exiled.Events.Patches.Events.Item
+{
+    using System.Collections.Generic;
+    using System.Reflection.Emit;
+
+    using Exiled.API.Features.Pools;
+    using Exiled.Events.EventArgs.Item;
+    using HarmonyLib;
+    using InventorySystem.Items.Radio;
+
+    using static HarmonyLib.AccessTools;
+
+    /// <summary>
+    /// Patches <see cref="RadioPickup.LateUpdate"/>
+    /// to add <see cref="Handlers.Item.UsingRadioPickupBattery"/> event.
+    /// </summary>
+    [HarmonyPatch(typeof(RadioPickup), nameof(RadioPickup.LateUpdate))]
+    internal class UsingRadioPickupBattery
+    {
+        private static IEnumerable<CodeInstruction> Transpiler(IEnumerable<CodeInstruction> instructions, ILGenerator generator)
+        {
+            List<CodeInstruction> newInstructions = ListPool<CodeInstruction>.Pool.Get(instructions);
+
+            LocalBuilder ev = generator.DeclareLocal(typeof(UsingRadioPickupBatteryEventArgs));
+
+            Label continueLabel = generator.DefineLabel();
+
+            int index = newInstructions.FindIndex(x => x.opcode == OpCodes.Ldloc_1);
+
+            newInstructions.InsertRange(
+                index,
+                new[]
+                {
+                    // this
+                    new(OpCodes.Ldarg_0),
+
+                    // num
+                    new(OpCodes.Ldloc_1),
+
+                    // true
+                    new(OpCodes.Ldc_I4_1),
+
+                    // UsingRadioPickupBatteryEventArgs ev = new(this, num, true);
+                    new(OpCodes.Newobj, GetDeclaredConstructors(typeof(UsingRadioPickupBatteryEventArgs))[0]),
+                    new(OpCodes.Dup),
+                    new(OpCodes.Dup),
+                    new(OpCodes.Stloc_S, ev.LocalIndex),
+
+                    // Handlers.Item.OnUsingRadioPickupBattery(ev);
+                    new(OpCodes.Call, Method(typeof(Handlers.Item), nameof(Handlers.Item.OnUsingRadioPickupBattery))),
+
+                    // if (ev.IsAllowed)
+                    //   goto continueLabel
+                    new(OpCodes.Callvirt, PropertyGetter(typeof(UsingRadioPickupBatteryEventArgs), nameof(UsingRadioPickupBatteryEventArgs.IsAllowed))),
+                    new(OpCodes.Brtrue_S, continueLabel),
+
+                    // return
+                    new(OpCodes.Ret),
+
+                    // num = ev.Drain;
+                    new CodeInstruction(OpCodes.Ldloc_S, ev.LocalIndex).WithLabels(continueLabel),
+                    new(OpCodes.Callvirt, PropertyGetter(typeof(UsingRadioPickupBatteryEventArgs), nameof(UsingRadioPickupBatteryEventArgs.Drain))),
+                    new(OpCodes.Stloc_1),
+                });
+
+            for (int z = 0; z < newInstructions.Count; z++)
+                yield return newInstructions[z];
+
+            ListPool<CodeInstruction>.Pool.Return(newInstructions);
+        }
+    }
+}