Predict Injector (syringes), cleanup (#25235)

At least the mode/transfer amount logic. Actual transfer logic needs Bloodstream which I didn't wanna move into shared.

Content.Shared/Chemistry/Components/InjectorComponent.cs

@@ -0,0 +1,104 @@
+using Content.Shared.Chemistry.EntitySystems;
+using Content.Shared.DoAfter;
+using Content.Shared.FixedPoint;
+using Robust.Shared.GameStates;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.Chemistry.Components;
+
+[Serializable, NetSerializable]
+public sealed partial class InjectorDoAfterEvent : SimpleDoAfterEvent
+{
+}
+
+/// <summary>
+/// Implements draw/inject behavior for droppers and syringes.
+/// </summary>
+/// <remarks>
+/// Can optionally support both
+/// injection and drawing or just injection. Can inject/draw reagents from solution
+/// containers, and can directly inject into a mobs bloodstream.
+/// </remarks>
+/// <seealso cref="SharedInjectorSystem"/>
+/// <seealso cref="InjectorToggleMode"/>
+[RegisterComponent, NetworkedComponent, AutoGenerateComponentState]
+public sealed partial class InjectorComponent : Component
+{
+    public const string SolutionName = "injector";
+
+    /// <summary>
+    /// Whether or not the injector is able to draw from containers or if it's a single use
+    /// device that can only inject.
+    /// </summary>
+    [DataField("injectOnly")]
+    public bool InjectOnly;
+
+    /// <summary>
+    /// Whether or not the injector is able to draw from or inject from mobs
+    /// </summary>
+    /// <remarks>
+    ///     for example: droppers would ignore mobs
+    /// </remarks>
+    [DataField("ignoreMobs")]
+    public bool IgnoreMobs;
+
+    /// <summary>
+    ///     The minimum amount of solution that can be transferred at once from this solution.
+    /// </summary>
+    [DataField("minTransferAmount")]
+    [ViewVariables(VVAccess.ReadWrite)]
+    public FixedPoint2 MinimumTransferAmount = FixedPoint2.New(5);
+
+    /// <summary>
+    ///     The maximum amount of solution that can be transferred at once from this solution.
+    /// </summary>
+    [DataField("maxTransferAmount")]
+    [ViewVariables(VVAccess.ReadWrite)]
+    public FixedPoint2 MaximumTransferAmount = FixedPoint2.New(50);
+
+    /// <summary>
+    /// Amount to inject or draw on each usage. If the injector is inject only, it will
+    /// attempt to inject it's entire contents upon use.
+    /// </summary>
+    [ViewVariables(VVAccess.ReadWrite)]
+    [DataField("transferAmount")]
+    [AutoNetworkedField]
+    public FixedPoint2 TransferAmount = FixedPoint2.New(5);
+
+    /// <summary>
+    /// Injection delay (seconds) when the target is a mob.
+    /// </summary>
+    /// <remarks>
+    /// The base delay has a minimum of 1 second, but this will still be modified if the target is incapacitated or
+    /// in combat mode.
+    /// </remarks>
+    [ViewVariables(VVAccess.ReadWrite)]
+    [DataField("delay")]
+    public TimeSpan Delay = TimeSpan.FromSeconds(5);
+
+    /// <summary>
+    /// The state of the injector. Determines it's attack behavior. Containers must have the
+    /// right SolutionCaps to support injection/drawing. For InjectOnly injectors this should
+    /// only ever be set to Inject
+    /// </summary>
+    [ViewVariables(VVAccess.ReadWrite)]
+    [AutoNetworkedField]
+    [DataField]
+    public InjectorToggleMode ToggleState = InjectorToggleMode.Draw;
+}
+
+/// <summary>
+/// Possible modes for an <see cref="InjectorComponent"/>.
+/// </summary>
+public enum InjectorToggleMode : byte
+{
+    /// <summary>
+    /// The injector will try to inject reagent into things.
+    /// </summary>
+    Inject,
+
+    /// <summary>
+    /// The injector will try to draw reagent from things.
+    /// </summary>
+    Draw
+}