Initial commit

mod/PLibCore/PStateMachines.cs

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+/*
+ * Copyright 2022 Peter Han
+ * 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.
+ */
+
+using System;
+
+namespace PeterHan.PLib.Core {
+	/// <summary>
+	/// Contains tools for dealing with state machines.
+	/// </summary>
+	public static class PStateMachines {
+		/// <summary>
+		/// Creates and initializes a new state. This method should be used in a postfix patch
+		/// on InitializeStates if new states are to be added.
+		/// </summary>
+		/// <typeparam name="T">The state machine type.</typeparam>
+		/// <typeparam name="I">The state machine Instance type.</typeparam>
+		/// <param name="sm">The base state machine.</param>
+		/// <param name="name">The state name.</param>
+		/// <returns>The new state.</returns>
+		public static GameStateMachine<T, I>.State CreateState<T, I>(
+				this GameStateMachine<T, I> sm, string name)
+				where T : GameStateMachine<T, I, IStateMachineTarget, object> where I :
+				GameStateMachine<T, I, IStateMachineTarget, object>.GameInstance {
+			var state = new GameStateMachine<T, I>.State();
+			if (string.IsNullOrEmpty(name))
+				name = "State";
+			if (sm == null)
+				throw new ArgumentNullException(nameof(sm));
+			state.defaultState = sm.GetDefaultState();
+			// Process any sub parameters
+			sm.CreateStates(state);
+			sm.BindState(sm.root, state, name);
+			return state;
+		}
+
+		/// <summary>
+		/// Creates and initializes a new state. This method should be used in a postfix patch
+		/// on InitializeStates if new states are to be added.
+		/// </summary>
+		/// <typeparam name="T">The state machine type.</typeparam>
+		/// <typeparam name="I">The state machine Instance type.</typeparam>
+		/// <typeparam name="M">The state machine Target type.</typeparam>
+		/// <param name="sm">The base state machine.</param>
+		/// <param name="name">The state name.</param>
+		/// <returns>The new state.</returns>
+		public static GameStateMachine<T, I, M>.State CreateState<T, I, M>(
+				this GameStateMachine<T, I, M> sm, string name) where M : IStateMachineTarget 
+				where T : GameStateMachine<T, I, M, object> where I :
+				GameStateMachine<T, I, M, object>.GameInstance {
+			var state = new GameStateMachine<T, I, M>.State();
+			if (string.IsNullOrEmpty(name))
+				name = "State";
+			if (sm == null)
+				throw new ArgumentNullException(nameof(sm));
+			state.defaultState = sm.GetDefaultState();
+			// Process any sub parameters
+			sm.CreateStates(state);
+			sm.BindState(sm.root, state, name);
+			return state;
+		}
+
+		/// <summary>
+		/// Clears the existing Enter actions on a state.
+		/// </summary>
+		/// <param name="state">The state to modify.</param>
+		public static void ClearEnterActions(this StateMachine.BaseState state) {
+			if (state != null)
+				state.enterActions.Clear();
+		}
+
+		/// <summary>
+		/// Clears the existing Exit actions on a state.
+		/// </summary>
+		/// <param name="state">The state to modify.</param>
+		public static void ClearExitActions(this StateMachine.BaseState state) {
+			if (state != null)
+				state.exitActions.Clear();
+		}
+
+		/// <summary>
+		/// Clears the existing Transition actions on a state. Parameter transitions are not
+		/// affected.
+		/// </summary>
+		/// <param name="state">The state to modify.</param>
+		public static void ClearTransitions(this StateMachine.BaseState state) {
+			if (state != null)
+				state.transitions.Clear();
+		}
+	}
+}