Class InputContextManager

Concrete implementation of IInputContextManager that maintains a registry of named InputContext objects and a LIFO stack of active contexts, applying action map changes and publishing Scylla events as contexts are pushed, popped, or removed.

Inheritance

object

InputContextManager

Implements

IInputContextManager

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Scylla.Input

Assembly: ScyllaInput.dll

Syntax

public class InputContextManager : IInputContextManager

Remarks

The internal stack is stored as a List<T> where index 0 is the top of the stack. All push operations insert at index 0 (Insert(0, context)) and all pop operations remove at index 0 (RemoveAt(0)), so ActiveContext is always _contextStack[0].

Blocking is evaluated lazily at query time (in IsContextBlocked(string) and ShouldProcessInput(string)) rather than cached, so blocking state always reflects the current stack composition without any explicit invalidation.

Every push and pop publishes three notifications: the C# event on this object, a SEX (Scylla Event eXchange) event via Scylla.Core.Events.ScyllaEvents.Publish<TEvent>(TEvent), and log entries at the Info level. Subscribers can choose whichever notification mechanism is most appropriate for their use case.

An instance is created and owned by the ScyllaInput module and accessed via ScyllaInput.Instance.ContextManager. Do not create additional instances independently of the module lifecycle.

Constructors

InputContextManager()

Initializes a new InputContextManager with empty context registry and stack. Call Initialize(IInputActionManager) before performing any stack operations.

Declaration

public InputContextManager()

Properties

ActiveContext

Gets the context currently at the top of the stack - the one whose action maps and blocking rules are applied most recently. Returns null when the stack is empty.

Declaration

public InputContext ActiveContext { get; }

Property Value

Type	Description
InputContext

ContextStack

Gets a read-only snapshot of the current context stack ordered from top (index 0) to bottom (highest index). Contexts lower in the list may be blocked depending on the blocking flags of contexts above them.

Declaration

public IReadOnlyList<InputContext> ContextStack { get; }

Property Value

Type	Description
IReadOnlyList<InputContext>

IsInitialized

Gets whether Initialize(IInputActionManager) has been called and completed successfully. Registration and stack operations are only valid while the manager is initialized. The value is reset to false by Shutdown().

Declaration

public bool IsInitialized { get; }

Property Value

Type	Description
bool

StackDepth

Gets the number of contexts currently on the stack. A value of 0 means the stack is empty and ActiveContext is null.

Declaration

public int StackDepth { get; }

Property Value

Type	Description
int

Methods

ClearContextStack()

Removes all contexts from the stack by calling PopContext() repeatedly until the stack is empty. Each pop fires the standard events.

Declaration

public void ClearContextStack()

GetAllContexts()

Returns a snapshot list containing all currently registered contexts in an unspecified order. The returned list is a new collection; modifications to it do not affect the manager's internal registry.

Declaration

public IReadOnlyList<InputContext> GetAllContexts()

Returns

Type	Description
IReadOnlyList<InputContext>	A new IReadOnlyList<T> of all registered InputContext instances. May be empty but never null.

GetContext(string)

Retrieves a registered context by its ID without affecting the stack.

Declaration

public InputContext GetContext(string contextID)

Parameters

Type	Name	Description
string	contextID	The ID of the context to retrieve. A null or empty string returns null.

Returns

Type	Description
InputContext	The InputContext instance, or null if no context with that ID is registered.

GetContextStackPosition(string)

Returns the zero-based position of the context in the stack, where 0 is the top (most recently pushed) context.

Declaration

public int GetContextStackPosition(string contextID)

Parameters

Type	Name	Description
string	contextID	The context ID to locate. A null or empty string returns -1.

Returns

Type	Description
int	The stack index of the context (0 = top), or -1 if the context is not on the stack.

HasContext(string)

Returns whether a context with the given ID is currently registered (not necessarily on the stack). Use IsContextActive(string) to check stack membership.

Declaration

public bool HasContext(string contextID)

Parameters

Type	Name	Description
string	contextID	The context ID to look up. A null or empty string returns false.

Returns

Type	Description
bool	true if a context with that ID exists in the registry; false otherwise.

Initialize(IInputActionManager)

Initializes the context manager with a reference to the action manager used to apply action map enable/disable changes when contexts are pushed or popped. Must be called once before any stack operations. Calling a second time while already initialized logs a warning and has no effect.

Declaration

public void Initialize(IInputActionManager actionManager)

Parameters

Type	Name	Description
IInputActionManager	actionManager	The IInputActionManager used to enable and disable Unity Input System action maps. Must not be null.

IsContextActive(string)

Returns whether the context with the given ID is currently present anywhere on the context stack. Does not indicate whether the context is blocked; use ShouldProcessInput(string) for combined active+unblocked checking.

Declaration

public bool IsContextActive(string contextID)

Parameters

Type	Name	Description
string	contextID	The context ID to look for. A null or empty string returns false.

Returns

Type	Description
bool	true if the context is on the stack at any position; false otherwise.

IsContextBlocked(string)

Returns whether the context with the given ID is prevented from receiving input by a higher-positioned context on the stack. A context that is not on the stack at all is also considered blocked (returns true).

Declaration

public bool IsContextBlocked(string contextID)

Parameters

Type	Name	Description
string	contextID	The context ID to evaluate. A null or empty string returns true (blocked).

Returns

Type	Description
bool	true if the context is not on the stack, or if any context above it on the stack has ConsumesAllInput set to true, or has BlocksLowerPriority set to true with a higher Priority value. false if the context is on the stack and no blocking context is above it.

PopContext()

Removes the context currently at the top of the stack, applies the new top context's action maps, fires the OnContextPopped and OnContextChanged events, and publishes the corresponding Scylla events.

Declaration

public InputContext PopContext()

Returns

Type	Description
InputContext	The context that was removed, or null if the stack was empty. A warning is logged when attempting to pop an empty stack.

PopToContext(string)

Repeatedly calls PopContext() until the specified context is at the top of the stack. If the context is not on the stack at all, no contexts are popped and 0 is returned. Each pop fires the standard events.

Declaration

public int PopToContext(string contextID)

Parameters

Type	Name	Description
string	contextID	The ID of the target context that should become the new top after popping. A null or empty string returns 0 immediately.

Returns

Type	Description
int	The number of contexts that were popped. Returns 0 if the target context is already at the top or is not on the stack.

PushContext(InputContext)

Pushes the given InputContext directly onto the top of the stack. If the context is not yet registered it is auto-registered before being pushed. Applies action maps and fires the same events as PushContext(string).

Declaration

public bool PushContext(InputContext context)

Parameters

Type	Name	Description
InputContext	context	The context to push. Must not be null. If the context is already on the stack the push is rejected and a warning is logged.

Returns

Type	Description
bool	true if the context was pushed successfully; false if context is null or the context is already on the stack.

PushContext(string)

Pushes a registered context onto the top of the stack by its ID. Applies the context's action maps, updates IsActive and IsTopContext flags, fires the OnContextPushed and OnContextChanged events, and publishes the corresponding Scylla events.

Declaration

public bool PushContext(string contextID)

Parameters

Type	Name	Description
string	contextID	The ID of the context to push. The context must already be registered via RegisterContext(InputContext). A null or empty string returns false without logging.

Returns

Type	Description
bool	true if the context was pushed successfully; false if the ID is null/empty, the context is not registered, or the context is already on the stack.

RegisterContext(InputContext)

Adds the given InputContext to the registry of known contexts so it can be pushed by ID later. Each context ID must be unique within the manager.

Declaration

public bool RegisterContext(InputContext context)

Parameters

Type	Name	Description
InputContext	context	The context to register. Must not be null and must have a non-null, non-empty ContextID.

Returns

Type	Description
bool	true if the context was added successfully; false if context is null, has an empty ID, or a context with the same ID is already registered. A warning is logged in all failure cases.

RemoveContext(string)

Removes a context from any position in the stack, not just the top. If the removed context was the top context, the new top is activated and action maps are re-applied. Fires OnContextPopped and, if the top changed, OnContextChanged.

Declaration

public bool RemoveContext(string contextID)

Parameters

Type	Name	Description
string	contextID	The ID of the context to remove. A null or empty string returns false.

Returns

Type	Description
bool	true if the context was found on the stack and removed; false if it was not on the stack.

ShouldProcessInput(string)

Returns whether a context is both on the stack and not blocked by any higher-priority context. Equivalent to IsContextActive(id) && !IsContextBlocked(id). Use this as the primary gate before polling input for a context-specific action.

Declaration

public bool ShouldProcessInput(string contextID)

Parameters

Type	Name	Description
string	contextID	The context ID to evaluate. A null or empty string returns false.

Returns

Type	Description
bool	true if the context is active and not blocked; false if the context is absent from the stack or is blocked by a higher context.

Shutdown()

Shuts down the context manager: clears the context stack (firing all pop events), clears the registry, releases the action manager reference, sets IsInitialized to false, and nullifies all event delegates. Has no effect if the manager is not currently initialized.

Declaration

public void Shutdown()

UnregisterContext(string)

Removes a context from the registry. If the context is currently on the stack it is also removed from the stack (equivalent to calling RemoveContext(string) first), triggering the appropriate events.

Declaration

public bool UnregisterContext(string contextID)

Parameters

Type	Name	Description
string	contextID	The ID of the context to unregister. A null or empty string causes the method to return false immediately without logging.

Returns

Type	Description
bool	true if a context with the given ID was found and removed; false if no such context is registered.

Update()

Performs any per-frame maintenance required by the context manager. Called automatically by the Input module each frame. The current implementation is a no-op because context changes are entirely event-driven, but the method is reserved for future features such as time-based context expiry.

Declaration

public void Update()

Events

OnContextChanged

Raised whenever the active (top-of-stack) context changes, either because a new context was pushed or the top context was popped or removed. The first argument is the previous top context (may be null if the stack was empty), and the second argument is the new top context (may be null if the stack is now empty).

Declaration

public event Action<InputContext, InputContext> OnContextChanged

Event Type

Type	Description
Action<InputContext, InputContext>

OnContextPopped

Raised after a context has been removed from the top of the stack (via PopContext()) or from an arbitrary position (via RemoveContext(string)) and its deactivation callback has been invoked. The argument is the removed context.

Declaration

public event Action<InputContext> OnContextPopped

Event Type

Type	Description
Action<InputContext>

OnContextPushed

Raised after a context has been pushed onto the stack and its action maps have been applied. The argument is the newly pushed context.

Declaration

public event Action<InputContext> OnContextPushed

Event Type

Type	Description
Action<InputContext>

Implements

IInputContextManager