Class InputControlPath

Functions for working with control path specs (like "/gamepad/*stick").

Inheritance

Object

InputControlPath

Namespace: UnityEngine.InputSystem

Syntax

public static class InputControlPath

Remarks

Control paths are a mini-language similar to regular expressions. They are used throughout the input system as string "addresses" of input controls. At runtime, they can be matched against the devices and controls present in the system to retrieve the actual endpoints to receive input from.

Like on a file system, a path is made up of components that are each separated by a forward slash (/). Each such component in turn is made up of a set of fields that are individually optional. However, one of the fields must be present (e.g. at least a name or a wildcard).

Field structure of each path component

<Layout>{Usage}#(DisplayName)Name

• Layout: The name of the layout that the control must be based on (either directly or indirectly).
• Usage: The usage that the control or device has to have, i.e. must be found in usages This field can be repeated several times to require multiple usages (e.g. "{LeftHand}{Vertical}").
• DisplayName: The name that displayName of the control or device must match.
• Name: The name that name or one of the entries in aliases must match. Alternatively, this can be a wildcard (*) to match any name.

Note that all matching is case-insensitive.

Various examples of control paths

// Matches all gamepads (also gamepads *based* on the Gamepad layout):
"<Gamepad>"

// Matches the "Submit" control on all devices:
"*/{Submit}"

// Matches the key that prints the "a" character on the current keyboard layout:
"<Keyboard>/#(a)"

// Matches the X axis of the left stick on a gamepad.
"<Gamepad>/leftStick/x"

// Matches the orientation control of the right-hand XR controller:
"<XRController>{RightHand}/orientation"

// Matches all buttons on a gamepad.
"<Gamepad>/<Button>"

The structure of the API of this class is similar in spirit to System.IO.Path, i.e. it offers a range of static methods that perform various operations on path strings.

To query controls on devices present in the system using control paths, use FindControls(String). Also, control paths can be used with Item[String] on every control. This makes it possible to do things like:

Find key that prints "t" on current keyboard:

Keyboard.current["#(t)"]

Fields

DoubleWildcard

Declaration

public const string DoubleWildcard = "**"

Field Value

Type	Description
String

Separator

Declaration

public const char Separator = '/'

Field Value

Type	Description
Char

Wildcard

Declaration

public const string Wildcard = "*"

Field Value

Type	Description
String

Methods

Combine(InputControl, String)

Declaration

public static string Combine(InputControl parent, string path)

Parameters

Type	Name	Description
InputControl	parent
String	path

Returns

Type	Description
String

Matches(String, InputControl)

Declaration

public static bool Matches(string expected, InputControl control)

Parameters

Type	Name	Description
String	expected
InputControl	control

Returns

Type	Description
Boolean

MatchesPrefix(String, InputControl)

Check whether the given path matches control or any of its parents.

Declaration

public static bool MatchesPrefix(string expected, InputControl control)

Parameters

Type	Name	Description
String	expected	A control path.
InputControl	control	An input control.

Returns

Type	Description
Boolean	True if the given path matches at least a partial path to control.

Remarks

// True as the path matches the Keyboard device itself, i.e. the parent of
// Keyboard.aKey.
InputControlPath.MatchesPrefix("<Keyboard>", Keyboard.current.aKey);

// False as the path matches none of the controls leading to Keyboard.aKey.
InputControlPath.MatchesPrefix("<Gamepad>", Keyboard.current.aKey);

// True as the path matches Keyboard.aKey itself.
InputControlPath.MatchesPrefix("<Keyboard>/a", Keyboard.current.aKey);

Exceptions

Type	Condition
ArgumentNullException	expected is null or empty -or- control is null.

Parse(String)

Splits a control path into its separate components.

Declaration

public static IEnumerable<InputControlPath.ParsedPathComponent> Parse(string path)

Parameters

Type	Name	Description
String	path	A control path such as "<Gamepad>/buttonSouth".

Returns

Type	Description
IEnumerable<InputControlPath.ParsedPathComponent>	An enumeration of the parsed components. The enumeration is empty if the given path is empty.

Remarks

You can use this method, for example, to separate out the components in a binding's path.

var parsed = InputControlPath.Parse("<XRController>{LeftHand}/trigger").ToArray();

Debug.Log(parsed.Length); // Prints 2.
Debug.Log(parsed[0].layout); // Prints "XRController".
Debug.Log(parsed[0].name); // Prints an empty string.
Debug.Log(parsed[0].usages.First()); // Prints "LeftHand".
Debug.Log(parsed[1].layout); // Prints null.
Debug.Log(parsed[1].name); // Prints "trigger".

// Find out if the given device layout is based on "TrackedDevice".
Debug.Log(InputSystem.IsFirstLayoutBasedOnSecond(parsed[0].layout, "TrackedDevice")); // Prints true.

// Load the device layout referenced by the path.
var layout = InputSystem.LoadLayout(parsed[0].layout);
Debug.Log(layout.baseLayouts.First()); // Prints "TrackedDevice".

Exceptions

Type	Condition
ArgumentNullException	path is null or empty.

See Also

path

FindControl(String)

ToHumanReadableString(String, out String, out String, InputControlPath.HumanReadableStringOptions, InputControl)

Create a human readable string from the given control path.

Declaration

public static string ToHumanReadableString(string path, out string deviceLayoutName, out string controlPath, InputControlPath.HumanReadableStringOptions options = InputControlPath.HumanReadableStringOptions.None, InputControl control = null)

Parameters

Type	Name	Description
String	path	A control path such as "<XRController>{LeftHand}/position".
String	deviceLayoutName	Receives the name of the device layout that the control path was resolved to. This is useful
String	controlPath	Receives the path to the referenced control on the device or null if not applicable. For example, with a path of "<Gamepad>/dpad/up", the resulting control path will be "dpad/up". This is useful when trying to look up additional resources (such as images) based on the control that is being referenced.
InputControlPath.HumanReadableStringOptions	options	Customize the resulting string.
InputControl	control	An optional control. If supplied and the control or one of its children matches the given path, display names will be based on the matching control rather than on static information available from InputControlLayouts.

Returns

Type	Description
String	A string such as "Left Stick/X [Gamepad]".

Remarks

This function is most useful for turning binding paths (see path) into strings that can be displayed in UIs (such as rebinding screens). It is used by the Unity editor itself to display binding paths in the UI.

The method uses display names (see displayName, displayName, and displayName) where possible. For example, "<XInputController>/buttonSouth" will be returned as "A [Xbox Controller]" as the display name of XInputController is "XBox Controller" and the display name of its "buttonSouth" control is "A".

Note that these lookups depend on the currently registered control layouts (see InputControlLayout) and different strings may thus be returned for the same control path depending on the layouts registered with the system.

InputControlPath.ToHumanReadableString("*/{PrimaryAction"); // -> "PrimaryAction [Any]"
InputControlPath.ToHumanReadableString("<Gamepad>/buttonSouth"); // -> "Button South [Gamepad]"
InputControlPath.ToHumanReadableString("<XInputController>/buttonSouth"); // -> "A [Xbox Controller]"
InputControlPath.ToHumanReadableString("<Gamepad>/leftStick/x"); // -> "Left Stick/X [Gamepad]"

See Also

path

ToDisplayString(InputBinding.DisplayStringOptions, InputControl)

GetBindingDisplayString(InputAction, Int32, InputBinding.DisplayStringOptions)

ToHumanReadableString(String, InputControlPath.HumanReadableStringOptions, InputControl)

Create a human readable string from the given control path.

Declaration

public static string ToHumanReadableString(string path, InputControlPath.HumanReadableStringOptions options = InputControlPath.HumanReadableStringOptions.None, InputControl control = null)

Parameters

Type	Name	Description
String	path	A control path such as "<XRController>{LeftHand}/position".
InputControlPath.HumanReadableStringOptions	options	Customize the resulting string.
InputControl	control	An optional control. If supplied and the control or one of its children matches the given path, display names will be based on the matching control rather than on static information available from InputControlLayouts.

Returns

Type	Description
String	A string such as "Left Stick/X [Gamepad]".

Remarks

This function is most useful for turning binding paths (see path) into strings that can be displayed in UIs (such as rebinding screens). It is used by the Unity editor itself to display binding paths in the UI.

The method uses display names (see displayName, displayName, and displayName) where possible. For example, "<XInputController>/buttonSouth" will be returned as "A [Xbox Controller]" as the display name of XInputController is "XBox Controller" and the display name of its "buttonSouth" control is "A".

Note that these lookups depend on the currently registered control layouts (see InputControlLayout) and different strings may thus be returned for the same control path depending on the layouts registered with the system.

InputControlPath.ToHumanReadableString("*/{PrimaryAction"); // -> "PrimaryAction [Any]"
InputControlPath.ToHumanReadableString("<Gamepad>/buttonSouth"); // -> "Button South [Gamepad]"
InputControlPath.ToHumanReadableString("<XInputController>/buttonSouth"); // -> "A [Xbox Controller]"
InputControlPath.ToHumanReadableString("<Gamepad>/leftStick/x"); // -> "Left Stick/X [Gamepad]"

See Also

path

ToDisplayString(InputBinding.DisplayStringOptions, InputControl)

GetBindingDisplayString(InputAction, Int32, InputBinding.DisplayStringOptions)

TryFindChild(InputControl, String, Int32)

Declaration

public static InputControl TryFindChild(InputControl control, string path, int indexInPath = 0)

Parameters

Type	Name	Description
InputControl	control
String	path
Int32	indexInPath

Returns

Type	Description
InputControl

TryFindChild<TControl>(InputControl, String, Int32)

Declaration

public static TControl TryFindChild<TControl>(InputControl control, string path, int indexInPath = 0)
    where TControl : InputControl

Parameters

Type	Name	Description
InputControl	control
String	path
Int32	indexInPath

Returns

Type	Description
TControl

Type Parameters

Name	Description
TControl

TryFindControl(InputControl, String, Int32)

Declaration

public static InputControl TryFindControl(InputControl control, string path, int indexInPath = 0)

Parameters

Type	Name	Description
InputControl	control
String	path
Int32	indexInPath

Returns

Type	Description
InputControl

TryFindControl<TControl>(InputControl, String, Int32)

Return the first child control that matches the given path.

Declaration

public static TControl TryFindControl<TControl>(InputControl control, string path, int indexInPath = 0)
    where TControl : InputControl

Parameters

Type	Name	Description
InputControl	control	Control root at which to start the search.
String	path	Path of the control to find. Can be null or empty, in which case null is returned.
Int32	indexInPath	Index in path at which to start parsing. Defaults to 0, i.e. parsing starts at the first character in the path.

Returns

Type	Description
TControl	The first (direct or indirect) child control of control that matches path.

Type Parameters

Name	Description
TControl

Remarks

Does not allocate.

Note that if multiple child controls match the given path, which one is returned depends on the ordering of controls. The result should be considered indeterministic in this case.

// Find X control of left stick on current gamepad.
InputControlPath.TryFindControl(Gamepad.current, "leftStick/x");

// Find control with PrimaryAction usage on current mouse.
InputControlPath.TryFindControl(Mouse.current, "{PrimaryAction}");

Exceptions

Type	Condition
ArgumentNullException	control is null.

See Also

Item[String]

TryFindControls(InputControl, String, Int32)

Declaration

public static InputControl[] TryFindControls(InputControl control, string path, int indexInPath = 0)

Parameters

Type	Name	Description
InputControl	control
String	path
Int32	indexInPath

Returns

Type	Description
InputControl[]

TryFindControls(InputControl, String, ref InputControlList<InputControl>, Int32)

Declaration

public static int TryFindControls(InputControl control, string path, ref InputControlList<InputControl> matches, int indexInPath = 0)

Parameters

Type	Name	Description
InputControl	control
String	path
InputControlList<InputControl>	matches
Int32	indexInPath

Returns

Type	Description
Int32

TryFindControls<TControl>(InputControl, String, Int32, ref InputControlList<TControl>)

Perform a search for controls starting with the given control as root and matching the given path from the given position. Puts all matching controls on the list and returns the number of controls that have been matched.

Declaration

public static int TryFindControls<TControl>(InputControl control, string path, int indexInPath, ref InputControlList<TControl> matches)
    where TControl : InputControl

Parameters

Type	Name	Description
InputControl	control	Control at which the given path is rooted.
String	path
Int32	indexInPath
InputControlList<TControl>	matches

Returns

Type	Description
Int32

Type Parameters

Name	Description
TControl

Remarks

Matching is case-insensitive.

Does not allocate managed memory.

Exceptions

Type	Condition
ArgumentNullException

TryGetControlLayout(String)

Declaration

public static string TryGetControlLayout(string path)

Parameters

Type	Name	Description
String	path

Returns

Type	Description
String

TryGetDeviceLayout(String)

From the given control path, try to determine the device layout being used.

Declaration

public static string TryGetDeviceLayout(string path)

Parameters

Type	Name	Description
String	path	A control path (like "/<gamepad>/leftStick")

Returns

Type	Description
String	The name of the device layout used by the given control path or null if the path does not specify a device layout or does so in a way that is not supported by the function.

Remarks

This function will only use information available in the path itself or in layouts referenced by the path. It will not look at actual devices in the system. This is to make the behavior predictable and not dependent on whether you currently have the right device connected or not.

Examples

InputControlPath.TryGetDeviceLayout("/<gamepad>/leftStick"); // Returns "gamepad".
InputControlPath.TryGetDeviceLayout("/*/leftStick"); // Returns "*".
InputControlPath.TryGetDeviceLayout("/gamepad/leftStick"); // Returns null. "gamepad" is a device name here.

Exceptions

Type	Condition
ArgumentNullException	path is null

TryGetDeviceUsages(String)

Declaration

public static string[] TryGetDeviceUsages(string path)

Parameters

Type	Name	Description
String	path

Returns

Type	Description
String[]

See Also

path

FindControls(String)