TouchControls class final

A thumb stick and some buttons, drawn over a game that has no keyboard, with numbered slots and switches where a game has them.

The third translator, beside DesktopInput and PadInput, and the one the device-independent input was written for in the first place — InputState.setStickAxis has said "for a stick or a d-pad" since before either existed, and its class doc has always promised that the touch build and the desktop build run the same game code. This is that promise being collected.

Where each control goes

A game with two or three verbs is a stick and a row of buttons. A game with six is not served by adding circles to the row, because its verbs are not six of the same kind:

control	kind	where
the TouchStick	analogue, held	bottom left, under the left thumb
buttons	held	bottom right, the last nearest the thumb
toggles	set, and stays set	a row just above buttons
slots	chosen, occasionally	up the right edge, out of the cluster
corner	set, and rarely wanted	top right corner, on its own

The two axes are how often and how bad a mistake is. What is pressed every second and costs nothing by accident sits where the thumb rests; what is wanted twice a minute and loses the game when pressed by mistake takes a deliberate reach. Nothing that is tapped by accident is next to something that is held.

A drag-to-look layer under this is the other half of the same rule: every pixel a control covers is a pixel the player cannot turn the view with, so the slots and the corner hug the edges.

Until 1.0.0-rc.1 the stick-and-row and the layout with slots and a corner were two widgets, TouchControls and TouchCluster, doing one job. This is both: a game that hands no slots and no corner gets the row it always had.

Each button says what it does to a screen reader. That is not the contradiction it looks like: a player with low vision, or one whose reader is on for something else entirely, meets these controls and gets "jump" rather than an unnamed circle. The stick is not labelled, because a thumb stick under a reader is a gesture nobody can perform.

One finger per control

Every control tracks the pointer id that claimed it, which is the whole of multi-touch and is not optional: a player walking and jumping is holding two fingers down at once, and a control that took the most recent pointer would snap the stick to the jump button.

Inheritance

Constructors

TouchControls({Key? key, required InputState state, required List<TouchAction> buttons, List<TouchToggle> toggles = const <TouchToggle>[], List<TouchSlot> slots = const <TouchSlot>[], int current = -1, TouchToggle? corner, double stickRadius = 64.0, double buttonRadius = 34.0, double margin = 28.0, DualAxisAction stickAction = DualAxisAction.move}): A stick and buttons over state, with no toggles, slots or corner unless given; sizes are in logical pixels.
const

Properties

buttonRadius → double: Each button's radius, in logical pixels.
final
buttons → List<TouchAction>: What the buttons on the right do, in the order they are drawn: the last is nearest the thumb.
final
corner → TouchToggle?: The one switch that is wanted rarely and costs something when pressed by mistake — a map, say — in the corner nothing else uses, or null.
final
current → int: Which of slots is in use, or −1 for none.
final
hashCode → int: The hash code for this object.
no setterinherited
key → Key?: Controls how one widget replaces another widget in the tree.
finalinherited
margin → double: How far the controls sit from the edges, in logical pixels. Generous, because the edges of a phone are where the system's own gestures live.
final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
slots → List<TouchSlot>: The numbered slots, or none for a game without them. See TouchSlots.
final
state → InputState: The input every control writes into, as a device would.
final
stickAction → DualAxisAction: What the stick asks for — walking unless the game says otherwise. See TouchStick.action.
final
stickRadius → double: The stick's radius, in logical pixels.
final
toggles → List<TouchToggle>: Controls that are set rather than held — see TouchToggle — and wanted often enough to sit by the thumb.
final

Methods

build(BuildContext context) → Widget: Describes the part of the user interface represented by this widget.
override
createElement() → StatelessElement: Creates a StatelessElement to manage this widget's location in the tree.
inherited
debugDescribeChildren() → List<DiagnosticsNode>: Returns a list of DiagnosticsNode objects describing this node's children.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void: Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode: Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String: A string representation of this object.
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug, int wrapWidth = 65}) → String: Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String: Returns a one-line detailed description of the object.
inherited
toStringShort() → String: A short, textual description of this widget.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited