LayoutGroupComponent(system, entity) 

Create a new LayoutGroupComponent instance.

Parameters

system	LayoutGroupComponentSystem	The ComponentSystem that created this Component.
entity	Entity	The Entity that this Component is attached to.

Vec2alignment 

Specifies the horizontal and vertical alignment of child elements. Values range from 0 to 1 where [0, 0] is the bottom left and [1, 1] is the top right. Defaults to [0, 1].

numberheightFitting 

Identical to LayoutGroupComponent#widthFitting but for the Y axis. Defaults to FITTING_NONE.

numberorientation 

Whether the layout should run horizontally or vertically. Can be:

• ORIENTATION_HORIZONTAL
• ORIENTATION_VERTICAL

Defaults to ORIENTATION_HORIZONTAL.

Vec4padding 

Padding to be applied inside the container before positioning any children. Specified as left, bottom, right and top values. Defaults to [0, 0, 0, 0] (no padding).

booleanreverseX 

Reverses the order of children along the x axis. Defaults to false.

booleanreverseY 

Reverses the order of children along the y axis. Defaults to true.

Vec2spacing 

Spacing to be applied between each child element. Defaults to [0, 0] (no spacing).

numberwidthFitting 

Fitting logic to be applied when positioning and scaling child elements. Can be:

• FITTING_NONE: Child elements will be rendered at their natural size.
• FITTING_STRETCH: When the natural size of all child elements does not fill the width of the container, children will be stretched to fit. The rules for how each child will be stretched are outlined below:
  1. Sum the LayoutChildComponent#fitWidthProportion values of each child and normalize so that all values sum to 1.
  2. Apply the natural width of each child.
  3. If there is space remaining in the container, distribute it to each child based on the normalized LayoutChildComponent#fitWidthProportion values, but do not exceed the LayoutChildComponent#maxWidth of each child.
• FITTING_SHRINK: When the natural size of all child elements overflows the width of the container, children will be shrunk to fit. The rules for how each child will be stretched are outlined below:
  1. Sum the LayoutChildComponent#fitWidthProportion values of each child and normalize so that all values sum to 1.
  2. Apply the natural width of each child.
  3. If the new total width of all children exceeds the available space of the container, reduce each child's width proportionally based on the normalized LayoutChildComponent#fitWidthProportion values, but do not exceed the LayoutChildComponent#minWidth of each child.
• FITTING_BOTH: Applies both STRETCH and SHRINK logic as necessary.

Defaults to FITTING_NONE.

booleanwrap 

Whether or not to wrap children onto a new row/column when the size of the container is exceeded. Defaults to false, which means that children will be be rendered in a single row (horizontal orientation) or column (vertical orientation). Note that setting wrap to true makes it impossible for the FITTING_BOTH fitting mode to operate in any logical manner. For this reason, when wrap is true, a LayoutGroupComponent#widthFitting or LayoutGroupComponent#heightFitting mode of FITTING_BOTH will be coerced to FITTING_STRETCH.

booleanenabled 

Enables or disables the component.

Entityentity 

The Entity that this Component is attached to.

ComponentSystemsystem 

The ComponentSystem used to create this Component.

fire(name, [arg1], [arg2], [arg3], [arg4], [arg5], [arg6], [arg7], [arg8]) 

Fire an event, all additional arguments are passed on to the event listener.

obj.fire('test', 'This is the message');

Parameters

name	string	Name of event to fire.
arg1	*	First argument that is passed to the event handler.
arg2	*	Second argument that is passed to the event handler.
arg3	*	Third argument that is passed to the event handler.
arg4	*	Fourth argument that is passed to the event handler.
arg5	*	Fifth argument that is passed to the event handler.
arg6	*	Sixth argument that is passed to the event handler.
arg7	*	Seventh argument that is passed to the event handler.
arg8	*	Eighth argument that is passed to the event handler.

Returns

EventHandler

Self for chaining.

hasEvent(name) 

Test if there are any handlers bound to an event name.

obj.on('test', function () { }); // bind an event to 'test'
obj.hasEvent('test'); // returns true
obj.hasEvent('hello'); // returns false

Parameters

name

string

The name of the event to test.

Returns

boolean

True if the object has handlers bound to the specified event name.

off([name], [callback], [scope]) 

Detach an event handler from an event. If callback is not provided then all callbacks are unbound from the event, if scope is not provided then all events with the callback will be unbound.

const handler = function () {
};
obj.on('test', handler);

obj.off(); // Removes all events
obj.off('test'); // Removes all events called 'test'
obj.off('test', handler); // Removes all handler functions, called 'test'
obj.off('test', handler, this); // Removes all handler functions, called 'test' with scope this

Parameters

name	string	Name of the event to unbind.
callback	HandleEventCallback	Function to be unbound.
scope	object	Scope that was used as the this when the event is fired.

Returns

EventHandler

Self for chaining.

on(name, callback, [scope]) 

Attach an event handler to an event.

obj.on('test', function (a, b) {
    console.log(a + b);
});
obj.fire('test', 1, 2); // prints 3 to the console

const evt = obj.on('test', function (a, b) {
    console.log(a + b);
});
// some time later
evt.off();

Parameters

name	string	Name of the event to bind the callback to.
callback	HandleEventCallback	Function that is called when event is fired. Note the callback is limited to 8 arguments.
scope	object	Object to use as 'this' when the event is fired, defaults to current this.

Returns

EventHandle

Can be used for removing event in the future.

once(name, callback, [scope]) 

Attach an event handler to an event. This handler will be removed after being fired once.

obj.once('test', function (a, b) {
    console.log(a + b);
});
obj.fire('test', 1, 2); // prints 3 to the console
obj.fire('test', 1, 2); // not going to get handled

Parameters

name	string	Name of the event to bind the callback to.
callback	HandleEventCallback	Function that is called when event is fired. Note the callback is limited to 8 arguments.
scope	object	Object to use as 'this' when the event is fired, defaults to current this.

Returns

EventHandle

• can be used for removing event in the future.