core/io.nacular.doodle.layout.constraints/ConstraintLayout

ConstraintLayout

abstract class ConstraintLayout : Layout

A Layout that positions Views using a set of constraints. These layouts are created using the constrain functions and follow the form:

val layout = constrain(view1, view2) { v1, v2 ->
    v1.left  eq     10
    v1.width lessEq parent.width / 2

    v2.edges eq     parent.edges - 10
}

Properties

exceptionThrown

abstract val exceptionThrown: Pool<(ConstraintLayout, ConstraintException) -> Unit>

Notified whenever an unhandled ConstraintException is thrown during layout.

Functions

constrain

abstract fun constrain(view: View, constraints: ConstraintDslContext.(Bounds) -> Unit): ConstraintLayout

Add constraints for view.

abstract fun constrain(first: View, second: View, constraints: ConstraintDslContext.(Bounds, Bounds) -> Unit): ConstraintLayout

Add constraints for 2 Views.

abstract fun constrain(first: View, second: View, third: View, constraints: ConstraintDslContext.(Bounds, Bounds, Bounds) -> Unit): ConstraintLayout

Add constraints for 3 Views.

abstract fun constrain(first: View, second: View, vararg others: View, constraints: ConstraintDslContext.(List<Bounds>) -> Unit): ConstraintLayout

Add constraints for several Views.

abstract fun constrain( first: View, second: View, third: View, fourth: View, constraints: ConstraintDslContext.(Bounds, Bounds, Bounds, Bounds) -> Unit): ConstraintLayout

Add constraints for 4 Views.

abstract fun constrain( first: View, second: View, third: View, fourth: View, fifth: View, constraints: ConstraintDslContext.(Bounds, Bounds, Bounds, Bounds, Bounds) -> Unit): ConstraintLayout

Add constraints for 5 Views.

unconstrain

abstract fun unconstrain(view: View, constraints: ConstraintDslContext.(Bounds) -> Unit): ConstraintLayout

Remove all constraints for view that were created by constraints.

abstract fun unconstrain(first: View, second: View, constraints: ConstraintDslContext.(Bounds, Bounds) -> Unit): ConstraintLayout

abstract fun unconstrain(first: View, second: View, third: View, constraints: ConstraintDslContext.(Bounds, Bounds, Bounds) -> Unit): ConstraintLayout

abstract fun unconstrain(first: View, second: View, vararg others: View, constraints: ConstraintDslContext.(List<Bounds>) -> Unit): ConstraintLayout

abstract fun unconstrain( first: View, second: View, third: View, fourth: View, constraints: ConstraintDslContext.(Bounds, Bounds, Bounds, Bounds) -> Unit): ConstraintLayout

abstract fun unconstrain( first: View, second: View, third: View, fourth: View, fifth: View, constraints: ConstraintDslContext.(Bounds, Bounds, Bounds, Bounds, Bounds) -> Unit): ConstraintLayout

Remove all constraints for the given Views that were created by constraints.

Inherited functions

item

open fun item(of: Sequence<Positionable>, at: Point): LookupResult

Gets the child within the Positionable at the given point. The default is to ignore these calls and let the caller perform their own search for the right child. But Layouts are free to return a value here if it can be done more efficiently.

layout

abstract fun layout(views: Sequence<Positionable>, min: Size, current: Size, max: Size, insets: Insets = None): Size

Positions and sizes the given views and returns a size appropriate to laying out these views within the given constraints.

preferredSize

open fun preferredSize(views: Sequence<Positionable>, min: Size, current: Size, max: Size, insets: Insets = None): Size

Determines the best size to contain the views given the constraints. The default implementation relies on layout with current = max for the answer.

requiresLayout

open fun requiresLayout(old: Size, new: Size): Boolean

Indicates whether a layout is needed because of the given size change to a container. This is called whenever the container's size changes.

open fun requiresLayout(child: Positionable, within: Size, old: Rectangle, new: Rectangle): Boolean

Indicates whether a layout is needed because of the given bounds change to a child within a container. This is called whenever the child's size changes.