Class “Constraint”
Represents a constraint on the layout of a widget that the parent uses to determine the position of one of its edges. See also ConstraintValue
Constructor | public |
Singleton | No |
Namespace | tabris |
Direct subclasses | None |
JSX support | No |
Constructor
new Constraint(reference, offset)
Parameter | Type | Optional | Description |
---|---|---|---|
reference | Percent | SiblingReference |
No | Sets the reference property. |
offset | Offset |
No | Sets the offset property. |
Methods
toArray()
A tuple consisting of the values of the reference
and offset
properties, i.e. [reference, offset]
.
Returns ConstraintArray
toString()
A string representation of the constraint as a space separated string in the pattern of 'reference offset'
.
Returns string
Static Methods
from(constraintValue)
Creates a new instance of Constraint using any valid constraint expression. For any other value, including null
and 'auto'
, the method throws.
Parameter | Type | Optional | Description |
---|---|---|---|
constraintValue | ConstraintValue |
No | The value to create an Constraint instance from. |
Returns Constraint
Properties
offset
An additional distance between the reference point and the edge of the widget itself.
Type | Offset |
Settable | On creation |
Change events | No |
This property can only be set via constructor. Once set, it cannot change anymore.
reference
A reference point from which the offset is added. Either a SiblingReference - indicating the opposing edge of that widget - or a Percent
instance, indicating a fraction of the width/height (padding excluded) of the parent widget.
If the sibling reference is a string it will be a valid selector string and not contain any pseudo selectors ('next()'
/'prev()'
).
Type | Percent | SiblingReference |
Settable | On creation |
Change events | No |
This property can only be set via constructor. Once set, it cannot change anymore.
Static Properties
next
A SiblingReference indicating the next widget in the list of children attached to the same parent. Used by the reference
property. Also available as LayoutData.next
.
Type | unique symbol |
Settable | No |
Change events | No |
prev
A SiblingReference indicating the previous widget in the list of children attached to the same parent. Used by the reference
property. Also available as LayoutData.prev
.
Type | unique symbol |
Settable | No |
Change events | No |