import dependencyObservable = require("ui/core/dependency-observable"); import proxy = require("ui/core/proxy"); import enums = require("ui/enums"); function isValidOrientation(value: any): boolean { return value === enums.Orientation.vertical || value === enums.Orientation.horizontal; } export var orientationProperty = new dependencyObservable.Property( "orientation", "ScrollView", new proxy.PropertyMetadata(enums.Orientation.vertical, dependencyObservable.PropertyMetadataSettings.AffectsLayout, undefined, isValidOrientation) );