NativeScript/ui/transition/fade-transition.ios.ts

import transition = require("ui/transition");

export class FadeTransition extends transition.Transition {
    public animateIOSTransition(containerView: UIView, fromView: UIView, toView: UIView, operation: UINavigationControllerOperation, completion: (finished: boolean) => void): void {
        toView.alpha = 0.0;
        fromView.alpha = 1.0;

        switch (operation) {
            case UINavigationControllerOperation.UINavigationControllerOperationPush:
                containerView.insertSubviewAboveSubview(toView, fromView);
                break;
            case UINavigationControllerOperation.UINavigationControllerOperationPop:
                containerView.insertSubviewBelowSubview(toView, fromView);
                break;
        }

        var duration = this.getDuration();
        var curve = this.getCurve();
        UIView.animateWithDurationAnimationsCompletion(duration, () => {
            UIView.setAnimationCurve(curve);
            toView.alpha = 1.0;
            fromView.alpha = 0.0;
        }, completion);
    }
}