Notify Layout Event Implementation

notify-layout-view.ts

import { StackLayout } from "tns-core-modules/ui/layouts/stack-layout";
import { isAndroid, isIOS } from "tns-core-modules/platform";
import { View } from "tns-core-modules/ui/core/view";
import { registerElement } from "nativescript-angular/element-registry";

export class NotifyLayoutView extends StackLayout {
    private listener: android.view.View.OnLayoutChangeListener
    public createNativeView() {
        const nativeView = super.createNativeView();
        if (isAndroid) {
            const owner = this;
            this.listener = new android.view.View.OnLayoutChangeListener({
                onLayoutChange(
                    v: android.view.View,
                    left: number, top: number, right: number, bottom: number,
                    oldLeft: number, oldTop: number, oldRight: number, oldBottom: number): void {
                    owner.notifyLayoutChanged();
                }
            });
            (<android.view.View>nativeView).addOnLayoutChangeListener(this.listener);
        }

        return nativeView;
    }

    onLayout(left: number, top: number, right: number, bottom: number): void {
        super.onLayout(left, top, right, bottom);
        if (isIOS) {
            this.notifyLayoutChanged();
        }
    }

    notifyLayoutChanged() {
        this.notify({ object: this, eventName: "layout" });
    }
}
// Register tag in the ns-angular renderer
registerElement("notify-layout-view", () => NotifyLayoutView);