NativeScript/apps/ui/app/perf/memory-leaks/background-image-page.ts

import * as frame from '@nativescript/core/ui/frame';
import { EventData } from '@nativescript/core/data/observable';
import { Page } from '@nativescript/core/ui/page';
import { Label } from '@nativescript/core/ui/label';
import * as application from '@nativescript/core/application';

var indexCounter = 0;
var navCounter = 0;
var images = ['gravatar', 'gravatar2', 'red'];

export function onLoad(args: EventData) {
	let index = indexCounter++ % 3;
	let page = <Page>args.object;
	page.backgroundImage = '~/resources/images/' + images[index] + '.png';
	setLabelText(page, navCounter, 'countInfo');
	getMemoryUsage(args);
}

export function navigate(args: EventData) {
	navCounter++;
	frame.topmost().navigate('perf/memory-leaks/background-image');
}

export function navigateBack(args: EventData) {
	navCounter--;
	frame.topmost().goBack();
}

function setLabelText(page: Page, text: number, id: string) {
	let label = <Label>page.getViewById(id);
	label.text = text + '';
}

function getMemoryUsage(args: EventData) {
	var mi = new android.app.ActivityManager.MemoryInfo();
	var activityManager = application.android.context.getSystemService(android.content.Context.ACTIVITY_SERVICE);
	activityManager.getMemoryInfo(mi);
	let usedMemory = mi.totalMem - mi.availMem;

	setLabelText(<Page>args.object, usedMemory, 'usedMemory');

	console.log('availMem in bytes: ' + mi.availMem);
	console.log('Percentage usage: ' + mi.availMem / mi.totalMem);
	console.log('Available memory (megabytes): ' + mi.availMem);
	console.log('Used memory (megabytes): ' + usedMemory);
}