fix(android): polyfill early usage

closes : #21

Author: triniwiz

packages/canvas-polyfill/index.ts

@@ -1,12 +1,20 @@
 require('globals');
-import {TNSXMLHttpRequest, FileReader, Blob} from './async/async';
-import {Element} from './DOM/Element';
-import {Document} from './DOM/Document';
+
+if (global.android && !(global as any).__canvasLoaded) {
+	try {
+		// load canvas lib if polyfill is called before
+		java.lang.System.loadLibrary('canvasnative');
+		(global as any).__canvasLoaded = true;
+	} catch (e) {}
+}
+import { TNSXMLHttpRequest, FileReader, Blob } from './async/async';
+import { Element } from './DOM/Element';
+import { Document } from './DOM/Document';
 import './window';
 import './resize';
 import './process';
-import {TextDecoder, TextEncoder} from '@nativescript/canvas';
-import {URL} from './URL';
+import { TextDecoder, TextEncoder } from '@nativescript/canvas';
+import { URL } from './URL';
 (global as any).document = (global as any).window.document = (global as any).document || new Document();
 Object.defineProperty(global, 'Element', {
 	value: Element,
@@ -46,7 +54,6 @@ if (!((global as any).TextEncoder instanceof TextEncoder)) {
 	});
 }
 
-
 if (!((global as any).URL instanceof URL)) {
 	Object.defineProperty(global, 'URL', {
 		value: URL,

packages/canvas/Canvas/index.android.ts

@@ -33,6 +33,7 @@ export class Canvas extends CanvasBase {
 		const activity =
 			Application.android.foregroundActivity || Application.android.startActivity;
 		this._canvas = new com.github.triniwiz.canvas.TNSCanvas(activity, useCpu);
+		(global as any).__canvasLoaded = true;
 	}
 
 	// @ts-ignore

packages/canvas/vue/index.js

@@ -0,0 +1,5 @@
+export default {
+	install(Vue) {
+		Vue.registerElement('Canvas', () => require('../').Canvas);
+	}
+}