Load all images during print action

When the print button is clicked, load all images from the page
before calling window.print

Add a timeout to make sure the user doesnt wait too long.

Change-Id: Ie922d239f9c5b5757237dc10b673fb500ff203ad
Depends-on: Id7f21606be3db22fe8dfde2db675f9905547cfea
Bug: T180058

includes/Minerva.hooks.php

@@ -49,12 +49,17 @@ class MinervaHooks {
 	) {
 		$testModule = [
 			'dependencies' => [
+				'mobile.startup',
 				'skins.minerva.notifications.badge'
 			],
 			'localBasePath' => dirname( __DIR__ ),
 			'remoteSkinPath' => 'MinervaNeue',
 			'targets' => [ 'mobile', 'desktop' ],
 			'scripts' => [
+				// additional scaffolding (minus initialisation scripts)
+				'resources/skins.minerva.scripts/DownloadIcon.js',
+				// test files
+				'tests/qunit/skins.minerva.scripts/test_DownloadIcon.js',
 				'tests/qunit/skins.minerva.notifications.badge/test_NotificationBadge.js'
 			],
 		];

jsduck.json

@@ -14,6 +14,7 @@
 		"jqXHR",
 		"View",
 		"Page",
+		"Skin",
 		"File",
 		"Router",
 		"Icon",

resources/skins.minerva.scripts/DownloadIcon.js

@@ -1,6 +1,7 @@
 ( function ( M ) {
 
 	var msg = mw.msg,
+		MAX_PRINT_TIMEOUT = 3000,
 		Icon = M.require( 'mobile.startup/Icon' );
 
 	/**
@@ -8,10 +9,12 @@
 	 * @class DownloadIcon
 	 * @extends Icon
 	 *
+	 * @param {Skin} skin
 	 * @constructor
 	 */
-	function DownloadIcon() {
+	function DownloadIcon( skin ) {
 		var options = {};
+		this.skin = skin;
 		options.tagName = 'li';
 		options.title = msg( 'minerva-download' );
 		options.name = 'download';
@@ -19,8 +22,47 @@
 	}
 
 	OO.mfExtend( DownloadIcon, Icon, {
+		/**
+		 * Replace download icon with a spinner
+		 */
+		showSpinner: function () {
+			this.options.name = 'spinner';
+			this.render();
+		},
+		/**
+		 * Restore download icon from spinner state
+		 */
+		hideSpinner: function () {
+			this.options.name = 'download';
+			this.render();
+		},
+		isTemplateMode: false,
+		/**
+		 * onClick handler for button that invokes print function
+		 */
 		onClick: function () {
-			window.print();
+			var self = this,
+				hideSpinner = this.hideSpinner.bind( this );
+
+			function doPrint() {
+				self.timeout = clearTimeout( self.timeout );
+				hideSpinner();
+				window.print();
+			}
+
+			// The click handler may be invoked multiple times so if a pending print is occurring
+			// do nothing.
+			if ( !this.timeout ) {
+				this.showSpinner();
+				// If all image downloads are taking longer to load then the MAX_PRINT_TIMEOUT
+				// abort the spinner and print regardless.
+				this.timeout = setTimeout( doPrint, MAX_PRINT_TIMEOUT );
+				this.skin.loadImagesList().always( function () {
+					if ( self.timeout ) {
+						doPrint();
+					}
+				} );
+			}
 		},
 		events: {
 			click: 'onClick'

tests/qunit/skins.minerva.scripts/test_DownloadIcon.js

@@ -0,0 +1,67 @@
+( function ( M ) {
+	var Skin = M.require( 'mobile.startup/Skin' ),
+		Deferred = $.Deferred,
+		DownloadIcon = M.require( 'skins.minerva.scripts/DownloadIcon' );
+
+	QUnit.module( 'Minerva DownloadIcon', {
+		setup: function () {
+			this.skin = new Skin( {} );
+		}
+	} );
+
+	QUnit.test( '#DownloadIcon (print after image download)', function ( assert ) {
+		var icon = new DownloadIcon( this.skin ),
+			d = Deferred(),
+			spy = this.sandbox.stub( window, 'print' );
+
+		this.sandbox.stub( this.skin, 'loadImagesList' ).returns( d.resolve() );
+
+		icon.onClick();
+		d.then( function () {
+			assert.ok( spy.calledOnce, 'Print occurred.' );
+		} );
+
+		return d;
+	} );
+
+	QUnit.test( '#DownloadIcon (print via timeout)', function ( assert ) {
+		var icon = new DownloadIcon( this.skin ),
+			d = Deferred(),
+			spy = this.sandbox.stub( window, 'print' );
+
+		this.sandbox.stub( this.skin, 'loadImagesList' ).returns( d );
+
+		window.setTimeout( function () {
+			d.resolve();
+		}, 3400 );
+
+		icon.onClick();
+		d.then( function () {
+			assert.ok( spy.calledOnce,
+				'Print was called once despite loadImagesList resolving after MAX_PRINT_TIMEOUT' );
+		} );
+
+		return d;
+	} );
+
+	QUnit.test( '#DownloadIcon (multiple clicks)', function ( assert ) {
+		var icon = new DownloadIcon( this.skin ),
+			d = Deferred(),
+			spy = this.sandbox.stub( window, 'print' );
+
+		this.sandbox.stub( this.skin, 'loadImagesList' ).returns( d );
+
+		window.setTimeout( function () {
+			d.resolve();
+		}, 3400 );
+
+		icon.onClick();
+		icon.onClick();
+		d.then( function () {
+			assert.ok( spy.calledOnce,
+				'Print was called once despite multiple clicks' );
+		} );
+
+		return d;
+	} );
+}( mw.mobileFrontend ) );