Canvas not showing/drawing anything in Windows Chrome - windows

I have a problem that the code below works in : IE 10, Firefox, Safari, Mac Chrome, but not for Windows Chrome.
$(function () {
var video_dom = document.querySelector('#v');
var canvas_draw = document.querySelector('#c');
var draw_interval = null;
video_dom.addEventListener('play', function () {
video_dom.width = canvas_draw.width = video_dom.offsetWidth;
video_dom.height = canvas_draw.height = video_dom.offsetHeight;
var ctx_draw = canvas_draw.getContext('2d');
draw_interval = setInterval(function () {
ctx_draw.drawImage(video_dom, 0, 0, video_dom.width, video_dom.height);
var dataURL = canvas_draw.toDataURL();
document.getElementById('canvasImg').src = dataURL;
}, 3500)
}, false);
})();
Also I get this error in console like: Uncaught TypeError: object is not a function.
Why is the canvas is working in the Mac version, but not the Windows version of Chrome?

I don't see why you're using a dollar sign ($) in front of your function when you're not using jQuery.
window.onload = function () {
var video_dom = document.querySelector('#v');
var canvas_draw = document.querySelector('#c');
...
};
Should be clear of errors.

Related

how to use fs functions? Getting ERROR fs.readFileSync is not a function

I am using PDFkit.js to export pdf. My page contains images. TO add images i am using
var doc = new PDFDocument({
bufferPages: true
});
var stream = doc.pipe(blobStream());
var iframe = $('iframe')[0];
var x = 0;
var y = 0;
var img;
doc.image('http://mylogo.png', 20, 15, {width:100})
.text('Proportional to width', 0, 0);
doc.flushPages();
// end and display the document in the iframe to the right
doc.end();
stream.on('finish', function() {
iframe.src = stream.toBlobURL('application/pdf');
});
Included In script:
<script src="{{asset('/js/pdfkit.standalone.js')}}"></script>
<script src="{{asset('/js/blob-stream.js')}}"></script>
But it is not displaying Image in PDF.
ERROR: fs.readFileSync is not a function

Moving element on Window scroll

You'll see in this JsFiddle https://jsfiddle.net/xpvt214o/402281/ there is an image scrolling within another one on window scroll.
How can I modify the below so that it doesn't start scrolling until it hits that element (after all the br tags)?
I've tried offsetting it but not getting anywhere.
It would also be fine if it just scrolled a lot slower.
jQuery(document).ready(
function() {
var $w = $(window);
var $d = $('.oh');
$(window).scroll(function(event) {
var st = $w.scrollTop();
_x = st;
lastScrollTop = st;
$d.css('bottom', _x);
});
});
Here's an example of what I'm trying to achieve https://www.sketchapp.com/
I found this which does what I'm looking for
https://codepen.io/JTParrett/pen/BkDie
$.fn.moveIt = function(){
var $window = $(window);
var instances = [];
$(this).each(function(){
instances.push(new moveItItem($(this)));
});
window.addEventListener('scroll', function(){
var scrollTop = $window.scrollTop();
instances.forEach(function(inst){
inst.update(scrollTop);
});
}, {passive: true});
}
var moveItItem = function(el){
this.el = $(el);
this.speed = parseInt(this.el.attr('data-scroll-speed'));
};
moveItItem.prototype.update = function(scrollTop){
this.el.css('transform', 'translateY(' + -(scrollTop / this.speed) +
'px)');
};
// Initialization
$(function(){
$('[data-scroll-speed]').moveIt();
});

Firefox convertImgToDataURLviaCanvas is not working on Firefox but working in chrome and IE

My following function is not working in firefox but works in chrome
function convertImgToDataURLviaCanvas(url, callback, outputFormat){
var img = new Image();
img.crossOrigin = 'Anonymous';
img.onload = function(){
var canvas = document.createElement('CANVAS');
var ctx = canvas.getContext('2d');
var dataURL;
canvas.height = this.height;
canvas.width = this.width;
ctx.drawImage(this, 0, 0);
dataURL = canvas.toDataURL(outputFormat);
callback(dataURL);
canvas = null;
};
img.src = url;
}
I have to pass the base64 encoded to a webservice, the encoded string which I am getting in firefox is failing at webservice end, but the one I am getting in chrome and IE is working. Following is the code which gets called on Imageupload
$("#avatar1").on('change',function(event){
var selectedFile = this.files[0];
var tmppath = URL.createObjectURL(event.target.files[0]);
// $('.profile-image').append('<img src="'+tmppath+'" />');
var convertFunction = convertImgToDataURLviaCanvas;
convertFunction(tmppath, function(base64Img){
console.log(base64Img);
var imagebase64Obj = new Object();
imagebase64Obj.data = base64Img;
$.ajax({
url : "/bin/mercer/saml/myProfileController?q=updateavatar",
type : "POST",
data : imagebase64Obj,
success : function(data, textStatus, jqXHR) {
// data - response from server
window.location.reload();
alert("success");
},
error : function(jqXHR, textStatus,
errorThrown) {
alert("error");
}
});
});
});
Please help me get what is going wrong, or some other variant function which works in firefox

Google maps in firefox6 zooms znd scrolls page

I have problem with Firefox6 (don't know if it also concerns earlier versions).
I want to embed Google Map on page, and when page has scrollbars (is longer than viewport) mouse wheel not only zooms map but also scrolls page. I tried to catch mousewheel event and stop propagation but this event isn catchable when cursor os over map. When cursor is over map controls (zoom control, google logo, etc) i can catch event and stop propagation.
What is more strange it not happens always. Sometimes page srolls and after few scrolls it stops and mousewheel only zooms map (as expected). Sometimes page doesn't scroll and sometimes it scrolls with zoom all the time. Can't find pattern.
Source code is simple:
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>test</title>
<script type="text/javascript" src="http://maps.googleapis.com/maps/api/js?sensor=false"></script>
<script type="text/javascript">
window.onload = function(){
var latlng = new google.maps.LatLng(52.25, 21.01);
mapOptions = {
zoom: 12,
center: latlng,
mapTypeId: google.maps.MapTypeId.ROADMAP,
streetViewControl: false,
zoomControl:true,
mapTypeControl:false
};
map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
}
</script>
</head>
<body>
<p style="height:500px;">-lot of text-</p>
<div id="map_canvas" style="width:500px; height:500px;"></div>
<p style="height:500px;">-lot of text-</p>
</body>
</html>
Your problem is also described on code.google.com, this problem is only in Firefox, but it isn't a Firefox bug:
http://code.google.com/p/gmaps-api-issues/issues/detail?id=3652
http://code.google.com/p/gmaps-api-issues/issues/detail?id=1605
Have also found out a workaround, that is not re-scrolling or re-zooming and works fine:
A new ScrollInterceptOverlay derived from google.maps.OverlayView, prepending a div on MapPanes.overlayMouseTarget:
Version with jQuery
// Ensure to have google.maps loaded:
// var gmap = new google.maps.Map($googlemap[0], mapOptions);
// Define a ScrollInterceptOverlay function
var ScrollInterceptOverlay = function (gmap) {
if (!(this instanceof ScrollInterceptOverlay)) return;
var $div;
var $mapDiv;
var initialize = function () {
$div = $('<div />').css({
position: 'absolute', top: 0, left: 0,
display: 'inline-block'
});
var div = $div[0];
if (div && div.addEventListener) {
// Internet Explorer, Opera, Google Chrome and Safari
div.addEventListener("mousewheel", mouseScrollStop);
// Firefox
div.addEventListener("DOMMouseScroll", mouseScrollStop);
div.addEventListener("MozMousePixelScroll", mouseScrollStop);
}
else if (div && div.attachEvent) { // IE before version 9
div.attachEvent("onmousewheel", mouseScrollStop);
}
this.setMap(gmap);
};
var mouseScrollStop = function (e) {
if (e && e.preventDefault) e.preventDefault();
};
this.onAdd = function () {
$div.prependTo(this.getPanes().overlayMouseTarget);
};
this.onRemove = function () {
var div = $div[0];
if (div && div.addEventListener) {
// Internet Explorer, Opera, Google Chrome and Safari
div.addEventListener("mousewheel", mouseScrollStop);
// Firefox
div.addEventListener("DOMMouseScroll", mouseScrollStop);
div.addEventListener("MozMousePixelScroll", mouseScrollStop);
}
else if (div && div.attachEvent) { // IE before version 9
div.attachEvent("onmousewheel", mouseScrollStop);
}
$div.detach();
};
this.draw = function () {
if ($mapDiv && $mapDiv.length === 1) {
$div.css({
width: $mapDiv.outerWidth(),
height: $mapDiv.outerHeight()
});
}
};
var base_setMap = this.setMap;
this.setMap = function (map) {
$mapDiv = $(map.getDiv());
base_setMap.call(this, map);
};
initialize.call(this);
};
// Setup prototype as OverlayView object
ScrollInterceptOverlay.prototype = new google.maps.OverlayView();
// Now create a new ScrollInterceptOverlay OverlayView object:
var mapScrollInterceptor = new ScrollInterceptOverlay(gmap);
This workaround is using jQuery, required for calculating outerWidth and outerHeight, but also for better reading.
Version with pure javaScript
Tested live: http://fiddle.jshell.net/fhSMM/7/
// Ensure to have google.maps loaded:
// var gmap = new google.maps.Map(googlemap, mapOptions);
// Define a ScrollInterceptOverlay class function
var ScrollInterceptOverlay = function () {
if (!(this instanceof ScrollInterceptOverlay)) return;
var div;
// private instance function
var mouseScrollStop = function (e) {
if (e && e.preventDefault) e.preventDefault();
};
// public instance function
this.onAdd = function () {
div = document.createElement('div');
div.style.display = 'inline-block';
div.style.position = 'absolute';
div.style.top = div.style.left = 0;
if (div.addEventListener) {
// Internet Explorer, Opera, Google Chrome and Safari
div.addEventListener("mousewheel", mouseScrollStop);
// Firefox
div.addEventListener("DOMMouseScroll", mouseScrollStop);
div.addEventListener("MozMousePixelScroll", mouseScrollStop);
}
else if (div.attachEvent) { // IE before version 9
div.attachEvent("onmousewheel", mouseScrollStop);
}
var pane = this.getPanes().overlayMouseTarget;
var firstChild = pane.firstChild;
if (!firstChild) {
pane.appendChild(div);
}
else {
pane.insertBefore(div, firstChild);
}
};
// public instance function
this.onRemove = function () {
if (div) {
if (div.removeEventListener) {
// Internet Explorer, Opera, Google Chrome and Safari
div.removeEventListener("mousewheel", mouseScrollStop);
// Firefox
div.removeEventListener("DOMMouseScroll", mouseScrollStop);
div.removeEventListener("MozMousePixelScroll", mouseScrollStop);
}
else if (div.detachEvent) { // IE before version 9
div.detachEvent("onmousewheel", mouseScrollStop);
}
var parent = div.parentNode;
parent.removeChild(div);
}
// do not delete div var'iable
div = undefined;
};
// public instance function
this.draw = function () {
var map = this.getMap();
if (map) {
var mapDiv = map.getDiv();
if (mapDiv) {
var rect = mapDiv.getBoundingClientRect();
div.style.width = rect.width + 'px';
div.style.height = rect.height + 'px';
}
}
};
};
// Setup prototype as OverlayView object
ScrollInterceptOverlay.prototype = new google.maps.OverlayView();
// Now create a new ScrollInterceptOverlay OverlayView object:
var mapScrollInterceptor = new ScrollInterceptOverlay();
mapScrollInterceptor.setMap(gmap);
Please visit also http://metadea.de/V/ about what (real) javaScript class functions are, and why I like jQuery :)
Works now for me.
Also in Firefox, the map is zooming on mousescroll, but no more scrolling the document.
Edit: Updated support for MozMousePixelScroll, refined jS
For now it looks like firefox bug. Will close question when bug will be fixed.
I had the same issue.
You could try to start Firefox with a brand new profile (e.g. by starting the Profile Manager - executing 'firefox -P' on windows systems - and choosing 'Create...') and see if the problem persists.
I had several old but seemingly empty user profiles lying around in the VMs I used to verify if this was a bug in FF 6 and obviously installing only the new binaries didn't help. On the other hand, creating a blank profile did, so I can only think of this being a migration glitch. If major versions of FF are going to be released on a bi-monthly basis, though, a lot of people are going to suffer from similar issues.
Why not take UI control of zooming? This works well for me.
<!DOCTYPE html>
<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<script type="text/javascript" src="http://maps.googleapis.com/maps/api/js?sensor=false"></script>
</head>
<body>
<div class="canvas" style="width:600px;height:400px;"></div>
<script>
// Load event
$(function() {
var myOptions = {
zoom: 8,
center: new google.maps.LatLng(-34.397, 150.644),
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map($('.canvas')[0], myOptions);
var overlay = new google.maps.OverlayView();
overlay.draw = function() {};
overlay.setMap(map);
// Only a Mozilla bug
if($.browser.mozilla) {
// Wait for the map DOM to be ready
google.maps.event.addListenerOnce(map, 'idle', function() {
$('.canvas > div > div:first-child > div').bind('DOMMouseScroll', function(e) {
// setTimeout needed otherwise the return false has no effect
setTimeout(function() {
// Calculate new center
var offset = $('.canvas').offset();
var pos = overlay.getProjection().fromContainerPixelToLatLng(new google.maps.Point(e.pageX-offset.left, e.pageY-offset.top));
// Calculate new zoom level
var zoom = map.getZoom();
if(e.detail < 0) zoom++;
else if(e.detail > 0) zoom--;
map.setCenter(pos);
map.setZoom(zoom);
}, 1);
// Stop propagation (prevent default)
return false;
});
});
}
});
</script>
<br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br>
</body>
</html>

MooTools - how to reload image?

Is there any way to reload the same image using mootools. I have a camera that gives me image, but I have to refresh it. I wrote this, but it doesn't work so well:
var url = "some valid url to some image.jpg";
var timer = 10;
var periodical;
var camera_container;
var refresh = (function() {
var loader = new Asset.image(url, {
onLoad : function() {
camera_container.empty();
camera_container.inject(loader);
}
});
});
window.addEvent('domready', function() {
// the periodical starts here, the * 1000 is because milliseconds required
refresh.periodical(timer * 1000, this);
camera_container = $('camera-image');
});
Any help appreciated. Thanks.
why not add a seeding bit to the url?
(function() {
var url = "some valid url to some image.jpg?";
this.timer = 10;
var counter = 0;
this.refresh = (function() {
var loader = new Asset.image(url + counter, {
onLoad: function() {
camera_container.empty();
camera_container.inject(loader);
counter++;
}
});
});
})();
window.addEvent('domready', function() {
// the periodical starts here, the * 1000 is because milliseconds required
refresh.periodical(timer * 1000, this);
this.camera_container = $('camera-image');
});
this way the url will always be path/image.jpg?n where n changes and will force the browser to re-fetch it.
I think something like this also can work:
<div id="image-holder">
<img src="http://www.image.com/image.jpg"/>
</div>
var srcImage = 'http://www.image.com/image.jpg';
var reloadTime = 4000;
var holder = document.id('image-holder');
var imageReload = function(){
holder.empty();
var newImage = new Element('img',{
id:'image',
src:srcImage ,
alt:'image new'
}).inject(holder);
}
var start = function() {
interval = imageReload.periodical(reloadTime);
};
start();

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