Develop Reference

When JQuery triggers the displaying of a div, the file upload function within the div breaks in mobile Safari

Okay, so I have a little JQuery script that checks the image dimensions of a photo and if the photo is large enough, it shows the customization functions below (AKA the "form.cart" class).
Everything works fine in all browsers but for some reason in mobile Safari, the "UPLOAD" button stops working (still works in Chrome for iOS funnily enough). By not working I mean the options to select a file from your photo gallery doesn't work. If I turn off the script, it works so there's something going on but I'm not sure what.
My only guess at this point is that it has something to do with the DOM not properly loading but I have no idea why Chrome and Safari for iOS are affected differently as I thought they both used the same rendering engine.
https://victoryposters.com/product/need-for-speed/ (use any photo)
$(document).ready(function() {
var _URL = window.URL || window.webkitURL;
$("#filecheck").change(function() {
var file, img;
if ((file = this.files[0])) {
img = new Image();
img.onload = function() {
//hide customization if less than 1800 x 1800
if (this.width < 1 && this.height < 1) {
$('.pass').css('display', 'none');
$('.fail').css('display', 'block');
$('form.cart').css('display', 'none');
}
//show customization if over than 1800 x 1800
else {
$('.pass').css('display', 'block');
$('.fail').css('display', 'none');
$('form.cart').css('display', 'block');
}
};
img.src = _URL.createObjectURL(file);
}
});
});
form.cart {
display: none;
}
<div class="droparea">
<span class="ppom-dragdrop-text" style="margin-top:0px;">Before proceeding, check the quality of the image you intend on using</span>
<label for="filecheck" class="et_pb_button et_pb_button_0 vic_btn et_pb_bg_layout_light"><i class="fas fa-check"></i> CHECK PHOTO</label>
<input type="file" name="photo" id="filecheck" />
<div class="pass"><i class="fas fa-thumbs-up"></i> Image quality good! Proceed to customisation.</div>
<div class="fail"><i class="fas fa-hand-paper"></i> Image quality too low. Please select a different image.</div>
</div>

How to display html as firefox panel without using sdk

I need to display html elements as contents of a popup panel using javascript in my firefox addon.
Displaying popup using SDK is what I'm looking for but I don't want to use SDK.
panel:
<popupset id="mainPopupSet">
<panel id="htmlPanel" type="arrow">
i want to use html elements like p,div,span, etc here.
</panel>
</popupset>
javascript to open panel:
document.getElementById('htmlPanel').innerHTML = 'my custom contents';
document.getElementById('htmlPanel').openPopup(null, "before_start", 0, 0, false, false);
it seems some elements are allowed but with different behavior! i also need to set CSS for elements inside panel.

I figure it out how to do it using an iframe
changed the XUL as follow:
<popupset id="mainPopupSet">
<panel id="htmlPanel" type="arrow">
<html:iframe id="htmlContainer"/>
</panel>
</popupset>
and create a javascript function to set html contents:
function setupPanel(contents, width, height)
{
var iframe = document.getElementById("htmlContainer");
iframe.setAttribute("src","data:text/html;charset=utf-8," + escape(contents));
iframe.width = width || 300; //default width=300
iframe.height = height || 300; //default height=300
}
and usage:
setupPanel("<p>this is raw HTML.</p>");
document.getElementById('htmlPanel').openPopup(null, "before_start", 0, 0, false, false);
thanks for your hints.

With animation can copy paste to scratchpad to run it.
var win = Services.wm.getMostRecentWindow('navigator:browser');
var panel = win.document.createElement('panel');
var props = {
type: 'arrow',
style: 'width:300px;height:100px;'
}
for (var p in props) {
panel.setAttribute(p, props[p]);
}
win.document.querySelector('#mainPopupSet').appendChild(panel);
panel.addEventListener('popuphiding', function (e) {
e.preventDefault();
e.stopPropagation();
//panel.removeEventListener('popuphiding', arguments.callee, false); //if dont have this then cant do hidepopup after animation as hiding will be prevented
panel.addEventListener('transitionend', function () {
//panel.hidePopup(); //just hide it, if want this then comment out line 19 also uncomment line 16
panel.parentNode.removeChild(panel); //remove it from dom //if want this then comment out line 18
}, false);
panel.ownerDocument.getAnonymousNodes(panel)[0].setAttribute('style', 'transform:translate(0,-50px);opacity:0.9;transition: transform 0.2s ease-in, opacity 0.15s ease-in');
}, false);
panel.openPopup(null, 'overlap', 100, 100);
to display html in it, do createElementNS('html namespace i cant recall right now','iframe') then set the src of this to the html you want it to display
the type:'arrow' here is important

Since this appears to be an overlay of browser.xul, if your panel will display static content or a simple template, you can take advantage of the fact that the XHTML namespace is already declared.
<popupset id="mainPopupSet">
<panel id="htmlPanel" type="arrow">
<html:div id="htmlplaceholder">
<html:p>Lorem ipsum</html:p>
<html:p>foo <html:strong>bar</html:strong></html:p>
</html:div>
</panel>
</popupset>
The Add-on SDK hosts the html content inside an iframe, perhaps you should consider this for more complex cases.

Cross platform Canvas image zoom and crop make selection area fixed

Heavily inspired by this, I have made a plugin that works in mobiles and desktops to crop an image
What I made is added touch support, added dynamic canvas size based on image dimensions and trying to add functionality of moving an image rather selection area like here. I wanted to buy this item but it has failed my test case in devices (I am sorry to mention here). So thought of customizing the first mentioned source.
Here is the fiddle.
my html is
<div class="container">
<canvas id="panel" width="779" height="519"></canvas>
</div>
<input type="button" value="crop Selection" id="crop-image" />
<img id="croppedSelection" height="100px" width="100px" />
And calling it like
var Cropper = new CanvasCrop(document.getElementById('panel'), 'http://www.script- tutorials.com/demos/197/images/image.jpg');
$('#crop-image').on('click', function(){
var src = Cropper.getBase64();
$('#croppedSelection').attr('src', src);
});
My only problem is now, how can I keep the selection area on screen while image parent is being scrolled as here.
Thanks, help will be greatly appreciated.
Source code is huge to fit here, so added a working fiddle.. Thanks
Edit
Updated fiddle fixed canvas height and width issue

I wrote this code because I was bored.
Add this class above your code. you do not need the class if you only want one viewer on the page, you can put this all in a simple object. perhaps you need more:
function viewer (html_viewer)
{
this.html_viewer=html_viewer;
Object.defineProperty (html_viewer,"viewer_instance",{writeable:false,configureable:false,enumerable:false,value:this});
this.Selections=new Array ();
html_viewer.addEventListener ("mousedown",this.startScrolling);
html_viewer.addEventListener ("mouseup", this.endScrolling);
html_viewer.addEventListener ("scroll",this.setSelectionPosition);
}
viewer.prototype.startScrolling=function ()
{
var Selections=this.viewer_instance.Selections, Selection;
var l=Selections.length;
for (var i=0;i<l;i++)
{
Selection=Selections[i];
Selection.startLeft=Selection.x;
Selection.startTop=Selection.y;
Selection.viewer_startScrollLeft=this.scrollLeft;
Selection.viewer_startScrollTop=this.scrollTop;
}
}
viewer.prototype.setSelectionPosition=function ()
{
var Selections=this.viewer_instance.Selections, Selection;
var l=Selections.length;
for (var i=0;i<l;i++)
{
Selection=Selections[i];
Selection.x=this.scrollLeft-Selection.viewer_startScrollLeft+Selection.startLeft;
Selection.y=this.scrollTop-Selection.viewer_startScrollTop+Selection.startTop;
}
this.viewer_instance.drawScene ();
}
viewer.prototype.endScrolling=function ()
{
var Selections=this.viewer_instance.Selections, Selection;
var l=Selections.length;
for (var i=0;i<l;i++)
{
Selection=Selections[i];
Selection.startLeft=null;
Selection.startTop=null;
Selection.viewer_startScrollLeft=null;
Selection.viewer_startScrollTop=null;
}
}
viewer.prototype.addSelection=function (Selection)
{
Selection.startLeft=null;
Selection.startTop=null;
Selection.viewer_startScrollLeft=null;
Selection.viewer_startScrollTop=null;
Selection.viewerIndex=this.Selections.length;
this.Selections.push (Selection);
}
viewer.prototype.removeSelection=function (viewerIndex)
{
var Selections=this.Selections, l=Selections.length, i;
Selection=Selections[viewerIndex];
delete Selection.startLeft;
delete Selection.startTop;
delete Selection.viewer_startScrollLeft;
delete Selection.viewer_startScrollTop;
delete Selection.viewerIndex;
for (i=viewerIndex+1;i<l;i++)
Selections[i].viewerIndex=i-1;
Selections.splice (viewerIndex,1);
}
var imageViewer= new viewer (document.getElementById("panel").parentNode);
After line 27
theSelection = new Selection(64, 64, 64, 64);
Add
imageViewer.addSelection (theSelection);
imageViewer.drawScene=drawScene;
That's all, if you have problems let me know.

need further discussion how to implement image crop. do you want a selection inside the canvas or do you want to resize the complete imageCropper container and make a crop
// look at
http://jsfiddle.net/ThorstenArtnerAustria/5qdDW/1/

How to load image on demand

I have this simple image zoom jQuery. Here is a Demo example. It uses the elevateZoom jQuery.
The code behind is very simple:
<img id="zoom_05" src='small_image1.png' data-zoom-image="large_image1.jpg"/>
<script>
$vc("#zoom_05").elevateZoom({
zoomType : "inner",
cursor: "crosshair"
});
</script>
My question, is how can i make the large image load on demand, only when the mouse is over it. Please have a look at this demo example and let me know what i need to add in the code.

img element (id="zoom_05") above, would not load large_image1.jpg on its own.
Large image load happens because elevateZoom() looks into its data-zoom-image value and immediately loads it. One way around this behaviour is to defer elevateZoom() until user hover's over the small image for the first time. Quick example:
jQuery( function () {
var elevate_zoom_attached = false, $zoom_05 = $("#zoom_05") ;
$zoom_05.hover(
// hover IN
function () {
if ( ! elevate_zoom_attached ) {
$zoom_05.elevateZoom({
zoomType : "inner",
cursor : "crosshair"
});
elevate_zoom_attached = true ;
};
},
// hover OUT
function () {
if ( elevate_zoom_attached) { // no need for hover any more
$zoom_05.off("hover");
}
}
);
}) ;
Mind you this is an quick, on-top-of-my-head code, but should work ...
Also in this case elevateZoom() action might not be immediate while large image loading is going on.

I used this idea to initiate zoom on any number of images on the same page by adding a zoom class to the image. It works without any HOVER OUT
<img class="zoom" src="myimage.png" data-zoom-image="mybigimage.png"/>
$('.zoom').hover(
// hover IN
function () {
var currImg = $(this); //get the current image
if (!currImg.hasClass('zoomon')) { //if it hasn't been initialized
currImg.elevateZoom(); //initialize elevateZoom
currImg.addClass('zoomon'); //add the zoomon class to the img so it doesn't re-initialize
}
})

Save canvas to image via toDataURL failed

I create a test code below and you can manipulate it on Jsfiddle:
http://jsfiddle.net/Stallman41/57hvX/31/
HTML:
<canvas id="test_canvas" style="background-color : #FFFF00" ; width="500px"
; height="340px"></canvas>
<br>
<button id="test_put_btn">Put an image</button>
<br>
<button id="save_dataURL">Save to dataURL</button>
<br>
<button id="draw_back">Final step: draw 3 images back.</button>
<br>
<img id="first_img"; width="100px" ; height="100px" ;></img>
<img id="second_img"; width="100px" ; height="100px" ></img>
<img id="third_img"; width="100px" ; height="100px" ;></img>
Javascript:
var drawing_plate;
var context;
var dataURL_arr = new Array();
$(document).ready(function () {
drawing_plate = document.getElementById("test_canvas");
context = drawing_plate.getContext('2d');
$("#test_canvas").bind("mousedown", Touch_Start);
$("#test_canvas").bind("mousemove", Touch_Move);
$("#test_canvas").bind("mouseup", Touch_End);
}); //document ready.
function Touch_Start(event) {
event.preventDefault();
touch = event;
touch_x = touch.pageX;
touch_y = touch.pageY;
line_start_x = touch.pageX - 0;
line_start_y = touch.pageY - 0;
context.beginPath();
context.moveTo(line_start_x, line_start_y);
}
function Touch_Move(event) {
event.preventDefault();
touch = event; //mouse
line_end_x = touch.pageX - 0;
line_end_y = touch.pageY - 0;
context.lineTo(line_end_x, line_end_y);
context.stroke();
}
$("#test_put_btn").click(function () {
var test_img = new Image();
test_img.src = "http://careerscdn.sstatic.net/careers/gethired/img/careers2- ad-header-so-crop.png";
context.drawImage(test_img, 0, 0);
});
$("#save_dataURL").click(function () {
dataURL_arr.push(drawing_plate.toDataURL("image/png"));
});
$("#draw_back").click(function () {
var f_image= $("#first_img")[0];
var s_image= $("#second_img")[0];
var t_image= $("#third_img")[0];
f_image.onload= function()
{
f_image.src= dataURL_arr[0];
}
f_image.src= dataURL_arr[0];
s_image.onload= function()
{
s_image.src= dataURL_arr[0];
}
s_image.src= dataURL_arr[0];
t_image.onload= function()
{
t_image.src= dataURL_arr[0];
}
t_image.src= dataURL_arr[0];
});
I develop a drawing plate on Android system, saving the drawings to a dataURL string. They can draw something on the canvas and put images on the canvas. And I need to let the users see their drawings on small icons.
I use canvas.toDataURL("image/png") to save the base64 string. And I choose <img> as the small icon container. However, what I got is only the drawings can be shown on the icon, and usually, when I write img.src= canvas.toDataURL("image/png"); the image shows nothing!
I investigate the issue for long time.
1. I think the problem might be the dataURL string is too long?
2. The support of the OS: Android?
The code in Jsfiddle here shows a similar procedure on my Android PhoneGap development.
First , you just draw something on the canvas, and press Press an image, and then Save to dataURL. But you should do the process three times. In this condition, the string array contains the base64 string generated by the drawings and the image.
In the final, you press Final step: draw 3 images back., nothing will be shown on the image icon.
In conclusion:
In my experience, as I write img.src= canvas.toDataURL("image/png"); (no matter the img is an dom element or var img = new Image();). It can't always work: sometimes it works... but sometimes not...(I work on Android 4.0.1, phonegap 1.7.0)
Second, especially if I store lots of base64 strings to an array, assigning them to lots of image DOM element, it definitely fails.
Third, if the user only draw something on the canvas, it can always work.( Except the example code in the Jsfiddle, but it works on my Android system...)
But if he draw an image context.drawImage(~) the image wouldn't show the pic.
Too much confusions...
I need to let the user can view their drawings in small icon, any alternative?
Some References:
1
2
3

I just stumbled across this question.
Click Put an image, then click Save to dataURL, then check your JavaScript console for something like:
SecurityError: DOM Exception 18
It's a browser security feature. Because you've inserted an image from a different domain, it counts as a cross-origin request.
If you eliminate the security error, you can export the canvas to a data URL.

Another thing in your code.
The image you try to draw onto the canvas into your test_put_btn onclick event handler, your image will never show up (or it will sometimes work accidentally) because you don't wait for your image to be loaded to draw it onto the canvas.
You have to handle the "onload" event of your image and draw it into the handler to permit the drawing of your image.
Before your test_img.src statement, you have to put :
test_img.onload = function()
{
context.drawImage(test_img, 0, 0);
};
Plus, the image you try to access is not accessible --> For me it does not work