I would like to be able to display a GIF while the image is being loaded. Is this possible with the script I am using?
From what I understand I would use something like
$('#image').load { loadingimage.hide }
Here is my code:
$.get('http://192.168.1.69:8090/VirtualRadar/AirportDataThumbnails.json?icao=' + p.Icao + '®=' + p.Reg , function(res) {
var error = res.status;
if (error == "404") {
$("#image").attr('src', "placeholder.jpg");
$("#image2").attr('src', "placeholder.jpg");
$("#imageurl").attr('href', "//airport-data.com");
} else {
var imgUrl = res.data[0].image;
var imgHref = res.data[0].link;
$("#image").attr('src', imgUrl);
$("#image2").attr('src', imgUrl);
$("#imageurl").attr('href', imgHref);
}
})
Use the Image.onload attribute or attach an event listener.. load the loading wheel image first then display that while the larger image is loading...
function loadImage(src){
return new Promise(done=>{
var i = new Image();
i.onload = ()=>done(i);
i.src = src;
});
}
const loadImgSrc = "https://media.giphy.com/media/3oEjI6SIIHBdRxXI40/giphy.gif";
const bigImgSrc = "https://www.gannett-cdn.com/-mm-/4252e7af1a3888197136b717f5f93523f21f8eb2/r=x1683&c=3200x1680/local/-/media/USATODAY/onpolitics/2012/10/03/bigbird-16_9.jpg";
loadImage(loadImgSrc).then(img=>{
img.style.maxWidth = "100%";
document.getElementById('myImg').appendChild(img);
loadImage(bigImgSrc).then(img=>{
img.style.maxWidth = "100%";
document.getElementById('myImg').innerHTML = '';
document.getElementById('myImg').appendChild(img);
});
})
<div id=myImg></div>
Related
What I'm trying to achieve: clicking on any image should either reveal a clear image if image is blurred or blur the image if image is clear
What's happening: clicking on blurred image clears the image, but clicking on it again does nothing. so, clicking on a clear image does not blur it (as it should).
Here's my code:
<script>
window.onload = init;
function init(e) {
var img = document.getElementsByTagName("img");
//var img = document.getElementById('pics');
img[0].onclick = unblur; // <- why not just img.onclick = unblur ??
img[1].onclick = unblur;
img[2].onclick = unblur;
console.log(img);
/*
var imageId = e.target.id; //zero
var img = document.getElementById(imageId);
*/
//img.onclick = unblur;
}
function unblur(e) {
var imageId = e.target.id; //zero
var img = document.getElementById(imageId);
var imageSource = img.src; //zeroblur.jpg
var clearImg = imageSource.substring(0, imageSource.length - 8);
var unblurredImg = imageId.concat('.jpg'); // zero.jpg
var blurredImg = imageId.concat('blur.jpg'); // zeroblur.jpg
console.log(imageSource);
console.log(img.src);
//console.log(imageSource);
if (img.src == unblurredImg) {
img.src = blurredImg;
} else {
img.src = unblurredImg; // image is clear, so hide the pic
}
/*
if (img.src == blurredImg) {
img.src = unblurredImg;
}
} */
//}
}
/*
//if (!(imageId instanceof img)) {
if (imageId !== "pics") {
if (img.src == blurredImg) {
img.src = unblurredImg;
} else if (img.src == unblurredImg) {
img.src = blurredImg;
} // image is blurred, so reveal the pic
else {
console.log("hi");
}
//debugger;
}
}
*/
/*
var img = document.getElementById('zero');
img.src = "zero.jpg";
*/
</script>
</head>
<body>
<div id="pics">
<img id="zero" src="zeroblur.jpg">
<img id="one" src="oneblur.jpg">
<img id="two" src="two.jpg">
</div>
</body>
</html>
I also noticed that if I switch the conditions in the function, unblur(e), to the following...
if (img.src == unblurredImg) {
img.src = blurredImg;
} else {
img.src = unblurredImg;
}
there's no response at all if a user clicks on a blurred image, whereas before (code above) the blurred image will at least reveal the cleared image.
Why is this happening? I see no difference between the two, besides just switching the order of the conditions.
There are various mistakes in your example. Take a look at the Code Snippet for a working example of what you are trying to achieve.
As for your comment:
// <- why not just img.onclick = unblur ??
Because document.getElementsByTagName returns an array of elements. Therefore, you must iterate through the elements to apply the onclick handlers to each one.
(function(document) {
var array = document.getElementsByTagName("img");
for (var i = 0; i < array.length; i++) {
array[i].onclick = toggleBlur;
}
function toggleBlur(event) {
var img = event.target;
var oldSrc = img.src; // Save to display in the console
if (img.src.endsWith("blur.jpg")) {
img.src = img.id + ".jpg";
} else {
img.src = img.id + "blur.jpg"
}
console.log(oldSrc + " -> " + img.src + " on element.id=" + img.id);
}
})(document);
<body>
<div id="pics">
<img id="zero" src="zero.jpg">
<img id="one" src="one.jpg">
<img id="two" src="twoblur.jpg">
</div>
</body>
I have a class, that is supposed to display grey overlay over page and display text and loading gif. Code looks like this:
function LoadingIcon(imgSrc) {
var elem_loader = document.createElement('div'),
elem_messageSpan = document.createElement('span'),
loaderVisible = false;
elem_loader.style.position = 'absolute';
elem_loader.style.left = '0';
elem_loader.style.top = '0';
elem_loader.style.width = '100%';
elem_loader.style.height = '100%';
elem_loader.style.backgroundColor = 'rgba(0, 0, 0, 0.5)';
elem_loader.style.textAlign = 'center';
elem_loader.appendChild(elem_messageSpan);
elem_loader.innerHTML += '<br><img src="' + imgSrc + '">';
elem_messageSpan.style.backgroundColor = '#f00';
this.start = function () {
document.body.appendChild(elem_loader);
loaderVisible = true;
};
this.stop = function() {
if (loaderVisible) {
document.body.removeChild(elem_loader);
loaderVisible = false;
}
};
this.setText = function(text) {
elem_messageSpan.innerHTML = text;
};
this.getElems = function() {
return [elem_loader, elem_messageSpan];
};
}
Problem is, when I use setText method, it sets innerHTML of elem_messageSpan, but it doesn't reflect to the span, that was appended to elem_loader. You can use getElems method to find out what both elements contains.
Where is the problem? Because I don't see single reason why this shouldn't work.
EDIT:
I call it like this:
var xml = new CwgParser('cwg.geog.cz/cwg.xml'),
loader = new LoadingIcon('./ajax-loader.gif');
xml.ondataparse = function() {
loader.stop();
document.getElementById('cover').style.display = 'block';
};
loader.setText('Loading CWG list...');
loader.start();
xml.loadXML();
xml.loadXML() is function that usually takes 3 - 8 seconds to execute (based on download speed of client), thats why I'm displaying loading icon.
The code:
function CreateAndAnimateEnemyImg() {
var enemy = new Image();
enemy.src = 'enemy.jpg';
enemy.class = 'Enemy';
enemy.width = '30px';
enemy.height = '30px';
document.body.appendChild(enemy);
enemy.onload = function () {
alert('2. Image has fully loaded.');
$('.Enemy').animate({ 'right': '+=20px' });
}
}
$("#Start").click(function () {
CreateAndAnimateEnemyImg();
});
The weird behavior is that the alert is raised but no image is shown, nor the animation is working. Any help please?
Change your code:
enemy.className = 'Enemy';
enemy.width = '30'; // no px needed
enemy.height = '30';
http://jsfiddle.net/UqcqN/
You have two mistakes: if you set width property you don't have to provide units. And you should set className property instead of class.
It is also recommended to set src after onload handler.
You have to enemy.src = 'enemy.jpg'; AFTER you define: enemy.onload.
i think no need for giving string kind of 'px';
rtefer this http://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_img_height
here is the complete demo Fiddle
function CreateAndAnimateEnemyImg() {
var enemy = new Image();
enemy.src = 'http://media.steampowered.com/apps/440/icons/icon_dueling_large.14fd9f2da0f24b2dfaac37d1600c821ddb6d3456.png';
enemy.class = 'Enemy';
enemy.width = '130';
enemy.height = '130';
document.body.appendChild(enemy);
enemy.onload = function () {
alert('2. Image has fully loaded.');
$('.Enemy').html(enemy);
console.log(enemy);
$('.Enemy').animate({ 'right': '+=20px' });
}
}
$("#Start").click(function () {
CreateAndAnimateEnemyImg();
});
I am working on something using HTML5 Canvas.
It's all working great, except right now, I can export the canvas content to PNG using Canvas2image. But I would like to export it to PDF. I've made some research and I'm pretty sure it's possible...but I can't seem to understand what I need to change in my code to make it work. I've read about a plugin called pdf.js...but I can't figure out how to implent it in my code.
First part :
function showDownloadText() {
document.getElementById("buttoncontainer").style.display = "none";
document.getElementById("textdownload").style.display = "block";
}
function hideDownloadText() {
document.getElementById("buttoncontainer").style.display = "block";
document.getElementById("textdownload").style.display = "none";
}
function convertCanvas(strType) {
if (strType == "PNG")
var oImg = Canvas2Image.saveAsPNG(oCanvas, true);
if (strType == "BMP")
var oImg = Canvas2Image.saveAsBMP(oCanvas, true);
if (strType == "JPEG")
var oImg = Canvas2Image.saveAsJPEG(oCanvas, true);
if (!oImg) {
alert("Sorry, this browser is not capable of saving " + strType + " files!");
return false;
}
oImg.id = "canvasimage";
oImg.style.border = oCanvas.style.border;
oCanvas.parentNode.replaceChild(oImg, oCanvas);
showDownloadText();
}
And the JS to that saves the image :
document.getElementById("convertpngbtn").onclick = function() {
convertCanvas("PNG");
}
document.getElementById("resetbtn").onclick = function() {
var oImg = document.getElementById("canvasimage");
oImg.parentNode.replaceChild(oCanvas, oImg);
hideDownloadText();
}
}
You need to use 2 plugins for this:
1) jsPDF
2) canvas-toBlob.js
Then add this piece of code to generate light weight PDF:
canvas.toBlob(function (blob) {
var url = window.URL || window.webkitURL;
var imgSrc = url.createObjectURL(blob);
var img = new Image();
img.src = imgSrc;
img.onload = function () {
var pdf = new jsPDF('p', 'px', [img.height, img.width]);
pdf.addImage(img, 0, 0, img.width, img.height);
pdf.save(fileName + '.pdf');
};
});
Look at this links:
http://www.codeproject.com/Questions/385045/export-html5-webpage-including-canvas-to-pdf
http://badassjs.com/post/708922912/pdf-js-create-pdfs-in-javascript
Most probably it will do the work you need
This jspdf is only useful in saving the file in the browser but we can't use that PDF generated to send to the server
I'm building a navigation bar where the images should be swapped out on mouseover; normally I use CSS for this but this time I'm trying to figure out javascript. This is what I have right now:
HTML:
<li class="bio"><img src="images/nav/bio.jpg" name="bio" /></li>
Javascript:
if (document.images) {
var bio_up = new Image();
bio_up.src = "images/nav/bio.jpg";
var bio_over = new Image();
bio_over.src = "images/nav/bio-ov.jpg";
}
function over_bio() {
if (document.images) {
document["bio"].src = bio_over.src
}
}
function up_bio() {
if (document.images) {
document["bio"].src = bio_up.src
}
}
However, all of the images have names of the form "xyz.jpg" and "xyz-ov.jpg", so I would prefer to just have a generic function that works for every image in the navbar, rather than a separate function for each image.
A quick-fire solution which should be robust enough provided all your images are of the same type:
$("li.bio a").hover(function() {
var $img = $(this).find("img");
$img[0].src = $img[0].src.replace(".jpg", "") + "-ov.jpg";
}, function() {
var $img = $(this).find("img");
$img[0].src = $img[0].src.replace("-ov.jpg", "") + ".jpg";
});
This should work will all image formats as long as the extension is between 2 and 4 characters long IE. png, jpeg, jpg, gif etc.
var images = document.getElementById('navbar').getElementsByTagName('img'), i;
for(i = 0; i < images.length; i++){
images[i].onmouseover = function(){
this.src = this.src.replace(/^(.*)(\.\w{2,4})$/, '$1'+'-ov'+'$2');
}
images[i].onmouseout = function(){
this.src = this.src.replace(/^(.*)-ov(\.\w{2,4})$/, '$1'+'$2');
}
}
Here's an idea in plain javascript (no jQuery):
function onMouseOverSwap(e) {
e.src = e.src.replace(/\.jpg$/", "-ov.jpg"); // add -ov onto end
}
function onMouseOutSwap(e) {
e.src = e.src.replace(/(-ov)+\.jpg$/, ".jpg"); // remove -ov
}