how to add scroll to my WinJS app VS2012 - javascript

I have a metro app (WinJS) in VS2012 which loads an image inside a by using an a from my local disk like which next function
function loadPictureFromFile(event) {
var selectedFile = event.target.files[0];
var reader = new FileReader();
imageElement = document.createElement("img"); //creates <img id="img"> element
imageElement.title = selectedFile.name; //set photo's name
reader.onload = function (event) {
imageElement.setAttribute("src", event.target.result); //picture's source
_divPicture.appendChild(imageElement); //Add's <img> element to Div element
};
reader.readAsDataURL(selectedFile);
}
but sometimes my image is too big to display on screen, it requires a scroll for viewing it completely, how to add it from javascript or WinJS after loading picture??

in your default.css simply add
body {
overflow-x:auto;
overflow-y:auto;
}

Related

How to save user uploaded image to `localStorage` and use it to change `background-image` using JS?

I'm trying to add to localStorage the user-uploaded image and use it as persistent background-image of the page.
I already have here the feature to upload and change the background, but not the ability to save it to localStorage.. What's the way to do it?
Here's the code I have so far:
const frame = document.getElementById('frame');
const file = document.getElementById('file');
const reader = new FileReader();
const userUploadedBackground = document.getElementById('image');
const imgData = getBase64Image(userUploadedBackground);
localStorage.setItem("imgData", imgData);
reader.addEventListener("load", function() {
frame.style.backgroundImage = `url(${ reader.result })`;
}, false);
file.addEventListener('change', function() {
const image = this.files[0];
if (image) reader.readAsDataURL(image);
}, false)
#frame {
width: 200px;
height: 200px;
background-size: cover;
}
<input id='file' type='file' />
<div id='frame'></div>
Thank you in advance for any help.
To accomplish this, you would have to upload the photo somewhere and then store the url in local storage. Then you can load it using event listeners and apply to document.body.style in JS

Determine the dimensions of image from dataURI

I'm allowing users to load their own image file from file system according to this post (last part - Images from the local file system)
https://stackoverflow.com/a/20285053
My Code
handleFiles: function (evt) {
var file = evt.target.files[0];
var reader = new FileReader();
reader.readAsDataURL(file);
reader.onloadend = function (e) {
var contents = e.target.result;
console.log(contents);
//apply contents to src of img element
};
},
After getting the dataUri, I want to display the image on screen, however some images are bigger than the area in which I'm displaying them. Is there a way to check the size of the image given the dataUri (width and height) and resize is accordingly?
I am placing the dataUri in the 'src' attribute of image tag.
You can simply create an element in memory and read the value from it. Assuming "contents" is the dataURI of the image
handleFiles: function (evt) {
var file = evt.target.files[0];
var reader = new FileReader();
reader.readAsDataURL(file);
reader.onloadend = function (e) {
var contents = e.target.result;
console.log(contents);
var memoryImg = document.createElement('img');
memoryImg.src = contents;
var width = memoryImg.width;
var height = memoryImg.height;
};
},
The element will be cleaned up as soon as the interpreter finishes your function.

Uploading an image from computer to Fabric.JS Canvas

Are there any Fabric.JS Wizards out there?
I've done my fair research and I can't seem to find much of an explanation on how to add an image to the fabric.JS canvas.
User Journey:
a) User uploads an image from an input file type button.
b) As soon as they have selected an image from their computer I want to place it into the users canvas.
So far I've got to storing the image into an expression, this is my code below:
scope.setFile = function(element) {
scope.currentFile = element.files[0];
var reader = new FileReader();
/**
*
*/
reader.onload = function(event) {
// This stores the image to scope
scope.imageSource = event.target.result;
scope.$apply();
};
// when the file is read it triggers the onload event above.
reader.readAsDataURL(element.files[0]);
};
My HTML/Angular:
<label class="app-file-input button">
<i class="icon-enter"></i>
<input type="file"
id="trigger"
onchange="angular.element(this).scope().setFile(this)"
accept="image/*">
</label>
If you haven't guessed yet I am using a MEAN stack. Mongoose, Express, Angular and Node.
The scope imageSource is what the image is store in. I've read this SO
and it talks about pushing the image to the Image object with my result, and then pass it to the fabric.Image object. Has anyone done a similar thing that they can help me with?
Thanks in advance
**** UPDATE ****
Directive defines the canvas variable:
var canvas = new fabric.Canvas(attrs.id, {
isDrawingMode: true
});
Upload image from computer with Fabric js.
var canvas = new fabric.Canvas('canvas');
document.getElementById('file').addEventListener("change", function (e) {
var file = e.target.files[0];
var reader = new FileReader();
reader.onload = function (f) {
var data = f.target.result;
fabric.Image.fromURL(data, function (img) {
var oImg = img.set({left: 0, top: 0, angle: 00,width:100, height:100}).scale(0.9);
canvas.add(oImg).renderAll();
var a = canvas.setActiveObject(oImg);
var dataURL = canvas.toDataURL({format: 'png', quality: 0.8});
});
};
reader.readAsDataURL(file);
});
canvas{
border: 1px solid black;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://rawgit.com/kangax/fabric.js/master/dist/fabric.min.js"></script>
<input type="file" id="file"><br />
<canvas id="canvas" width="450" height="450"></canvas>
once you have a dataURL done, you can do either:
reader.onload = function(event) {
// This stores the image to scope
fabric.Image.fromURL(event.target.result, function(img) {
canvas.add(img);
});
scope.$apply();
};
Or you put on your image tag an onload event where you do:
var img = new fabric.Image(your_img_element);
canvas.add(img);
This is for drag and drop from desktop using the dataTransfer interface.
canvas.on('drop', function(event) {
// prevent the file to open in new tab
event.e.stopPropagation();
event.e.stopImmediatePropagation();
event.e.preventDefault();
// Use DataTransfer interface to access the file(s)
if(event.e.dataTransfer.files.length > 0){
var files = event.e.dataTransfer.files;
for (var i = 0, f; f = files[i]; i++) {
// Only process image files.
if (f.type.match('image.*')) {
// Read the File objects in this FileList.
var reader = new FileReader();
// listener for the onload event
reader.onload = function(evt) {
// put image on canvas
fabric.Image.fromURL(evt.target.result, function(obj) {
obj.scaleToHeight(canvas.height);
obj.set('strokeWidth',0);
canvas.add(obj);
});
};
// Read in the image file as a data URL.
reader.readAsDataURL(f);
}
}
}
});
Resources
https://developer.mozilla.org/en-US/docs/Web/API/HTML_Drag_and_Drop_API/File_drag_and_drop

Drag and drop and scale images but user's upload pic isn't draggable and resizable

Hello guys i found this amazing drag and drop and resize image and i am trying to add a custom modification. I added an upload button so user can upload a photo.
i added the function bellow to find the last img id, create a new one and replace the latest id and img source. The user's photo uploading well but it's not draggable and resizable like other objects.
Official projects link is: http://tympanus.net/Tutorials/ImageVampUp/
The code that i added is:
<script>
$(document).ready(function() {
$("input").change(function(e) {
for (var i = 0; i < e.originalEvent.srcElement.files.length; i++) {
var file = e.originalEvent.srcElement.files[i];
var reader = new FileReader();
reader.onloadend = function() {
var newoid = parseInt($("#objects .obj_item:last img").attr("ID").split("_")[1], 10) + 1;
var newoimage = reader.result;
$("#objects").append("<div class='obj_item' style='width:80px; height:80px; float:left; margin-left:5px; margin-top:5px;'><img id='"+newoid+"' width='80' height='80' class='ui-widget-content' src='"+newoimage+"' alt='el'/></div>");
//$('#obj_25').attr('src', reader.result);
}
reader.readAsDataURL(file);
}
});
});
</script>
and inside projects left bar i added a div with an input so user can load the pic:
<input type='file' onchange="readURL(this);" />
Just invoke the following putting it in a function after the image is appended:
$('#objects img:last').resizable({
/* only diagonal (south east) */
handles : 'se',
stop : resizestop
}).parent('.ui-wrapper').draggable({
revert : 'invalid'
});

Uploaded Image does not show in Safari 5.1 on Windows

I am using this tutorial to upload Image and display it. It works well in Chrome and Firefox but it is not showing uploaded image in safari. Why?
HTML
<div id="page-wrapper">
<h1>Image File Reader</h1>
<div>
Select an image file:
<input type="file" id="fileInput">
</div>
<div id="fileDisplayArea"></div>
Javascript
window.onload = function() {
var fileInput = document.getElementById('fileInput');
var fileDisplayArea = document.getElementById('fileDisplayArea');
fileInput.addEventListener('change', function(e) {
var file = fileInput.files[0];
var imageType = /image.*/;
if (file.type.match(imageType)) {
var reader = new FileReader();
reader.onload = function(e) {
fileDisplayArea.innerHTML = "";
var img = new Image();
img.src = reader.result;
fileDisplayArea.appendChild(img);
}
reader.readAsDataURL(file);
} else {
fileDisplayArea.innerHTML = "File not supported!"
}
});
}
Open web development tools (Firebug for Firefox or CTRL+SHIFT+J in Chrome), select the image element with the element inspector and have a look at the URL that it is loading from and determine how it is different from the URL it should be loading from.
Since you're using Safari 5.1 on Windows, the FileReader API isn't supported and Safari on Windows will no longer be updated your best bet is to use a placeholder image from the server and call this battle a draw. Safari 5.1 market share on Windows is trivial at best and will only decrease as time goes on. Part of programming is knowing when to walk away from a fight.
if (window.FileReader)
{
//Your FileReader code here.
}
else
{
//Insert an image from the server here.
}

Categories

Resources