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Stop Web Workers in HTML5

I have worked on Web Workers. What if I need to stop Web Workers. Is there any method available to achieve this?
Nishtha Thakur
Answered on 6th Apr, 2018

Web Workers allow for long-running scripts that are not interrupted by scripts that respond to clicks or other user interactions and allows long tasks to be executed without yielding to keep the page responsive.Web Workers don't stop by themselves but the page that started them can stop them by calling ... Read More

Is HTML5 canvas and image on polygon possible?

I am learning HTML5 Canvas these days. Is HTML5 canvas and image on polygon possible or not?
George John
Answered on 6th Apr, 2018

Yes, it is possible. Create a pattern using the image, and then set the pattern to fillStyle.Here, obj is our image object:var context = canvas.getContext("2d"); var pattern = context.createPattern(obj, "repeat"); context.fillStyle = pattern;You need to manipulate the image to fit an arbitrary polygon:context.save(); context.setTransform(m11, m12, m21, m22, dx, dy); context.drawImage(obj); ... Read More

Image button with HTML5

I am learning HTML5 these days. I want to add image button With HTML5. Where should I send the following image for the button? ,
Chandu yadav
Answered on 6th Apr, 2018

To add image button with HTML5, use the <button> element and set the image inside it before it is closed </button>:<button type = "submit" name = "learn" value = "myimage">    <p>Tutorials for all</p>    <img src="https://www.tutorialspoint.com/latest/inter-process-communication.png " /> </button> Read More

Detect folders in Safari with HTML5

How can I detect folders in Safari web browser? How can I achieve this with HTML5?
Smita Kapse
Answered on 6th Apr, 2018

You can try to run the following code to detect folders in Safari:Array.prototype.forEach.call(e.dataTransfer.files, function (file) {    var r = new FileReader();    r.onload = function (event) {       addFile(file);    };    r.onerror = function (event) {       alert("Uploading folders isn't supported in Safari browser!"); ... Read More

Creating content with HTML5 Canvas much more complicated than authoring with Flash

What is the role of Canvas and Flash? Why creating content with HTML5 Canvas much more complicated than authoring with Flash?
Anvi Jain
Answered on 6th Apr, 2018

Flash provides amazing GUI and lots of visual features for animations. It allows the user build everything inside a particular platform without a full integration into the browser wrapped inside the browser with the main scopes that are multimedia and other kinds of animation.HTML5 element <canvas> gives you an easy ... Read More

HTML5 Canvas Degree Symbol

How can I achive the degree symbol on HTML5 Canvas? The following is my canvas style: ,
Maheshwari Thakur
Answered on 6th Apr, 2018

For HTML5 Canvas degree symbol, try to run the following code:<!DOCTYPE html> <html>    <head>       <meta charset="utf-8">       <style media="screen">          body {             margin:5em;             background:#eee;           ... Read More

How to stop dragend's default behavior in drag and drop?

I want to stop the dragend’s default behavior in drag and drop. How can i achieve this in HTML?
Ankith Reddy
Answered on 6th Apr, 2018

To stop dragend’s default behavior, you need to detect if the mouse is over the drop target where you want to drop.This is what you should do only if you are hovering over the my list: listContainer.insertBefore(source, myNode);Use jQuery:if ($(mylist).parent().find(":hover")) {    listContainer.insertBefore(source, myNode); } Read More

Proper use of flex properties when nesting flex containers

How can I properly use the flex properties when nesting flex containers in HTML?
Nitya Raut
Answered on 6th Apr, 2018

A flex container is always the parent and a flex item is always the child because the scope of a flex formatting context is limited to a parent/child relationship.Descendants of a flex container beyond the children are not part of flex layout and will not accept flex properties.You need to ... Read More

HTML5 Canvas Font Size Based on Canvas Size

How can I scale font size based on HTML5 Canvas size? The font size should be: ,
George John
Answered on 6th Apr, 2018

To scale fonts, let us see an example.Canvas: 800px Font Size: 60pxYou need to use the following code for our example to scale font size based on canvas:var fontBase = 800; var fontSize = 60; function getFont() {    var ratio = fontSize / fontBase;    var cSize = ... Read More

HTML5 Canvas fit to window

I want to fit my HTML5 Canvas to window. Which CSS styles should I use to achieve this?
Jennifer Nicholas
Answered on 6th Apr, 2018

You need to use CSS to fit canvas to windows.#box {    overflow: hidden; } #canvas {    position: absolute;    top: 0px;    left: 0px; }

Fractional font sizes for HTML5 Canvas?

How can I set fractional font sizes with HTML5 Canvas? What are the steps involved?
Chandu yadav
Answered on 6th Apr, 2018

For fractional font sizes, during initialization render the text at the standard font size. After that measure the line length, Use a hidden canvas to render the text onto and then use drawImage to the main canvas with a multiplier on the width.ctx.font = (font_size * zoom) + "px Georgia"; ... Read More

How to make an Ember.js app offline with server sync when available?

I want to make an Ember.js app offline with server sync. How can I achieve this?
Maheshwari Thakur
Answered on 6th Apr, 2018

Use the ember-localstorage adapter.App.store = DS.Store.create({    revision: 11,    adapter: DS.LSAdapter.create() });You need to define the adapter you want to use for client-side storage:App.Store = DS.SyncStore.extend({    revision: 10,    adapter: DS.IndexedDB.adapter({       mappings: {          person: App.Person,          persons: App.Person, ... Read More

How to handle errors in HTML5 Web Workers?

I want to handle errors perfectly in Web Workers with HTML. How can I achieve this?
Vrundesha Joshi
Answered on 6th Apr, 2018

The following shows an example of an error handling function in a Web Worker JavaScript file that logs errors to the console.<!DOCTYPE HTML> <html>    <head>       <title>Big for loop</title>       <script>          var worker = new Worker('bigLoop.js');          worker.onmessage ... Read More

How to make the user login for an offline web app?

What are the steps I should follow to make users login for an offline web app?
George John
Answered on 6th Apr, 2018

While logging in i.e. online, you need to first authenticate against the server and if it works, store the username and a hashed password in the database.If you can find the account in the database, then you need to generate a new hash, only if the user has changed the ... Read More

Crop Canvas / Export HTML5 Canvas with certain width and height

How can I crop canvas with certain width and height in HTML5? Should I create a temporary HTML Canvas first?
Rishi Rathor
Answered on 6th Apr, 2018

For this, create a temporary canvas for drawing on the current canvas. After that use toDataUrl() method on the temporary canvas:var c = document.getElementsByTagName("canvas"); var ctx = c[0].getContext("2d"); var data = ctx.getImageData(0, 0, c[0].width, c[0].height); var compositeOperation = ctx.globalCompositeOperation; ctx.globalCompositeOperation = "destination-over"; ctx.fillStyle = "#800000"; ctx.fillRect(0, 0, c[0].width, c[0].height); ... Read More

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