Solved

Real-time transparency slider

Posted on 2013-10-27
6
493 Views
Last Modified: 2013-11-09
I need to take an existing image and set the transparency in real-time, with a slider.  Assistance is greatly appreciated.
0
Comment
Question by:frugalmule
6 Comments
 
LVL 108

Expert Comment

by:Ray Paseur
ID: 39605832
You can do this easily in Photoshop.  If that's not what you're looking for, please tell us a little more about the application needs, thanks.
0
 

Author Comment

by:frugalmule
ID: 39635183
I'm trying to choose a background color for a webpage and need the code format that would work best for that.
0
 
LVL 25

Expert Comment

by:Kyle Hamilton
ID: 39635700
it's not clear what you are asking.

Are you building an application that allows people to pick colors from an image that they dynamically set transparency on? Javascript/CSS?

or,

Are you just trying to find a "good" background color for your website based on some image you have? Do you have photoshop? You can get the HEX code for the color by right clicking in the photoshop file.
0
 
LVL 42

Accepted Solution

by:
Rob Jurd, EE MVE earned 500 total points
ID: 39636069
seeing as you posted this in the jquery and web topics:

http://jsbin.com/EGiwotir/1/

move the slider to change the opacity of the EE image.

Use the 3 sliders below that to change the background colour.
0
 
LVL 42

Expert Comment

by:Rob Jurd, EE MVE
ID: 39636217
For reference, given the jsbin may not always be accessible:

html:
<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>JS Bin</title>
  <link rel="stylesheet" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css" />
  <script src="http://code.jquery.com/jquery-1.9.1.js"></script>
  <script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
</head>
<body>
  <div style='background-color: blue' class="swatch">
  <img id='myimage' src="http://experts.cachefly.net/0/images/experts-exchange/experts-exchange-logo.png" alt="">
    </div>
  <p></p>
  <div id="slider"></div>
  
  <div id="red"></div>
<div id="green"></div>
<div id="blue"></div>
 
<div id="swatch" class="swatch ui-widget-content ui-corner-all"></div>
  <div style="margin-top:30px;">
  <p><span>Opacity: </span><span id='opacity'>1</span></p>
  <p><span>Colour: #</span><span id='colour'></span></p>
    </div>
</body>
</html>

Open in new window


css:
#red, #green, #blue {
    float: left;
    clear: left;
    width: 300px;
    margin: 15px;
  }
  #swatch {
    width: 120px;
    height: 100px;
    margin-top: 18px;
    margin-left: 350px;
    background-image: none;
  }
  #red .ui-slider-range { background: #ef2929; }
  #red .ui-slider-handle { border-color: #ef2929; }
  #green .ui-slider-range { background: #8ae234; }
  #green .ui-slider-handle { border-color: #8ae234; }
  #blue .ui-slider-range { background: #729fcf; }
  #blue .ui-slider-handle { border-color: #729fcf; }

Open in new window


javascript:
 $(function() {
   $( "#slider" ).slider({
     min: 0,
     max: 1,
     step: 0.1,
     slide: function( event, ui ) {
       var opc = 1-ui.value;
        $( "#myimage" ).css( "opacity",opc );
       $("#opacity").text(opc);
      }
   });
  });

function hexFromRGB(r, g, b) {
    var hex = [
      r.toString( 16 ),
      g.toString( 16 ),
      b.toString( 16 )
    ];
    $.each( hex, function( nr, val ) {
      if ( val.length === 1 ) {
        hex[ nr ] = "0" + val;
      }
    });
    return hex.join( "" ).toUpperCase();
  }
  function refreshSwatch() {
    var red = $( "#red" ).slider( "value" ),
      green = $( "#green" ).slider( "value" ),
      blue = $( "#blue" ).slider( "value" ),
      hex = hexFromRGB( red, green, blue );
    $("#colour").text(hex);
    $( ".swatch" ).css( "background-color", "#" + hex );
  }
  $(function() {
    $( "#red, #green, #blue" ).slider({
      orientation: "horizontal",
      range: "min",
      max: 255,
      value: 127,
      slide: refreshSwatch,
      change: refreshSwatch
    });
    $( "#red" ).slider( "value", 255 );
    $( "#green" ).slider( "value", 140 );
    $( "#blue" ).slider( "value", 60 );
  });

Open in new window

0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
stop navigation from wrapping 7 58
Centering Vertically 3 28
Change color of modular 8 22
How to hide the rows in Table when the value is empty ? 4 19
Building a website can seem like a daunting task to the uninitiated but it really only requires knowledge of two basic languages: HTML and CSS.
This article discusses four methods for overlaying images in a container on a web page
The viewer will learn how to create a basic form using some HTML5 and PHP for later processing. Set up your basic HTML file. Open your form tag and set the method and action attributes.: (CODE) Set up your first few inputs one for the name and …
In this sixth video of the Xpdf series, we discuss and demonstrate the PDFtoPNG utility, which converts a multi-page PDF file to separate color, grayscale, or monochrome PNG files, creating one PNG file for each page in the PDF. It does this via a c…

895 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

14 Experts available now in Live!

Get 1:1 Help Now