Use HTML5 technology to develop your own cool color picker_html5 tutorial skills-H5 Tutorial-php.cn

Use HTML5 technology to develop your own cool color picker_html5 tutorial skills

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Release： 2016-05-16 15:48:40

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You may have seen many color pickers developed using jquery/js. Today we will use HTML5 technology to implement a better color picker ourselves. Hope you all like it!

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The code is as follows:

The code is very simple and contains two parts, a click element and an element used to display the color selector.

JavaScript code

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The code is as follows:

$(function(){
var bCanPreview = true; // can preview
// create canvas and context objects
var canvas = document.getElementById('picker');
var ctx = canvas.getContext('2d');
// drawing active image
var image = new Image();
image.onload = function () {
ctx.drawImage( image, 0, 0, image.width, image.height); // draw the image on the canvas
}
// select desired colorwheel
var imagesrc="images/colorwheel1.png";
switch ($(canvas).attr('var')) {
case '2':
imagesrc="images/colorwheel2.png";
break;
case '3' :
imagesrc="images/colorwheel3.png";
break;
case '4':
imagesrc="images/colorwheel4.png";
break;
case ' 5':
imagesrc="images/colorwheel5.png";
break;
}
image.src = imageSrc;
$('#picker').mousemove(function(e ) { // mouse move handler
if (bCanPreview) {
// get coordinates of current position
var canvasOffset = $(canvas).offset();
var canvasX = Math.floor( e.pageX - canvasOffset.left);
var canvasY = Math.floor(e.pageY - canvasOffset.top);
// get current pixel
var imageData = ctx.getImageData(canvasX, canvasY, 1, 1);
var pixel = imageData.data;
// update preview color
var pixelColor = "rgb(" pixel[0] ", " pixel[1] ", " pixel[2 ] ")";
$('.preview').css('backgroundColor', pixelColor);
// update controls
$('#rVal').val(pixel[0]) ;
$('#gVal').val(pixel[1]);
$('#bVal').val(pixel[2]);
$('#rgbVal'). val(pixel[0] ',' pixel[1] ',' pixel[2]);
var dColor = pixel[2] 256 * pixel[1] 65536 * pixel[0];
$( '#hexVal').val('#' ('0000' dColor.toString(16)).substr(-6));
}
});
$('#picker') .click(function(e) { // click event handler
bCanPreview = !bCanPreview;
});
$('.preview').click(function(e) { // preview click
$('.colorpicker').fadeToggle("slow", "linear");
bCanPreview = true;
});
});

Everyone As you can see, this is a very short js code that is used to create a new canvas and object, and then we draw a circular color plate. You can choose different color base plates. A parameter is used here to set different options. As follows:

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The code is as follows:

Now we add events: mousemove, click events. jQuery is used here to display and hide the selector.

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The code is as follows:

$('.preview').click (function(e) { // preview click $('.colorpicker').fadeToggle("slow", "linear"); bCanPreview = true; });

When our mouse moves On the selected object, we need to refresh the information. For example, the current color

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The code is as follows:

$('#picker').mousemove(function(e) { // mouse move handler
if (bCanPreview) {
// get coordinates of current position
var canvasOffset = $ (canvas).offset();
var canvasX = Math.floor(e.pageX - canvasOffset.left);
var canvasY = Math.floor(e.pageY - canvasOffset.top);
/ / get current pixel
var imageData = ctx.getImageData(canvasX, canvasY, 1, 1);
var pixel = imageData.data;
// update preview color
var pixelColor = "rgb( " pixel[0] ", " pixel[1] ", " pixel[2] ")";
$('.preview').css('backgroundColor', pixelColor);
// update controls
$('#rVal').val(pixel[0]);
$('#gVal').val(pixel[1]);
$('#bVal').val (pixel[2]);
$('#rgbVal').val(pixel[0] ',' pixel[1] ',' pixel[2]);
var dColor = pixel[2] 256 * pixel[1] 65536 * pixel[0];
$('#hexVal').val('#' ('0000' dColor.toString(16)).substr(-6));
}
});
$('#picker').click(function(e) { // click event handler
bCanPreview = !bCanPreview;
});

CSS code

CSS for different color base plates:

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The code is as follows:

/* colorpicker styles */
.colorpicker {
background-color: #222222;
border-radius: 5px 5px 5px 5px;
box-shadow: 2px 2px 2px #444444;
color: #FFFFFF;
font-size: 12px;
position: absolute;
width: 460px;
}
#picker {
cursor: crosshair;
float: left;
margin: 10px;
border: 0;
}
.controls {
float: right;
margin: 10px;
}
.controls > div {
border: 1px solid #2F2F2F;
margin-bottom: 5px;
overflow: hidden;
padding: 5px ;
}
.controls label {
float: left;
}
.controls > div input {
background-color: #121212;
border: 1px solid #2F2F2F;
color: #DDDDDD;
float: right;
font-size: 10px;
height: 14px;
margin-left: 6px;
text-align: center;
text-transform: uppercase;
width: 75px;
}
.preview {
background: url("../images/select.png") repeat scroll center center transparent;
border-radius: 3px;
box-shadow: 2px 2px 2px #444444;
cursor: pointer;
height: 30px;
width: 30px;
}

Hope you all like it