jQuery rounded slider | 易学教程

问题

I would like to do a rounded slider like the image below. Is jQuery able to do this?

I know how a straight slider works but I would like to make a HTML5 rounded slider. Here is what I found online http://jsfiddle.net/XdvNg/1/ - but I dont know how to get the slider value one the user lets go

回答1:

Here is what I came up with:

jsBin demo

$(function () {
    var $circle = $('#circle'),
        $handler = $('#handler'),
        $p = $('#test'),
        handlerW2 = $handler.width()/2,
        rad = $circle.width()/2,
        offs = $circle.offset(),
        elPos = {x:offs.left, y:offs.top},
        mHold = 0,
        PI2 = Math.PI/180;
    $handler.mousedown(function() { mHold = 1; });
    $(document).mousemove(function(e) {
        if (mHold) {
            var mPos = {x:e.pageX-elPos.x, y:e.pageY-elPos.y},
                atan = Math.atan2(mPos.x-rad, mPos.y-rad),
                deg  = -atan/PI2+180,
                perc = (deg*100/360)|0,
                X = Math.round(rad*  Math.sin(deg*PI2)),    
                Y = Math.round(rad* -Math.cos(deg*PI2));
            $handler.css({left:X+rad-handlerW2, top:Y+rad-handlerW2, transform:'rotate('+deg+'deg)'});
        }
    }).mouseup(function() { mHold = 0; });
});

回答2:

Here is little improved version of Roko's script: jsFiddle demo

To calculate mouse position I use event offset(little fix for firefox), corrected if event target isn't #rotationSliderContainer. I add also attraction to multiples of 90 degrees.

$(function(){
    var $container = $('#rotationSliderContainer');
    var $slider = $('#rotationSlider');
    var $degrees = $('#rotationSliderDegrees');

    var sliderWidth = $slider.width();
    var sliderHeight = $slider.height();
    var radius = $container.width()/2;
    var deg = 0;    

    X = Math.round(radius* Math.sin(deg*Math.PI/180));
    Y = Math.round(radius*  -Math.cos(deg*Math.PI/180));
    $slider.css({ left: X+radius-sliderWidth/2, top: Y+radius-sliderHeight/2 });

    var mdown = false;
    $container
    .mousedown(function (e) { mdown = true; e.originalEvent.preventDefault(); })
    .mouseup(function (e) { mdown = false; })
    .mousemove(function (e) {
        if(mdown)
        {

            // firefox compatibility
            if(typeof e.offsetX === "undefined" || typeof e.offsetY === "undefined") {
               var targetOffset = $(e.target).offset();
               e.offsetX = e.pageX - targetOffset.left;
               e.offsetY = e.pageY - targetOffset.top;
            }

            if($(e.target).is('#rotationSliderContainer'))
                var mPos = {x: e.offsetX, y: e.offsetY};
            else
                var mPos = {x: e.target.offsetLeft + e.offsetX, y: e.target.offsetTop + e.offsetY};

            var atan = Math.atan2(mPos.x-radius, mPos.y-radius);
            deg = -atan/(Math.PI/180) + 180; // final (0-360 positive) degrees from mouse position 


            // for attraction to multiples of 90 degrees
            var distance = Math.abs( deg - ( Math.round(deg / 90) * 90 ) );

            if( distance <= 5 )
                deg = Math.round(deg / 90) * 90;

            if(deg == 360)
                deg = 0;

            X = Math.round(radius* Math.sin(deg*Math.PI/180));
            Y = Math.round(radius*  -Math.cos(deg*Math.PI/180));

            $slider.css({ left: X+radius-sliderWidth/2, top: Y+radius-sliderHeight/2 });              

            var roundDeg = Math.round(deg);

            $degrees.html(roundDeg + '&deg;');
            $('#imageRotateDegrees').val(roundDeg);

        }
    });
});

回答3:

Here is the jQuery roundSlider plugin for your requirement, it works fine in mobile devices and touch devices also.

This roundslider having the similar options like the jQuery ui slider. It support default, min-range and range slider type. Not only the round slider it also supports various circle shapes such as quarter, half and pie circle shapes.

For more details check the demos and documentation page.

Please check the demo from jsFiddle.

Screenshot of the Output: