knobKnob是一款使用css3 transform和jQuery制作的旋钮插件。
HTML
html结构非常简单,只需要放一个空的id为control
的div即可,后面的html代码由jQuery在运行时动态产生。
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>Shiny Switches with CSS3 & jQuery | Tutorialzine Demo</title> <!-- CSS stylesheets --> <link rel="stylesheet" href="assets/css/styles.css" /> <link rel="stylesheet" href="assets/knobKnob/knobKnob.css" /> <!--[if lt IE 9]> <script src="http://html5shiv.googlecode.com/svn/trunk/html5.js"></script> <![endif]--> </head> <body> <section id="main"> <div id="bars"> <div id="control"> <!-- The knob markup will go here --> </div> <!-- The colorful dividers will go here --> </div> </section> <!-- JavaScript includes --> <script src="http://code.jquery.com/jquery-1.7.1.min.js"></script> <script src="assets/knobKnob/transform.js"></script> <script src="assets/knobKnob/knobKnob.jquery.js"></script> <script src="assets/js/script.js"></script> </body> </html>
JAVASCRIPT
(function($){ $.fn.knobKnob = function(props){ var options = $.extend({ snap: 0, value: 0, turn: function(){} }, props || {}); var tpl = '<div class="knob">\ <div class="top"></div>\ <div class="base"></div>\ </div>'; return this.each(function(){ var el = $(this); el.append(tpl); var knob = $('.knob',el) knobTop = knob.find('.top'), startDeg = -1, currentDeg = 0, rotation = 0, lastDeg = 0, doc = $(document); if(options.value > 0 && options.value <= 359){ rotation = currentDeg = options.value; knobTop.css('transform','rotate('+(currentDeg)+'deg)'); options.turn(currentDeg/359); } knob.on('mousedown', function(e){ e.preventDefault(); var offset = knob.offset(); var center = { y : offset.top + knob.height()/2, x: offset.left + knob.width()/2 }; var a, b, deg, tmp, rad2deg = 180/Math.PI; knob.on('mousemove.rem',function(e){ a = center.y - e.pageY; b = center.x - e.pageX; deg = Math.atan2(a,b)*rad2deg; // we have to make sure that negative // angles are turned into positive: if(deg<0){ deg = 360 + deg; } // Save the starting position of the drag if(startDeg == -1){ startDeg = deg; } // Calculating the current rotation tmp = Math.floor((deg-startDeg) + rotation); // Making sure the current rotation // stays between 0 and 359 if(tmp < 0){ tmp = 360 + tmp; } else if(tmp > 359){ tmp = tmp % 360; } // Snapping in the off position: if(options.snap && tmp < options.snap){ tmp = 0; } // This would suggest we are at an end position; // we need to block further rotation. if(Math.abs(tmp - lastDeg) > 180){ return false; } currentDeg = tmp; lastDeg = tmp; knobTop.css('transform','rotate('+(currentDeg)+'deg)'); options.turn(currentDeg/359); }); doc.on('mouseup.rem',function(){ knob.off('.rem'); doc.off('.rem'); // Saving the current rotation rotation = currentDeg; // Marking the starting degree as invalid startDeg = -1; }); }); }); }; })(jQuery);