jQuery.gestures={};(function($){var canvas;var active=false;var recording=false;var previous={x:0,y:0};var chain=[];var registered=[];var error=null;var color;function exec(chain){if(chain.length){fun=registered[chain.join('')];if(fun){fun.call(this);}else{if(error){error($.map(chain,function(e){if(e=='U')return'Up';if(e=='D')return'Down';if(e=='L')return'Left';if(e=='R')return'Right';}).join(', '));}}}}
function get_last_move(previous,cur){var diff={x:cur.x-previous.x,y:cur.y-previous.y};var mv=null;if(Math.abs(diff.x)>Math.abs(diff.y)){if(diff.x<=-10)mv='L';if(diff.x>=10)mv='R';}else{if(diff.y<=-10)mv='U';if(diff.y>=10)mv='D';}
return mv;}
function drawline(previous,cur){var context=document.getElementById('gestures_canvas').getContext('2d');context.strokeStyle=color;context.beginPath();context.moveTo(previous.x,previous.y);context.lineTo(cur.x,cur.y);context.closePath();context.stroke();}
function setup(){if(active){recording=false;chain=[];canvas.hide().css({position:'fixed',top:0,left:0,}).attr({height:$(window).height(),width:$(window).width()}).show();}}
$.gestures.init=function(ob){ob=$.extend(ob,{active:false,color:'#4ECAF2'});color=ob.color;$('body').append('<canvas id="gestures_canvas"/>');canvas=$('#gestures_canvas');$(window).resize(setup);$('body').mousedown(function(e){if(active){recording=true;previous={x:e.clientX,y:e.clientY}}});$('body').mousemove(function(e){if(active&&recording){var pos={x:e.clientX,y:e.clientY};drawline(previous,pos);var mv=get_last_move(previous,pos);if(mv!=null){if(chain[chain.length-1]!=mv){chain.push(mv);}}
previous={x:e.clientX,y:e.clientY}}});$('body').mouseup(function(e){if(active&&recording){var c=chain;setup();exec(c);}});if(ob.active)$.gestures.enable();else $.gestures.disable();}
$.gestures.register=function(gesture,fun){registered[gesture.replace(/,/g,'')]=fun;}
$.gestures.error=function(fun){error=fun;}
$.gestures.enable=function(){active=true;setup();}
$.gestures.disable=function(){active=false;$(canvas).hide();}
$.gestures.active=function(){return active;}})(jQuery)