jquery.mobile.forms.slider.js

/*
* jQuery Mobile Framework : "slider" plugin
* Copyright (c) jQuery Project
* Dual licensed under the MIT or GPL Version 2 licenses.
* http://jquery.org/license
*/

( function( $, undefined ) {

$.widget( "mobile.slider", $.mobile.widget, {
	options: {
		theme: null,
		trackTheme: null,
		disabled: false,
		initSelector: "input[type='range'], :jqmData(type='range'), :jqmData(role='slider')"
	},

	_create: function() {

		// TODO: Each of these should have comments explain what they're for
		var self = this,

			control = this.element,

			parentTheme = $.mobile.getInheritedTheme( control, "c" ),

			theme = this.options.theme || parentTheme,

			trackTheme = this.options.trackTheme || parentTheme,

			cType = control[ 0 ].nodeName.toLowerCase(),

			selectClass = ( cType == "select" ) ? "ui-slider-switch" : "",

			controlID = control.attr( "id" ),

			labelID = controlID + "-label",

			label = $( "[for='"+ controlID +"']" ).attr( "id", labelID ),

			val = function() {
				return  cType == "input"  ? parseFloat( control.val() ) : control[0].selectedIndex;
			},

			min =  cType == "input" ? parseFloat( control.attr( "min" ) ) : 0,

			max =  cType == "input" ? parseFloat( control.attr( "max" ) ) : control.find( "option" ).length-1,

			step = window.parseFloat( control.attr( "step" ) || 1 ),

			slider = $( "<div class='ui-slider " + selectClass + " ui-btn-down-" + trackTheme +
									" ui-btn-corner-all' role='application'></div>" ),

			handle = $( "<a href='#' class='ui-slider-handle'></a>" )
				.appendTo( slider )
				.buttonMarkup({ corners: true, theme: theme, shadow: true })
				.attr({
					"role": "slider",
					"aria-valuemin": min,
					"aria-valuemax": max,
					"aria-valuenow": val(),
					"aria-valuetext": val(),
					"title": val(),
					"aria-labelledby": labelID
				}),
			options;

		$.extend( this, {
			slider: slider,
			handle: handle,
			dragging: false,
			beforeStart: null,
			userModified: false
		});

		if ( cType == "select" ) {

			slider.wrapInner( "<div class='ui-slider-inneroffset'></div>" );

			options = control.find( "option" );

			control.find( "option" ).each(function( i ) {

				var side = !i ? "b":"a",
					corners = !i ? "right" :"left",
					theme = !i ? " ui-btn-down-" + trackTheme :( " " + $.mobile.activeBtnClass );

				$( "<div class='ui-slider-labelbg ui-slider-labelbg-" + side + theme + " ui-btn-corner-" + corners + "'></div>" )
					.prependTo( slider );

				$( "<span class='ui-slider-label ui-slider-label-" + side + theme + " ui-btn-corner-" + corners + "' role='img'>" + $( this ).getEncodedText() + "</span>" )
					.prependTo( handle );
			});

		}

		label.addClass( "ui-slider" );

		// monitor the input for updated values
		control.addClass( cType === "input" ? "ui-slider-input" : "ui-slider-switch" )
			.change( function() {
				self.refresh( val(), true );
			})
			.keyup( function() { // necessary?
				self.refresh( val(), true, true );
			})
			.blur( function() {
				self.refresh( val(), true );
			});

		// prevent screen drag when slider activated
		$( document ).bind( "vmousemove", function( event ) {
			if ( self.dragging ) {
				self.refresh( event );
				self.userModified = self.userModified || self.beforeStart !== control[0].selectedIndex;
				return false;
			}
		});

		slider.bind( "vmousedown", function( event ) {
			self.dragging = true;
			self.userModified = false;

			if ( cType === "select" ) {
				self.beforeStart = control[0].selectedIndex;
			}
			self.refresh( event );
			return false;
		});

		slider.add( document )
			.bind( "vmouseup", function() {
				if ( self.dragging ) {

					self.dragging = false;

					if ( cType === "select" ) {

						if ( !self.userModified ) {
							//tap occurred, but value didn't change. flip it!
							handle.addClass( "ui-slider-handle-snapping" );
							self.refresh( !self.beforeStart ? 1 : 0 );
						}
					}
					return false;
				}
			});

		slider.insertAfter( control );

		// NOTE force focus on handle
		this.handle
			.bind( "vmousedown", function() {
				$( this ).focus();
			})
			.bind( "vclick", false );

		this.handle
			.bind( "keydown", function( event ) {
				var index = val();

				if ( self.options.disabled ) {
					return;
				}

				// In all cases prevent the default and mark the handle as active
				switch ( event.keyCode ) {
				 case $.mobile.keyCode.HOME:
				 case $.mobile.keyCode.END:
				 case $.mobile.keyCode.PAGE_UP:
				 case $.mobile.keyCode.PAGE_DOWN:
				 case $.mobile.keyCode.UP:
				 case $.mobile.keyCode.RIGHT:
				 case $.mobile.keyCode.DOWN:
				 case $.mobile.keyCode.LEFT:
					event.preventDefault();

					if ( !self._keySliding ) {
						self._keySliding = true;
						$( this ).addClass( "ui-state-active" );
					}
					break;
				}

				// move the slider according to the keypress
				switch ( event.keyCode ) {
				 case $.mobile.keyCode.HOME:
					self.refresh( min );
					break;
				 case $.mobile.keyCode.END:
					self.refresh( max );
					break;
				 case $.mobile.keyCode.PAGE_UP:
				 case $.mobile.keyCode.UP:
				 case $.mobile.keyCode.RIGHT:
					self.refresh( index + step );
					break;
				 case $.mobile.keyCode.PAGE_DOWN:
				 case $.mobile.keyCode.DOWN:
				 case $.mobile.keyCode.LEFT:
					self.refresh( index - step );
					break;
				}
			}) // remove active mark
			.keyup( function( event ) {
				if ( self._keySliding ) {
					self._keySliding = false;
					$( this ).removeClass( "ui-state-active" );
				}
			});

		this.refresh(undefined, undefined, true);
	},

	refresh: function( val, isfromControl, preventInputUpdate ) {

		if ( this.options.disabled || this.element.attr('disabled')) { 
			this.slider.addClass('ui-disabled');
			return;
		}

		var control = this.element, percent,
			cType = control[0].nodeName.toLowerCase(),
			min = cType === "input" ? parseFloat( control.attr( "min" ) ) : 0,
			max = cType === "input" ? parseFloat( control.attr( "max" ) ) : control.find( "option" ).length - 1;

		if ( typeof val === "object" ) {
			var data = val,
				// a slight tolerance helped get to the ends of the slider
				tol = 8;
			if ( !this.dragging ||
					data.pageX < this.slider.offset().left - tol ||
					data.pageX > this.slider.offset().left + this.slider.width() + tol ) {
				return;
			}
			percent = Math.round( ( ( data.pageX - this.slider.offset().left ) / this.slider.width() ) * 100 );
		} else {
			if ( val == null ) {
				val = cType === "input" ? parseFloat( control.val() ) : control[0].selectedIndex;
			}
			percent = ( parseFloat( val ) - min ) / ( max - min ) * 100;
		}

		if ( isNaN( percent ) ) {
			return;
		}

		if ( percent < 0 ) {
			percent = 0;
		}

		if ( percent > 100 ) {
			percent = 100;
		}

		var newval = Math.round( ( percent / 100 ) * ( max - min ) ) + min;

		if ( newval < min ) {
			newval = min;
		}

		if ( newval > max ) {
			newval = max;
		}

		// Flip the stack of the bg colors
		if ( percent > 60 && cType === "select" ) {
			// TODO: Dead path?
		}
		this.handle.css( "left", percent + "%" );
		this.handle.attr( {
				"aria-valuenow": cType === "input" ? newval : control.find( "option" ).eq( newval ).attr( "value" ),
				"aria-valuetext": cType === "input" ? newval : control.find( "option" ).eq( newval ).getEncodedText(),
				title: newval
			});

		// add/remove classes for flip toggle switch
		if ( cType === "select" ) {
			if ( newval === 0 ) {
				this.slider.addClass( "ui-slider-switch-a" )
					.removeClass( "ui-slider-switch-b" );
			} else {
				this.slider.addClass( "ui-slider-switch-b" )
					.removeClass( "ui-slider-switch-a" );
			}
		}

		if ( !preventInputUpdate ) {
			var valueChanged = false;

			// update control"s value
			if ( cType === "input" ) {
				valueChanged = control.val() !== newval;
				control.val( newval );
			} else {
				valueChanged = control[ 0 ].selectedIndex !== newval;
				control[ 0 ].selectedIndex = newval;
			}
			if ( !isfromControl && valueChanged ) {
				control.trigger( "change" );
			}
		}
	},

	enable: function() {
		this.element.attr( "disabled", false );
		this.slider.removeClass( "ui-disabled" ).attr( "aria-disabled", false );
		return this._setOption( "disabled", false );
	},

	disable: function() {
		this.element.attr( "disabled", true );
		this.slider.addClass( "ui-disabled" ).attr( "aria-disabled", true );
		return this._setOption( "disabled", true );
	}

});

//auto self-init widgets
$( document ).bind( "pagecreate create", function( e ){
	$.mobile.slider.prototype.enhanceWithin( e.target );
});

})( jQuery );