API: progressbar ProgressBar.js (YUI Library)

# Yahoo! UI Library

### ProgressBar Widget 2.8.1

Yahoo! UI Library > progressbar > ProgressBar.js (source view)
Search:
Filters Show Private Show Protected Show Deprecated

    /**
     *
     * @module progressbar
     * @requires yahoo, dom, event, element
     * @optional animation
     * @title ProgressBar Widget
     */

    (function () {
    	var Dom = YAHOO.util.Dom,
    		Lang = YAHOO.lang,
    		// ClassNames
    		CLASS_PROGBAR = 'yui-pb',
    		CLASS_MASK = CLASS_PROGBAR + '-mask',
    		CLASS_BAR = CLASS_PROGBAR + '-bar',
    		CLASS_ANIM = CLASS_PROGBAR + '-anim',
    		CLASS_TL = CLASS_PROGBAR + '-tl',
    		CLASS_TR = CLASS_PROGBAR + '-tr',
    		CLASS_BL = CLASS_PROGBAR + '-bl',
    		CLASS_BR = CLASS_PROGBAR + '-br',

    		// Configuration attributes
    		WIDTH = 'width',
    		HEIGHT = 'height',
    		MIN_VALUE = 'minValue',
    		MAX_VALUE = 'maxValue',
    		VALUE = 'value',
    		ANIM = 'anim',
    		DIRECTION = 'direction',
    		DIRECTION_LTR = 'ltr',
    		DIRECTION_RTL = 'rtl',
    		DIRECTION_TTB = 'ttb',
    		DIRECTION_BTT = 'btt',
    		BAR_EL = 'barEl',
    		MASK_EL = 'maskEl',
    		ARIA_TEXT_TEMPLATE = 'ariaTextTemplate',

    		// Events
    		START = 'start',
    		PROGRESS = 'progress',
    		COMPLETE = 'complete';

    	/**
    	 * The ProgressBar widget provides an easy way to draw a bar depicting progress of an operation,
    	 * a level meter, rating or any such simple linear measure.
    	 * It allows for highly customized styles including animation, vertical or horizontal and forward or reverse.
    	 * @namespace YAHOO.widget
    	 * @class ProgressBar
    	 * @extends YAHOO.util.Element
    	 * @param oConfigs {object} An object containing any configuration attributes to be set
    	 * @constructor
    	 */
    	var Prog = function(oConfigs) {
    		YAHOO.log('Creating ProgressBar instance','info','ProgressBar');

    		Prog.superclass.constructor.call(this, document.createElement('div') , oConfigs);
    		this._init(oConfigs);

    	};

    	YAHOO.widget.ProgressBar = Prog;

        /**
         * String containing the HTML string which is the basis for the Progress Bar.
         *
         * @property ProgressBar.MARKUP
         * @type String
         * @static
         * @final
         * @default (too long)
         */
    	Prog.MARKUP = [
    		'<div class="',
    		CLASS_BAR,
    		'"></div><div class="',
    		CLASS_MASK,
    		'"><div class="',
    		CLASS_TL,
    		'"></div><div class="',
    		CLASS_TR,
    		'"></div><div class="',
    		CLASS_BL,
    		'"></div><div class="',
    		CLASS_BR,
    		'"></div></div>'
    	].join('');

    	Lang.extend(Prog, YAHOO.util.Element, {
    		/**
    		 * Initialization code for the widget, separate from the constructor to allow for overriding/patching.
    		 * It is called after <a href="#method_initAttributes">initAttributes</a>
    		 *
    		 * @method _init
    		 * @param oConfigs {Object} (Optional) Object literal definition of configuration values.
    		 * @protected
    		 */
    		 _init: function (oConfigs) {
    			/**
    			 * Fires when the value is about to change.  It reports the starting value
    			 * @event start
    			 * @type CustomEvent
    			 * @param value {Number} the current (initial) value
    			 */
    			// No actual creation required, event will be created when subscribed to
    			//this.createEvent(START);
    			/**
    			 * If animation is active, it will trigger several times during the animation providing intermediate values
    			 * If animation is not active, it will fire only once providing the end value
    			 * @event progress
    			 * @type CustomEvent
    			 * @param  value{Number} the current, changing value
    			 */
    			// No actual creation required, event will be created when subscribed to
    			//this.createEvent(PROGRESS);
    			/**
    			 * Fires at the end of the animation or immediately upon changing values if animation is not loaded
    			 * @event complete
    			 * @type CustomEvent
    			 * @param value {Number} the current (final)  value
    			 */
    			// No actual creation required, event will be created when listened to
    			//this.createEvent(COMPLETE);

    		},
    		/**
    		 * Implementation of Element's abstract method. Sets up config values.
    		 *
    		 * @method initAttributes
    		 * @param oConfigs {Object} (Optional) Object literal definition of configuration values.
    		 * @private
    		 */
    		initAttributes: function (oConfigs) {
    			YAHOO.log('Initializing configuration attributes','info','ProgressBar');

    		    Prog.superclass.initAttributes.call(this, oConfigs);
    			this.set('innerHTML',Prog.MARKUP);
    			this.addClass(CLASS_PROGBAR);

    			// I need to apply at least the following styles, if present in oConfigs,
    			// to the ProgressBar so when it later reads the width and height,
    			// they are already set to the correct values.
    			// id is important because it can be used as a CSS selector.
    			var key, presets = ['id',WIDTH,HEIGHT,'class','style'];
    			while((key = presets.pop())) {
    				if (key in oConfigs) {
    					this.set(key,oConfigs[key]);
    				}
    			}

    			/**
    			 * @attribute barEl
    			 * @description Reference to the HTML object that makes the moving bar (read-only)
    			 * @type HTMLElement (div)
    			 * @readonly
    			 */
    		    this.setAttributeConfig(BAR_EL, {
    		        readOnly: true,
    		        value: this.getElementsByClassName(CLASS_BAR)[0]
    		    });
    			/**
    			 * @attribute maskEl
    			 * @description Reference to the HTML object that overlays the bar providing the mask. (read-only)
    			 * @type HTMLElement (table)
    			 * @readonly
    			 */
    		    this.setAttributeConfig(MASK_EL, {
    		        readOnly: true,
    		        value: this.getElementsByClassName(CLASS_MASK)[0]
    		    });

    			/**
    			 * @attribute direction
    			 * @description Direction of movement of the bar.
    			 *    It can be any of 'ltr' (left to right), 'rtl' (the reverse) , 'ttb' (top to bottom) or 'btt'.
    			 *    Can only be set once and only before rendering.
    			 * @default 'ltr'
    			 * @type String (any of "ltr", "rtl", "ttb" or "btt")
    			 */
    			this.setAttributeConfig(DIRECTION, {
    				value:DIRECTION_LTR,
    				validator:function(value) {
    					if (this._rendered) { return false; }
    					switch (value) {
    						case DIRECTION_LTR:
    						case DIRECTION_RTL:
    						case DIRECTION_TTB:
    						case DIRECTION_BTT:
    							return true;
    						default:
    							return false;
    					}
    				},
    				method: function(value) {
    					this._barSizeFunction = this._barSizeFunctions[this.get(ANIM)?1:0][value];
    				}
    			});

    			/**
    			 * @attribute maxValue
    			 * @description Represents the top value for the bar.
    			 *   The bar will be fully extended when reaching this value.
    			 *   Values higher than this will be ignored.
    			 * @default 100
    			 * @type Number
    			 */
    		    this.setAttributeConfig(MAX_VALUE, {
    		        value: 100,
    				validator: Lang.isNumber,
    				method: function (value) {
    					this.get('element').setAttribute('aria-valuemax',value);
    					if (this.get(VALUE) > value) { this.set(VALUE,value); }
    				}
    		    });

    			/**
    			 * @attribute minValue
    			 * @description Represents the lowest value for the bar.
    			 *   The bar will be totally collapsed when reaching this value.
    			 *    Values lower than this will be ignored.
    			 * @default 0
    			 * @type Number
    			 */

    		    this.setAttributeConfig(MIN_VALUE, {
    		        value: 0,
    				validator: Lang.isNumber,
    				method: function (value) {
    					this.get('element').setAttribute('aria-valuemin',value);
    					if (this.get(VALUE) < value) { this.set(VALUE,value); }
    				}
    		    });
    			/**
    			 * @attribute width
    			 * @description Width of the ProgressBar.
    			 *     If a number, it will be assumed to be in pixels.
    			 *     If a string it should be a valid setting for the CSS width attribute.
    			 *     It will always be returned as a string including units.
    			 * @default "200px"
    			 * @type Number or String
    			 */

    		    this.setAttributeConfig(WIDTH, {
    				getter: function() {
    					return this.getStyle(WIDTH);
    				},
    				method: this._widthChange
    		    });

    			/**
    			 * @attribute height
    			 * @description Height of the ProgressBar.
    			 *     If a number, it will be assumed to be in pixels.
    			 *     If a string it should be a valid setting for the CSS height attribute.
    			 *     It will always be returned as a string including units.
    			 * @default "20px"
    			 * @type Number or String
    			 */
    		    this.setAttributeConfig(HEIGHT, {
    				getter:function() {
    					return this.getStyle(HEIGHT);
    				},
    				method: this._heightChange
    		    });

    			/**
    			 * @attribute ariaTextTemplate
    			 * @description Text to be voiced by screen readers.
    			 *     The text is processed by <a href="YAHOO.lang.html#method_substitute">YAHOO.lang.substitute</a>.
    			 *     It can use the placeholders {value}, {minValue} and {maxValue}
    			 * @default "{value}"
    			 * @type String
    			 */
    			this.setAttributeConfig(ARIA_TEXT_TEMPLATE, {
    				value:'{value}'
    			});

    			/**
    			 * @attribute value
    			 * @description The value for the bar.
    			 *     Valid values are in between the minValue and maxValue attributes.
    			 * @default 0
    			 * @type Number
    			 */
    			this.setAttributeConfig(VALUE, {
    				value: 0,
    				validator: function(value) {
    					return Lang.isNumber(value) && value >= this.get(MIN_VALUE) && value <= this.get(MAX_VALUE);
    				},
    				method: this._valueChange
    		    });

    			/**
    			 * @attribute anim
    			 * @description it accepts either a boolean (recommended) or an instance of <a href="YAHOO.util.Anim.html">YAHOO.util.Anim</a>.
    			 *   If a boolean, it will enable/disable animation creating its own instance of the animation utility.
    			 *   If given an instance of <a href="YAHOO.util.Anim.html">YAHOO.util.Anim</a> it will use that instance.
    			 *   The <a href="YAHOO.util.Anim.html">animation</a> utility needs to be loaded.
    			 *   When read, it returns the instance of the animation utility in use or null if none.
    			 *   It can be used to set the animation parameters such as easing methods or duration.
    			 * @default null
    			 * @type {boolean} or {instance of YAHOO.util.Anim}
    			 */
    			this.setAttributeConfig(ANIM, {
    				validator: function(value) {
    					return !!YAHOO.util.Anim;
    				},
    				setter: this._animSetter
    			});

    		},
    		/**
    		 *  Renders the ProgressBar into the given container.
    		 *  If the container has other content, the ProgressBar will be appended to it.
    		 *  If the second argument is provided, the ProgressBar will be inserted before the given child.
    		 * The method is chainable since it returns a reference to this instance.
    		 * @method render
    		 * @param el {HTML Element}  HTML element that will contain the ProgressBar
    		 * @param before {HTML Element}  (optional) If present, the ProgressBar will be inserted before this element.
    		 * @return {YAHOO.widget.ProgressBar}
    		 * @chainable
    		 */
    		render: function(parent,before) {

    			YAHOO.log('start render','info','ProgressBar');
    			if (this._rendered) { return; }
    			this._rendered = true;

    			var direction = this.get(DIRECTION);

    			// If the developer set a className attribute on initialization,
    			// Element would have wiped out my own classNames
    			// So I need to insist on them, plus add the one for direction.
    			this.addClass(CLASS_PROGBAR);
    			this.addClass(CLASS_PROGBAR + '-' + direction);

    			var container = this.get('element');
    			container.tabIndex = 0;
    			container.setAttribute('role','progressbar');
    			container.setAttribute('aria-valuemin',this.get(MIN_VALUE));
    			container.setAttribute('aria-valuemax',this.get(MAX_VALUE));

    			this.appendTo(parent,before);

    			// I need to use the non-animated bar resizing function for initial redraw
    			this._barSizeFunction = this._barSizeFunctions[0][direction];
    			this.redraw();
    			this._previousValue = this.get(VALUE);
    			this._fixEdges();
    			// I can now set the correct bar resizer
    			if (this.get(ANIM)) {
    				this._barSizeFunction = this._barSizeFunctions[1][direction];
    			}

    			this.on('minValueChange',this.redraw);
    			this.on('maxValueChange',this.redraw);

    			return this;
    		},

    		/**
    		 * Recalculates the bar size and position and redraws it
    		 * @method redraw
    		 * @return  void
    		 */
    		redraw: function () {
    			YAHOO.log('Redraw','info','ProgressBar');
    			this._recalculateConstants();
    			this._valueChange(this.get(VALUE));
    		},

    		/**
    		 * Destroys the ProgressBar, related objects and unsubscribes from all events
    		 * @method destroy
    		 * @return  void
    		 */
    		destroy: function() {
    			YAHOO.log('destroy','info','ProgressBar');
    			this.set(ANIM,false);
    			this.unsubscribeAll();
    			var el = this.get('element');
    			if (el.parentNode) { el.parentNode.removeChild(el); }
    		},
    		/**
    		 * The previous value setting for the bar.  Used mostly as information to event listeners
    		 * @property _previousValue
    		 * @type Number
    		 * @private
    		 * @default  0
    		 */
    		_previousValue:0,
    		/**
    		 * The actual space (in pixels) available for the bar within the mask (excludes margins)
    		 * @property _barSpace
    		 * @type Number
    		 * @private
    		 * @default  100
    		 */
    		_barSpace:100,
    		/**
    		 * The factor to convert the actual value of the bar into pixels
    		 * @property _barSpace
    		 * @type Number
    		 * @private
    		 * @default  1
    		 */
    		_barFactor:1,

    		/**
    		 * A flag to signal that rendering has already happened
    		 * @property _rendered
    		 * @type boolean
    		 * @private
    		 * @default  false
    		 */
    		_rendered:false,

    		/**
    		 * Function to be used to calculate bar size.
    		 * It is picked from <a href="#property_barSizeFunctions">_barSizeFunctions</a>
    		 * depending on direction and whether animation is active.
    		 * @property _barSizeFunction
    		 * @type {function}
    		 * @default null
    		 * @private
    		 */
    		_barSizeFunction: null,

    		/**
    		 * Method called when the height attribute is changed
    		 * @method _heightChange
    		 * @param {int or string} value New height, in pixels if int or string including units
    		 * @return void
    		 * @private
    		 */
    		_heightChange: function(value) {
    			if (Lang.isNumber(value)) {
    				value += 'px';
    			}
    			this.setStyle(HEIGHT,value);
    			this._fixEdges();
    			this.redraw();
    		},

    		/**
    		 * Method called when the height attribute is changed
    		 * @method _widthChange
    		 * @param {int or string} value New width, in pixels if int or string including units
    		 * @return void
    		 * @private
    		 */
    		_widthChange: function(value) {
    			if (Lang.isNumber(value)) {
    				value += 'px';
    			}
    			this.setStyle(WIDTH,value);
    			this._fixEdges();
    			this.redraw();
    		},

    		/**
    		 * Due to rounding differences, some browsers fail to cover the whole area
    		 * with the mask quadrants when the width or height is odd.  This method
    		 * stretches the lower and/or right quadrants to make the difference.
    		 * @method _fixEdges
    		 * @return void
    		 * @private
    		 */
    		_fixEdges:function() {
    			if (!this._rendered || YAHOO.env.ua.ie || YAHOO.env.ua.gecko ) { return; }
    			var maskEl = this.get(MASK_EL),
    				tlEl = Dom.getElementsByClassName(CLASS_TL,undefined,maskEl)[0],
    				trEl = Dom.getElementsByClassName(CLASS_TR,undefined,maskEl)[0],
    				blEl = Dom.getElementsByClassName(CLASS_BL,undefined,maskEl)[0],
    				brEl = Dom.getElementsByClassName(CLASS_BR,undefined,maskEl)[0],
    				newSize = (parseInt(Dom.getStyle(maskEl,HEIGHT),10) -
    				parseInt(Dom.getStyle(tlEl,HEIGHT),10)) + 'px';

    			Dom.setStyle(blEl,HEIGHT,newSize);
    			Dom.setStyle(brEl,HEIGHT,newSize);
    			newSize = (parseInt(Dom.getStyle(maskEl,WIDTH),10) -
    				parseInt(Dom.getStyle(tlEl,WIDTH),10)) + 'px';
    			Dom.setStyle(trEl,WIDTH,newSize);
    			Dom.setStyle(brEl,WIDTH,newSize);
    		},

    		/**
    		 * Calculates some auxiliary values to make the rendering faster
    		 * @method _recalculateConstants
    		 * @return  void
    		 * @private
    		 */
    		_recalculateConstants: function() {
    			YAHOO.log('Recalculating auxiliary factors','info','ProgressBar');
    			var barEl = this.get(BAR_EL);

    			switch (this.get(DIRECTION)) {
    				case DIRECTION_LTR:
    				case DIRECTION_RTL:
    					this._barSpace = parseInt(this.get(WIDTH),10) -
    						(parseInt(Dom.getStyle(barEl,'marginLeft'),10) || 0) -
    						(parseInt(Dom.getStyle(barEl,'marginRight'),10) || 0);
    					break;
    				case DIRECTION_TTB:
    				case DIRECTION_BTT:
    					this._barSpace = parseInt(this.get(HEIGHT),10) -
    						(parseInt(Dom.getStyle(barEl,'marginTop'),10) || 0)-
    						(parseInt(Dom.getStyle(barEl,'marginBottom'),10) || 0);
    					break;
    			}
    			this._barFactor = this._barSpace / (this.get(MAX_VALUE) - (this.get(MIN_VALUE) || 0))  || 1;
    		},

    		/**
    		 * Called in response to a change in the <a href="#config_anim">anim</a> attribute.
    		 * It creates and sets up or destroys the instance of the animation utility that will move the bar
    		 * @method _animSetter
    		 * @return  void
    		 * @private
    		 */
    		_animSetter: function (value) {
    			var anim, barEl = this.get(BAR_EL);
    			if (value) {
    				YAHOO.log('Turning animation on','info','ProgressBar');
    				if (value instanceof YAHOO.util.Anim) {
    					anim = value;
    				} else {
    					anim = new YAHOO.util.Anim(barEl);
    				}
    				anim.onTween.subscribe(this._animOnTween,this,true);
    				anim.onComplete.subscribe(this._animComplete,this,true);

    				// Temporary solution until http://yuilibrary.com/projects/yui2/ticket/2528222 gets solved:
    				var oldSetAttribute = anim.setAttribute,
    					pb = this;
    				switch(this.get(DIRECTION)) {
    					case DIRECTION_BTT:
    						anim.setAttribute = function(attr , val , unit) {
    							val = Math.round(val);
    							oldSetAttribute.call(this,attr,val,unit);
    							Dom.setStyle(barEl,'top',(pb._barSpace - val) + 'px');
    						};
    						break;
    					case DIRECTION_RTL:
    						anim.setAttribute = function(attr , val , unit) {
    							val = Math.round(val);
    							oldSetAttribute.call(this,attr,val,unit);
    							Dom.setStyle(barEl,'left',(pb._barSpace - val) + 'px');
    						};
    						break;
    				}
    				// up to here

    			} else {
    				YAHOO.log('Turning animation off','info','ProgressBar');
    				anim = this.get(ANIM);
    				if (anim) {
    					anim.onTween.unsubscribeAll();
    					anim.onComplete.unsubscribeAll();
    				}
    				anim = null;
    			}
    			this._barSizeFunction = this._barSizeFunctions[anim?1:0][this.get(DIRECTION)];
    			return anim;
    		},

    		_animComplete: function() {
    			YAHOO.log('Animation completed','info','ProgressBar');
    			var value = this.get(VALUE);
    			this._previousValue = value;
    			this.fireEvent(PROGRESS,value);
    			this.fireEvent(COMPLETE, value);
    			Dom.removeClass(this.get(BAR_EL),CLASS_ANIM);
    		},
    		_animOnTween:function (name,oArgs) {
    			var value = Math.floor(this._tweenFactor * oArgs[0].currentFrame + this._previousValue);
    			// The following fills the logger window too fast
    			//YAHOO.log('Animation onTween at: ' + value,'info','ProgressBar');
    			this.fireEvent(PROGRESS,value);
    		},

    		/**
    		 * Called in response to a change in the <a href="#config_value">value</a> attribute.
    		 * Moves the bar to reflect the new value
    		 * @method _valueChange
    		 * @return  void
    		 * @private
    		 */
    		_valueChange: function (value) {
    			YAHOO.log('set value: ' + value,'info','ProgressBar');
    			var anim = this.get(ANIM),
    				pixelValue = Math.floor((value - this.get(MIN_VALUE)) * this._barFactor),
    				barEl = this.get(BAR_EL);

    			this._setAriaText(value);
    			if (this._rendered) {
    				if (anim) {
    					anim.stop();
    					if (anim.isAnimated()) { anim._onComplete.fire(); } // see: http://yuilibrary.com/projects/yui2/ticket/2528217
    				}
    				this.fireEvent(START,this._previousValue);
    				this._barSizeFunction(value, pixelValue, barEl, anim);
    			}
    		},

    		/**
    		 * Utility method to set the ARIA value attributes
    		 * @method _setAriaText
    		 * @return  void
    		 * @private
    		 */
    		 _setAriaText: function(value) {
    			// When animated, this fills the logger window too fast
     			//YAHOO.log('Show template','info','ProgressBar');

    			var container = this.get('element'),
    				text = Lang.substitute(this.get(ARIA_TEXT_TEMPLATE),{
    					value:value,
    					minValue:this.get(MIN_VALUE),
    					maxValue:this.get(MAX_VALUE)
    				});
    			container.setAttribute('aria-valuenow',value);
    			container.setAttribute('aria-valuetext',text);
    		}
    	});
    	/**
    	 * Collection of functions used by to calculate the size of the bar.
    	 * One of this will be used depending on direction and whether animation is active.
    	 * @property _barSizeFunctions
    	 * @type {collection of functions}
    	 * @private
    	 */
    	var b = [{},{}];
    	Prog.prototype._barSizeFunctions = b;

    	b[0][DIRECTION_LTR] = function(value, pixelValue, barEl, anim) {
    		Dom.setStyle(barEl,WIDTH,  pixelValue + 'px');
    		this.fireEvent(PROGRESS,value);
    		this.fireEvent(COMPLETE,value);
    	};
    	b[0][DIRECTION_RTL] = function(value, pixelValue, barEl, anim) {
    		Dom.setStyle(barEl,WIDTH,  pixelValue + 'px');
    		Dom.setStyle(barEl,'left',(this._barSpace - pixelValue) + 'px');
    		this.fireEvent(PROGRESS,value);
    		this.fireEvent(COMPLETE,value);
    	};
    	b[0][DIRECTION_TTB] = function(value, pixelValue, barEl, anim) {
    		Dom.setStyle(barEl,HEIGHT,  pixelValue + 'px');
    		this.fireEvent(PROGRESS,value);
    		this.fireEvent(COMPLETE,value);
    	};
    	b[0][DIRECTION_BTT] = function(value, pixelValue, barEl, anim) {
    		Dom.setStyle(barEl,HEIGHT,  pixelValue + 'px');
    		Dom.setStyle(barEl,'top',  (this._barSpace - pixelValue) + 'px');
    		this.fireEvent(PROGRESS,value);
    		this.fireEvent(COMPLETE,value);
    	};
    	b[1][DIRECTION_LTR] = function(value, pixelValue, barEl, anim) {
    		Dom.addClass(barEl,CLASS_ANIM);
    		this._tweenFactor = (value - this._previousValue) / anim.totalFrames  / anim.duration;
    		anim.attributes = {width:{ to: pixelValue }};
    		anim.animate();
    	};
    	b[1][DIRECTION_RTL] =  b[1][DIRECTION_LTR];
    	b[1][DIRECTION_TTB] =  function(value, pixelValue, barEl, anim) {
    		Dom.addClass(barEl,CLASS_ANIM);
    		this._tweenFactor = (value - this._previousValue) / anim.totalFrames  / anim.duration;
    		anim.attributes = {height:{to: pixelValue}};
    		anim.animate();
    	};
    	b[1][DIRECTION_BTT] =  b[1][DIRECTION_TTB];

    })();

Copyright © 2010 Yahoo! Inc. All rights reserved.