carousel-beta.js

来自「这是YUI的源码及相关示例。里面有很多很炫的Javascript效果。」· JavaScript 代码 · 共 2,061 行 · 第 1/5 页

         */
        blur: function () {
            this._carouselEl.blur();
            this.fireEvent(blurEvent);
        },

        /**
         * Clears the items from Carousel.
         *
         * @method clearItems
         * public
         */
        clearItems: function () {
            var n = this.get("numItems");

            while (n > 0) {
                this.removeItem(0);
                n--;
            }
        },

        /**
         * Set focus on the Carousel.
         *
         * @method focus
         * @public
         */
        focus: function () {
            var selItem,
                numVisible,
                selectOnScroll,
                selected,
                first,
                last,
                isSelectionInvisible,
                focusEl,
                itemsTable;

            if (this._isAnimationInProgress) {
                // this messes up real bad!
                return;
            }

            selItem              = this.get("selectedItem");
            numVisible           = this.get("numVisible");
            selectOnScroll       = this.get("selectOnScroll");
            selected             = this.getItem(selItem);
            first                = this.get("firstVisible");
            last                 = first + numVisible - 1;
            isSelectionInvisible = (selItem < first || selItem > last);
            focusEl              = (selected && selected.id) ?
                                   Dom.get(selected.id) : null;
            itemsTable           = this._itemsTable;

            if (!selectOnScroll && isSelectionInvisible) {
                focusEl = (itemsTable && itemsTable.items &&
                           itemsTable.items[first]) ?
                        Dom.get(itemsTable.items[first].id) : null;
            }

            if (focusEl) {
                try {
                    focusEl.focus();
                } catch (ex) {
                    // ignore focus errors
                }
            }

            this.fireEvent(focusEvent);
        },

        /**
         * Hide the Carousel.
         *
         * @method hide
         * @public
         */
        hide: function () {
            if (this.fireEvent(beforeHideEvent) !== false) {
                this.removeClass(this.CLASSES.VISIBLE);
                this.fireEvent(hideEvent);
            }
        },

        /**
         * Initialize the Carousel.
         *
         * @method init
         * @public
         * @param el {HTMLElement | String} The html element that represents
         * the Carousel container.
         * @param attrs {Object} The set of configuration attributes for
         * creating the Carousel.
         */
        init: function (el, attrs) {
            var elId  = el,     // save for a rainy day
                parse = false;

            if (!el) {
                return;
            }

            this._itemsTable = { loading: {}, numItems: 0, items: [], size: 0 };

            if (JS.isString(el)) {
                el = Dom.get(el);
            } else if (!el.nodeName) {
                return;
            }

            if (el) {
                if (!el.id) {   // in case the HTML element is passed
                    el.setAttribute("id", Dom.generateId());
                }
                this._parseCarousel(el);
                parse = true;
            } else {
                el = this._createCarousel(elId);
            }
            elId = el.id;

            Carousel.superclass.init.call(this, el, attrs);

            this.initEvents();

            if (parse) {
                this._parseCarouselItems();
            }

            if (!attrs || typeof attrs.isVertical == "undefined") {
                this.set("isVertical", false);
            }

            this._parseCarouselNavigation(el);
            this._navEl = this._setupCarouselNavigation();

            instances[elId] = this;

            loadItems.call(this);
        },

        /**
         * Initialize the configuration attributes used to create the Carousel.
         *
         * @method initAttributes
         * @public
         * @param attrs {Object} The set of configuration attributes for
         * creating the Carousel.
         */
        initAttributes: function (attrs) {
            attrs = attrs || {};
            Carousel.superclass.initAttributes.call(this, attrs);

            /**
             * @attribute currentPage
             * @description The current page number (read-only.)
             * @type Number
             */
            this.setAttributeConfig("currentPage", {
                    readOnly : true,
                    value    : 0
            });

            /**
             * @attribute firstVisible
             * @description The index to start the Carousel from (indexes begin
             * from zero)
             * @default 0
             * @type Number
             */
            this.setAttributeConfig("firstVisible", {
                    method    : this._setFirstVisible,
                    validator : this._validateFirstVisible,
                    value     : attrs.firstVisible || this.CONFIG.FIRST_VISIBLE
            });

            /**
             * @attribute selectOnScroll
             * @description Set this to true to automatically set focus to
             * follow scrolling in the Carousel.
             * @default true
             * @type Boolean
             */
            this.setAttributeConfig("selectOnScroll", {
                    validator : JS.isBoolean,
                    value     : attrs.selectOnScroll || true
            });

            /**
             * @attribute numVisible
             * @description The number of visible items in the Carousel's
             * viewport.
             * @default 3
             * @type Number
             */
            this.setAttributeConfig("numVisible", {
                    method    : this._setNumVisible,
                    validator : this._validateNumVisible,
                    value     : attrs.numVisible || this.CONFIG.NUM_VISIBLE
            });

            /**
             * @attribute numItems
             * @description The number of items in the Carousel.
             * @type Number
             */
            this.setAttributeConfig("numItems", {
                    method    : this._setNumItems,
                    validator : this._validateNumItems,
                    value     : this._itemsTable.numItems
            });

            /**
             * @attribute scrollIncrement
             * @description The number of items to scroll by for arrow keys.
             * @default 1
             * @type Number
             */
            this.setAttributeConfig("scrollIncrement", {
                    validator : this._validateScrollIncrement,
                    value     : attrs.scrollIncrement || 1
            });

            /**
             * @attribute selectedItem
             * @description The index of the selected item.
             * @type Number
             */
            this.setAttributeConfig("selectedItem", {
                    method    : this._setSelectedItem,
                    validator : JS.isNumber,
                    value     : 0
            });

            /**
             * @attribute revealAmount
             * @description The percentage of the item to be revealed on each
             * side of the Carousel (before and after the first and last item
             * in the Carousel's viewport.)
             * @default 0
             * @type Number
             */
            this.setAttributeConfig("revealAmount", {
                    method    : this._setRevealAmount,
                    validator : this._validateRevealAmount,
                    value     : attrs.revealAmount || 0
            });

            /**
             * @attribute isCircular
             * @description Set this to true to wrap scrolling of the contents
             * in the Carousel.
             * @default false
             * @type Boolean
             */
            this.setAttributeConfig("isCircular", {
                    validator : JS.isBoolean,
                    value     : attrs.isCircular || false
            });

            /**
             * @attribute isVertical
             * @description True if the orientation of the Carousel is vertical
             * @default false
             * @type Boolean
             */
            this.setAttributeConfig("isVertical", {
                    method    : this._setOrientation,
                    validator : JS.isBoolean,
                    value     : attrs.isVertical || false
            });

            /**
             * @attribute navigation
             * @description The set of navigation controls for Carousel
             * @default <br>
             * { prev: null, // the previous navigation element<br>
             *   next: null } // the next navigation element
             * @type Object
             */
            this.setAttributeConfig("navigation", {
                    method    : this._setNavigation,
                    validator : this._validateNavigation,
                    value     : attrs.navigation || {
                                        prev: null, next: null, page: null }
            });

            /**
             * @attribute animation
             * @description The optional animation attributes for the Carousel.
             * @default <br>
             * { speed: 0, // the animation speed (in seconds)<br>
             *   effect: null } // the animation effect (like
             *   YAHOO.util.Easing.easeOut)
             * @type Object
             */
            this.setAttributeConfig("animation", {
                    validator : this._validateAnimation,
                    value     : attrs.animation || { speed: 0, effect: null }
            });

            /**
             * @attribute autoPlay
             * @description Set this to time in milli-seconds to have the
             * Carousel automatically scroll the contents.
             * @type Number
             */
            this.setAttributeConfig("autoPlay", {
                    validator : JS.isNumber,
                    value     : attrs.autoPlay || 0
            });
        },

        /**
         * Initialize and bind the event handlers.
         *
         * @method initEvents
         * @public
         */
        initEvents: function () {
            var cssClass = this.CLASSES;

            this.on("keydown", this._keyboardEventHandler);

            this.subscribe(afterScrollEvent, syncNavigation);
            this.on(afterScrollEvent, this.focus);

            this.subscribe(itemAddedEvent, syncUI);
            this.subscribe(itemAddedEvent, syncNavigation);

            this.subscribe(itemRemovedEvent, syncUI);
            this.subscribe(itemRemovedEvent, syncNavigation);

            this.on(itemSelectedEvent, this.focus);

            this.subscribe(loadItemsEvent, syncUI);

            this.subscribe(pageChangeEvent, this._syncPagerUI);

            this.subscribe(renderEvent, syncNavigation);
            this.subscribe(renderEvent, this._syncPagerUI);

            this.on("selectedItemChange", function (ev) {
                setItemSelection.call(this, ev.newValue, ev.prevValue);
                this._updateTabIndex(this.getElementForItem(ev.newValue));
                this.fireEvent(itemSelectedEvent, ev.newValue);
            });

            this.on("firstVisibleChange", function (ev) {
                if (!this.get("selectOnScroll")) {
                    this._updateTabIndex(this.getElementForItem(ev.newValue));
                }
            });

            // Handle item selection on mouse click
            this.on("click", this._itemClickHandler);

            // Handle page navigation
            this.on("click", this._pagerClickHandler);

            // Restore the focus on the navigation buttons
            Event.onFocus(this.get("element"), function (ev, obj) {
                obj._updateNavButtons(Event.getTarget(ev), true);
            }, this);

            Event.onBlur(this.get("element"), function (ev, obj) {
                obj._updateNavButtons(Event.getTarget(ev), false);
            }, this);

        },

        /**
         * Return the ITEM_TAG_NAME at index or null if the index is not found.
         *
         * @method getElementForItem
         * @param index {Number} The index of the item to be returned
         * @return {Element} Return the item at index or null if not found
         * @public
         */
        getElementForItem: function (index) {
            if (index < 0 || index >= this.get("numItems")) {
                return null;
            }

            // TODO: may be cache the item
            if (this._itemsTable.numItems > index) {
                if (!JS.isUndefined(this._itemsTable.items[index])) {
                    return Dom.get(this._itemsTable.items[index].id);
                }
            }

            return null;
        },

        /**
         * Return the ITEM_TAG_NAME for all items in the Carousel.
         *
         * @method getElementForItems
         * @return {Array} Return all the items
         * @public
         */
        getElementForItems: function () {
            var els = [], i;

            for (i = 0; i < this._itemsTable.numItems; i++) {
                els.push(this.getElementForItem(i));
            }

            return els;
        },

        /**
         * Return the item at index or null if the index is not found.