From 1f803344d67ff7a98dba3c8c2ffb4408cf18297f Mon Sep 17 00:00:00 2001
From: cagataycivici <cagatay.civici@gmail.com>
Date: Sun, 9 Dec 2018 00:35:53 +0300
Subject: [PATCH] Accessibility for ListBox

---
 src/components/listbox/ListBox.vue |  64 ++++-
 src/components/utils/DomHandler.js | 382 +++++++++++++++++++++++++++++
 2 files changed, 438 insertions(+), 8 deletions(-)
 create mode 100644 src/components/utils/DomHandler.js

diff --git a/src/components/listbox/ListBox.vue b/src/components/listbox/ListBox.vue
index 0d0f18556..b4cba7cd6 100644
--- a/src/components/listbox/ListBox.vue
+++ b/src/components/listbox/ListBox.vue
@@ -8,8 +8,8 @@
         </div>
         <div class="p-listbox-list-wrapper" :style="listStyle">
             <ul class="p-listbox-list">
-                <li v-for="(option, i) of visibleOptions" tabindex="0" :class="['p-listbox-item', {'p-highlight': isSelected(option)}]" 
-                    :key="getOptionLabel(option)" @click="onOptionClick($event, option)" @touchend="onOptionTouchEnd()">
+                <li v-for="(option, i) of visibleOptions" tabindex="0" :class="['p-listbox-item', {'p-highlight': isSelected(option)}]" :aria-label="getOptionLabel(option)"
+                    :key="getOptionLabel(option)" @click="onOptionSelect($event, option)" @touchend="onOptionTouchEnd()" @keydown="onOptionKeyDown($event, option)">
                     <slot :option="option" :index="i">  
                         {{getOptionLabel(option)}}
                     </slot>
@@ -21,6 +21,7 @@
 
 <script>
 import ObjectUtils from '../utils/ObjectUtils';
+import DomHandler from '../utils/DomHandler';
 
 export default {
     props: {
@@ -48,15 +49,15 @@ export default {
         getOptionValue(option) {
             return this.optionValue ? ObjectUtils.resolveFieldData(option, this.optionValue) : option;
         },
-        onOptionClick(event, option) {
+        onOptionSelect(event, option) {
             if (this.disabled) {
                 return;
             }
             
             if(this.multiple)
-                this.onOptionClickMultiple(event, option);
+                this.onOptionSelectMultiple(event, option);
             else
-                this.onOptionClickSingle(event, option);
+                this.onOptionSelectSingle(event, option);
                 
             this.optionTouched = false;
         },
@@ -67,7 +68,7 @@ export default {
         
             this.optionTouched = true;
         },
-        onOptionClickSingle(event, option) {
+        onOptionSelectSingle(event, option) {
             let selected = this.isSelected(option);
             let valueChanged = false;
             let value = null;
@@ -96,7 +97,7 @@ export default {
                 this.updateModel(event, value);
             }
         },
-        onOptionClickMultiple(event, option) {        
+        onOptionSelectMultiple(event, option) {        
             let selected = this.isSelected(option);
             let valueChanged = false;
             let value = null;
@@ -158,7 +159,54 @@ export default {
         updateModel(event, value) {
             this.$emit('input', value);
             this.$emit('change', {originalEvent: event, value: value});
-        }
+        },
+        onOptionKeyDown(event, option) {
+            let item = event.currentTarget;
+
+            switch (event.which) {
+                //up arrow
+                case 40:
+                    let nextItem = this.findNextItem(item);
+                    if(nextItem) {
+                        nextItem.focus();
+                    }
+                    
+                    event.preventDefault();
+                break;
+
+                //down arrow
+                case 38:
+                    let prevItem = this.findPrevItem(item);
+                    if(prevItem) {
+                        prevItem.focus();
+                    }
+                    
+                    event.preventDefault();
+                break;
+
+                //enter
+                case 13:
+                    this.onOptionSelect(event, option);
+                    event.preventDefault();
+                break;
+            }
+        },
+        findNextItem(item) {
+            let nextItem = item.nextElementSibling;
+
+            if (nextItem)
+                return DomHandler.hasClass(nextItem, 'p-disabled') ? this.findNextOption(nextItem) : nextItem;
+            else
+                return null;
+        },
+        findPrevItem(item) {
+            let prevItem = item.previousElementSibling;
+            
+            if (prevItem)
+                return DomHandler.hasClass(prevItem, 'p-disabled') ? this.findPrevItem(prevItem) : prevItem;
+            else
+                return null;
+        } 
     },
     computed: {
         visibleOptions() {
diff --git a/src/components/utils/DomHandler.js b/src/components/utils/DomHandler.js
new file mode 100644
index 000000000..3df8bf588
--- /dev/null
+++ b/src/components/utils/DomHandler.js
@@ -0,0 +1,382 @@
+export default class DomHandler {
+    
+    static innerWidth(el) {
+        let width = el.offsetWidth;
+        let style = getComputedStyle(el);
+
+        width += parseFloat(style.paddingLeft) + parseFloat(style.paddingRight);
+        return width;
+    }
+
+    static width(el) {
+        let width = el.offsetWidth;
+        let style = getComputedStyle(el);
+
+        width -= parseFloat(style.paddingLeft) + parseFloat(style.paddingRight);
+        return width;
+    }
+
+    static getWindowScrollTop() {
+        let doc = document.documentElement;
+        return (window.pageYOffset || doc.scrollTop) - (doc.clientTop || 0);
+    }
+
+    static getWindowScrollLeft() {
+        let doc = document.documentElement;
+        return (window.pageXOffset || doc.scrollLeft) - (doc.clientLeft || 0);
+    }
+
+    static getOuterWidth(el, margin) {
+        if (el) {
+            let width = el.offsetWidth;
+
+            if (margin) {
+                let style = getComputedStyle(el);
+                width += parseFloat(style.marginLeft) + parseFloat(style.marginRight);
+            }
+
+            return width;
+        }
+        else {
+            return 0;
+        }
+    }
+
+    static getOuterHeight(el, margin) {
+        if (el) {
+            let height = el.offsetHeight;
+
+            if (margin) {
+                let style = getComputedStyle(el);
+                height += parseFloat(style.marginTop) + parseFloat(style.marginBottom);
+            }
+    
+            return height;
+        }
+        else {
+            return 0;
+        }
+    }
+
+    static getViewport() {
+        let win = window,
+            d = document,
+            e = d.documentElement,
+            g = d.getElementsByTagName('body')[0],
+            w = win.innerWidth || e.clientWidth || g.clientWidth,
+            h = win.innerHeight || e.clientHeight || g.clientHeight;
+
+        return {width: w, height: h};
+    }
+
+    static getOffset(el) {
+        var rect = el.getBoundingClientRect();
+
+        return {
+            top: rect.top + document.body.scrollTop,
+            left: rect.left + document.body.scrollLeft
+        };
+    }
+
+    static generateZIndex() {
+        this.zindex = this.zindex||999;
+        return ++this.zindex;
+    }
+
+    static getCurrentZIndex() {
+        return this.zindex;
+    }
+    
+    static index(element) {
+        let children = element.parentNode.childNodes;
+        let num = 0;
+        for (var i = 0; i < children.length; i++) {
+            if (children[i] === element) return num;
+            if (children[i].nodeType === 1) num++;
+        }
+        return -1;
+    }
+
+    static addMultipleClasses(element, className) {
+        if (element.classList) {
+            let styles = className.split(' ');
+            for (let i = 0; i < styles.length; i++) {
+                element.classList.add(styles[i]);
+            }
+
+        }
+        else {
+            let styles = className.split(' ');
+            for (let i = 0; i < styles.length; i++) {
+                element.className += ' ' + styles[i];
+            }
+        }
+    }
+
+    static addClass(element, className) {
+        if (element.classList)
+            element.classList.add(className);
+        else
+            element.className += ' ' + className;
+    }
+
+    static removeClass(element, className) {
+        if (element.classList)
+            element.classList.remove(className);
+        else
+            element.className = element.className.replace(new RegExp('(^|\\b)' + className.split(' ').join('|') + '(\\b|$)', 'gi'), ' ');
+    }
+
+    static hasClass(element, className) {
+        if (element.classList)
+            return element.classList.contains(className);
+        else
+            return new RegExp('(^| )' + className + '( |$)', 'gi').test(element.className);
+    }
+
+    static find(element, selector) {
+        return element.querySelectorAll(selector);
+    }
+
+    static findSingle(element, selector) {
+        return element.querySelector(selector);
+    }
+
+    static getHeight(el) {
+        let height = el.offsetHeight;
+        let style = getComputedStyle(el);
+
+        height -= parseFloat(style.paddingTop) + parseFloat(style.paddingBottom) + parseFloat(style.borderTopWidth) + parseFloat(style.borderBottomWidth);
+
+        return height;
+    }
+
+    static getWidth(el) {
+        let width = el.offsetWidth;
+        let style = getComputedStyle(el);
+
+        width -= parseFloat(style.paddingLeft) + parseFloat(style.paddingRight) + parseFloat(style.borderLeftWidth) + parseFloat(style.borderRightWidth);
+
+        return width;
+    }
+
+    static absolutePosition(element, target) {
+        let elementDimensions = element.offsetParent ? { width: element.offsetWidth, height: element.offsetHeight } : this.getHiddenElementDimensions(element)
+        let elementOuterHeight = elementDimensions.height;
+        let elementOuterWidth = elementDimensions.width;
+        let targetOuterHeight = target.offsetHeight;
+        let targetOuterWidth = target.offsetWidth;
+        let targetOffset = target.getBoundingClientRect();
+        let windowScrollTop = this.getWindowScrollTop();
+        let windowScrollLeft = this.getWindowScrollLeft();
+        let viewport = this.getViewport();
+        let top, left;
+
+        if (targetOffset.top + targetOuterHeight + elementOuterHeight > viewport.height)
+            top = targetOffset.top + windowScrollTop - elementOuterHeight;
+        else
+            top = targetOuterHeight + targetOffset.top + windowScrollTop;
+
+        if (targetOffset.left + targetOuterWidth + elementOuterWidth > viewport.width)
+            left = targetOffset.left + windowScrollLeft + targetOuterWidth - elementOuterWidth;
+        else
+            left = targetOffset.left + windowScrollLeft;
+
+        element.style.top = top + 'px';
+        element.style.left = left + 'px';
+    }
+
+    static relativePosition(element, target) {
+        var elementDimensions = element.offsetParent ? { width: element.offsetWidth, height: element.offsetHeight } : this.getHiddenElementDimensions(element);
+        var targetHeight = target.offsetHeight;
+        var targetWidth = target.offsetWidth;
+        var targetOffset = target.getBoundingClientRect();
+        var viewport = this.getViewport();
+        var top, left;
+
+        if ((targetOffset.top + targetHeight + elementDimensions.height) > viewport.height)
+            top = -1 * (elementDimensions.height);
+        else
+            top = targetHeight;
+
+        if ((targetOffset.left + elementDimensions.width) > viewport.width)
+            left = targetWidth - elementDimensions.width;
+        else
+            left = 0;
+
+        element.style.top = top + 'px';
+        element.style.left = left + 'px';
+    }
+    static getHiddenElementOuterHeight(element) {
+        element.style.visibility = 'hidden';
+        element.style.display = 'block';
+        let elementHeight = element.offsetHeight;
+        element.style.display = 'none';
+        element.style.visibility = 'visible';
+
+        return elementHeight;
+    }
+
+    static getHiddenElementOuterWidth(element) {
+        element.style.visibility = 'hidden';
+        element.style.display = 'block';
+        let elementWidth = element.offsetWidth;
+        element.style.display = 'none';
+        element.style.visibility = 'visible';
+
+        return elementWidth;
+    }
+
+    static getHiddenElementDimensions(element) {
+        var dimensions = {};
+        element.style.visibility = 'hidden';
+        element.style.display = 'block';
+        dimensions.width = element.offsetWidth;
+        dimensions.height = element.offsetHeight;
+        element.style.display = 'none';
+        element.style.visibility = 'visible';
+
+        return dimensions;
+    }
+
+    static fadeIn(element, duration) {
+        element.style.opacity = 0;
+
+        var last = +new Date();
+        var opacity = 0;
+        var tick = function () {
+            opacity = +element.style.opacity + (new Date().getTime() - last) / duration;
+            element.style.opacity = opacity;
+            last = +new Date();
+
+            if (+opacity < 1) {
+                (window.requestAnimationFrame && requestAnimationFrame(tick)) || setTimeout(tick, 16);
+            }
+        };
+
+        tick();
+    }
+
+    static fadeOut(element, ms) {
+        var opacity = 1,
+            interval = 50,
+            duration = ms,
+            gap = interval / duration;
+
+        let fading = setInterval(() => {
+            opacity -= gap;
+
+            if (opacity <= 0) {
+                opacity = 0;
+                clearInterval(fading);
+            }
+            
+            element.style.opacity = opacity;
+        }, interval);
+    }
+
+    static getUserAgent() {
+        return navigator.userAgent;
+    }
+
+    static appendChild(element, target) {
+        if(this.isElement(target))
+            target.appendChild(element);
+        else if(target.el && target.el.nativeElement)
+            target.el.nativeElement.appendChild(element);
+        else
+            throw new Error('Cannot append ' + target + ' to ' + element);
+    }
+
+    static scrollInView(container, item) {
+        let borderTopValue = getComputedStyle(container).getPropertyValue('borderTopWidth');
+        let borderTop = borderTopValue ? parseFloat(borderTopValue) : 0;
+        let paddingTopValue = getComputedStyle(container).getPropertyValue('paddingTop');
+        let paddingTop = paddingTopValue ? parseFloat(paddingTopValue) : 0;
+        let containerRect = container.getBoundingClientRect();
+        let itemRect = item.getBoundingClientRect();
+        let offset = (itemRect.top + document.body.scrollTop) - (containerRect.top + document.body.scrollTop) - borderTop - paddingTop;
+        let scroll = container.scrollTop;
+        let elementHeight = container.clientHeight;
+        let itemHeight = this.getOuterHeight(item);
+
+        if (offset < 0) {
+            container.scrollTop = scroll + offset;
+        }
+        else if ((offset + itemHeight) > elementHeight) {
+            container.scrollTop = scroll + offset - elementHeight + itemHeight;
+        }
+    }
+
+    static clearSelection() {
+        if(window.getSelection) {
+            if(window.getSelection().empty) {
+                window.getSelection().empty();
+            } else if(window.getSelection().removeAllRanges && window.getSelection().rangeCount > 0 && window.getSelection().getRangeAt(0).getClientRects().length > 0) {
+                window.getSelection().removeAllRanges();
+            }
+        }
+        else if(document['selection'] && document['selection'].empty) {
+            try {
+                document['selection'].empty();
+            } catch(error) {
+                //ignore IE bug
+            }
+        }
+    }
+
+    static calculateScrollbarWidth() {
+        if(this.calculatedScrollbarWidth != null)
+            return this.calculatedScrollbarWidth;
+        
+        let scrollDiv = document.createElement("div");
+        scrollDiv.className = "p-scrollbar-measure";
+        document.body.appendChild(scrollDiv);
+
+        let scrollbarWidth = scrollDiv.offsetWidth - scrollDiv.clientWidth;
+        document.body.removeChild(scrollDiv);
+
+        this.calculatedScrollbarWidth = scrollbarWidth;
+        
+        return scrollbarWidth;
+    }
+
+    static getBrowser() {
+        if(!this.browser) {
+            let matched = this.resolveUserAgent();
+            this.browser = {};
+
+            if (matched.browser) {
+                this.browser[matched.browser] = true;
+                this.browser['version'] = matched.version;
+            }
+
+            if (this.browser['chrome']) {
+                this.browser['webkit'] = true;
+            } else if (this.browser['webkit']) {
+                this.browser['safari'] = true;
+            }
+        }
+
+        return this.browser;
+    }
+
+    static resolveUserAgent() {
+        let ua = navigator.userAgent.toLowerCase();
+        let match = /(chrome)[ ]([\w.]+)/.exec(ua) ||
+            /(webkit)[ ]([\w.]+)/.exec(ua) ||
+            /(opera)(?:.*version|)[ ]([\w.]+)/.exec(ua) ||
+            /(msie) ([\w.]+)/.exec(ua) ||
+            (ua.indexOf("compatible") < 0 && /(mozilla)(?:.*? rv:([\w.]+)|)/.exec(ua)) ||
+            [];
+
+        return {
+            browser: match[1] || "",
+            version: match[2] || "0"
+        };
+    }
+
+    static isVisible(element) {
+        return element.offsetParent != null;
+    } 
+}
\ No newline at end of file