From 79803baf11ab56ee237494c0676c1ba636928c36 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tu=C4=9F=C3=A7e=20K=C3=BC=C3=A7=C3=BCko=C4=9Flu?=
 <tugcekucukoglu.860@gmail.com>
Date: Thu, 4 Aug 2022 17:17:49 +0300
Subject: [PATCH] SelectButton | hidden checkbox and radio roles added

---
 api-generator/components/selectbutton.js      |  6 ++
 src/components/selectbutton/SelectButton.d.ts |  4 +
 src/components/selectbutton/SelectButton.vue  | 98 +++++++++++++++----
 src/views/selectbutton/SelectButtonDemo.vue   | 12 +--
 src/views/selectbutton/SelectButtonDoc.vue    | 62 +++++++-----
 5 files changed, 137 insertions(+), 45 deletions(-)

diff --git a/api-generator/components/selectbutton.js b/api-generator/components/selectbutton.js
index e63a2062e..427a71ac9 100644
--- a/api-generator/components/selectbutton.js
+++ b/api-generator/components/selectbutton.js
@@ -46,6 +46,12 @@ const SelectButtonProps = [
         type: "string",
         default: "null",
         description: "A property to uniquely identify an option."
+    },
+    {
+        name: "aria-labelledby",
+        type: "string",
+        default: "null",
+        description: "Identifier of the underlying element."
     }
 ];
 
diff --git a/src/components/selectbutton/SelectButton.d.ts b/src/components/selectbutton/SelectButton.d.ts
index b3ed0b168..3ee6a7344 100755
--- a/src/components/selectbutton/SelectButton.d.ts
+++ b/src/components/selectbutton/SelectButton.d.ts
@@ -51,6 +51,10 @@ export interface SelectButtonProps {
      * A property to uniquely identify an option.
      */
     dataKey?: string | undefined;
+    /**
+     * Identifier of the underlying element.
+     */
+    "aria-labelledby"?: string | undefined;
 }
 
 export interface SelectButtonSlots {
diff --git a/src/components/selectbutton/SelectButton.vue b/src/components/selectbutton/SelectButton.vue
index 20b7245c0..2a8015873 100755
--- a/src/components/selectbutton/SelectButton.vue
+++ b/src/components/selectbutton/SelectButton.vue
@@ -1,8 +1,7 @@
 <template>
-    <div :class="containerClass" role="group">
-        <div v-for="(option, i) of options" :key="getOptionRenderKey(option)" :aria-label="getOptionLabel(option)" role="button" :aria-pressed="isSelected(option)"
-            :class="getButtonClass(option)" :tabindex="isOptionDisabled(option) ? null : '0'" v-ripple
-            @click="onOptionSelect($event, option)" @keydown="onKeydown($event, option)" @focus="onFocus($event)" @blur="onBlur($event)">
+    <div ref="container" :class="containerClass" role="group" :aria-labelledby="ariaLabelledby">
+        <div v-for="(option, i) of options" :key="getOptionRenderKey(option)" :tabindex="i === focusedIndex ? '0' : '-1'" :aria-label="getOptionLabel(option)" :role="multiple ? 'checkbox' : 'radio'" :aria-checked="isSelected(option)" :aria-disabled="optionDisabled"
+            :class="getButtonClass(option, i)" @click="onOptionSelect($event, option, i)" @keydown="onKeydown($event, option, i)" @focus="onFocus($event)" @blur="onBlur($event, option)" v-ripple>
             <slot name="option" :option="option" :index="i">
                 <span class="p-button-label">{{getOptionLabel(option)}}</span>
             </slot>
@@ -11,7 +10,7 @@
 </template>
 
 <script>
-import {ObjectUtils} from 'primevue/utils';
+import {ObjectUtils,DomHandler} from 'primevue/utils';
 import Ripple from 'primevue/ripple';
 
 export default {
@@ -25,9 +24,31 @@ export default {
         optionDisabled: null,
 		multiple: Boolean,
         disabled: Boolean,
-        dataKey: null
+        dataKey: null,
+        'aria-labelledby': {
+            type: String,
+			default: null
+        }
+    },
+    data() {
+        return {
+            focusedIndex: 0
+        }
+    },
+    mounted() {
+        this.defaultTabIndexes();
     },
     methods: {
+        defaultTabIndexes() {
+            let opts = DomHandler.find(this.$refs.container, '.p-button');
+            let firstHighlight = DomHandler.findSingle(this.$refs.container, '.p-highlight');
+
+            for (let i = 0; i < opts.length; i++) {
+                if ((DomHandler.hasClass(opts[i], 'p-highlight') && ObjectUtils.equals(opts[i], firstHighlight)) || (firstHighlight === null && i == 0)) {
+                    this.focusedIndex = i;
+                }
+            }
+        },
         getOptionLabel(option) {
             return this.optionLabel ? ObjectUtils.resolveFieldData(option, this.optionLabel) : option;
         },
@@ -40,7 +61,7 @@ export default {
         isOptionDisabled(option) {
             return this.optionDisabled ? ObjectUtils.resolveFieldData(option, this.optionDisabled) : false;
         },
-        onOptionSelect(event, option) {
+        onOptionSelect(event, option, index) {
             if (this.disabled || this.isOptionDisabled(option)) {
                 return;
             }
@@ -49,7 +70,7 @@ export default {
             let optionValue = this.getOptionValue(option);
             let newValue;
 
-            if(this.multiple) {
+            if (this.multiple) {
                 if (selected)
                     newValue = this.modelValue.filter(val => !ObjectUtils.equals(val, optionValue, this.equalityKey));
                 else
@@ -59,16 +80,10 @@ export default {
                 newValue = selected ? null : optionValue;
             }
 
+            this.focusedIndex = index;
             this.$emit('update:modelValue', newValue);
             this.$emit('change', {event: event, value: newValue});
         },
-        onKeydown(event, option) {
-            //space
-            if (event.which === 32) {
-                this.onOptionSelect(event, option);
-                event.preventDefault();
-            }
-        },
         isSelected(option) {
             let selected = false;
             let optionValue = this.getOptionValue(option);
@@ -89,11 +104,60 @@ export default {
 
             return selected;
         },
+        onKeydown(event, option, index) {
+            switch (event.code) {
+                case 'Space': {
+                    this.onOptionSelect(event, option, index);
+                    event.preventDefault();
+                    break;
+                }
+
+                case 'ArrowDown':
+                case 'ArrowRight': {
+                    this.changeTabIndexes(event, 'next');
+                    event.preventDefault();
+                    break;
+                }
+
+                case 'ArrowUp':
+                case 'ArrowLeft': {
+                    this.changeTabIndexes(event, 'prev');
+                    event.preventDefault();
+                    break;
+                }
+                
+                default:
+                    //no op
+                break;
+            }
+        },
+        changeTabIndexes(event, direction) {
+            let firstTabableChild, index;
+            for (let i = 0; i <= this.$refs.container.children.length - 1; i++) {
+                if (this.$refs.container.children[i].getAttribute('tabindex') === '0')
+                    firstTabableChild = {elem: this.$refs.container.children[i], index: i};
+            }
+
+            if (direction === 'prev') {
+                if (firstTabableChild.index === 0) index = this.$refs.container.children.length - 1;
+                else index = firstTabableChild.index - 1;
+            }
+            else {
+                if (firstTabableChild.index === this.$refs.container.children.length - 1) index = 0;
+                else index = firstTabableChild.index + 1;
+            }
+
+            this.focusedIndex = index;
+            this.$refs.container.children[index].focus();
+        },
         onFocus(event) {
             this.$emit('focus', event);
         },
-        onBlur(event) {
-            this.$emit('blur', event);
+        onBlur(event, option) {
+            if (event.target && event.target.parentElement && event.relatedTarget && event.relatedTarget.parentElement && event.target.parentElement.getAttribute('aria-labelledby') !== event.relatedTarget.parentElement.getAttribute('aria-labelledby')) {
+                this.defaultTabIndexes();
+            }
+            this.$emit('blur', event, option);
         },
         getButtonClass(option) {
             return ['p-button p-component', {
diff --git a/src/views/selectbutton/SelectButtonDemo.vue b/src/views/selectbutton/SelectButtonDemo.vue
index fd9412cbe..94d086ec7 100755
--- a/src/views/selectbutton/SelectButtonDemo.vue
+++ b/src/views/selectbutton/SelectButtonDemo.vue
@@ -10,14 +10,14 @@
 
         <div class="content-section implementation">
             <div class="card">
-                <h5>Single Selection</h5>
-                <SelectButton v-model="value1" :options="options" />
+                <h5 id="single">Single Selection</h5>
+                <SelectButton v-model="value1" :options="options" aria-labelledby="single" />
 
-                <h5>Multiple Selection</h5>
-                <SelectButton v-model="value2" :options="paymentOptions" optionLabel="name" multiple />
+                <h5 id="multiple">Multiple Selection</h5>
+                <SelectButton v-model="value2" :options="paymentOptions" optionLabel="name" multiple aria-labelledby="multiple"  />
 
-                <h5>Custom Content</h5>
-                <SelectButton v-model="value3" :options="justifyOptions" optionLabel="value" dataKey="value" >
+                <h5 id="custom">Custom Content</h5>
+                <SelectButton v-model="value3" :options="justifyOptions" optionLabel="value" dataKey="value" aria-labelledby="custom"  >
                     <template #option="slotProps">
                         <i :class="slotProps.option.icon"></i>
                     </template>
diff --git a/src/views/selectbutton/SelectButtonDoc.vue b/src/views/selectbutton/SelectButtonDoc.vue
index a91edf8d8..3d57fc269 100755
--- a/src/views/selectbutton/SelectButtonDoc.vue
+++ b/src/views/selectbutton/SelectButtonDoc.vue
@@ -175,11 +175,11 @@ export default {
         <h5>Accessibility</h5>
         <DevelopmentSection>
             <h6>Screen Reader</h6>
-            <p>The container element that wraps the buttons has a <i>group</i> role whereas each button element uses <i>button</i> role and <i>aria-pressed</i> is updated depending on selection state.
-            Value to describe an option is automatically set using the <i>aria-label</i> property that refers to the label of an option so it is still suggested to define a label even the option display
-            consists of presentational content like icons only.</p>
+            <p>SelectButton component uses hidden native checkbox role for multiple selection and hidden radio role for single selection that is only visible to screen readers.
+            Value to describe the component can be provided via <i>aria-labelledby</i> property.</p>
 
             <h6>Keyboard Support</h6>
+            <p>Keyboard interaction is derived from the native browser handling of checkboxs in a group.</p>
             <div class="doc-tablewrapper">
                 <table class="doc-table">
                     <thead>
@@ -191,7 +191,25 @@ export default {
                     <tbody>
                         <tr>
                             <td><i>tab</i></td>
-                            <td>Moves focus to the buttons.</td>
+                            <td>Moves focus to the first selected option, if there is none then first option receives the focus.</td>
+                        </tr>
+                        <tr>
+                            <td>
+                                <span class="inline-flex flex-column">
+                                    <i class="mb-1">right arrow</i>
+                                    <i>up arrow</i>
+                                </span>
+                            </td>
+                            <td>Moves focus to the previous option.</td>
+                        </tr>
+                        <tr>
+                            <td>
+                                <span class="inline-flex flex-column">
+                                    <i class="mb-1">left arrow</i>
+                                    <i>down arrow</i>
+                                </span>
+                            </td>
+                            <td>Moves focus to the next option.</td>
                         </tr>
                         <tr>
                             <td><i>space</i></td>
@@ -217,14 +235,14 @@ export default {
                     content: `
 <template>
     <div>
-        <h5>Single Selection</h5>
-        <SelectButton v-model="value1" :options="options" />
+        <h5 id="single">Single Selection</h5>
+        <SelectButton v-model="value1" :options="options" aria-labelledby="single" />
 
-        <h5>Multiple Selection</h5>
-        <SelectButton v-model="value2" :options="paymentOptions" optionLabel="name" multiple />
+        <h5 id="multiple">Multiple Selection</h5>
+        <SelectButton v-model="value2" :options="paymentOptions" optionLabel="name" multiple aria-labelledby="multiple" />
 
-        <h5>Custom Content</h5>
-        <SelectButton v-model="value3" :options="justifyOptions" optionLabel="value" dataKey="value">
+        <h5 id="custom">Custom Content</h5>
+        <SelectButton v-model="value3" :options="justifyOptions" optionLabel="value" dataKey="value" aria-labelledby="custom">
             <template #option="slotProps">
                 <i :class="slotProps.option.icon"></i>
             </template>
@@ -261,14 +279,14 @@ export default {
                     content: `
 <template>
     <div>
-        <h5>Single Selection</h5>
-        <SelectButton v-model="value1" :options="options" />
+        <h5 id="single">Single Selection</h5>
+        <SelectButton v-model="value1" :options="options" aria-labelledby="single" />
 
-        <h5>Multiple Selection</h5>
-        <SelectButton v-model="value2" :options="paymentOptions" optionLabel="name" multiple />
+        <h5 id="multiple">Multiple Selection</h5>
+        <SelectButton v-model="value2" :options="paymentOptions" optionLabel="name" multiple aria-labelledby="multiple" />
 
-        <h5>Custom Content</h5>
-        <SelectButton v-model="value3" :options="justifyOptions" optionLabel="value" dataKey="value">
+        <h5 id="custom">Custom Content</h5>
+        <SelectButton v-model="value3" :options="justifyOptions" optionLabel="value" dataKey="value" aria-labelledby="custom">
             <template #option="slotProps">
                 <i :class="slotProps.option.icon"></i>
             </template>
@@ -307,14 +325,14 @@ export default {
                     tabName: 'Browser Source',
                     imports: `<script src="https://unpkg.com/primevue@^3/selectbutton/selectbutton.min.js"><\\/script>`,
                     content: `<div id="app">
-            <h5>Single Selection</h5>
-            <p-selectbutton v-model="value1" :options="options"></p-selectbutton>
+            <h5 id="single">Single Selection</h5>
+            <p-selectbutton v-model="value1" :options="options" aria-labelledby="single"></p-selectbutton>
 
-            <h5>Multiple Selection</h5>
-            <p-selectbutton v-model="value2" :options="paymentOptions" option-label="name" multiple></p-selectbutton>
+            <h5 id="multiple">Multiple Selection</h5>
+            <p-selectbutton v-model="value2" :options="paymentOptions" option-label="name" multiple aria-labelledby="multiple"></p-selectbutton>
 
-            <h5>Custom Content</h5>
-            <p-selectbutton v-model="value3" :options="justifyOptions" option-label="value" data-key="value">
+            <h5 id="custom">Custom Content</h5>
+            <p-selectbutton v-model="value3" :options="justifyOptions" option-label="value" data-key="value" aria-labelledby="custom">
                 <template #option="slotProps">
                     <i :class="slotProps.option.icon"></i>
                 </template>