From 09ebaa9b73c8d42bd47f31ff15b459b977ec69e8 Mon Sep 17 00:00:00 2001
From: cagataycivici <cagatay.civici@gmail.com>
Date: Sun, 30 Dec 2018 22:20:10 +0300
Subject: [PATCH] Base MultiSelect Implementation

---
 src/components/multiselect/MultiSelect.css |   8 +-
 src/components/multiselect/MultiSelect.vue | 137 +++++++++++++++++++--
 2 files changed, 130 insertions(+), 15 deletions(-)

diff --git a/src/components/multiselect/MultiSelect.css b/src/components/multiselect/MultiSelect.css
index c6627b06f..ec114cd4a 100644
--- a/src/components/multiselect/MultiSelect.css
+++ b/src/components/multiselect/MultiSelect.css
@@ -27,7 +27,7 @@
     position: absolute;
 }
 
-.p-multiselect .p-multiselect-label-container  {
+.p-multiselect .p-multiselect-label-container {
     overflow: hidden;
 }
 
@@ -48,7 +48,7 @@
 
 .p-multiselect.p-disabled .p-multiselect-trigger,
 .p-multiselect.p-disabled .p-multiselect-label {
-    cursor: auto
+    cursor: auto;
 }
 
 .p-multiselect-panel {
@@ -69,6 +69,8 @@
 
 .p-multiselect-panel .p-multiselect-list {
     border: 0 none;
+    margin: 0;
+    list-style-type: none;
 }
 
 .p-multiselect-panel .p-multiselect-item {
@@ -88,7 +90,7 @@
     vertical-align: middle;
 }
 
-.p-multiselect-panel .p-multiselect-item label {
+.p-multiselect-panel .p-multiselect-item > span {
     display: inline-block;
     vertical-align: middle;
 }
diff --git a/src/components/multiselect/MultiSelect.vue b/src/components/multiselect/MultiSelect.vue
index 3e53aef94..1e98f7269 100644
--- a/src/components/multiselect/MultiSelect.vue
+++ b/src/components/multiselect/MultiSelect.vue
@@ -1,5 +1,5 @@
 <template>
-    <div :class="containerClass" @click="onClick">
+    <div ref="container" :class="containerClass" @click="onClick">
         <div class="p-hidden-accessible">
             <input ref="focusInput" type="text" role="listbox" readonly :disabled="disabled" @focus="onFocus" @blur="onBlur" @keydown="onKeyDown" :tabindex="tabindex"/>
         </div>
@@ -9,10 +9,32 @@
         <div class="p-multiselect-trigger">
             <span class="p-multiselect-trigger-icon pi pi-chevron-down p-c"></span>
         </div>
+        <transition name="p-input-overlay" @enter="onOverlayEnter" @leave="onOverlayLeave">
+            <div ref="overlay" class="p-multiselect-panel" v-if="overlayVisible">
+                <div ref="itemsWrapper" class="p-multiselect-items-wrapper" :style="{'max-height': scrollHeight}">
+                    <ul class="p-multiselect-items p-multiselect-list p-component">
+                        <li v-for="(option, i) of visibleOptions" :class="['p-multiselect-item', {'p-highlight': isSelected(option), 'p-disabled': isOptionDisabled(option)}]"
+                            :aria-label="getOptionLabel(option)" :key="getOptionLabel(option)" @click="onOptionSelect($event, option)" @keydown="onOptionKeyDown($event, option)" :tabindex="tabindex||'0'">
+                            <div class="p-checkbox p-component">
+                                <div :class="['p-checkbox-box p-component', {'p-highlight': isSelected(option)}]">
+                                    <span :class="['p-checkbox-icon p-c', {'pi pi-check': isSelected(option)}]"></span>
+                                </div>
+                            </div>
+                            <slot name="option" :option="option" :index="i">
+                                <span>{{getOptionLabel(option)}}</span>
+                            </slot>
+                        </li>
+                    </ul>
+                </div>
+            </div>
+        </transition>
     </div>
 </template>
 
 <script>
+import ObjectUtils from '../utils/ObjectUtils';
+import DomHandler from '../utils/DomHandler';
+
 export default {
     props: {
         value: null,
@@ -58,6 +80,21 @@ export default {
         isOptionDisabled(option) {
             return this.optionDisabled ? ObjectUtils.resolveFieldData(option, this.optionDisabled) : false;
         },
+        isSelected(option) {
+            let selected = false;
+            let optionValue = this.getOptionValue(option);
+
+            if (this.value) {
+                for (let val of this.value) {
+                    if (ObjectUtils.equals(val, optionValue, this.dataKey)) {
+                        selected = true;
+                        break;
+                    }
+                }
+            }
+
+            return selected;
+        },
         onFocus() {
             this.focused = true;
         },
@@ -65,14 +102,17 @@ export default {
             this.focused = false;
         },
         onClick() {
-
+            if (!this.$refs.overlay || !this.$refs.overlay.contains(event.target)) {
+                this.overlayVisible = !this.overlayVisible;
+                this.$refs.focusInput.focus();
+            }
         },
         onKeyDown(event) {
             switch(event.which) {
                 //down
                 case 40:
                     if (this.visibleOptions && this.overlayVisible && event.altKey) {
-                        this.overlayVisible = true;
+                        this.overlayVisible = false;
                     } 
                 break;
 
@@ -88,25 +128,102 @@ export default {
                 case 13:
                 case 27:
                     if (this.overlayVisible) {
-                        this.hideOverlay();
+                        this.overlayVisible = false;
                         event.preventDefault();
                     }
                 break;
 
                 //tab
                 case 9:
-                    this.hideOverlay();
+                    this.overlayVisible = false;
                 break;
 
                 default:
                 break;
             }
         },
+        onOptionSelect(event, option) {
+            if (this.disabled || this.isOptionDisabled(option)) {
+                return;
+            }
+
+            let selected = this.isSelected(option);
+            let valueChanged = false;
+            let value = null;
+
+            if (selected)
+                value = this.value.filter(val => !ObjectUtils.equals(val, this.getOptionValue(option), this.dataKey));
+            else
+                value = [...this.value || [], this.getOptionValue(option)];
+
+            this.$emit('input', value);
+            this.$emit('change', {originalEvent: event, value: value});
+        },
+        onOptionKeyDown(event, option) {
+            let listItem = event.target;
+        
+            switch(event.which) {
+                //down
+                case 40:
+                    var nextItem = this.findNextItem(listItem);
+                    if (nextItem) {
+                        nextItem.focus();
+                    }
+                    
+                    event.preventDefault();
+                break;
+                
+                //up
+                case 38:
+                    var prevItem = this.findPrevItem(listItem);
+                    if (prevItem) {
+                        prevItem.focus();
+                    }
+                    
+                    event.preventDefault();
+                break;
+                
+                //enter
+                case 13:
+                    this.onOptionSelect(event, option);
+                    event.preventDefault();
+                break;
+
+                default:
+                break;
+            }
+        },
+        findNextItem(item) {
+            let nextItem = item.nextElementSibling;
+
+            if (nextItem)
+                return DomHandler.hasClass(nextItem, 'p-disabled') ? this.findNextItem(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;
+        },
+        onOverlayEnter() {
+            this.alignOverlay();
+            this.bindOutsideClickListener();
+        },
+        onOverlayLeave() {
+            this.unbindOutsideClickListener();
+        },
+        alignOverlay() {
+            DomHandler.relativePosition(this.$refs.overlay, this.$refs.container);
+        },
         bindOutsideClickListener() {
             if (!this.outsideClickListener) {
                 this.outsideClickListener = (event) => {
-                    if (this.$refs.overlay && !this.$refs.overlay.contains(event.target)) {
-                        this.hideOverlay();
+                    if (this.overlayVisible && this.$refs.overlay && !this.$refs.overlay.contains(event.target)) {
+                        this.overlayVisible = false;
                     }
                 };
                 document.addEventListener('click', this.outsideClickListener);
@@ -118,10 +235,6 @@ export default {
                 this.outsideClickListener = null;
             }
         },
-        hideOverlay() {
-            this.overlayVisible = false;
-            this.unbindOutsideClickListener();
-        },
         getLabelByValue(val) {
             let label = null;
 
@@ -174,7 +287,7 @@ export default {
                         label += ',';
                     }
 
-                    label += this.findLabelByValue(this.value[i]);
+                    label += this.getLabelByValue(this.value[i]);
                 }
             }
             else {