Revert "Fixed #1755 - New selectionMode for PickList"

This reverts commit 4f246b64e4.

api-generator/components/picklist.js

@@ -11,12 +11,6 @@ const PickListProps = [
         default: "null",
         description: "Selected items in the list as a multidimensional array."
     },
-    {
-        name: "selectionMode",
-        type: "string",
-        default: "null",
-        description: 'Defines selection mode, options are "single" and "multiple".'
-    },
     {
         name: "metaKeySelection",
         type: "boolean",

src/components/picklist/PickList.d.ts

@@ -3,7 +3,6 @@ import { VNode } from 'vue';
 interface PickListProps {
     modelValue?: any[][];
     selection?: any[][];
-    selectionMode?: string;
     dataKey?: string;
     metaKeySelection?: boolean;
     listStyle?: any;

src/components/picklist/PickList.vue

@@ -72,10 +72,6 @@ export default {
             type: Array,
             default: () => [[],[]]
         },
-        selectionMode: {
-            type: String,
-            default: null
-        },
         dataKey: {
             type: String,
             default: null
@@ -391,20 +387,19 @@ export default {
                     _selection = selectionList.filter((val, index) => index !== selectedIndex);
                 }
                 else {
-                    if (metaKey) {
-                        _selection = this.isMultipleSelectionMode() ? selectionList ? [...selectionList] : [] : [];
-                    }
-                    else {
-                        _selection = [];
-                    }
-
+                    _selection = (metaKey) ? selectionList ? [...selectionList] : [] : [];
                     _selection.push(item);
                 }
             }
             else {
-                _selection = this.isMultipleSelectionMode() ? selectionList ? [...selectionList] : [] : [];
+                if (selected) {
+                    _selection = selectionList.filter((val, index) => index !== selectedIndex);
+                }
+                else {
+                    _selection = selectionList ? [...selectionList] : [];
                     _selection.push(item);
                 }
+            }
 
             let newSelection = [...this.d_selection];
             newSelection[listIndex] = _selection;
@@ -554,12 +549,6 @@ export default {
                 document.head.removeChild(this.styleElement);
                 this.styleElement = null;
             }
-        },
-        isSingleSelectionMode() {
-            return this.selectionMode === 'single';
-        },
-        isMultipleSelectionMode() {
-            return this.selectionMode === 'multiple';
         }
     },
     computed: {

src/views/picklist/PickListDoc.vue

@@ -104,12 +104,6 @@ import PickList from 'primevue/picklist';
                         <td>null</td>
                         <td>Selected items in the list as a multidimensional array.</td>
                     </tr>
-                    <tr>
-                        <td>selectionMode</td>
-                        <td>string</td>
-                        <td>null</td>
-                        <td>Defines selection mode, options are "single" and "multiple".</td>
-                    </tr>
                     <tr>
                         <td>metaKeySelection</td>
                         <td>boolean</td>