TreeView: provide a way to control ability to select nodes

packages/devextreme/js/__internal/ui/hierarchical_collection/data_adapter.ts

@@ -51,6 +51,8 @@ export interface DataAdapterOptions {
   onNodeChanged: (node: InternalNode) => void;
 
   searchMode: SearchMode;
+
+  allowDisabledNodeSelection: boolean;
 }
 
 SearchBoxController.setEditorClass(TextBox);
@@ -69,6 +71,7 @@ class DataAdapter {
     dataConverter: new HierarchicalDataConverter(),
     onNodeChanged: noop,
     sort: null,
+    allowDisabledNodeSelection: true,
   };
 
   _selectedNodesKeys: ItemKey[] = [];
@@ -162,8 +165,12 @@ class DataAdapter {
     return this.options.multipleSelection ? this.getData() : this.getFullData();
   }
 
-  _isNodeVisible(node: InternalNode): boolean {
-    return node.internalFields.item.visible !== false;
+  _isNodeVisible(node?: InternalNode): boolean {
+    return node?.internalFields.item.visible !== false;
+  }
+
+  _isNodeDisabled(node?: InternalNode): boolean {
+    return node?.internalFields.item.disabled === true;
   }
 
   _getByKey(data: (InternalNode | null)[], key: ItemKey): InternalNode | null {
@@ -432,6 +439,10 @@ class DataAdapter {
     return this.options.dataConverter.getItemsCount();
   }
 
+  _getDisabledItemsCount(): number {
+    return this.options.dataConverter.getDisabledItemsCount();
+  }
+
   getVisibleItemsCount(): number {
     return this.options.dataConverter.getVisibleItemsCount();
   }
@@ -509,7 +520,16 @@ class DataAdapter {
       : this._dataStructure;
 
     each(dataStructure, (_index: number, node: InternalNode) => {
-      if (node && this._isNodeVisible(node)) {
+      if (!this._isNodeVisible(node)) {
+        return;
+      }
+
+      if (this.options.allowDisabledNodeSelection) {
+        this._setFieldState(node, SELECTED, state);
+        return;
+      }
+
+      if (!this._isNodeDisabled(node)) {
         this._setFieldState(node, SELECTED, state);
       }
     });
@@ -522,10 +542,14 @@ class DataAdapter {
   }
 
   isAllSelected(): boolean | undefined {
-    if (this.getSelectedNodesKeys().length) {
-      return this.getSelectedNodesKeys().length === this.getVisibleItemsCount() ? true : undefined;
+    if (!this.getSelectedNodesKeys().length) {
+      return false;
     }
-    return false;
+
+    const countedNodesAmount = this.getVisibleItemsCount()
+      - (!this.options.allowDisabledNodeSelection ? this._getDisabledItemsCount() : 0);
+
+    return this.getSelectedNodesKeys().length === countedNodesAmount ? true : undefined;
   }
 
   toggleExpansion(key: ItemKey, state: boolean): void {

packages/devextreme/js/__internal/ui/hierarchical_collection/data_converter.ts

@@ -72,6 +72,8 @@ class DataConverter {
 
   private _visibleItemsCount = 0;
 
+  private _disabledItemsCount = 0;
+
   _indexByKey: Record<string | number, number> = {};
 
   private _dataAccessors!: DataAccessors;
@@ -128,6 +130,10 @@ class DataConverter {
       this._visibleItemsCount += 1;
     }
 
+    if (item.disabled === true) {
+      this._disabledItemsCount += 1;
+    }
+
     const { items, ...itemWithoutItems } = item;
 
     const node = {
@@ -265,6 +271,10 @@ class DataConverter {
     return this._itemsCount;
   }
 
+  getDisabledItemsCount(): number {
+    return this._disabledItemsCount;
+  }
+
   getVisibleItemsCount(): number {
     return this._visibleItemsCount;
   }
@@ -302,6 +312,7 @@ class DataConverter {
   ): (InternalNode | null)[] {
     this._itemsCount = 0;
     this._visibleItemsCount = 0;
+    this._disabledItemsCount = 0;
     this._rootValue = rootValue;
     this._dataType = dataType;
     this._indexByKey = {};

packages/devextreme/js/__internal/ui/tree_view/tree_view.base.ts

@@ -97,6 +97,8 @@ export interface TreeViewBaseProperties extends Properties<TreeViewNode>, Omit<
   deferRendering?: boolean;
 
   _supportItemUrl?: boolean;
+
+  allowDisabledNodeSelection?: boolean;
 }
 
 class TreeViewBase extends HierarchicalCollectionWidget<TreeViewBaseProperties, TreeViewNode> {
@@ -281,6 +283,7 @@ class TreeViewBase extends HierarchicalCollectionWidget<TreeViewBaseProperties,
       createChildren: null,
       onSelectAllValueChanged: null,
       _supportItemUrl: false,
+      allowDisabledNodeSelection: true,
     };
 
     // eslint-disable-next-line @typescript-eslint/no-unsafe-return
@@ -438,6 +441,10 @@ class TreeViewBase extends HierarchicalCollectionWidget<TreeViewBaseProperties,
       case 'collapseIcon':
         this.repaint();
         break;
+      case 'allowDisabledNodeSelection':
+        this._initDataAdapter();
+        this.repaint();
+        break;
       default:
         super._optionChanged(args);
     }
@@ -688,6 +695,7 @@ class TreeViewBase extends HierarchicalCollectionWidget<TreeViewBaseProperties,
       expandNodesRecursive = true,
       selectionRequired = false,
       dataStructure = 'tree',
+      allowDisabledNodeSelection,
     } = this.option();
 
     return {
@@ -700,6 +708,7 @@ class TreeViewBase extends HierarchicalCollectionWidget<TreeViewBaseProperties,
       dataType: dataStructure,
       sort: this._dataSource?.sort(),
       langParams: this._dataSource?.loadOptions?.()?.langParams,
+      allowDisabledNodeSelection,
     };
   }