Method collapseAll

src/cdk/tree/tree.ts:722–728

Collapse all data nodes in the tree.

()

  /** Collapse all data nodes in the tree. */
  collapseAll(): void {
    if (this.treeControl) {
      this.treeControl.collapseAll();
    } else if (this._expansionModel) {
      this._forEachExpansionKey(keys => this._expansionModel?.deselect(...keys));
    }
  }

  /** Level accessor, used for compatibility between the old Tree and new Tree */
  _getLevelAccessor() {