Merge pull request #63 from dukefirehawk/migrated/bug-fix-5

Fixed material tree runtime exception

Author: dukefirehawk

angular_components/lib/src/material_tree/group/material_tree_group.dart

@@ -130,9 +130,18 @@ class MaterialTreeGroupComponent<T> extends MaterialTreeNode<T?>
         padding += checkboxWidth;
       }
     }
+
     return '${padding}px';
   }
 
+  String getLastIndent(OptionGroup group) {
+    if (group.isNotEmpty) {
+      return getIndent(group.last);
+    }
+
+    return '0px';
+  }
+
   void handleExpansion(Event e, Object option) {
     toggleExpansion(option as T);
     e.stopPropagation();

angular_components/lib/src/material_tree/group/material_tree_group.html

@@ -83,7 +83,7 @@
   </li>
   <li *ngIf="viewMoreLinkVisible">
     <div class="view-more-link-item"
-         [style.padding-left]="getIndent(visibleGroup.last)">
+         [style.padding-left]="getLastIndent(visibleGroup)">
       <div class="material-tree-shift"
            [style.padding-left]="fixedPadding">
         <a class="view-more-link"

angular_components/lib/src/material_tree/material_tree_node.dart

@@ -42,14 +42,13 @@ class MaterialTreeNode<T> {
   MaterialTreeNode(this._root, this._changeDetector,
       {IsExpandable<T>? isExpandable}) {
     _group = _EMPTY_OPTION_GROUP;
+
     if (!_root.supportsHierarchy) {
       _isExpandable = (_) => false;
       _parent = _NotAParent();
     } else {
       _isExpandable = isExpandable ?? hasChildren;
-
-      // TODO: Type not match
-      _parent = _root.options as Parent<T, Iterable<OptionGroup<T>>>;
+      _parent = _root.options as Parent<T, List<OptionGroup<T>>>;
     }
     // TODO(google).
     final Object? options = _root.options;

examples/material_tree_example/lib/src/material_tree_demo_options.dart

@@ -79,7 +79,7 @@ final SelectionOptions filterableNestedOptions =
 
 /// An example implementation of [SelectionOptions] with [Parent].
 class _NestedSelectionOptions<T> extends SelectionOptions<T>
-    implements Parent<T, List<OptionGroup<T>>?> {
+    implements Parent<T, List<OptionGroup<T>>> {
   final Map<T, List<OptionGroup<T>>> _children;
 
   _NestedSelectionOptions(List<OptionGroup<T>> options, this._children)
@@ -89,8 +89,9 @@ class _NestedSelectionOptions<T> extends SelectionOptions<T>
   bool hasChildren(T item) => _children.containsKey(item);
 
   @override
-  DisposableFuture<List<OptionGroup<T>>?> childrenOf(T parent, [_]) {
-    return DisposableFuture<List<OptionGroup<T>>?>.fromValue(_children[parent]);
+  DisposableFuture<List<OptionGroup<T>>> childrenOf(T parent, [_]) {
+    return DisposableFuture<List<OptionGroup<T>>>.fromValue(
+        _children[parent] ?? []);
   }
 }
 
@@ -102,7 +103,7 @@ class _NestedFilterableSelectionOptions<T extends String>
   @override
   String? currentQuery;
 
-  List<OptionGroup<T>>? _unfilteredOptionGroups;
+  List<OptionGroup<T>> _unfilteredOptionGroups = [];
 
   _NestedFilterableSelectionOptions(
       List<OptionGroup<T>> options, Map<T, List<OptionGroup<T>>> children)
@@ -113,7 +114,7 @@ class _NestedFilterableSelectionOptions<T extends String>
   @override
   DisposableFuture<bool> filter(Object? filterQuery, {int? limit = -1}) {
     var filteredResults = <OptionGroup<T>>[];
-    for (var optionGroup in _unfilteredOptionGroups!) {
+    for (var optionGroup in _unfilteredOptionGroups) {
       var resultOptionGroup = _filterGroup(filterQuery as String?, optionGroup);
       if (resultOptionGroup != null) {
         filteredResults.add(resultOptionGroup);
@@ -139,7 +140,7 @@ class _NestedFilterableSelectionOptions<T extends String>
     if (currentQuery != null) {
       filter(currentQuery, limit: currentLimit);
     } else {
-      super.optionGroups = _unfilteredOptionGroups!;
+      super.optionGroups = _unfilteredOptionGroups;
     }
   }
 }