A treeview for Flutter. Based on the listview.

Hi,

I am wondering if there was ever an attempt to add search functionality or a filter bar to the list view. I think that would be a great addition to this package.

Please consider checking if mounted before calling setState() in tree_view.dart https://github.com/sooxie/list_treeview/blob/c10335ca5645272618a9d4506a1ced9d47778f96/lib/tree/tree_view.dart#L78

From:

 void updateView() {
    setState(() => {});
  }

to

 void updateView() {
    if (mounted) {
      setState(() => {});
    }
  }

I/flutter ( 2032): The TreeViewController sending notification was: I/flutter ( 2032): Instance of 'TreeViewController' I/flutter ( 2032): ════════════════════════════════════════════════════════════════════════════════════════════════════ I/flutter ( 2032): ══╡ EXCEPTION CAUGHT BY FOUNDATION LIBRARY ╞════════════════════════════════════════════════════════ I/flutter ( 2032): The following assertion was thrown while dispatching notifications for TreeViewController: I/flutter ( 2032): setState() called after dispose(): _ListTreeViewState#b42b1(lifecycle state: defunct, not mounted) I/flutter ( 2032): This error happens if you call setState() on a State object for a widget that no longer appears in I/flutter ( 2032): the widget tree (e.g., whose parent widget no longer includes the widget in its build). This error I/flutter ( 2032): can occur when code calls setState() from a timer or an animation callback. I/flutter ( 2032): The preferred solution is to cancel the timer or stop listening to the animation in the dispose() I/flutter ( 2032): callback. Another solution is to check the "mounted" property of this object before calling I/flutter ( 2032): setState() to ensure the object is still in the tree. I/flutter ( 2032): This error might indicate a memory leak if setState() is being called because another object is I/flutter ( 2032): retaining a reference to this State object after it has been removed from the tree. To avoid memory I/flutter ( 2032): leaks, consider breaking the reference to this object during dispose().

Hi,

thanks for writing the plugin, it works quite well.

We came across the situation in which we need to udpate NodeData we have extended while using the same TreeViewController to keep nodes expanded / collapsed after the update.

I considered writing methods to update the node and implemented them in this fork https://github.com/archie-sh/list_treeview but its nicer to apply the logic on the custom objects on our app side and just notifying the tree that there has been a change.

I would suggest expsoing notifiyListeneres in a rebuild method. e.g.

void rebuild() { notifyListeners(); }

Regards.

Hey good job on building this package I have a use case where i need to set shrinkWrap property of ListView.the only thing i can do is to copy the file to my project and edit but it would be awesome to allow users to do so easly.

Kind regards!

I have added the toggleNodeOnTap property to the ListTreeView class to make it possible to toggle the node from a button press instead of clicking the node itself. I need this feature because in my application, clicking a node will trigger the Navigator to switch pages. To expand or collapse nodes I'm using an IconButton that calls TreeViewController.expandOrCollapse from the node widget (ListTile in my case).

when I dispose the controller & reset it with data. after that, I m using the parentOfItem() method to get parent data but it returns a Null check operator used on a null value.

The read me mentions these method in controller to insert nodes but they all seems need a parent. Is it possible to insert items at root level?

_controller.insertAtFront(dataNode, newNode);
//_controller.insertAtRear(dataNode, newNode);
//_controller.insertAtIndex(1, dataNode, newNode);

Hey,

we use BloC to handle our state of the View. After a navigation event and returning to the view that contains the ListTreeView i reload the Data that is displayed by the ListTreeView.

If i set the treeData() a second time, the itemBuilder of the ListTreeView uses the old data of the initial TreeData() call.

How can i force the ListTreeView to reload the Data so changes are displayed? In my example i have an item with an int value that is display in the ListTreeView. Inside the itemBuilder i do something like this:

treeViewController.treeData(lChecklistNodeData);
return ListTreeView(
      controller: treeViewController,
      itemBuilder: (BuildContext context, NodeData data) {
        ChecklistNodeData item = data as ChecklistNodeData;

return Text('${item.intValue}');
});

As i said this is working fine the first time, but when i reload the data and the build() method is retriggered the Data in the itemBuilder function is not refreshed. I checked the data i pass to treeData() and it is definitly the new data. But still the itemBuilder uses the data of the first set of treeData().

I managed to refresh the Parent items by resetting the TreeViewController treeViewController = new TreeViewController();

but this leads to only the parents showing up. All child elements are missing after the second rebuild if i do this.

Thanks in advance

Hi,

I'm this widget and so far, it works flawlessly. But I see that, as the number levels in the tree go higher - eventually I see the overflow error on the right of the tree.

How can the tree view auto scroll to the right as the depth of the tree increases. Can you please point to an example for the same?