Added Tree items won't show when tree view is expanded

Question

I have an application for iOS/android developed with Delphi XE8 FMX.

In the app I have a treeview with tree items. When I add a tree item to a node when that same parent node is expanded, then I need to either a) collapse and expand the parent node from the app itself or b) do that programmatically ( see below ) to get the tree item to show right away. I tried calling 'repaint', but that did not work. Is there a better work around? Sometimes when calling the collapseall, expandall like I do below, then some of the tree nodes become unresponsive ( non-selectable ) until after I first select the top most tree node.

procedure TnewForm.AddTreeItemClick(Sender: TObject);
var
  t:TTreeViewItem;
begin
  t:=TTreeViewItem.Create(nil);
  t.Text:=NewTreeItemEdit.Text;
  if TreeView.Selected<>nil then
  begin
    t.Parent:=TreeView.Selected
  end else
    t.Parent:=TreeView;
  //Treeview.Repaint;
  treeview.CollapseAll;
  treeview.ExpandAll;
  NewTreeItemEdit.Text:='';
end;

How can I make dynamically added tree items show right away without collapsing/expanding the treeview?

Answer 1

You could try this.

procedure TnewForm.AddTreeItemClick(Sender: TObject);
var
  t:TTreeViewItem;
begin
  t:=TTreeViewItem.Create(nil);
  t.Text:=NewTreeItemEdit.Text;
  if TreeView.Selected<>nil then
  begin
    t.Parent:=TreeView.Selected
  end else
    t.Parent:=TreeView;
  //Treeview.Repaint;
  treeview.Selected := t;
  NewTreeItemEdit.Text:='';
end;

Answer 2

Dsm's solution works, but changes the TreeView's selection. If you want the selection to remain unchanges, but instead just that the added item is instantly visible, then expand its parent:

procedure TForm1.AddTreeItemClick(Sender: TObject);
var
  T :TTreeViewItem;
begin
  T := TTreeViewItem.Create(nil);
  T.Text := NewTreeItemEdit.Text;
  if TreeView.Selected <> nil then
  begin
    T.Parent := TreeView.Selected;
    TreeView.Selected.IsExpanded := True;
  end else
    T.Parent := TreeView;
  NewTreeItemEdit.Text := '';
end;

Answer 3

Similar problem with Windows / XE8. The workaround that did it for me:

  if Assigned(TV.Selected) then
    begin
      N := TTreeviewItem.Create(Self);
      N.Text := 'Another child';
      N.Parent := TV.Selected;
      N.IsExpanded := TRUE; // This seems to do the trick
    end;

Hopefully this will get attention in next releases.