B4J Question Treeview.multiselect - there must be an easier way

[johnmie]

My USB-Stick catalogue app contains a standard treeview of folders and files with options to view, delete or move files. This works fine when selecting a single entry, but with multiple selections (with ctrl or shift) it gets very complicated.

For now I use a workaround with two maps + last and previously selected items, but there must be an easier way (e.g. with JavaObject - selected.items as list or array), but I don't know how.

Can you help me? Many thanks in advance.
john m.

 

[Chris2]

There may be other/better ways but when using a TreeView to make selections I use CheckboxTreeItems.

TreeView.SetCheckBoxesMode

For Each ParentName as String in ParentNames 'ParentNames is a list'

    Dim pItem As CheckboxTreeItem
    pItem.Initialize("pi", ParentName)
   
    For Each ChildName as String in ChildNames 'ChildNames is a list'

        Dim cItem As CheckboxTreeItem
        cItem.Initialize("ci", ChildName)
        pItem.Children.Add(cItem)
   
    Next

   TreeView.Root.Children.add(pItem)

Next

Then use a B4XSet to store the selections in the ci_CheckedChange event

Private Sub ci_CheckedChange(checked As Boolean)  
   
    Dim cti As CheckboxTreeItem = Sender
    If checked Then
        setCheckedItems.Add(cti.Text)
    Else
        If setCheckedItems.Contains(cti.Text) Then setCheckedItems.Remove(cti.Text)
    End If

End Sub

[untested code typed on the fly!]

 

[johnmie]

Thanks, Chris2 for your feedback.
since I already found (on the forum) items like

• jo.RunMethodJO("getSelectionModel", Null).RunMethod("clearSelection", Null) and
• jo.InitializeStatic("java.io.File").RunMethod("listRoots", Null)

I was convinced there was also a Java RunMethod to list all the selected rows. But which?

 

[Chris2]

My knowledge of JavaObject is limited, but based on this and this, try these:

jo.RunMethodJO("getSelectionModel", Null).RunMethod("getSelectedItems", Null)
jo.RunMethodJO("getSelectionModel", Null).RunMethod("getSelectedIndices", Null)

[I'm sure there's someone out there who will correct this if it's wrong]

 

[johnmie]

I knew there is a better way, thank you for pointing in the right direction!
"getSelectedItems" did it and saved about 80 lines of code and on top of it I can use it on two different Treeviews (see code below).

Sub SelList(TW As TreeView)
selectedList.initialize
Dim jo As JavaObject = TW
selectedList = jo.RunMethodJO("getSelectionModel", Null).RunMethod("getSelectedItems", Null)
For i = 0 To selectedList.Size-1
Log(selectedList.Get(i).As(TreeItem).text)
Next
End Sub

Best, john m.