Problems implementing a custom TreeView grid editor

[Karl B]

I'm trying to implement a custom TreeView editor on the GridView and I'm experiencing two problems.
1. My editor is confined to the size of the cell and it needs to be much larger than that
2. When I attempt to data bind the control nothing is displayed.

Sample code:

public class TreeEditor : BaseGridEditor
      {

      protected override RadElement CreateEditorElement ()
          {
          RadTreeViewElement treeViewElement = new RadTreeViewElement ();
          //BindData (treeViewElement); // This doesn't work
          LoadData (treeViewElement); // This displays data
          return treeViewElement;
          }

      private static void BindData(RadTreeViewElement treeViewElement)
      {
          List<NodeData> Nodes = new List<NodeData>();
          NodeData root = new NodeData() { ID = 0 };
          root.Children.Add(new NodeData() { ID = 1 });
          root.Children.Add(new NodeData() { ID = 2 });
          Nodes.Add(root);
          treeViewElement.DataSource = Nodes;
          treeViewElement.DisplayMember = "ID\\ID";
          treeViewElement.ChildMember = "Nodes\\Children";
      }

      private static void LoadData (RadTreeViewElement treeViewElement)
          {
          RadTreeNode root = treeViewElement.Nodes.Add ("Root");
          root.Nodes.Add ("First", 1);
          root.Nodes.Add ("Second", 1);
          }

      public override object Value
          {
          get
              {
              RadTreeViewElement editor = (RadTreeViewElement) this.EditorElement;
              if (editor.SelectedNode == null)
                  return string.Empty;

              return editor.SelectedNode.ToString ();
              }
          set
              {
              //TODO: ?
              }
          }
      }

[Dess | Tech Support Engineer, Principal]

Hello Karl,

Thank you for writing.

I have prepared a sample code snippet demonstrating an approach how to implement custom editor with RadTreeView. In order avoid difference in rows height when the editor is active, the custom tree view editor is placed in a popup:

public Form1()
{
    InitializeComponent();
    this.radGridView1.EditorRequired += radGridView1_EditorRequired;
    this.radGridView1.CellEditorInitialized += radGridView1_CellEditorInitialized;

    GridViewComboBoxColumn comboColumn = new GridViewComboBoxColumn("Description");
    comboColumn.FieldName = "Description";
    comboColumn.DisplayMember = "Description";
    comboColumn.ValueMember = "Description";
    comboColumn.DataSource = accounts1.Concat(accounts2).ToList();
    this.radGridView1.Columns.Add(comboColumn);

    this.radGridView1.AutoGenerateColumns = false;
    List<Account> items = new List<Account>();
    foreach (Account a in accounts1.Concat(accounts2).ToList())
    {
        items.Add(new Account(a.AccountID, a.Description));
    }
    this.radGridView1.DataSource = items;
}

private void radGridView1_CellEditorInitialized(object sender, GridViewCellEventArgs e)
{
    TreeEditor editor = e.ActiveEditor as TreeEditor;
    if (editor != null)
    {
        TreeEditorElement treeElement = editor.EditorElement as TreeEditorElement;
        treeElement.TreeView.BindingContext = this.radGridView1.BindingContext;
        treeElement.TreeView.DataSource = accountTypes;

        treeElement.TreeView.DisplayMember = "Title\\Description";
        treeElement.TreeView.ChildMember = "AccountTypes\\Accounts";
        treeElement.TreeView.FullRowSelect = true;

        treeElement.TreeView.SelectedNodes.Clear();

        string text = this.radGridView1.CurrentCell.Value + "";

        foreach (RadTreeNode n in treeElement.TreeView.Nodes)
        {
            RadTreeNode selected = GetNodeByName(n, text);
            if (selected != null)
            {
                selected.Current = true;
                selected.Selected = true;

                selected.Expanded = true;
                if (selected.Level > 0)
                {
                    selected.Parent.Expanded = true;
                }
            }
        }
    }
}

private static RadTreeNode GetNodeByName(RadTreeNode n, string t)
{
    RadTreeNode foundNode = null;
    if (n.Text == t)
    {
        foundNode = n;
    }
    else
    {
        foreach (RadTreeNode node in n.Nodes)
        {
            foundNode = GetNodeByName(node, t);
            if (foundNode != null)
            {
                break;
            }
        }
    }
    return foundNode;
}

void radGridView1_EditorRequired(object sender, EditorRequiredEventArgs e)
{
    if (this.radGridView1.CurrentColumn.Name == "Description")
    {
        e.EditorType = typeof(TreeEditor);
    }
}

public class TreeEditor: BaseGridEditor
{
    public override object Value

    {
        get

        {
            TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;

            SelectedTreeNodeCollection treeNodes = treeElement.TreeView.SelectedNodes;
            StringBuilder sb = new StringBuilder();
            foreach (RadTreeNode node in treeNodes)
            {
                sb.AppendFormat("{0}", node.Text);
            }
            return sb.ToString();
        }

        set

        {
            string text = ((GridComboBoxCellElement)this.OwnerElement).Value + "";

            TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;

            foreach (RadTreeNode n in treeElement.TreeView.Nodes)
            {
                RadTreeNode selected = GetNodeByName(n, text);
                if (selected != null)
                {
                    selected.Selected = true;
                }
            }
        }
    }

    public override void BeginEdit()
    {
        base.BeginEdit();

        TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;
        treeElement.Button.DropDownButtonElement.DropDownMenu.PopupElement.MinSize = new Size(300, 300);
        treeElement.Button.ShowDropDown();
    }

    protected override RadElement CreateEditorElement()
    {
        return new TreeEditorElement();
    }

    private RadTreeNode FindTreeNode(RadTreeNode node, string value)
    {
        if (node.Text == value)
        {
            return node;
        }

        foreach (RadTreeNode subNode in node.Nodes)
        {
            RadTreeNode found = FindTreeNode(subNode, value);

            if (found != null)
            {
                return found;
            }
        }

        return null;
    }
}

public class TreeEditorElement: RadHostItem
{
    public TreeEditorElement() : base(new RadDropDownButton())

    {
        this.Button.Items.Add(new TreeMenuItem());
        this.TreeView.MultiSelect = true;
        TreeView.Nodes.Add(new RadTreeNode("Root"));
        TreeView.Nodes[0].Nodes.Add(new RadTreeNode("Item 1"));
        TreeView.Nodes[0].Nodes.Add(new RadTreeNode("Item 2"));
        TreeView.ExpandAll();
    }

    public RadDropDownButton Button

    {
        get
        {
            return (RadDropDownButton)this.HostedControl;
        }
    }

    public RadTreeView TreeView

    {
        get
        {
            return (RadTreeView)((RadMenuHostItem)this.Button.Items[0]).HostedControl;
        }
    }
}

public class TreeMenuItem: RadMenuHostItem
{
    public TreeMenuItem() : base(new RadTreeView())
    {
    }

    protected override SizeF MeasureOverride(SizeF availableSize)
    {
        base.MeasureOverride(availableSize);

        return new SizeF(100, 300);
    }
}

public class Account
{
    public int AccountID { get; set; }

    public string Description { get; set; }

    public Account()
    {
    }

    public Account(int accountID, string description)
    {
        this.AccountID = accountID;
        this.Description = description;
    }
}

public class AccountType
{
    public int AccountTypeID { get; set; }

    public string Title { get; set; }

    public List<Account> Accounts { get; set; }

    public AccountType(int accountTypeID, string title, List<Account> accounts)
    {
        this.AccountTypeID = accountTypeID;
        this.Title = title;
        this.Accounts = accounts;
    }
}

static List<Account> accounts1 = new List<Account>()
{
    new Account(1,"Rent Expence description 1"),
    new Account(2, "Rent Expence description 2")
};

static List<Account> accounts2 = new List<Account>()
{
    new Account(1,"Investment Income description 1"),
    new Account(2, "Investment Income description 2")
};

List<AccountType> accountTypes = new List<AccountType>()
{
    new AccountType(1,"Expence",accounts1),
    new AccountType(2,"Income ",accounts2),
};

I hope this information helps. Should you have further questions, I would be glad to help.
 
Regards,
Desislava
Telerik

 

 

[Karl B]

That's great thanks. I noticed that when I hit enter it closes the popup but still shows the dropdown button. Any suggestions on how I can hide this button without causing an event leak in this scenario?

[Dess | Tech Support Engineer, Principal]

Hello Karl,

Thank you for writing back.

The drop down is displayed as the RadTreeView is placed in a RadMenuHostItem inside a RadHostItem. You can deal with the undesired behavior that when pressing Enter key the popup is closed, but the editor is still active. Here is the modified code snippet for the TreeEditor class:

public class TreeEditor: BaseGridEditor
{
    //some other code
    public override void BeginEdit()
    {
        base.BeginEdit();

        TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;
        treeElement.Button.DropDownButtonElement.DropDownMenu.PopupElement.MinSize = new Size(300, 300);
        treeElement.Button.ShowDropDown();
        treeElement.Button.DropDownClosed += Button_DropDownClosed;
    }

    public override bool EndEdit()
    {
        bool result = base.EndEdit();
        TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;
        treeElement.Button.DropDownClosed -= Button_DropDownClosed;
        return result;
    }

    private void Button_DropDownClosed(object sender, EventArgs e)
    {
        RadDropDownButton ddButton = sender as RadDropDownButton;
        if (ddButton != null)
        {
            RadGridView grid = ddButton.Parent as RadGridView;
            if (grid != null)
            {
                grid.EndEdit();
            }
        }
    }
    //some other code
}

I hope this information helps. If you have any additional questions, please let me know.

Regards,
Desislava
Telerik

 

 

[Karl B]

Thank you so much for your hard work.

[Karl B]

How can this be modified so that the tree captures the mouse wheel to scroll the treeview? Currently the mouse wheel will close the editor.

[Dess | Tech Support Engineer, Principal]

Hello Karl,

Thank you for writing back.

In order to force the RadTreeView to accept MouseWheel messages for scrolling, you need to focus the TreeEditorElement.TreeView in the TreeEditor.BeginEdit event. Afterwards, you should cancel the TreeEditorElement.Button.DropDownButtonElement.DropDownMenu.DropDownClosing event in order to keep the popup opened while scrolling. You can use a flag to indicate whether the drop-down should be closed. Here is just a an example demonstrating how to close the popup when selecting a node:

public override void BeginEdit()
{
    base.BeginEdit();

    TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;

    treeElement.TreeView.Focus();
    isSelected = false;
    treeElement.Button.DropDownButtonElement.DropDownMenu.DropDownClosing -= DropDownMenu_DropDownClosing;
    treeElement.Button.DropDownButtonElement.DropDownMenu.DropDownClosing += DropDownMenu_DropDownClosing;
    treeElement.TreeView.SelectedNodeChanged -= TreeView_SelectedNodeChanged;
    treeElement.TreeView.SelectedNodeChanged += TreeView_SelectedNodeChanged;
}

bool isSelected = false;

private void TreeView_SelectedNodeChanged(object sender, RadTreeViewEventArgs e)
{
    isSelected = true;
    TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;
    treeElement.Button.DropDownButtonElement.DropDownMenu.ClosePopup(RadPopupCloseReason.Mouse);
}

private void DropDownMenu_DropDownClosing(object sender, RadPopupClosingEventArgs args)
{
    RadDropDownButtonPopup popup = sender as RadDropDownButtonPopup;
    if (popup != null && !isSelected)
    {
        args.Cancel = true;
    }
}

I hope this information helps. If you have any additional questions, please let me know.

Regards,
Dess
Telerik

[Karl B]

In the last example how can I force an EndEdit on the grid after the popup has closed? Thanks.

[Hristo]

Hi Karl,

Thank you for writing back.

In order to accomplish this task, you would need to handle the DropDownClosed event of the Button element and in the handler call the EndEdit method of the grid. Please see my code snippet below: 

public override void BeginEdit()
{
    base.BeginEdit();

    TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;

    //more code
    treeElement.Button.DropDownClosed += Button_DropDownClosed;
}

private void Button_DropDownClosed(object sender, EventArgs e)
{
    RadDropDownButton ddButton = sender as RadDropDownButton;
    if (ddButton != null)
    {
        RadGridView grid = ddButton.Parent as RadGridView;
        if (grid != null)
        {
            grid.EndEdit();
        }
    }
}

I hope this helps. Should you have further questions please do not hesitate to write back.

Regards,
Hristo Merdjanov
Telerik

[Karl B]

I can't get this to work with the mouse wheel changes. Using the code below blanks out the cell when I select an item on the tree

public class TreeEditor : BaseGridEditor
    {
    public override object Value
        {
        get
            {
            TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;
            SelectedTreeNodeCollection treeNodes = treeElement.TreeView.SelectedNodes;
            StringBuilder sb = new StringBuilder();

            foreach (RadTreeNode node in treeNodes)
                {
                sb.AppendFormat("{0}", node.Text);
                }

            return sb.ToString();
            }
        set
            {
            string text = ((GridComboBoxCellElement)this.OwnerElement).Value + "";
            TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;
            }
        }

    public override void BeginEdit()
        {
        base.BeginEdit();

        TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;
        treeElement.Button.DropDownButtonElement.DropDownMenu.PopupElement.MinSize = new Size(300, 300);
        treeElement.Button.ShowDropDown();

        //mouse wheel changes-
        treeElement.TreeView.Focus();
        isSelected = false;
        treeElement.Button.DropDownButtonElement.DropDownMenu.DropDownClosing -= DropDownMenu_DropDownClosing;
        treeElement.Button.DropDownButtonElement.DropDownMenu.DropDownClosing += DropDownMenu_DropDownClosing;
        treeElement.TreeView.SelectedNodeChanged -= TreeView_SelectedNodeChanged;
        treeElement.TreeView.SelectedNodeChanged += TreeView_SelectedNodeChanged;
        // end mouse wheel

        treeElement.Button.DropDownClosed += Button_DropDownClosed;
        }

    private bool isSelected;
    private void TreeView_SelectedNodeChanged(object sender, RadTreeViewEventArgs e)
        {
        isSelected = true;
        TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;
        treeElement.Button.DropDownButtonElement.DropDownMenu.ClosePopup(RadPopupCloseReason.Mouse);


        RadGridView grid = e.TreeView.Parent as RadGridView;
        if (grid != null)
            {
            grid.EndEdit();
            }
        }

    private void DropDownMenu_DropDownClosing(object sender, RadPopupClosingEventArgs args)
        {
        RadDropDownButtonPopup popup = sender as RadDropDownButtonPopup;
        if (popup != null && !isSelected)
            {
            args.Cancel = true;
            }
        }

    private void Button_DropDownClosed(object sender, EventArgs e)
        {
        RadDropDownButton ddButton = sender as RadDropDownButton;
        if (ddButton != null)
            {
            RadGridView grid = ddButton.Parent as RadGridView;
            if (grid != null)
                {
                grid.EndEdit();
                }
            }
        }

    protected override RadElement CreateEditorElement()
        {
        return new TreeEditorElement();
        }
    }

[Hristo]

Hi Karl,

Thank you for writing back.

Closing the dropdown before editing the cell does not pass properly the selected value. I am sending you attached my modified project, allowing scrolling inside the tree and node selection.

I hope that it would fit your scenario. Should you have further questions please do not hesitate to write back.

Regards,
Hristo Merdjanov
Telerik

[Karl B]

Thanks for your continued help. When I run your project the popup tree closes when I use my scroll wheel. 

This has been going on for a while so to review I need a combination of all these behaviors.

1. Click on cell -> tree pops up on first click
2. Scroll mouse wheel ->  scrolls pop up tree
3. Click on tree item -> tree is closed and cell is filled. No drop down button displayed

I believe all of issues have been addressed in this thread but I can't figure out how to make them all work at the same time.

 

Note- In order to run the solution I had to remove the "Source" directory from the project and in VS right clicked on the project and chose Telerik UI For Winforms/Convert To Telerik Windows Form Application.

 Also I added extra data to make the mouse scrolling more obvious-

static List<Account> accounts1 = new List<Account>()
{
    new Account(1,"Rent Expence description 1"),
    new Account(2,"Rent Expence description 1"),
    new Account(3,"Rent Expence description 1"),
    new Account(4,"Rent Expence description 1"),
    new Account(5,"Rent Expence description 1"),
    new Account(6,"Rent Expence description 1"),
    new Account(7,"Rent Expence description 1"),
    new Account(8,"Rent Expence description 1"),
};

static List<Account> accounts2 = new List<Account>()

{
    new Account(1,"Investment Income description 1"),
    new Account(2, "Investment Income description 2"),
    new Account(3,"Investment Income description 1"),
    new Account(4,"Investment Income description 1"),
    new Account(5,"Investment Income description 1"),
    new Account(6,"Investment Income description 1"),
    new Account(7,"Investment Income description 1"),
    new Account(8,"Investment Income description 1"),
    new Account(9,"Investment Income description 1")
};

[Hristo]

Hi Karl,

Thank you for writing back.

I am sending you attached the sample project which I believe addresses all of the features you would like to implement. 

Besides the project, I am also sending you a gif file showing the result on my end.

I hope this helps. Should you have further questions please do not hesitate to write back.

Regards,
Hristo Merdjanov
Telerik

[Karl B]

Sorry but this is not doing everything correctly. It does not scroll with the mouse wheel. In your gif I see you are clicking and dragging the scroll bars.
If I apply Dess's solution from June 08 to your latest project (link and new code shown below), scrolling with the mousewheel works but I need the window to close when clicking outside the popup or when the escape button is pressed as it did before adding these changes. Now it will only close when clicking on the tree.

 

http://www.telerik.com/forums/problems-implementing-a-custom-treeview-grid-editor#HcsEPKPbXUmdDY6CPANs-Q

 

public override void BeginEdit()
{
    base.BeginEdit();

    TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;
    treeElement.Button.Visible = false;

    treeElement.TreeView.Focus();
    treeElement.TreeView.SelectedNodeChanged -= TreeView_SelectedNodeChanged;
    treeElement.TreeView.SelectedNodeChanged += TreeView_SelectedNodeChanged;

// begin mouse wheel changes
    isSelected = false;
    treeElement.Button.DropDownButtonElement.DropDownMenu.DropDownClosing -= DropDownMenu_DropDownClosing;
    treeElement.Button.DropDownButtonElement.DropDownMenu.DropDownClosing += DropDownMenu_DropDownClosing;
}
bool isSelected = false;
private void DropDownMenu_DropDownClosing(object sender, RadPopupClosingEventArgs args)
    {
    RadDropDownButtonPopup popup = sender as RadDropDownButtonPopup;
    if (popup != null && !isSelected)
        {
        args.Cancel = true;
        }
    }

private void TreeView_SelectedNodeChanged(object sender, RadTreeViewEventArgs e)
    {
    isSelected = true;
// end mouse wheel changes
    TreeEditorElement treeElement = this.EditorElement as TreeEditorElement;
    ((RadDropDownButton)treeElement.HostedControl).DropDownButtonElement.PerformClick();
    treeElement.Button.DropDownButtonElement.DropDownMenu.ClosePopup(RadPopupCloseReason.Mouse);
}

[Hristo]

Hi Karl,

Thank you for writing back.

I extended the sample project to include the custom solution regarding the scrolling behavior. The popup now closes when the Esc key is pressed and also if you click somewhere outside of the editor.

Besides the project I am also sending you a gif file showing the result on my end.

I hope this helps. Should you have further questions please do not hesitate to write back.

Regards,
Hristo Merdjanov
Telerik