Siticone Tree View

The SiticoneTreeView is an enhanced version of the standard Windows Forms TreeView control. It introduces Tri-State Checkboxes (automatically checking/unchecking parent and child nodes) and a robust event system that provides detailed information about node interactions, state changes, and bulk updates.

Behavior & Checkboxes

Core properties controlling the hierarchical checkbox logic and interaction.

Property	Type	Description & Usage Example
`CheckBoxes`	bool	treeView.CheckBoxes = true; Enables or disables checkboxes next to each tree node. Must be true for Tri-State logic to work.
`EnableTriStateCheckboxes`	bool	treeView.EnableTriStateCheckboxes = true; Enables smart checking logic: Checking a parent automatically checks all children (Cascade Down). Unchecking a parent unchecks all children. Checking all children automatically checks the parent (Cascade Up).
`ItemHeight`	int	treeView.ItemHeight = 35; Sets the vertical spacing for each node, allowing for touch-friendly layouts.
`Indent`	int	treeView.Indent = 25; The horizontal indentation distance for child nodes.

Public Methods

Helper methods for programmatic control over nodes.

SetNodeChecked(TreeNode, bool, bool)

// Programmatically checks a node and triggers the associated events.
// node: The target TreeNode.
// isChecked: True to check, False to uncheck.
// fireEvents: Whether to raise NodeStateChanged events (default: true).
siticoneTreeView1.SetNodeChecked(myNode, true, true);

GetNodeInfo(TreeNode)

// Retrieves detailed state information about a specific node.
// Returns a NodeStateChangeEventArgs object containing level, parent, children, etc.
var info = siticoneTreeView1.GetNodeInfo(selectedNode);
Console.WriteLine($"Node Level: {info.NodeLevel}, Child Count: {info.ChildCount}");

Events

The control provides a rich set of events that offer far more detail than standard TreeView events. They use custom event arguments like NodeInteractionEventArgs and TreeStateChangeEventArgs.

Event	Description
`NodeStateChanging`	Fired before a checkbox state changes. Can be cancelled. Args: `CurrentCheckedState`, `ProposedCheckedState`, `Cancel`.
`NodeStateChanged`	Fired after a single node's checkbox state has changed. Args: `OldCheckedState`, `NewCheckedState`, `ChangeSource` (UserClick, Programmatic, Cascade).
`TreeStateChanged`	Fired when a bulk update occurs (e.g., checking a parent cascades to 50 children). Args: `ChangedNodes` (List), `TotalNodesAffected`, `TriggerNode`.
`NodeInteraction`	A unified event for all user interactions (Click, DoubleClick, Expand, Collapse, Select). Args: `InteractionType`, `ClickLocation`, `MouseButton`.
`NodeTextClicked`	Fired specifically when the user clicks the text label of a node (excluding the checkbox area).
`CheckboxClicked`	Fired specifically when the user clicks the checkbox area of a node.

Detailed Usage Examples

Example 1: Handling Tri-State Changes

Logs when a user checks a parent node, showing how many child nodes were affected by the cascade.

C# - Bulk Update Event

private void siticoneTreeView1_TreeStateChanged(object sender, TreeStateChangeEventArgs e)
{
                if (e.ChangeType == TreeStateChangeType.CascadeDown)
    {
                Console.WriteLine($"User clicked parent node '{e.TriggerNode.Text}'.");
                Console.WriteLine($"Total nodes updated: {e.TotalNodesAffected}");
                Console.WriteLine($"Nodes checked: {e.CheckedNodesCount}");
                Console.WriteLine($"Nodes unchecked: {e.UncheckedNodesCount}");
    }
}

Example 2: Preventing Node Check

Uses the NodeStateChanging event to prevent users from unchecking specific "locked" nodes.

C# - Cancel Event

private void siticoneTreeView1_NodeStateChanging(object sender, NodeStateChangingEventArgs e)
{
                // Check a custom tag or property
                if (e.Node.Tag != null && e.Node.Tag.ToString() == "Locked")
    {
                // Prevent unchecking
                if (!e.ProposedCheckedState) 
        {
            e.Cancel = true;
                MessageBox.Show("This node cannot be disabled.");
        }
    }
}

Example 3: Detailed Click Handling

Differentiates between clicking the text vs. clicking the checkbox.

C# - Interaction Events

private void siticoneTreeView1_NodeTextClicked(object sender, NodeInteractionEventArgs e)
{
                // Triggered only when clicking the text label
                Console.WriteLine($"Opening details for: {e.NodeText}");
                OpenDetailsPanel(e.Node);
}

private void siticoneTreeView1_CheckboxClicked(object sender, NodeInteractionEventArgs e)
{
                // Triggered only when clicking the checkbox
                Console.WriteLine($"Toggling selection for: {e.NodeText}");
}

Example 4: Lazy Loading with Expansion Event

Uses the NodeExpandedDetailed event to load child nodes dynamically only when requested.

C# - Lazy Load

private void siticoneTreeView1_NodeExpandedDetailed(object sender, NodeInteractionEventArgs e)
{
                // Check if node has a dummy child indicating it needs loading
                if (e.Node.Nodes.Count == 1 && e.Node.Nodes[0].Text == "...")
    {
        e.Node.Nodes.Clear();
        
                // Load actual data
                var data = GetChildrenFor(e.Node.Tag);
                foreach (var item in data)
        {
                var newNode = new TreeNode(item.Name);
            newNode.Tag = item.Id;
            e.Node.Nodes.Add(newNode);
        }
    }
    
                Console.WriteLine($"Node '{e.NodeText}' expanded at {e.InteractionTime}");
}