TreeItemView constructor
      const
      TreeItemView({ 
    
- Key? key,
- required Widget child,
- Widget? leading,
- Widget? trailing,
- VoidCallback? onPressed,
- VoidCallback? onDoublePressed,
- ValueChanged<bool> ? onExpand,
- bool? expandable,
- FocusNode? focusNode,
Creates a TreeItemView with comprehensive tree item functionality.
Configures a tree item widget with interaction support, optional expansion, and customizable leading/trailing elements.
Parameters:
- key(Key?): Widget identifier for the widget tree
- child(Widget, required): Main content widget for the tree item
- leading(Widget?, optional): Widget displayed before the content
- trailing(Widget?, optional): Widget displayed after the content
- onPressed(VoidCallback?, optional): Callback for press/click events
- onDoublePressed(VoidCallback?, optional): Callback for double-click events
- onExpand(ValueChanged
- expandable(bool?, optional): Whether the item can be expanded
- focusNode(FocusNode?, optional): Focus node for keyboard navigation
Example:
TreeItemView(
  leading: Icon(Icons.folder),
  trailing: Badge(child: Text('3')),
  expandable: true,
  onPressed: () => handleSelection(),
  onDoublePressed: () => handleOpen(),
  onExpand: (expanded) => handleExpansion(expanded),
  child: Text('Project Folder'),
)
Implementation
const TreeItemView({
  super.key,
  required this.child,
  this.leading,
  this.trailing,
  this.onPressed,
  this.onDoublePressed,
  this.onExpand,
  this.expandable,
  this.focusNode,
});