Adding Nodes

Learn how to add nodes to your TeeTree hierarchies using various methods

Overview

TeeTree provides multiple ways to add nodes to your tree structure. You can add root nodes, child nodes, and sibling (brother) nodes using simple method calls.

Adding Root Nodes

The simplest way to add a node is using the Add method without a parent:

// Add a root node (without parent)
MyRoot := Tree1.Add('This is a Root node');

You can also use the AddRoot method explicitly:

// Add one root node
Tree1.AddRoot('Root num: ' + IntToStr(Tree1.Roots.Count + 1));

Adding Child Nodes

There are several ways to add child nodes to an existing parent:

Method 1: Using AddChild

// Add a child node to a parent
MyRoot.AddChild('This is a child node.');

Method 2: Using Add with Parent Parameter

// Another way to add a child node
Tree1.Add('Another child node', MyRoot);

Method 3: Using Shapes.AddChild

// Adding a child using the Shapes collection
Tree1.Shapes.AddChild(MyNode, '7.AddChild');

Adding Sibling Nodes

To add a node at the same level as an existing node:

// Add a brother (sibling) node
MyNode.AddBrother('Brother node');

Chaining Node Creation

You can create multiple levels of nodes in a single statement:

// Recursive way - create child and grandchild in one line
MyRoot.AddChild('Third child.').AddChild('Hello');

// Adding nodes and children in the same line
Tree1.Add('10.Another Root').Add('Child').Add('Sub-Child');

Adding Nodes at Specific Positions

You can specify X and Y coordinates when adding nodes:

// Add a node at specific coordinates (X=200, Y=100)
Tree1.Add(200, 100, 'At 100,100', nil);

Complete Example

Here’s a complete example showing various ways to add nodes:

procedure TAddMethodsForm.FormCreate(Sender: TObject);
var
  MyNode: TTreeNodeShape;
  AnotherNode: TTreeNodeShape;
  MyRoot: TTreeNodeShape;
begin
  // Add a root node
  MyRoot := Tree1.Add('This is a Root node');

  // Add children nodes
  MyRoot.AddChild('This is a child node.');
  Tree1.Add('Another child node', MyRoot);

  // Recursive way
  MyRoot.AddChild('Third child.').AddChild('Hello');

  // Expand root to show children
  MyRoot.Expanded := True;

  // Add multiple nodes
  MyNode := Tree1.Add('MyNode');
  MyNode.Add('Children');
  MyNode.AddBrother('Brother');

  // Chain multiple levels
  Tree1.Add('Another Root').Add('Child').Add('Sub-Child');
end;

Interactive Example: Add Buttons

Create an interactive form that allows users to add nodes dynamically:

procedure TAddChildrenForm.ButtonAddChildClick(Sender: TObject);
var
  Node: TTreeNodeShape;
begin
  // Add one child node and select it
  with Tree1.Selected.First do
  begin
    Node := AddChild('Child num: ' + IntToStr(Count + 1));
    Expanded := True;  // Expand to show the new child
  end;

  // Select the newly created node
  Tree1.Selected.Clear;
  Node.Selected := True;
end;

procedure TAddChildrenForm.ButtonAddBrotherClick(Sender: TObject);
var
  Node: TTreeNodeShape;
begin
  // Add one brother node and select it
  with Tree1.Selected.First do
  begin
    if Assigned(Parent) then
    begin
      Node := AddBrother('Child num: ' + IntToStr(Parent.Count + 1));
      Expanded := True;
    end
    else  // node has no parent, add as root
      Node := Tree1.AddRoot('Root num: ' + IntToStr(Tree1.Roots.Count + 1));
  end;

  Tree1.Selected.Clear;
  Node.Selected := True;
end;

Key Points

• Use Add or AddRoot for root nodes without parents
• Use AddChild to add child nodes to a parent
• Use AddBrother to add sibling nodes at the same level
• Chain method calls to create multiple levels efficiently
• Set Expanded := True to show newly added children
• Preserve node references when you need to manipulate them later

Removing Nodes

To remove nodes from the tree:

// Destroy node completely
Tree1.Selected.First.Free;

// Remove from parent (make it a root node)
Tree1.Selected.First.Parent := nil;