TTree - TeeTree

Overview

TTree (and its base class TCustomTree) is the main visual component in TeeTree. It maintains a network-hierarchy of nodes, similar to Microsoft TreeView, but with enhanced features. Each node is a full standalone component with properties, methods, and events.

Class Hierarchy

TCustomTeePanelExtended
  └─ TCustomTree
      └─ TTree

Key Features

Hierarchical node structure with parent-child relationships
Visual connections between nodes
Multiple selection support
Drag and drop functionality
Zoom and pan capabilities
Grid display options
Custom node shapes and styles
Database integration (via TDBTree)

Properties

Core Properties

Roots

TNodeShapeList

List of root-level nodes in the tree. Root nodes have no parent.

Shapes

TTreeShapeList

Collection of all nodes in the tree, regardless of hierarchy.

Selected

TSelectedShapeList

List of currently selected nodes and selection formatting options.

Connections

TTreeConnectionList

List of all connection objects that link nodes together.

Display Properties

ShowText

Boolean

default:"True"

When True, node text is displayed.

ShowImages

Boolean

default:"True"

When True, node images are displayed.

ShowHintShapes

Boolean

default:"True"

When True, shows hints when hovering over nodes.

ShowRootCross

Boolean

default:"True"

When True, displays expand/collapse cross-box for root nodes.

BufferedDisplay

Boolean

default:"True"

When True, uses double-buffering for smoother display.

Interaction Properties

AllowDelete

Boolean

default:"True"

When True, allows users to delete nodes using the Delete key.

AllowResize

Boolean

default:"True"

When True, allows users to resize nodes by dragging handles.

ReadOnly

Boolean

default:"False"

When True, prevents editing of node positions and text.

SingleSelection

Boolean

default:"True"

When True, only one node can be selected at a time.

SnapToGrid

Boolean

default:"True"

When True, nodes snap to grid when moved.

Keyboard navigation style: tnExplorer, tnNearest, tnNone, or tnCircularExplorer.

Mouse wheel behavior: wnSelection, wnScrollVert, wnScrollHoriz, wnZoom, or wnNone.

Visual Components

CrossBox

TTreeNodeCrossBox

Configuration for the expand/collapse cross-box displayed on nodes with children.

Grid

TTreeGrid

Grid display options including step size, color, and visibility.

HotTrack

TTreeHotTrack

Highlight settings when hovering over nodes.

Page

TTreePage

Page size and boundary configuration for printing.

Images

TImageList

Image list for node icons.

Scrolling

HorzScrollBar

TTeeScrollBar

Horizontal scrollbar configuration.

VertScrollBar

TTeeScrollBar

Vertical scrollbar configuration.

ScrollMouseButton

TMouseButton

default:"mbRight"

Mouse button used for panning: mbLeft, mbRight, or mbMiddle.

Drag and Drop

DragAndDrop

TTreeDragDrop

Automatic drag and drop configuration.

Text Editing

TextEditor

TTreeTextEditor

Configuration for inline text editing with a memo control.

Advanced Properties

GlobalFormat

TTreeGlobal

Global formatting settings applied to all new nodes, including default border, brush, font, and child manager.

Designing

Boolean

default:"False"

When True, enables design-time features at runtime.

AssignParent

Boolean

default:"False"

When True, newly added nodes copy format from their parent node.

CreateConnections

Boolean

default:"False"

When True, adding a child node automatically creates a connection object.

NoOwnerShapes

Boolean

default:"False"

When True, new nodes are created without VCL Owner (nil).

ZoomCentered

Boolean

default:"False"

When True, zoom operations center on the current view.

Methods

Adding Nodes

Add

function

Adds a new node to the tree.Overloads:

function Add(const Text: String): TTreeNodeShape;
function Add(const Text: String; const Parent: TTreeNodeShape): TTreeNodeShape;
function Add(X, Y: Integer; const Text: String; const Parent: TTreeNodeShape): TTreeNodeShape;

Parameters:

Text - Text to display in the node
Parent - Optional parent node
X, Y - Optional position coordinates

Returns: The newly created node

AddRoot

function

Adds a new root-level node.

function AddRoot(const RootText: String): TTreeNodeShape;

Parameters:

RootText - Text to display in the root node

Returns: The newly created root node

AddShape

function

Adds a new node at specific coordinates.

function AddShape(X, Y: Integer; const AText: String; const AParentShape: TTreeNodeShape): TTreeNodeShape;

AddShapeClass

function

Adds a new node using a specific node class.

function AddShapeClass(X, Y: Integer; const AText: String; const AParentShape: TTreeNodeShape; const AClass: TTreeNodeShapeClass): TTreeNodeShape;

Node Management

DeleteShape

procedure

Deletes a node and all its children.

procedure DeleteShape(const AShape: TTreeNodeShape);

Clear

procedure

Removes all nodes from the tree.

procedure Clear;

CloneShape

function

Creates a copy of a node.

function CloneShape(const AShape: TTreeNodeShape): TTreeNodeShape;

ClickedShape

function

Finds the node at the specified coordinates.

function ClickedShape(x, y: Integer): TTreeNodeShape;

Returns: Node at coordinates, or nil if none

Selection

SelectConnection

procedure

Selects a connection.

procedure SelectConnection(const AConnection: TTreeConnection);

Expand/Collapse

FullExpandCollapse

procedure

Expands or collapses all nodes.

procedure FullExpandCollapse(Expand: Boolean);

Zoom and View

ZoomRectangle

procedure

Zooms to fit a specific rectangle.

procedure ZoomRectangle(R: TRect);

ZoomFromCenter

procedure

Zooms from a specific point.

procedure ZoomFromCenter(NewZoom: Integer; X, Y: Integer);

ZoomReset

procedure

Resets zoom to 100%.

procedure ZoomReset;

ZoomSetHome

procedure

Saves current zoom and position as default.

procedure ZoomSetHome;
procedure ZoomSetHome(const ZoomParams: TTreeZoomDefault);

CenterInView

procedure

Centers a node in the viewport.

procedure CenterInView(const Shape: TTreeNodeShape; Animated: Boolean = True);

Text Editing

StartEditing

procedure

Begins editing a node’s text.

procedure StartEditing(const AShape: TTreeNodeShape);

StopEditing

procedure

Stops text editing.

procedure StopEditing;

Sorting

Sort

procedure

Sorts all nodes alphabetically.

procedure Sort(Ascending: Boolean = True; IgnoreCase: Boolean = True);

Loading and Saving

LoadFromTextFile

function

Loads tree structure from a text file.

function LoadFromTextFile(const FileName: String): TTreeNodeShape;

LoadFromStrings

function

Loads tree structure from string list.

function LoadFromStrings(const Strings: TStrings): TTreeNodeShape;

Drawing

BeginUpdate

procedure

Suspends drawing to improve performance during batch operations.

procedure BeginUpdate;

EndUpdate

procedure

Resumes drawing after BeginUpdate.

procedure EndUpdate;

Events

Node Events

OnClickShape

TClickShapeEvent

Fired when a node is clicked.

property OnClickShape: TClickShapeEvent;
// procedure(Sender: TTreeNodeShape; Button: TMouseButton; Shift: TShiftState; X, Y: Integer)

OnDblClickShape

TClickShapeEvent

Fired when a node is double-clicked.

OnSelectShape

TNotifyShapeEvent

Fired when a node is selected.

property OnSelectShape: TNotifyShapeEvent;
// procedure(Sender: TTreeNodeShape)

OnUnSelectShape

TNotifyShapeEvent

Fired when a node is deselected.

OnNewShape

TTreeNewShapeEvent

Fired when a new node is created.

property OnNewShape: TTreeNewShapeEvent;
// procedure(Sender: TCustomTreePanel; NewShape: TTreeNodeShape)

OnMovingShape

TMovingShapeEvent

Fired when a node is being moved.

property OnMovingShape: TMovingShapeEvent;
// procedure(Sender: TTreeNodeShape; var DeltaX, DeltaY: Integer)

OnResizingShape

TTreeResizingShape

Fired when a node is being resized.

property OnResizingShape: TTreeResizingShape;
// procedure(Sender: TTreeNodeShape; ACorner: TTreeShapeHandle; var DeltaX, DeltaY: Integer)

OnMouseEnterShape

TMouseShapeEvent

Fired when mouse enters a node.

OnMouseLeaveShape

TMouseShapeEvent

Fired when mouse leaves a node.

Expand/Collapse Events

OnExpandingCollapsing

TExpandingCollapsingEvent

Fired before a node expands or collapses. Can be cancelled.

property OnExpandingCollapsing: TExpandingCollapsingEvent;
// procedure(Sender: TTreeNodeShape; var Expand: Boolean)

OnExpandedCollapsed

TNotifyShapeEvent

Fired after a node has expanded or collapsed.

Connection Events

OnClickConnection

TClickConnectionEvent

Fired when a connection is clicked.

OnDblClickConnection

TClickConnectionEvent

Fired when a connection is double-clicked.

OnNewConnection

TTreeNewConnectionEvent

Fired when a new connection is created.

OnSelectConnection

TNotifyConnectionEvent

Fired when a connection is selected.

OnAddingConnection

TTreeAddingConnectionEvent

Fired before a connection is added. Can be cancelled.

property OnAddingConnection: TTreeAddingConnectionEvent;
// procedure(Node1, Node2: TTreeNodeShape; var Add: Boolean)

Edit Events

OnStartEditing

TNotifyShapeEventStartEdit

Fired before editing begins. Can be cancelled.

property OnStartEditing: TNotifyShapeEventStartEdit;
// procedure(Shape: TTreeNodeShape; var AllowEditing: Boolean)

OnStopEditing

TNotifyShapeEvent

Fired when editing ends.

Delete Events

OnDeletingShapes

TDeleteShapesEvent

Fired before nodes are deleted. Can be cancelled.

property OnDeletingShapes: TDeleteShapesEvent;
// procedure(Sender: TSelectedShapeList; var AllowDelete: Boolean)

OnDeletedShapes

TNotifyEvent

Fired after nodes have been deleted.

Drag and Drop Events

OnDragDropShape

TDragDropShapeEvent

Fired when a node is dropped.

property OnDragDropShape: TDragDropShapeEvent;
// procedure(Sender: TCustomTree; Dragged, Parent: TTreeNodeShape)

Drawing Events

OnBeforeDraw

TNotifyEvent

Fired before the tree is drawn.

OnAfterDraw

TNotifyEvent

Fired after the tree is drawn.

Other Events

OnChanging

TTreeChangingEvent

Fired before any change. Can be cancelled.

property OnChanging: TTreeChangingEvent;
// procedure(Sender: TCustomTree; Node: TTreeNodeShape; var Allow: Boolean)

OnClickBackground

TTreeClick

Fired when empty area is clicked.

OnShowHint

TShowHintShapeEvent

Fired when showing a node hint.

property OnShowHint: TShowHintShapeEvent;
// procedure(Sender: TCustomTree; Shape: TTreeNodeShape; var Text: String)

OnCheckedShape

TNotifyEvent

Fired when a node’s checkbox is checked or unchecked.

OnSortCompare

TTreeSortCompareEvent

Fired during sorting to compare two nodes.

property OnSortCompare: TTreeSortCompareEvent;
// procedure(Node1, Node2: TTreeNodeShape; var Compare: Integer)

Usage Examples

Creating a Simple Tree

var
  Root, Child1, Child2: TTreeNodeShape;
begin
  // Create root node
  Root := Tree1.AddRoot('Root');
  
  // Add children
  Child1 := Root.AddChild('Child 1');
  Child2 := Root.AddChild('Child 2');
  
  // Expand root
  Root.Expanded := True;
end;

Handling Node Selection

procedure TForm1.Tree1SelectShape(Sender: TTreeNodeShape);
begin
  ShowMessage('Selected: ' + Sender.Text[0]);
end;

Customizing Node Appearance

var
  Node: TTreeNodeShape;
begin
  Node := Tree1.AddRoot('Custom Node');
  Node.Color := clYellow;
  Node.Border.Color := clBlue;
  Node.Border.Width := 2;
  Node.Font.Style := [fsBold];
  Node.Shadow.Visible := True;
end;

Using Grid and Snap

begin
  Tree1.Grid.Visible := True;
  Tree1.Grid.Step := 20;
  Tree1.SnapToGrid := True;
end;

Batch Operations

var
  i: Integer;
begin
  Tree1.BeginUpdate;
  try
    for i := 1 to 1000 do
      Tree1.AddRoot('Node ' + IntToStr(i));
  finally
    Tree1.EndUpdate;
  end;
end;

Components

Shapes

Child Managers

Utilities

​Overview

​Class Hierarchy

​Key Features

​Properties

​Core Properties

​Display Properties

​Interaction Properties

​Visual Components

​Scrolling

​Drag and Drop

​Text Editing

​Advanced Properties

​Methods

​Adding Nodes

​Node Management

​Selection

​Expand/Collapse

​Zoom and View

​Text Editing

​Sorting

​Loading and Saving

​Drawing

​Events

​Node Events

​Expand/Collapse Events

​Connection Events

​Edit Events

​Delete Events

​Drag and Drop Events

​Drawing Events

​Other Events

​Usage Examples

​Creating a Simple Tree

​Handling Node Selection

​Customizing Node Appearance

​Using Grid and Snap

​Batch Operations

​See Also

Build docs developers (and LLMs) love

Overview

Class Hierarchy

Key Features

Properties

Core Properties

Display Properties

Interaction Properties

Visual Components

Scrolling

Drag and Drop

Text Editing

Advanced Properties

Methods

Adding Nodes

Node Management

Selection

Expand/Collapse

Zoom and View

Text Editing

Sorting

Loading and Saving

Drawing

Events

Node Events

Expand/Collapse Events

Connection Events

Edit Events

Delete Events

Drag and Drop Events

Drawing Events

Other Events

Usage Examples

Creating a Simple Tree

Handling Node Selection

Customizing Node Appearance

Using Grid and Snap

Batch Operations

See Also