TTreeItem / TTVItem

Source: source/classes/treeitem.prg, source/classes/ttvitem.prg

TTreeItem implements a linked-list tree node for custom tree widgets. Each node stores a prompt, level, bitmaps, action codeblock, and cargo data, and maintains prev/next/child pointers via an associated TTree object. TTVItem wraps a native Win32 TreeView item (HTREEITEM) for use with the standard Windows tree control, providing insert, expand, edit, check-box and persistence operations.

TTreeItem — Linked-List Tree Node

Key DATA Members

DATA	Type	Description
`cPrompt`	Character	Node display text
`oTree`	Object	Reference to the child TTree object (children), nil if leaf
`lOpened`	Logical	Node is expanded (children visible)
`nLevel`	Numeric	Indentation level (0 = root)
`hBmpOpen`	Handle	Bitmap handle for expanded state
`hBmpClose`	Handle	Bitmap handle for collapsed state
`bAction`	Codeblock	Code block executed when the node is activated
`Cargo`	Any	User-defined data attached to the node

Methods

Method	Description
`New( cPrompt, nLevel, hBmpOpen, hBmpClose, bAction, uCargo, uValue )`	Create a new tree node at the specified level
`Open()`	Expand the node to show children
`Close()`	Collapse the node to hide children
`Toggle()`	Toggle between open and closed state
`Add( cPrompt )`	Add a sibling node after this one (linked-list insert)
`AddChild( cPrompt, lFirst )`	Add a child node (creates or uses existing TTree)
`Delete( oRoot )`	Remove this node from the list
`MoveUp( oRoot )`	Move the node up in the list
`MoveDown( oRoot )`	Move the node down in the list
`Sort( oRoot, lAsc, lRecurs )`	Sort siblings by prompt, optionally recursive
`Promote()`	Decrease indentation level by one
`Demote()`	Increase indentation level by one
`Parent( nParent )`	Find the ancestor at a given level
`ByIndex[ n ]`	Access child/sub-node by index (operator [] overload)

TTVItem — TreeView Item Wrapper

Key DATA Members

DATA	Type	Description
`oParent`	Object	Parent TTVItem (nil for root items)
`hItem`	Handle	HTREEITEM handle identifying the native tree item
`aItems`	Array	Child TTVItem objects
`nImage`	Numeric	Zero-based image index in the tree image list
`Cargo`	Any	User-defined data
`lBold`	Logical	Item text is bold

Methods

Method	Description
`New( hItem, oTree, Cargo, cPrompt, nImage, oParent )`	Wrap an existing native tree item handle
`Add( cPrompt, nImage, Cargo )`	Insert a child item into the native tree
`Expand()`	Expand the tree item (TVE_EXPAND)
`Collapse()`	Collapse the tree item (TVE_COLLAPSE)
`Toggle()`	Toggle expand/collapse (TVE_TOGGLE)
`Edit()`	Start in-place label editing (TVM_EDITLABEL)
`SetCheck( lOnOff )`	Set or clear the check-box state
`GetCheck()`	Get the current check-box state
`GetText()`	Get the item display text
`SetText( cText )`	Set the item display text
`Bold()`	Make the item text bold
`Normal()`	Remove bold formatting
`Save()`	Serialize the item (prompt, image, cargo) to a string
`Load( cInfo )`	Deserialize and restore the item from a saved string
`MakeVisible()`	Scroll the tree to ensure this item is visible

Example: Tree Construction

#include "FiveWin.ch"

function Main()

   local oTreeView, oRoot, oItem1, oItem2

   // TTVItem example with native TreeView
   DEFINE WINDOW oWnd TITLE "Tree Demo" SIZE 400, 300

   oTreeView = TTreeView():New( 10, 10, 380, 280, oWnd )

   oRoot = TTVItem():New( TVInsertItem( oTreeView:hWnd, "Root", 0, 0 ),;
                          oTreeView, NIL, "Root", 0, NIL )

   oItem1 = oRoot:Add( "Child 1", 1, "data1" )
   oItem2 = oRoot:Add( "Child 2", 1, "data2" )

   oItem1:Add( "Grandchild", 2, "deep" )

   oRoot:Expand()

   ACTIVATE WINDOW oWnd CENTERED

return nil

Notes

TTreeItem is designed for a custom linked-list tree where each node can optionally hold a child TTree (via oTree). The linked list is doubly linked via oPrev/oNext.
TTVItem wraps a native Windows tree item handle and delegates all display/structure operations to the common control via SendMessage.
TTVItem Save() / Load() serialize the cPrompt, nImage, Cargo and lBold properties.
GetCheck() / SetCheck() require the tree to have the TVS_CHECKBOXES style.
The Value accessor/assign in TTreeItem delegates to a bSetGet codeblock, allowing the node to act as a SET/GET variable.

TTreeItem / TTVItem

TTreeItem — Linked-List Tree Node

Key DATA Members

Methods

TTVItem — TreeView Item Wrapper

Key DATA Members

Methods

Example: Tree Construction

Notes

See Also