TExplorerList / TItemListbar

Source: source/classes/texplist.prg

TExplorerList inherits from: TControl. TItemListbar is an internal collaboration class for individual items.

TExplorerList is a vertical navigation list control with expandable/collapsible items, similar to the Windows Explorer folder tree or Outlook bar. Each item can display a bitmap, text, and optional child items with indentation. The control supports keyboard navigation, mouse hover effects, gradient selection highlighting, and vertical scrolling for overflow content.

Key DATA Members (TExplorerList)

DATA	Type	Description
`aItems`	Array	Array of TItemListbar objects
`bChange`	Block	Code block executed when the selected item changes
`oItemSelected`	Object	Currently selected TItemListbar item
`oVScroll`	Object	Vertical scroll bar control
`nSeparation`	Numeric	Vertical spacing between top-level items (default 15)
`nVirtualHeight`	Numeric	Total virtual height of all items
`nVirtualTop`	Numeric	Current scroll offset in virtual pixels
`nFade`	Numeric	Alpha level for fade animation (0-255)

Methods

Method	Description
`New( nTop, nLeft, oWnd, lPixel, lDesign, nWidth, nHeight, nSeparation )`	Create the explorer list control
`AddItem( cText, cBitmap, aGradSel, aGradOver, aGradOverSel, nClrInSel, nClrOutSel, nClrInOverSel, nClrOutOverSel, nClrInOver, nClrOutOver, nClrText, bAction )`	Add a new item with text, bitmap, and gradient/hover colors
`DelItem( uVal )`	Delete an item by position or object reference
`GetItem( nPos )`	Return the item at the given position
`SetOption( n )`	Select an item by index
`GoDown( nSkip ) / GoUp( nSkip )`	Navigate to the next/previous visible item
`CheckScroll()`	Recalculate scroll range based on item positions

TItemListbar (Item Objects)

DATA	Type	Description
`cText`	Character	Display text
`hBitmap`	Handle	Item bitmap handle
`lSelected`	Logical	Is this item currently selected
`lOver`	Logical	Is the mouse hovering over this item
`lOpened`	Logical	Are child items expanded
`lParent`	Logical	Does this item have children
`nLevel`	Numeric	Hierarchy depth (0 = top-level)
`bAction`	Block	Code block executed when item is clicked

TItemListbar supports AddItem() to create child items, OpenClose() to expand/collapse children, and Click() to trigger actions.

Example: Navigation List with Groups

#include "FiveWin.ch"

function Main()

   local oWnd, oList, oInbox, oSent

   DEFINE WINDOW oWnd TITLE "TExplorerList Demo" SIZE 300, 400

   @ 10, 10 EXPLORERLIST oList SIZE 280, 380 OF oWnd

   oInbox := oList:AddItem( "Inbox", "inbox.bmp" )
   oInbox:AddItem( "Today", "mail.bmp" )
   oInbox:AddItem( "Yesterday", "mail.bmp" )

   oSent := oList:AddItem( "Sent Items", "sent.bmp" )
   oSent:AddItem( "This Week", "mail.bmp" )

   oList:AddItem( "Deleted Items", "trash.bmp" )

   ACTIVATE WINDOW oWnd CENTERED

return nil

Notes