THeader

Source: source/classes/theader.prg

Inherits from: TControl

THeader is a wrapper for the Win32 SysHeader32 common control. It provides a clickable, resizable column header bar typically used above list views or custom grid controls. Each column can display a prompt, have a specific width, support click-to-sort arrows, and fire an action when clicked. The control supports hot-track highlighting and full-drag column resizing.

Key DATA Members

DATA	Type	Description
`aPrompts`	Array	Array of column header caption strings
`aSizes`	Array	Array of column widths in pixels
`bAction`	Block	Code block executed on column click. Receives nItem index and Self.

Methods

Method	Description
`New( oWnd, nTop, nLeft, nW, nH, aPrompts, aSizes, oFont, nClrFore, nClrBack, bAction )`	Create a new THeader control
`ReDefine( nId, oWnd, aPrompts, aSizes, oFont, nClrFore, nClrBack, bAction )`	Redefine from dialog resource
`InsertItem( nIndex, cCaption, nWidth, nAlign )`	Insert a new column at the specified position
`SetItem( nIndex, cCaption, nWidth, nAlign, nSort )`	Modify an existing column's properties
`GetItem( nIndex )`	Retrieve column information (caption, width, alignment)

Example: Three-Column Header with Click Action

#include "FiveWin.ch"

function Main()

   local oWnd, oHeader, aPrompts, aSizes

   aPrompts := { "Name", "Date", "Size" }
   aSizes   := { 150, 100, 80 }

   DEFINE WINDOW oWnd TITLE "Header Demo" SIZE 400, 200

   oHeader := THeader():New( oWnd, 10, 10, 380, 22, aPrompts, aSizes,,, ;
                             , { | nItem, oCtrl | MsgInfo( "Column " + Str( nItem ) ) } )

   ACTIVATE WINDOW oWnd CENTERED

return nil

Notes

THeader wraps the SysHeader32 common control (or SysHeader on Clipper). It is registered with the WC_HEADER window class.
Columns support hot-track highlighting (HDS_HOTTRACK) and full-drag resizing (HDS_FULLDRAG).
When the themed mode is active (IsAppThemed()), the control applies the HDS_FLAT style for a modern appearance.
The bAction code block fires on HDN_ITEMCLICK notifications, receiving the column index (1-based) and the THeader object as parameters.
Use SetItem() with the nSort parameter to display a sort arrow indicator (up or down) on a column.
Column alignment is controlled by the nAlign parameter in InsertItem()/SetItem(), using HDF_LEFT, HDF_CENTER, or HDF_RIGHT constants.

THeader

Key DATA Members

Methods

Example: Three-Column Header with Click Action

Notes

See Also