Method XbpBrowse():addColumn()

Classes Class XbpBrowse() :addColumn()

Attaches a column (XbpColumn object) to an XbpBrowse object.

:addColumn( <oXbpColumn> ) --> oXbpColumn
or
:addColumn( <bDataLink>, ;
            [<nWidth>], ;
            [<cHeading|nHeadID>], ;
            [<cFooting|nFootID>], ;
            [<nType>] ) --> oXbpColumn

<oXbpColumn> is an XbpColumn object that retrieves data from a table to be displayed by the XbpBrowse object. An XbpColumn object that has not executed its :create() method can be passed.

Instead of an object the first parameter can be a data code block whose return value is to be displayed in a column on the screen. In this case, the XbpBrowse object creates an XbpColumn object and assigns <bDataLink> to its :dataLink instance variable.

<nWidth> defines the width of a column as number of characters. The width of a column then depends on the font used for displaying data. The default value for<nWidth> is the constant XBP_AUTOSIZE. This means that the column width is calculated from the return value of <bDataLink>.

<cHeading|nHeadID>

The heading of a table column can be defined as a character string <cHeading>, or as numeric resource ID of a bitmap <nHeadID>. The default value is NIL, which causes a column to be created without a heading.

<cFooting|nFootID>

The footing of a table column can be defined as a character string <cFooting>, or as numeric resource ID of a bitmap <nFootID>. The default value is NIL, which causes a column to be created without a footing.

<nType>

This parameter defines the type of the XbpColumn object to be created by the XbpBrowse object. Constants defined in XBP.CH are used for <nType>. They are listed in the table below:

Constant	Description
XBPCOL_TYPE_BITMAP	The column displays bitmaps
XBPCOL_TYPE_ICON	The column displays icons
XBPCOL_TYPE_SYSICON	The column displays system-icons
XBPCOL_TYPE_FILEICON	The column displays normal file-icons
XBPCOL_TYPE_FILEMINIICON	The column displays small file-icons
XBPCOL_TYPE_TEXT *)	The column displays textual data
default value

The method returns the attached XbpColumn object.

The method :addColumn() attaches a table column to an XbpBrowse object. Display of columns is done by XbpColumn objects. The method must receive either a configured XbpColumn object or a data code block which returns data to be displayed in a column. In this case, the XbpBrowse object creates the XbpColumn object and attaches it to itself.

Parameters for width, heading, footing and column type are optional. The type determines whether a column is to display text, icons or bitmaps. Depending on column type, the data code block must return corresponding data:

XBPCOL_TYPE_TEXT

The default value of <nType> (XBPCOL_TYPE_TEXT) is used to display data stored in a database or an array. In this case, <bDataLink>accesses a variable and returns its value.

XBPCOL_TYPE_BITMAP , XBPCOL_TYPE_ICON

When the constants XBPCOL_TYPE_BITMAP or XBPCOL_TYPE_ICON are specified, <bDataLink> must return the numeric resource ID of a bitmap or icon. Either must be linked as a resource to the EXE.

XBPCOL_TYPE_SYSICON

With XBPCOL_TYPE_SYSICON, <bDataLink> must return a constant prefixed with XBPSTATIC_SYSICON_. These constants are defined in XBP.CH.

XBPCOL_TYPE_FILEICON , XBPCOL_TYPE_FILEMINIICON

An XbpColumn object displays file names as symbols when either constant XBPCOL_TYPE_FILEICON or XBPCOL_TYPE_FILEMINIICON defines the column type. The<bDataLink> code block must return a fully-qualified file name including drive and path as character string.

Windows uses the Windows Bitmap file format as the default image format. If a numeric resource id is assigned to <nHeadID> or <nFootID>, it must be the id of a BITMAP resource linked into the application. In order to use the other image file formats, an XbpBitmap object must be assigned to the respective parameter instead. See XbpBitmap:load()for further information.

Adding a column to a browse implicitly defines the column's unique position in the browser's column array. This position is reflected in the :index member variable of a column, and is used as the identifier in methods like :delColumn().

Method XbpBrowse():addColumn() Foundation