TEgColumn

Class: TEgColumn

Declared in: EgDBGridEx

TColumn descendant used for every column of a TEgDBGridEx grid. Adds properties that let an individual column override nineteen grid-wide behaviors and mirror all ten of the grid’s events, plus its own image index/alignment and sub-title properties, which have no grid-wide equivalent.

Member Overview

Nineteen properties and all ten events below are live-tracking overrides of an identically-named TEgDBGridEx member - each has its own page, which states the mirrored behavior briefly and links back to the grid-wide page for the full explanation. The other seven properties (AssignedValues, ImageAlignment, ImageIndex, SubTitle, SubTitleFont, TitleImageAlignment, TitleImageIndex) and the three methods have no grid-wide equivalent.

Properties	Methods	Events
`AssignedValues`	`Assign`	`OnBeforeDrawCell`
`CellVAlign`	`Create`	`OnCellDblClick`
`CellWordWrap`	`RestoreDefaults`	`OnCellImageClick`
`CheckFrames`		`OnCellRightClick`
`CheckKind`		`OnCheckChange`
`ClickableCursor`		`OnBeforeDrawTitle`
`ClicksOnRowSelect`		`OnGraphicError`
`DetectBlobImages`		`OnTitleCellClick`
`EditColor`		`OnTitleCellRightClick`
`ExtendedStrEditor`		`OnTitleImageClick`
`ImageAlignment`
`ImageIndex`
`ImageOnSelectedOnly`
`MemoMaxChars`
`MinFontSize`
`ShowImageOnEmpty`
`ShowImageOverGraphic`
`ShrinkFontToFit`
`SubTitle`
`SubTitleFont`
`TitleImageAlignment`
`TitleImageIndex`
`UseColorOnStyles`
`UseFixedColorOnStyles`
`UseFixedFontColorOnStyles`
`UseFontColorOnStyles`

Usage

Image index and alignment

ImageIndex and TitleImageIndex seed the image shown in a column’s data cells and title cell, from the grid’s Images list, before OnBeforeDrawCell / OnBeforeDrawTitle run - either event can still freely raise, lower, or clear whatever these properties seeded. ImageAlignment and TitleImageAlignment position that image independently of the column’s own text alignment.

Title image clicks

OnTitleImageClick fires when a click lands specifically on this column’s title image, mirroring the grid’s own OnTitleImageClick (which runs first when both are assigned). Requires TitleImageIndex to actually be set.

Cell image clicks

OnCellImageClick fires when a click lands specifically on this column’s data-cell ImageIndex icon, mirroring the grid’s own OnCellImageClick (which runs first when both are assigned) - instead of the native OnCellClick, not alongside it. See the grid-level event for the full scope and gating rules (ImageOnSelectedOnly / ShowImageOnEmpty).

Overrides of grid-wide properties and events

Nineteen properties - CellVAlign, CellWordWrap, CheckFrames, CheckKind, ClickableCursor, ClicksOnRowSelect, DetectBlobImages, EditColor, ExtendedStrEditor, ImageOnSelectedOnly, MemoMaxChars, MinFontSize, ShowImageOnEmpty, ShowImageOverGraphic, ShrinkFontToFit, UseColorOnStyles, UseFixedColorOnStyles, UseFixedFontColorOnStyles, and UseFontColorOnStyles - each mirror the grid-wide property of the same name but can be overridden per column. A column left at its default follows the grid live, the same way Vcl.DBGrids.TColumn’s own AssignedValues tracks its native overrides; the read-only AssignedValues property on TEgColumn reports which of the nineteen are currently overridden on that column. ClickableCursor is the one exception worth calling out: a column’s own override only ever affects that column’s data cells (checkbox, ImageIndex icon) - its title (sort arrow, title image) always follows the grid-level ClickableCursor directly, never the column’s override.

Eight further events - OnCheckChange, OnBeforeDrawCell, OnBeforeDrawTitle, OnCellDblClick, OnTitleCellClick, OnGraphicError, OnCellRightClick, and OnTitleCellRightClick - are also available per column, alongside the grid-wide event of the same name; both fire when assigned, grid first, so a column’s own handler can react to or override whatever the grid-wide handler already decided.

Sub-title

SubTitle adds an optional second line below Title.Caption, drawn with this column’s own SubTitleFont. Has no grid-wide equivalent - it is purely a per-column addition, not an override of anything TEgDBGridEx itself has. See SubTitle’s own page for the row- height and layout details, and TitleRowHeightPx for the one combination that is not supported.

Construction, copying, and reset

Create seeds ImageIndex/ TitleImageIndex to -1 and ImageAlignment/ TitleImageAlignment/ Title.Alignment to their documented defaults. Assign copies this unit’s own additions between columns (only the nineteen overridable properties actually set on the source, per its AssignedValues), and RestoreDefaults clears every one of them back to “follow the grid”, as if the column had just been created.