Edit button at the cell level. CellButtons collection

In the columns of the grid - TColumnEh and vertical grid rows - TFieldRow there is a collection of buttons - CellButtons. The collection contains TCellButtonEh type elements. CellButton element specifies the button in the grid cell. CellButton element is similar to EditButton element (edit button), but unlike the EditButton is pressed without opening a text editor. Set of TCellButtonEh properties are similar to a list of properties in TEditButtonEh and have additional properties.

It is also possible to display button face in the cells content area. To do this, set the CellButton.HorzPlacement property to ebhpInContentEh.

In the following screenshot, the first column displays three CellButtons with the CellButton.HorzPlacement = ebhpInContentEh property set. Using the CellButton.OnGetEnabledState event, properties are set to deactivate buttons depending on the editing status of the current record.

TCellButtonEh has next additional properties and events:

Properties:

property HorzPlacement: TEditButtonHorzPlacementEh default ebhpRightEh;

It specifies the location of the buttons in the grid cell horizontally. TEditButtonHorzPlacementEh type has the following values:

ebhpLeftEh - button is aligned to the left edge of the cell.

ebhpRightEh - button is aligned to the right edge of the cell.

ebhpInContentEh - The button is displayed in the content area of the cell. In this case, the cell content specified by the TColumnEh.FieldName property is not displayed.

property AutoFade: Boolean

Make the button image faded when the mouse cursor is not over the button. The default is True.

property Caption: String

The content of the button as text. If this property is set, then the button icon specified by the Style property is not used.

property Margins: TPaddings

Padding from the edges of the button.

Events:

property OnGetEnabledState: TCellButtonGetEnabledStateEventEh;

type  
  TCellButtonGetEnabledStateEventEh = procedure(Grid: TCustomDBAxisGridEh; 
  AxisBar: TAxisBarEh; CellButton: TCellButtonEh; 
  var ButtonEnabled: Boolean) of object;

The event is called for every record in the grid. You can set ButtonEnabled property to set that particular record button is not available for the press. In this case, it will be drawn in the Disabled styles.

property OnDraw: TDrawCellButtonEventEh;

  type  TDrawCellButtonEventEh = procedure(Grid: TCustomDBAxisGridEh; 
    AxisBar: TAxisBarEh; CellButton: TCellButtonEh; Canvas: TCanvas; 
    Cell, AreaCell: TGridCoord; const ARect: TRect; 
    ButtonDrawParams: TCellButtonDrawParamsEh; var Handled: Boolean) of object;

The event is called when rendering the button in a grid cell. In the event you can specify the parameters of the rendering by assigning the appropriate properties in ButtonDrawParams parameter, or you yourself can draw the image button, or you can call the default method of rendering - CellButton.DefaultDrawEditButton. In the second and third case, set the Handled parameter to True to prevent the grid drawing the cell after the event.

property OnMouseClick: TMouseCellButtonEventEh;

This event is fired when pressing the mouse button.

property OnMouseDown: TMouseCellButtonEventEh;

Event is fired when the button is clicked with the mouse.

See example of using CellButtons in the Project:

Demos\DBGridEh.CellButtons\Project1.dpr