DialogChar is an overridden Boolean function used to apply Lazarus messages with accelerator keys for columns in the grid. Message contains the TLMKey instance with the message examined in the method. DialogChar examines each of the Columns defined for the grid to determine if the CharCode for the Message is an accelerator key appearing in the title for the column. When a match is found, the HeaderClick method is called to activate the column.

The return value contains the result from the inherited DialogChar method.

DoCompareCells signals the OnCompareCells event handler (when assigned) to perform the comparison. The return value contains the relative sort order for the compared cells, and uses the following values:

-1

The cell at ACol and ARow occurs comes before the cell at BCol and BRow.

0

The specified cells have the same value.

1

The cell at ACol and ARow occurs comes after the cell at BCol and BRow.

When OnCompareCells is not assigned, the return value is always 0.

DoCopyToClipboard is a virtual method in TCustomGrid, and has an empty implementation. It is overridden in descendent classes, like TCustomStringGrid, to perform the actions required for the class type.

DoCopyToClipboard is called from the KeyDown method when the Ctrl+C or Meta+C (macOS, iOS, Darwin) key is handled for the control.

DoCutToClipboard is a virtual method in TCustomGrid, and has an empty implementation. It is overridden in descendent classes, like TCustomStringGrid, to perform the actions required for the class type.

DoCutToClipboard is called from the KeyDown method when the Shift+X key is handled for the control.

DoEditButtonClick is a procedure used to perform actions requires when the button for a cell editor or button column is clicked.

ACol and ARow contain the Integer coordinates for the cell where the action occurred.

DoEditButtonClick signals the OnEditButtonClick and OnButtonClick event handlers when they have been assigned for the grid control.

DoEditButtonClick is used in the implementation of the EditButtonClicked method used in cell editor controls, and the MouseUp method.

DoEditorHide is a procedure used to hide the cell Editor for the control.

When gfEditingDone is included in the GridFlags for the control, and CanFocus indicates that the control can be focused, it is used as the ActiveControl in the parent Form. The Visible property in Editor is set to False to hide the cell editor for the control.

DoEditorHide is called from the EditorHide method.

Calls ScrollToCell to position the grid on the cell indicated by the Col and Row properties.

String- and Button-style editor controls are updated to use the alignment defined for the current column. If Columns has not been enabled, the default alignment for the cell is taLeftJustify. Calls EditSetValue to copy the cell content into the cell Editor.

The Editor.SetFocus method is called when the grid control currently has focus and the cell editor can receive focus. InvalidateCell is called to redraw the cell at the position in Col and Row.

DoEditorShow is called from the EditorShow method.

DoExit is an overridden method in TCustomGrid. It ensures that an active editor control and the active selection are updated when the grid control loses focus.

If the editor for the control is not always visible (goAlwaysShowEditor in Options), InvalidateFocused is called to invalidate the cell or the row. ResetEditor is called to sync and re-display the Editor when needed. SelectActive is set to False when the internal grid state is gsSelecting, and it is reset to gsNormal.

The inherited DoExit method is called to signal the OnExit event handler (when assigned).

DoExit is called from the CMExit method when it handles the corresponding control message.

DoEnter is an overridden method in TCustomGrid. The inherited DoEnter method is called on entry to signal the OnEnter event handler (when assigned).

It ensures that the active selection and optional editor control are restored when grid control receives focus. If the Editor is not locked for update, and is always visible, the Editor class is re-selected and it is displayed in the active cell. When the Editor is not always visible (goAlwaysShowEditor is not in Options), InvalidateFocused is called to request the active cell or row selection to be redrawn.

DoEnter is called from the CMEnter method when it handles the corresponding control message.

DoLoadColumn is a method used to signal the OnLoadColumn event handler (when assigned) to load a column from an external XML configuration file. DoLoadColumn is called from the private LoadColumns method, and occurs immediately after a TColumn instance has been created, initialized, and added to the Columns collection. The event handler can be used to override or augment the values loaded from the XML storage into the TColumn instance.

DoSaveColumn is a method used to signal the OnSaveColumn event handler (when assigned) when a column definition is saved to an external XML configuration file.

DoSaveColumn is called from the private SaveColumns method, and occurs immediately after a TColumn instance in the Columns collection is written to the XML storage. It is also called from the SaveContent method when the Columns collection has not been enabled in the control.

DoMouseWheel is an overridden method in TCustomGrid used to apply a mouse wheel operation to the control. It ensures that the SelectActive property is reset to False when MouseWheelOption applies to the selection cursor instead of the visible area for the grid control.

DoMouseWheel calls the inherited method to signal the OnMouseWheel event handler (when assigned), and to apply the mouse wheel movement using the parameter values. The inherited method also determines the return value. It is False if an OnMouseWheel is not found or the message cannot handle the WheelDelta value using DoMouseWheelUp or DoMouseWheelDown.

DoMouseWheel is called from the inherited WMMouseWheel method when the LM_MOUSEWHEEL message is handled for the control.

DoMouseWheelDown is a an overridden method in TCustomGrid called when the mouse wheel is scrolled downward. It calls the inherited method on entry to signal the OnMouseWheelDown event handler (when assigned). The return value is set to True if the action was handled in OnMouseWheelDown.

If the action is not handled in OnMouseWheelDown, the GridMouseWheel method is called to scroll to the next selectable area in the control using the specified Shift modifier. When Shift contains ssCtrl (Ctrl key), the horizontal position is updated instead of the vertical. The return value is set to True when the action is handled in this manner.

Use MouseWheelOption to specify whether mouse wheel operations are applied to the grid cursor (selection / editing) or the visible area for the control.

See DoMouseWheelUp for the actions performed when the mouse wheel is scrolled in the upward direction.

DoMouseWheelDown is called from the inherited DoMouseWheel method when an OnMouseWheel event handler was not found, or it did not handle the notification.

DoMouseWheelUp is an overridden method in TCustomGrid called when the mouse wheel is scrolled upward. It calls the inherited method on entry to signal the OnMouseWheelUp event handler (when assigned). The return value is set to True if the action was handled in OnMouseWheelUp.

If the action is not handled in OnMouseWheelUp, the GridMouseWheel method is called to scroll to the previous selectable area in the control using the specified Shift modifier. When Shift contains ssCtrl (Ctrl key), the horizontal position is updated instead of the vertical. The return value is set to True when the action is handled in this manner.

Use MouseWheelOption to specify whether mouse wheel operations are applied to the grid cursor (selection / editing) or the visible area for the control.

See DoMouseWheelDown for the actions performed when the mouse wheel is scrolled in the downward direction.

DoMouseWheelUp is called from the inherited DoMouseWheel method when an OnMouseWheel event handler was not found, or it did not handle the notification.

DoMouseWheelLeft is an overridden method in TCustomGrid which handles a horizontal mouse wheel scroll message towards the left of the grid control. DoMouseWheelLeft is called from the inherited DoMouseWheelHorz method when an unhandled scroll wheel message with a negative WheelDelta value occurs.

DoMouseWheelLeft calls the inherited method on entry to signal the OnMouseWheelLeft event handler (when assigned). The return value is set to True if the message is handled in the method.

If the message is not handled in the inherited method, the GridMouseWheel method is called using the ssCtrl modifier and the current mouse position as arguments. This is the equivalent of a Ctrl+MouseWheelUp message. The return value is set to True when the message is handled in this manner.

See DoMouseWheelRight for the actions performed for a Ctrl+MouseWheelDown scroll message.

Use MouseWheelOption to specify whether mouse wheel operations are applied to the grid cursor (selection / editing) or the visible area for the control.

DoMouseWheelRight is an overridden method in TCustomGrid which handles a horizontal mouse wheel scroll message towards the right of the grid control. DoMouseWheelRight is called from the inherited DoMouseWheelHorz method when an unhandled scroll wheel message with a positive WheelDelta value occurs.

DoMouseWheelRight calls the inherited method on entry to signal the OnMouseWheelRight event handler (when assigned). The return value is set to True if the message is handled in the method.

If the message is not handled in the inherited method, the GridMouseWheel method is called using the ssCtrl modifier and the current mouse position as arguments. This is the equivalent of a Ctrl+MouseWheelDown message. The return value is set to True when the message is handled in this manner.

See DoMouseWheelLeft for the actions performed for a Ctrl+MouseWheelUp scroll message.

Use MouseWheelOption to specify whether mouse wheel operations are applied to the grid cursor (selection / editing) or the visible area for the control.

DoAutoAdjustLayout is an overridden method in TCustomGrid.

AMode contains the layout policy applied in the method, and contains a value from the TLayoutAdjustmentPolicy enumeration. AXProportion and AYProportion contain the horizontal and vertical scaling factors applied for the specified layout policy.

DoAutoAdjustLayout calls the inherited method on entry to apply the scaling factors for the grid control. This includes scaling its width and/or height using values in Align and/or Anchors. The BaseBounds for the control may also be affected.

When AMode contains lapAutoAdjustWithoutHorizontalScrolling or lapAutoAdjustForDPI, the layout policy is applied to the columns and rows in the control. When Columns has been enabled the factor in AXProportion is applied to MinSize, MaxSize and the stored Width for each of the TGridColumn entries. AXProportion is also applied to the values in Cols and DefaultColWidth.

The value in AYProportion is applied to the values stored in Rows and DefaultRowHeight.

DoAutoAdjustLayout is called from the inherited AutoAdjustLayout method.

DoOnChangeBounds is an overridden method in TCustomGrid. It calls the inherited method on entry to signal any assigned OnChangeBounds event handlers and to update flag values for the control.

DoOnChangeBounds updates cached column and row sizes, and scroll bar information when the bounds for the control have been changed.

DoOPDeleteColRow is a method which performs actions needed to delete the specified column or row from the grid control.

IsColumn indicates whether a column or row is affected in the method. When set to True, the specified column number is deleted from the control. Otherwise, the specified row number is removed.

Use Index to specify the position for the column or row removed in the method.

Prior to removing the specified column or row, private methods are called to validate values used by or affected in the operation like:

Index

Checks whether the value in Index is a valid column or row number. An EGridException exception is raised if Index has an invalid index value for the grid control.

FixedCols, FixedRows

Ensures that new fixed column or row counts are valid for the number of columns or rows on the grid control. An EGridException is raised if the new values are not within the limits for the column or row count.

Col, Row, ColCount, RowCount

Ensures that values for Col or Row are range limited to the new column or row count for the control. Calls MoveNextSelectable to scroll the grid control to the new origin cell when needed.

DoOPDeleteColRow ensures that a visible cell editor in the column or row is deactivated by setting EditorMode to False.

The ColRowDeleted method is called when the affected data has been removed from the grid control and the cached values in GCache. In a descendent class (TCustomDrawGrid), the the OnColRowDeleted event handler is signalled (when assigned).

Col and Row are updated if the operation causes the selection range to be changed, and SelectCell is called to include the cell in Selection. Sizes for auto-filled columns are recalculated when needed. The cell Editor is updated when needed for the new selection and position on the grid control.

DoOPExchangeColRow is used to exchange or swap column or row values at the specified positions in the grid control.

IsColumn indicates whether columns or rows are affected in the method. When set to True, Index and WithIndex refer to column positions. Otherwise, they refer to row positions.

TGridColumn instances in Columns are exchanged when the collection has been enabled in the control. Column widths in Cols, or row heights in Rows are also exchanged in the method.

DoOPExchangeColRow calls the ColRowExchanged method to perform the notification which informs the grid control to exchange their column or row data.

AdjustEditorBounds is called to reposition the cell Editor for the grid when the operation requires it to be moved.

When a value in Index or WithIndex is a sort column for the grid, the value in the SortColumn property is updated to reflect the (ex)changed value.

DoOPExchangeColRow is called from the Sort method when the StrictSort property is set to False.

DoOPMoveColRow is called from the MouseUp method when the mouse button is released during a column or row drag operation.

DoOPMoveColRow ensures that FromIndex and ToIndex contain valid index values for the grid. When FromIndex and ToIndex contain the same value, the drag operation has ended without changing the position for the column or row. In this situation, the grid control is redrawn and no additional actions are performed in the method.

IsColumn determines whether column or row data is affected in the method. When set to True, the index values refer to column positions on the grid. Otherwise, the index values refer to row positions.

Column Movement

Column movements are handled using either the Columns collection or the internal list of column widths maintained in the grid control. When Columns has been enabled, and column order is not locked using GridFlags, the MoveColumn method in the collection is used to move the specified column to its new position.

If Columns have not been defined, the internal column list is used to perform the operation. ColRowMoved is called to perform an event notification (implemented in descendent classes) when the action has been completed.

Row Movement

Row movements are handled using the internal list of row heights in the control. The Move method in in the list is called to relocate the specified row to its new position. ColRowMoved is called to perform an event notification (implemented in descendent classes) when the action has been completed.

DoOPMoveColRow calls AdjustEditorBounds to re-select the active cell and position an active cell editor (when needed). For a column movement, the value in SortColumn is updated to reflect the new position for the sort column.

DoPasteFromClipboard is a virtual method and has an empty implementation in TCustomGrid. It must be overridden in a descendent class to use the data and selection ranges(s) allowed in the implementation.

DoPasteFromClipboard is called from the KeyDown method when a Shift+V key is handled for the control.

DoPrepareCanvas signals the OnPrepareCanvas event handler (when assigned) to prepare the Canvas to draw the specified cell using the specified state. It is called from the PrepareCanvas method, and allows the default actions performed in the caller to be overridden.

DoOnResize is an overridden method in TCustomGrid. It calls the inherited method on entry to signal the OnResize event handler(s) assigned to the control or its parents. If the active update counter is 0, the Invalidate method in the widgetset class instance is called to refresh the control.

DoOnResize is called from the Resize method in the ancestor class.

DoUTF8KeyPress is an overridden method used to apply the UTF-8-encoded character in UTF8Key to the active cell Editor for the control. The return value is True if the character is successfully handled.

DoUTF8KeyPress calls the inherited method on entry to determine if the character is handled in the ancestor class. No additional actions are performed in the method when the character is handled in the ancestor.

Otherwise, EditingAllowed is called to determine if a cell editor can be displayed for the column number in Col. When allowed, the EditorShowChar method is called to apply the value in UTF8Key to the cell Editor. The value in UTF8Key is set to an empty string (''), and the return is set to True on successful completion of the operation.

DrawBorder is used to draw the border around the grid using the client rectangle for the control. No actions are performed in the method when Flat is set to False or BorderStyle has a value other than bsSingle.

DrawBorder ensures that the Pen color in Canvas is updated to use the value in BorderColor. The width for the Pen is set to 1 pixel for the drawing operation. Drawing methods in Canvas are called to draw the borders on the Left, Right, Top, and Bottom edges for the control.

DrawBorder is called from the Paint method, and occurs after the inherited Paint method and its OnPaint event handler have been executed.

Draws both the fixed rows and any visible data rows using cached information in the grid control. Calls DrawRow to render each row by its row number in the control.

DrawAllRows is called from the Paint method.

Shifts the specified rectangle by one pixel on the left- and right-hand edges when UseRightToLeftAlignment is set to True. Calls the FillRect method in the TCanvas instance to draw the adjusted rectangle.

DrawFillRect is called from the DrawCell method.

Calls PrepareCanvas to initialize the Canvas for the control to the state in AState. Calls DrawFillRect to fill the rectangle in ARect using the background for the cell. Calls DrawCellGrid to render fixed or non-fixed cells using the state in AState, including horizontal and vertical grid lines when enabled.

DrawCell is called from the DrawRow method when it renders the visible cells in the grid row.

DrawCellGrid is a procedure used to draw cell grid lines for both a fixed and a non-fixed cell in the grid control.

DrawCellGrid ensures that the control Canvas (and its Pen) are updated to use the values needed to draw the fixed or non-fixed cell at the location specified in ACol and ARow.

For a fixed cell (when gdFixed is in AState), grid lines are drawn when gdoFixedVertLine or gdoFixedHorzLine is found in the Options property. The Pen in the control Canvas is updated to reflect a non-zero value in GridLineWidth.

When Flat is set to False, the value in AState is used to determine the color used for the Pen. Canvas drawing methods, like MoveTo and LineTo, are used to draw the cell grid lines at the coordinates in ARect. The value in UseRightToLeftAlignment determines how values in ARect are adjusted for the operation.

When Flat is set to True, the value in FixedGridLineColor is used as the color for the Pen.

For a non-fixed cell (gdFixed is not in AState), grid lines are drawn when gdoVertLine or gdoHorzLine is found in the Options property. The Pen in the control Canvas is updated to use the GridLineWidth, GridLineStyle, and GridLineColor for the control. Canvas drawing methods, like MoveTo and LineTo, are used to draw the cell grid lines at the coordinates in ARect. The value in UseRightToLeftAlignment determines how values in ARect are adjusted for the operation.

DrawCellGrid is called from the DrawCell method after preparing the Canvas and drawing the filled rectangle with the background for the cell.

The implementation for DrawTextInCell is empty in TCustomGrid. It is overridden in descendent classes.

DrawThemedCell is a procedure used to draw the cell at the specified coordinates using the theme services for the platform or widget set.

aCol contains the column number for the affected cell.

aRow contains the row number for the affected cell.

aRect contains the screen coordinates for the cell rendered in the method.

aState contains the grid drawing state applied to the cell. aState contains a value from the TGridDrawState enumeration that determines the theme service element details used for the drawing operation.

DrawCellText is a procedure used to draw the text specified in AText using the given text rectangle on the Canvas for the control. The Canvas also contains the alignment and layout used for the text drawn in the method.

ARect contains the Canvas coordinates for the text is drawn. DrawCellText adjusts the bounds in ARect to account for the cell padding used in the control (varCellPadding) as needed for the text alignment and layout. The TextRect method in the Canvas is called to render the text.

Values in the ACol, ARow, and AState parameters are not used in DrawCellText.

DrawCellText is used in the implementation of the DrawColumnText, DrawCellAutonumbering, and DrawTextInCell methods where AText contains the column title, row number, or content for a given cell.

DrawGridCheckboxBitmaps is used to draw a bitmap used for a check box at the cell coordinates in ACol and aRow. AState contains the check box state for the cell, and determines the image displayed in the specified cell.

GetImageForCheckBox is called to get the image list, image index, and/or bitmap used in the cell. Use the OnUserCheckBoxImage or OnUserCheckboxBitmap event handler to get a custom image or bitmap displayed for the value in AState. If GetImageForCheckBox is unable to find either a bitmap or an image, ThemeServices is used to get the theme element details for the check box state.

The bitmap/image/theme element may be scaled if the control Font uses a display density (PPI) different than the value used for the Screen.

When Columns has been Enabled, the GetColumnAlignment and GetColumnLayout methods are used to determine the image alignment and layout used for the check box cell. If Columns has not been enabled, the image is centered horizontally in the cell using the vertical alignment defined for text on the Canvas.

DrawGridCheckboxBitmaps adjusts ARect to use the cell padding for the control (varCellPadding) along with the size, alignment and layout needed for the grid column.

The check box bitmap is drawn using the mechanism needed for the image source; ThemeServices.DrawElement, Canvas.StretchDraw, or TScaledImageListResolution.StretchDraw.

DrawGridCheckboxBitmaps is called from the DrawCellCheckboxBitmaps method.

DrawButtonCell is a method used to draw a cell which appears in a button-style column. DrawButtonCell uses ThemeServices to get the theme element details used to render the button for the cell.

AState contains the drawing state for the button, and determines the theme element details used for the drawing state. The ThemeServices.DrawElement method is called to render the button on the control Canvas at the location specified in ARect.

DrawButtonCell is called from DefaultDrawCell when the column has a button-style definition.

DrawColumnText is a method used to draw the text and image for a grid column title at the cell coordinates specified in ACol and ARow. DrawColumnText calls DrawColumnTitleImage to draw the sort indicator for the column. DrawCellText is called to render the text for the cell using the specified drawing state.

DrawColumnText is called from the DefaultDrawCell method in descendent classes for cells which are fixed column titles.

DrawColumnTitleImage is a method used to draw the image(s) used in the column title at the index position in AColumnIndex. ARect contains the bounds for the cell where the image is drawn.

When AColumnIndex contains the same value as the SortColumn property, a sort indicator is drawn for the column. GetSortTitleImageInfo is called to determine whether theme services is used to drawn native sort buttons using theme element details. The image size may be scaled when the display density (PPI) for the control Font has a value other than 96.

DrawColumnTitleImage ensures that image padding (DEFIMAGEPADDING) is applied to the bounds in ARect. The top and bottom bounds are adjusted so that the image is vertically centered in the area in ARect.

DrawColumnTitleImage calls the DrawElement method in ThemeServices to draw the sort indicator.

When native sort indicators are not used for the column, an image scaled to the display density is retrieved from the image list. DrawColumnTitleImage ensures that image padding (DEFIMAGEPADDING) is applied to the bounds in ARect. The top and bottom bounds are adjusted so that the image is vertically centered in the area in ARect. The Draw method in the scaled image resolution is called to draw the image on the control Canvas.

TitleImageList is used to determine if an additional image is displayed for the column at AColumnIndex. When TitleImageList has been assigned, the GetTitleImageInfo method is called to get the image list and position used for the column. When an image is defined in Columns, an image scaled to the size size needed for the display density (PPI) is retrieved from TitleImageList. The bounds in ARect is adjusted to include padding around the image (DEFIMAGEPADDING) using the image layout for the column. The Draw method in the scaled image resolution is called to render the image to the control Canvas.

DrawColumnTitleImage is called from the DrawColumnText method.

DrawFocusRect has an empty implementation in TCustomGrid. It is overridden in descendent classes.

DrawRow is a method used to draw the columns for the row number specified in ARow. DrawRow calls ColRowToOffSet to get the upper and lower bounds for the row, and ensures that the bounds are within the clipping area for the control Canvas.

No actions are performed in the method when the client area for the row does not fit within the clipping rectangle for the control Canvas.

DrawRow iterates over the columns in the visible area in the grid to determine if each cell fits vertically within the clipping rectangle for the control Canvas. If column spanning (goColSpanning) has been enabled in the Options for the grid, the cell extent is determined for each cell. DoDrawCell is called to render the cells.

DrawRow draws the focus rectangle for the row when row selection (goRowSelect) is enabled in the Options for the grid control. DrawFocusRect is called to render the focus rectangle.

DrawRow draws fixed cells used for title columns when the row is one of the fixed rows.

DrawRow is called from the DrawAllRows method.

When Sender is the TButtonCellEditor for the control, the DoEditButtonClick method is called using the Col and Row numbers from the TButtonCellEditor class instance. Otherwise, DoEditButtonClick is called using the values in the Col and Row properties.

EditorDoGetValue creates a GM_GETVALUE TGridMessage with the Col, Row, and value for the cell. It is dispatched to the Editor for the control. SetEditText is called prior to exiting from the method; not used in TCustomGrid - but relevant in descendent classes with an event handler for the action.

Always returns True in TCustomGrid. It is overridden in descendent classes like TCustomDbGrid.

Calls GetColumnReadonly using the value in Col as the column number.

When the Columns collection has been enabled, the ReadOnly property in the TGridColumn instance determines the return value. Otherwise, the value from GetDefaultColumnReadOnly is used as the return value (False in TCustomGrid).

EditorHide ensures that an active, visible cell editor is locked / hidden / unlocked in the method. No actions are performed in the method when EditorLocked returns True, or the Editor is not visible.

EditorHide sets the value in EditorMode to False, and sets GridState to gsNormal.

No additional actions are performed when the Editor does not have a Parent (when the parent form is closing). If the Editor has an assigned Parent, the Editor is locked and DoEditorHide is called to hide the Editor. If the Editor was focused on entry, SetFocus is called to restore focus to the grid control. The editor is unlocked prior to exiting from the method.

Returns True if both the grid and the specified column allow editing. The return value is True when all of the following conditions are satisfied:

• goEditing is included in the Options property
• ACol contains a valid column index
• RowCount has a value larger than the value in FixedRows
• The Columns collection has been Enabled (contains at least one visible column)
• A TGridColumn instance exists for the column index in ACol
• The TGridColumn instance is not marked as read-only

EditorSelectAll is a method used to select the entire content in the current cell when the Editor is active and visible. EditorSelectAll creates, configures, and dispatches a TGridMessage using the GM_SELECTALL message constant to the Editor in the grid control.

No actions are performed in the method when Editor has not been assigned (contains Nil).

EditorSelectAll is called from the EditorShow method when its SelAll argument is set to True, and from the IMEStartComposition method.

Displays and enables the cell Editor for the selected cell, and optionally selects all content in the cell.

No actions are performed in the method at design-time, or during LCL component streaming. The grid control must have an allocated Handle, and be Enabled and Visible (including the Parent). In addition, both the grid and the column must allow editing. Use Options to enable editing in grid cells. Use Columns to define TGridColumn instances with editable columns using the required button style for the column data.

No actions are performed in the method when Editor has not been assigned, or has already been displayed, or is currently locked by a call to LockEditor.

EditorShow sets the value in EditorMode to True, and saves the existing cell value on entry. EditorShowing is set to True to indicate that the Editor is visible, and calls doEditorShow to display the Editor control.

SelAll indicates whether all of the content in the current cell is selected in the Editor for the control. When set to True, the EditorSelectAll method is called to post the GM_SELECTALL message to the Editor control. The value in GridState is set to gsNormal prior to exiting from the method.

EditorShow is called when the value goAlwaysShowEditor is included in the Options for the grid control. It is also called from methods like:

• ResetEditor
• MouseDown
• MouseUp
• DoEnter
• KeyDown
• KeyPress
• MoveExtend
• MoveNextSelectable
• EditorShowInCell
• EditorShowChar
• EditorSetMode

EditorWidthChanged performs actions needed to update the width for the cell Editor when a column width in the grid has been changed. EditorWidthChanged calls the EditorPos method to set the position, bounds, and font for the Editor.

EditorWidthChanged is called when a new value is assigned to the indexed ColWidths property, and when column widths are adjusted when AutoFillColumns is set to True.

FirstGridColumn is an Integer function used to get the ordinal position of the first column appearing after any fixed column in the grid control. The return value contains the value in the FixedCols property.

FirstGridColumn is used in the implementation of methods including:

• GetColWidths
• GetIsCellTitle
• ColumnIndexFromGridColumn
• GridColumnFromColumnIndex
• ColumnsChanged

FixedGrid is a Boolean function used to determine whether all columns in the grid are defined as fixed columns, or all rows are defined as fixed rows. The return value is True when FixedCols is equal to ColCount OR FixedRows is equal to RowCount.

FixedGrid is used in the implementation of methods like: SetFixedCols, SetFixedRows, MouseToGridZone, MouseDown, MouseMove, MouseUp, TryMoveSelect, EditorAlwaysShown, and FixPosition.

FontChanged is an overridden method used to perform actions needed when the Font for the control has been changed.

FontChanged ensures that the internal default heights for rows and columns are reset to 0 (zero). This causes the default column and row heights to be recalculated when the DoAutoAdjustLayout method is called.

When csCustomPaint is included in ControlState, the Font is assigned to the Canvas for the control.

Otherwise, the FontChanged method is called for the ancestor class and the Columns collection (when Enabled). If the default title font is used for the control, the Font is assigned to TitleFont property.

FontChanged is assigned as the OnChange event handler for the Font property in the constructor for the class instance.

GetAutoFillColumnInfo is a method used to get sizing information for an auto-fill column specified in Index. AMin, AMax, and APriority are variable arguments updated with the values for the requested column.

GetAutoFillColumnInfo calls ColumnFromGridColumn to get the TGridColumn instance in Columns with the requested values. If a column exists with the requested Index, its properties are stored in the variable parameters. When Index is a fixed column in the grid, the value in APriority is set to 0 (zero) which disables auto-sizing for the column. If Columns has not been Enabled for the control, or the column index is not valid, APriority is set to 1.

GetAutoFillColumnInfo is called when AutoFillColumns is set to True, and the column sizes are recalculated for the the grid control.

GetCellHintText signals the OnGetCellHint event handler (when assigned) to get the hint text for the cell at the position in ACol and ARow. The return value contains the hint text returned from the event handler, or an empty string ('') when the event handler has not been assigned.

GetCellHintText is called from the ShowCellHintWindow method when Options contains the value goCellHints and CellHintPriority is not set to chpTruncOnly.

Always returns an empty string ('') in TCustomGrid. Overridden in descendent classes.

Calls ColumnFromGridColumn to get the TGridColumn instance in Columns for the column number in the Column parameter.

ForTitle indicates the alignment used as the return value for the specified column number. When set to True, the alignment for the Title in the TGridColumn instance is used as the return value. Otherwise, the alignment property in the TGridColumn instance is used as the return value.

Called from the PrepareCanvas and DrawGridCheckboxBitmaps methods.

GetColumnColor ensures that the correct color value is used to render the background for the specified column number.

When the Columns collection has been enabled, the color is retrieved from the TGridColumn instance. The Color property in TGridColumn is used when ForTitle is set to False. Otherwise, the Color in the Title for the column instance is used.

If the Columns collection has not been enabled, the color is retrieved from the Color or FixedColor properties in the grid control. FixedColor is used when ForTitle is set to True.

GetColumnColor is called from the PrepareCanvas method.

Use properties like AlternateColor, FixedHotColor, FocusColor, and SelectedColor to control when the corresponding Options are enabled for the grid control.

GetColumnTitle is a String function used to get the text displayed as the column title for column number specified in Column. ColumnFromGridColumn is called to get the non-fixed TGridColumn instance at the specified position in the Columns collection.

If a column exists at the position in Column, the Caption stored in its Title property is used as the return value. If Column does not represent a valid non-fixed column position, or the Columns collection has not been enabled, the value from the GetDefaultColumnTitle method is used as the return value.

GetColumnTitle is called from the DrawColumnText method when the image and text for the column header is drawn.

GetColumnWidth calls ColumnFromGridColumn to get the TGridColumn instance for the column number in the Column parameter. If the grid column is assigned, its Width property is used as the return value for the method.

The grid column may be unassigned (contain Nil) if Column is not a valid column number for the control, or Columns has not been Enabled for the grid. In this situation, GetDefaultColumnWidth is called to get the return value for the method.

AAutoAdvance contains the navigation direction requested in the method. When it is set to aaNone, the values in ACol and ARow always contain 0 (zero) indicating no relative movement.

When Inverse is set to True, the cell navigation order in AAutoAdvance is reversed. When row selection is enabled in the grid Options (using goRowSelect), ACol is set to the first non-fixed column in the grid. Otherwise, it is set to the last column in the grid. Other auto-advance values are handled as follows:

• aaLeft is treated as if it were aaRight
• aaRightDown is treated as if it were aaLeftUp
• aaLeftDown is treated as if it were aaRightUp
• aaRightUp is treated as if it were aaLeftDown
• aaLeftUp is treated as if it were aaRightDown

The next cell for the navigation order is calculated and returned in the ACol and ARow arguments. The return value is True if the values in ACol and ARow were successfully selected as the current cell in the grid.

GetDefaultColumnAlignment is a TAlignment function which provides the default horizontal alignment for text in the columns for the grid control. It is used in the GetColumnAlignment method when Columns are not Enabled for the control. GetDefaultColumnAlignment returns the Alignment value from DefaultTextStyle as stored in the constructor for the class instance.

GetDefaultColumnWidth is an Integer function which retrieves the default width for the specified Column in the grid control. GetDefaultColumnWidth is used in the GetColumnWidth method when Columns have not been enabled for the control. It returns the value stored in the DefaultColWidth property.

Use the indexed ColWidths property to set the width for an individual column when the Columns collection has not been enabled. Or, use the Columns collection to maintain column definitions including their editing and display attributes.

GetDefaultColumnLayout gets the default vertical layout for text in the specified Column. The DefaultTextStyle property is used as the source for the text Layout, and contains the value assigned in the constructor for the class instance.

GetDefaultColumnLayout is called from GetColumnLayout when a TGridColumn instance cannot be located in Columns for the specified column number. This occurs when Column is invalid for the defined Columns in the control, or when Columns has not been Enabled (contains at least one visible column).

Change values in the DefaultTextStyle property to override the default values assigned in the Create method. Use the Columns collection to change the text layout used in a column when Columns are Enabled.

GetDefaultColumnTitle provides the text used for the specified column number when Columns have not been enabled for the grid control. GetDefaultColumnTitle always returns an empty string ('') in TCustomGrid.

GetDefaultColumnTitle is called from the GetColumnTitle method.

GetDefaultEditor is a TWinControl function used to get the default Editor control for the specified column number.

GetDefaultEditor calls EditingAllowed to determine if the column can be edited. When editing is permitted, the Columns collection is used to get the ButtonStyle stored in the TGridColumn instance. If the column uses the cbsAuto button style and has a valid non-empty PickList, the cbsPickList button style is used.

If Columns has not been enabled, the cbsAuto button style is always used for the Editor control.

GetDefaultEditor calls EditorByStyle to create the Editor with the button style needed for the control. The return value is Nil if the column does not allow editing, or the current cell is a fixed column or row header.

For an Editor using the cbsPickList button style, its items and drop-down row count are set using values from the column definition in Columns.

GetDefaultEditor is called from the SelectEditor method prior to selecting the cell and signalling the OnSelectEditor event handler (when assigned). Use the OnSelectEditor event handler to override the Editor style or its configuration.

GetDefaultRowHeight is an Integer function used to get the default height for a row in the grid control.

GetDefaultRowHeight uses a TCanvas instance to get the height for the text displayed in a row. If the control Canvas is unassigned, or does not have an allocated handle, a temporary TCanvas instance is created using the Font for the control. The TextHeight method in Canvas is called to get the return value for the method.

GetDefaultRowHeight is called from the GetDefRowHeight method used to get the value for the DefaultRowHeight property.

GetGridDrawState is a TGridDrawState function used to get the state flags for the cell specified in ACol and ARow. The return value can contain the following enumeration values:

gdFixed

ARow is one of the FixedRows for the grid.

gdFocused

ACol and ARow have the same values as the Col and Row properties.

gdSelected

ACol and ARow have the same values as the Col and Row properties, or the cell is included in a selection range.

gdRowHighlight

Row highlighting is enabled in Options, Row and aRow have the same value, and the cell is not a fixed cell.

gdPushed

ACol and ARow match the cached PushedCell coordinates.

gdHot

ACol and ARow match the cached HotCell coordinates, and the cell is not "pushed".

GetGridDrawState is called from the DrawRow and ShowCellHintWIndow methods.

GetImageForCheckBox signals the OnUserCheckboxBitmap event handler (when assigned) to get a bitmap used for the check box state. If a valid TBitmap instance is not assigned in the event handler, the OnUserCheckBoxImage event handler is signalled (when assigned) to get the TImageList, TBitmap, and ImageIndex used for the purpose.

GetImageForCheckBox is used in the implementation of the DrawGridCheckboxBitmaps and DrawCellText methods in TCustomGrid.

GetScrollBarPosition is an Integer function used to get the position for the scroll bar specified in Which. GetScrollBarPosition calls the GetScrollInfo routine in the LCL interface to get the TScrollInfo structure with the position for the scroll bar in Which.

The return value contain the position from the TScrollInfo structure. The return value is 0 (zero) if the Handle for the grid control has not been allocated.

Called from the CalcScrollbarsRange method when the grid has been scrolled or when a size value in ColWidths has been changed.

Called from the PrepareCanvas method when fixed cells are drawn, or when DefaultDrawing is enabled for the control.

GetEditMask provides the mask posted in a grid message to an active cell Editor control. It occurs immediately before the grid message that posts the cell value to the editor control.

GetEditMask always returns an empty string ('') in TCustomGrid. It is overridden in descendent classes.

GetEditText always returns an empty string ('') in TCustomGrid. It is overridden in descendent classes like TCustomDrawGrid and TCustomStringGrid to signal an OnGetEditText event handler.

GetEditText is called from the EditorDoSetValue method when TGridMessages are dispatched to the Editor to set the edit mask and value used in the control.

GetFirstVisibleColumn is an Integer function used to get the column number for the first visible non-fixed column in the grid. A visible column is one which starts after the fixed columns specified in FixedCols and has a non-zero width for the column in ColWidths.

The return value contains the column number (zero-based) for the column matching the criteria. If a non-fixed column with a non-zero width is not found, the return value is set to ColCount.

GetFirstVisibleColumn is called from the KeyDown method when handling Tab key navigation for the grid control.

GetFirstVisibleRow is an Integer function used to get the row number for the first visible non-fixed row in the grid. A visible row is one which starts after the fixed rows specified in FixedRows and has a non-zero height for the row in RowHeights.

The return value contains the row number (zero-based) for the row matching the criteria. If a non-fixed row with a non-zero height is not found, the return value is set to RowCount.

GetFirstVisibleRow is called from the KeyDown method when handling Tab key navigation for the grid control.

GetLastVisibleColumn is an Integer function used to get the column number for the last visible non-fixed column in the grid. A visible column is one which has a non-zero width for the column in ColWidths.

The return value contains the column number (zero-based) for the column matching the criteria. If a column with a non-zero width is not found, the return value contains -1.

GetLastVisibleColumn is called from the KeyDown method when handling Tab key navigation for the grid control.

GetLastVisibleRow is an Integer function used to get the row number for the last visible non-fixed row in the grid. A visible row is one which has a non-zero height for the row in RowHeights.

The return value contains the row number (zero-based) for the row matching the criteria. If a row with a non-zero height is not found, the return value contains -1.

GetLastVisibleRow is called from the KeyDown method when handling Tab key navigation for the grid control.

GetTitleShowPrefix determines whether the DT_NOPREFIX DrawText flag is included in the Canvas text style for the specified column. When GetTitleShowPrefix returns False, the DT_NOPREFIX flag in included in the text style.

GetTitleShowPrefix is called from the PrepareCanvas method when drawing a cell in the fixed rows for the grid.

GetPxTopLeft is used to implement scrolling operations in the WMHScroll and WMVScroll window message handlers.

GridColumnFromColumnIndex is an Integer function used to get the position in Columns for the visible column represented by ColumnIndex. It is necessary because a grid can include 0 or more fixed columns. This is a problem because: A) the fixed columns are both optional and variable, and B) the Columns collection uses ordinal values and never includes a column definition for fixed column.

ColumnIndex refers to the ordinal position for a visible column in the display area for the grid control. The return value is calculated as ColumnIndex + FirstGridColumn. In previous versions of the LCL, the value was derived using values from VisibleIndex and FixedCols.

The return value is -1 if the computed value is larger than ColCount-1.

GridColumnFromColumnIndex is used when a new value is assigned to the Index property in a TGridColumn instance. It is also used in the DialogChar method to locate and perform the OnClick handler for the column header where an accelerator key is found.

GridMouseWheel ensures that the Delta value for the mouse wheel event is correctly applied for horizontal scroll messages. These are the scroll messages which occurs when the Ctrl key is pressed. GridMouseWheel calls the MoveNextSelectable for both horizontal and vertical messages, but the value in Delta is used as the column argument when Ctrl is included in the Shift modifier. Otherwise, Delta is used as the Row argument.

GridMouseWheel is called from methods like: DoMouseWheelDown, DoMouseWheelUp, DoMouseWheelLeft, and DoMouseWheelRight.

HeaderClick ensures that the value in SortOrder is toggled when Index contains the SortColumn defined for the grid control. SortOrder is set to soAscending when Index contains a column number other than SortColumn. SortColumn is updated in the method to use the value in Index as the active sort column.

HeaderClick calls the Sort method to sort all non-fixed rows in the grid control using the content from the column number in Index.

No actions are performed in the method when ColumnClickSorts is set to False.

IsColumn indicates whether the header click applies to a column or a row. When set to True, the mouse click occurred in a fixed header for the column number in Index. This parameter implies that similar handling is provided in the method for a header click on a fixed header in a row. No actions are performed for a header click on a row.

HeaderClick is overridden in descendent classes like TCustomDrawGrid to perform additional actions.

HeaderClick is called from methods like DialogChar and MouseUp.

HeaderSized is used to perform actions needed when the header for a column or row has been resized in the grid control.

IsColumn indicates whether the sizing action applies to a column or a row. When set to True, the column header has been resized. When set to False, the row header was resized.

Index indicates the column or row number in the grid where the resizing action occurred.

HeaderSized has an empty implementation in TCustomGrid. It is overridden in descendent classes like TCustomDrawGrid to perform additional actions.

HeaderSized is called from methods like MouseUp (when column or row sizing is completed) and DblClick (when column sizing is enabled in the grid Options).

HeaderSizing has an empty implementation in TCustomGrid. It is overridden in descendent classes.

HideCellHintWindow is a method used to cancel the current hint display, and to restore the saved Hint for the grid control. HideCellHintWindow calls the CancelHint method in the Application singleton to discard the current hint window.

Called when a new value is assigned to the ColCount property (SetColCount).

Returns True when AIndex is a valid column index in the range 0..ColCount-1.