TsWorksheetGrid - Highlight a row when header is clicked
lazarus / 49-FPSpreadsheet

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straetch · 2025-09-24 11:43

I want the user to easily follow the same row when scrolling
horizontally.
The property goRowHighlight works only in the grid itself (I suppose
as the worksheetgrid is inherited from TCustomGrid).
Clicking on a header does not seem to trigger any event.

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wp · 2025-09-24 13:53

Yes, TsWorksheetGrid is a specialized variant of TCustomGrid, and most
of what you can do with TCustomGrid you can do also with
TsWorksheetGrid.

Highlighting rows: Provider a handler for the OnPrepareCanvas event.
Here you can dim or brighten the cell backgrounds in the selected row
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i uses 
GraphUtil; function GrayValue(AColor: TColor): Byte;begin  Result :=
round((0.3*Red(AColor) + 0.59*Green(AColor) +
0.11*Blue(AColor)));end; procedure
TForm1.sWorksheetGrid1PrepareCanvas(Sender: TObject; aCol,  aRow:
Integer; aState: TGridDrawState);var  grid: TsWorksheetGrid;  c:
TColor;begin  grid := Sender as TsWorksheetGrid;  if (goRowHighlight
in grid.Options) and (aRow = grid.Row) then  begin    c :=
ColorToRGB(grid.Canvas.Brush.Color);    if GrayValue(c) >= 128 then  
  grid.Canvas.Brush.Color := GetShadowColor(c, -20)    else     
grid.Canvas.Brush.Color := GetHighlightColor(c, 50);  end;end;
Click on fixed cells: Provider a handler for the OnMouseDown event and
move the active cell into the row (or column) of the clicked header
cell:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.sWorksheetGrid1MouseDown(Sender: TObject;  Button:
TMouseButton; Shift: TShiftState; X, Y: Integer);var  grid:
TsWorksheetGrid;  C, R: Integer;begin  grid := (Sender as
TsWorksheetgrid);  if (Button = mbLeft) and (grid.HeaderCount = 1)
then  begin    grid.MouseToCell(X, Y, C, R);    if C = 0 then     
grid.Row := R    else if R = 0 then      grid.Col := C;  end;end;

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straetch · 2025-09-24 19:00

I think there is a misunderstanding of the term "header". In the
documentation of TCustomGrid the header is a (fixed) row (or column)
of the grid itself.
I was referring to "header" as in : "ShowHeaders (boolean): can be
used to turn off the column and row headers ('A', 'B', 'C', ..., '1',
'2', '3')." (ref. FPSpreadsheet wiki).
I am looking for a way to highlight a grid row by clicking that
header.

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wp · 2025-09-24 21:22

Quote from: straetch on September 24, 2025, 09:00:32 pmI am looking
for a way to highlight a grid row by clicking that header.
Isn't that what my posted code fragments are doing? The
OnPrepareCanvas handler draws the highlighted row in a way that keeps
the background colors of the cells, and the OnMouseDown handler moves
the active cell into the row of the clicked header so that it is drawn
as highlighted.

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straetch · 2025-09-25 12:54

Many thanks.
Initially I was using the worksheetgrid click event. But that does not
trigger when a header is clicked.