Filling blank space in delphi stringgrid

Question

I have a grid that can be resized. And i'm now stuggeling with filling the blank space around columns in the grid. I'm trying to achieve this on FormResize.

First i calculate what is the total of columns width and then i'm comparing it to the string grid width. if the stringgrid widths is bigger then i add to each columns width equal portions of the blank space left. This is how it looks in formResize Procedure:

procedure TBDDTool.FormResize(Sender: TObject);
var
  totColWidth,i : integer;
begin
  totColWidth := 0;
  for i := 0 to sgFilePreview.ColCount - 1 do
    totColWidth := totColWidth + sgFilePreview.ColWidths[i];
  if sgFilePreview.Width > TotColWidth then
    begin
      for i := 0 to sgFilePreview.ColCount - 1 do
        begin
          sgFilePreview.ColWidths[i] := round(sgFilePreview.ColWidths[i] +
                ((sgFilePreview.Width - totColWidth)/(sgFilePreview.colCount)));
        end;
    end;

end;

This actualy doesn't work cause sgFilePReview.Width is the width of my grid. And i don't know how to get the width of the whole space inside the grid, like every columns + blank space left. How can i get the real width of the grid? Cause sgFilePreview.Width return the width of the grid but as seen from outside the grid.

Thank you!

EDIT

Addine new columns

          for val in sLineSplitted do
        begin
          if Pos('#',val) <> 0 then propVal := copy(val,0,pos('#',val)-1)
          else propVal := val;
          col := col +1;
          if (row = 1) then
            begin
              if (col >1) then
      //Add column
              sgFilePreview.ColCount := col;
              sgFilePreview.Cols[col-1].Text := propVal;
              SetLength(aSourceData[row-1],col);
              aSourceData[row-1,col-1] := val;
            end
          else
            begin
            sgFilePreview.RowCount := row;
              SetLength(aSourceData[row-1],col);
              aSourceData[row-1, col-1] := val;
              sgFilePreview.Cells[col-1, row-1] := propVal;
              pnlFileManager.Visible := true;
            end;


        end;

Auto size columns to fit word if the world is bigger than the cell's width

    procedure TBDDTool.AutoSizeGrid(Grid: TStringGrid);
const
  ColWidthMin = 10;
var
  C,R,W, ColWidthMax: integer;
begin

  for c := 0 to Grid.ColCount - 1 do
    begin
      ColWidthMax := ColWidthMin;
      for R := 0 to Grid.RowCount - 1 do
        begin
          W := Grid.Canvas.TextWidth(Grid.Cells[C,R]);
          if W > ColWidthMax then
            ColWidthMax :=W;
        end;
        Grid.ColWidths[C] := ColWidthMax +5;
    end;


end;    

Answer 1

The main problem why these empty spaces are occurring to you even when you have too many columns so that all of them can be seen at the same time is the fact that in StringGrid scrolling works a bit different than you are used to in other controls.

When you scroll around in StringGrid the scrolling position is always aligned to the position of TopLeft visible cell. So if the combined width of visible cols isn't the same as ClientWidth this means that you will either have partially visible col at the right side or and empty space when you have scrolled all the way to the right.

Now one possible way to avoid this is to resize the columns so that they always fit into the client width (no partially visible columns). But the problem is that this becomes practically impossible if you have different widths for each column.

In case if you can live with the fact that all columns will have same width you can use the code below which works in most cases. It isn't perfect because you can only set column width to integer values where sometimes you would need larger precision.

procedure TForm1.FormResize(Sender: TObject);
var cwDefaultWidth: Integer;
    VisibleCols: Integer;
    ColWidth: Integer;
begin
  cwDefaultWidth := 64;
  VisibleCols := StringGrid1.ClientWidth div cwDefaultWidth;
  if VisibleCols >= StringGrid1.ColCount then
  begin
    ColWidth := Round(StringGrid1.ClientWidth / StringGrid1.ColCount-1);
  end
  else
  begin
    ColWidth := Round(StringGrid1.ClientWidth / VisibleCols-1);    
  end;
  StringGrid1.DefaultColWidth := ColWidth;
end;

But if you are using variable column widths then the only thing that you could do is adjust the size of the last column so that it's width fills the empty space that would otherwise appear.

In order to do that you would first have to check to see if you are scrolled fully to the right. Then you would have to sum up the width of currently seen columns. You could do this by using:

for I := StringGrid1.LeftCol to StringGrid1.RowCount-1 do
begin
  VisibleColsWidth := VisibleColsWidth + StringGrid1.ColWidths[I];
end;

Then you subtract this width from StringGrid1.ClientWidth and you get the width of empty space. So finally you increase the size of last column for the empty space width.

I really hope that even if my answer doesn't provide you with an actual solution it would at least guide you towards finding the right solution.