15 replies to this topic

[user22]

Hi,

i want to sort my grid by rows and in the way the columns are ordered.
In detail: if i compare row 1 and row 2 then at first i compare the first column (order by position, not by index!) from row 1 and row 2. If both values are equal i compare the second column and so on ... till i have a difference (or no more columns are left).
I tried this using custom sort and changing the sorted column after a column move in the column move event, but in the compare procedure i get Cell1 and Cell2 and don't know how to get the other Cells if this one are equal. I would need the row information from Cell1 and Cell2 to check the other Cells, but Cell1.RowIndex and Cell2.RowIndex are always identical, so something is wrong - either the Rowindex or my concept.
Or is there another way?

thanks,
user22

[Boki (Berg)]

Hello,

I recommend reading next article first:
http://www.bergsoft....page=customsort

there is also demo attached and you may modify it for your needs.

Cell.RowIndex is empty when accessed to it directly, something else need to be done

Best regards

[Boki (Berg)]

PS. If you can send me some small examle, maybe I can modify it too.

[user22]

Hi Boki,

i have read this article very carefully before, believe me :-) But i need the possibility that if Cell1 and Cell2 are equal i can compare two values from another column in the row of Cell1 respectively Cell2.

bye,
user22

Or maybe we can have something like a SortRow function where i get two rownumbers instead of two Cells??

[Boki (Berg)]

Hello,

Maybe function GetCellIndex may help for this situation? I will need to add it first.

Best regards

[user22]

Hello Boki,

if GetCellIndex will help me to find the row from this Cell, then yes.
But what do you think about my suggestion of a row-depending sort?

thank you very much,
user22

[Boki (Berg)]

Hello,

I will add it now. I will send you code when I finish it.

Can you please give me more details about this event. As I understand, it is similar to OnCompare but with RowIndex parameter?

regards

[Boki (Berg)]

Hello,

I have add 2 methods:

In NxCells.pas, in public of TCells add:

CODE

function TCells.GetCellRowIndex(ACell: TCell): Integer;
var
  i: Integer;
begin
  for i := 0 to Pred(FColCount) do
  begin
    Result := FCellsList[i].IndexOf(ACell);
    if Result <> -1 then Exit;
  end;
end;

In NxGrid.pas, in public of TNextGrid add:

CODE

function TNextGrid.GetCellRowIndex(ACell: TCell): Integer;
begin
  Result := FCells.GetCellRowIndex(ACell);
end;

I hope that this is it

regards

[user22]

Hi Boki,

i tried to add it but i get the compiler error that ACol in new function TCells.GetCellRowIndex(ACell: TCell) in NxCells.pas is not defined ??

thanks,
Helmut

... and yes, SortRows method should work like normal sort but instead of using OnCompare with two Cells we have two rownumbers as parameter and depending on the return value you do nothing or you exchange the two rows (like in onCompare).
Maybe we will name the event OnCompareRows(rowindex1, rowindex2): integer and i can start it with ... myNextGrid.SortRows;
But it would be good if SortRows can work without OnCompareRows() too - if this event is not defined, it sorts internally using the cells depending on the datatype and it uses the visible order of the rows. So it compares the two cells in the first column, if they are equal then it compares the cells in the second column ...
This is the functionality i need as fast as possible, so i try to do all the necessary steps in my application and so i need the row info.
But then at next we could think about using hidden columns too or not or only using hidden columns, having a property "sortAfterColMoving" where grid executes SortRows automatically after a column has been moved to another position, ... and so on

[Boki (Berg)]

Hello Helmut,

I have Edit post before you post for code in TCells. Please try again

If you like, I may add OnCompareRows now. Both events will be called, OnCompare for cell, OnCompareRow for Row. If this is ok, I will add it now.

regards

[user22]

Hi Boki,

i have solved the compiler-error in changing ACol to ACell.ColumnIndex
Hope this is okay, the first sorting tests where fine.

And here is the source what i do in the moment to have "RowSorting", maybe you have some comments about it (or you see something is wrong):

CODE

procedure TFoList.CompareRows(Sender: TObject; Cell1, Cell2: TCell;
var Compare: Integer);
var x, col, r1, r2: integer;
ng: TNextGrid;
begin
ng := TNextGrid(sender);
r1 := ng.GetCellRowIndex(Cell1);
r2 := ng.GetCellRowIndex(Cell2);

compare := 0;
for x := 0 to ng.Columns.Count - 1 do begin
col := ng.Columns.PositionItem[x].Index;
if ng.Cells[col,r1] = ng.Cells[col,r2] then continue;
case ng.Columns[col].ColumnType of
ctBoolean:
if ng.Cell[col,r1].AsBoolean // true/false is different, but what is higher?
then compare := 1 else compare := -1;
ctAutoInc, ctInteger:
if ng.Cell[col,r1].AsInteger > ng.Cell[col,r2].AsInteger
then compare := 1 else compare := -1;
ctDate, ctFloat:
if ng.Cell[col,r1].AsFloat > ng.Cell[col,r2].AsFloat
then compare := 1 else compare := -1;
ctGuid, ctString:
if ng.Cells[col,r1] > ng.Cells[col,r2]
then compare := 1 else compare := -1;
end;
if compare <> 0 then break; // don't compare columns like ctGraphic, ctVirtual, ...
end;
end;

As you can see, with GetCellRowIndex i get the same information as i would get with OnCompareRows, so there is not really a need for it now, i think.

thank you very much!

[Boki (Berg)]

Hello Helmut,

I will do some testings now, and then answer you.

regards

[Boki (Berg)]

Hello Helmut,

I have do some research. It will a releative easy to add OnRowCompare event. If you still need it urgently, I may add it.

In next period, I will automatically update ColIndex and RowIndex for cell, so RowIndex will be able to read from Cell directly.

regards

[user22]

Hi Boki,

in the moment i have a solution i can live with, so there is no need to implement something urgently. I would prefer to have ColIndex and RowIndex with actual values in Cell object when OnCompare is executed.

best regards

[nevel]

Hi Helmut,

Could you please explain how you managed to get it working?
Your CompareRows procedure looks fine, but when do you call it?

Thanks in advance.

[user22]

Hi Nevel,

my grids where always sorted by column sequence - so for example if a grid is sorted by name and the user wants to sort it by birthdate then he moves the birthdate column in first position and the grid knows now that it has to sort the data by date (and persons with same date are sorted by name, which is now the second column, and so on).

bye,
Helmut