StringGrid - possible to make a drag/move of rows feature?

[JohnLM 14]

Win7, D11.2, FMX app, using TStringGrid and FireDAC and SQLite

 

I was wondering, is it possible to make the TStringGrid have a drag or moveable rows feature?

 

In a barcode app that I am working on, there will be times when I might want to reorient some of the rows that I scan barcodes off of products. I have a [delete] tbutton feature to delete rows. When I do this, I will resync the line numbers only.  So, say I delete some rows and/or want to move one or more rows, the line number order will be out of sync. Sorting them shouldn't be a problem for just that column, while the remaining columns will stay in the same order. I can re-sort just the [Line Number] column. 

 

Back to the drag/move rows..

 

Methods:

1) Because my S10+ phone is so small, I use a pen for it most of the time. That is what I will use to move the rows up/down. So, I'd like to be able to drag rows that way. But if it is not possible, then

 

2) be able to move rows up/down using two tbuttons for the [up] and [down] on the form instead. 

 

What do you guys think?  Is there a way to make this happen for the TStringGrid component?

Edited December 27, 2022 by JohnLM

[programmerdelphi2k 237]

hi @JohnLM

• first, in FMX StringGrid/Grid all values is a "string" by default!
  • each column is independent each other
  • there is not "row concept", but "Cols with lines"... Then, you has many "lines" in a column!
• you can try using "mouse event" or drag'n'drop!

 

here my sample using "mouse event":

• Here, I'm not testing if the values are OK, or if it's the same line, etc... just showing a general idea of the process!
• The rest is up to you!

// FMX StringGrid using mouse event to "move" content of each "row" in all columns

type
  TMyCellsData = TArray<string>;

  TRecRowContent = record
    FRow: integer;       // what is the row?
    FData: TMyCellsData; // what is the data? = all in string representation
  end;

var
  LRowSrcContent: TRecRowContent;
  LRowTrgContent: TRecRowContent;
  LRowMoving    : boolean = false;

procedure TForm1.FormCreate(Sender: TObject);
begin
  StringGrid1.OnMouseDown := MyOnMouseDown;
  StringGrid1.OnMouseUp   := MyOnMouseUp;
  //
  StringGrid1.Options := StringGrid1.Options + [TGridOption.RowSelect]; // avoid "edit cell" on click!
end;

// simulating a rowwwwwwwwwwwwwwwwwwww....... in col1 + col2 + col3 + ...
procedure MyGetWholeRow(AStringGrid: TStringGrid; ARow: integer; out AMyCellsData: TRecRowContent);
begin
  AMyCellsData.FRow := ARow; // what is the row?
  AMyCellsData.FData := []; // clear old-datas  
  //
  for var i: integer   := 0 to (AStringGrid.ColumnCount - 1) do
    AMyCellsData.FData := AMyCellsData.FData + [AStringGrid.Cells[i, ARow]];
end;

procedure TForm1.MyOnMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Single);
begin
  inherited;
  //
  if (ssCtrl in Shift) then // using "Ctrl" just for test
    begin
      MyGetWholeRow(StringGrid1, StringGrid1.RowByPoint(X, Y), LRowSrcContent);
      //
      LRowMoving := true;
    end;
end;

procedure TForm1.MyOnMouseUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Single);
var
  LRow: integer;
begin
  inherited;
  //
  if LRowMoving and (ssCtrl in Shift) then
    begin
      LRow := StringGrid1.RowByPoint(X, Y);
      //
      MyGetWholeRow(StringGrid1, LRow, LRowTrgContent); // before override row-datas
      //
      for var i: integer                          := 0 to high(LRowSrcContent.FData) do // move data
        StringGrid1.Cells[i, LRowTrgContent.FRow] := LRowSrcContent.FData[i];
      //
      for var i: integer                          := 0 to high(LRowTrgContent.FData) do // restore row-datas
        StringGrid1.Cells[i, LRowSrcContent.FRow] := LRowTrgContent.FData[i];
    end;
  //
  LRowMoving           := false;
  LRowSrcContent.FRow  := -1;
  LRowSrcContent.FData := [];
  LRowTrgContent.FRow  := -1;
  LRowTrgContent.FData := [];
end;

 

Edited December 27, 2022 by programmerdelphi2k

[JohnLM 14]

I will have a look at this later.  I'm trying to work out another unrelated issue that came up in and can't seem to get it working. As always, thanks for your response.