asked on

TDBGrid Title Header Glyphs

I would like to Add the capability of showing a up & down arrow glyph to the column that is currently sorted based on its sort order.

See screenshot for an example from another program i found.

Currently, I change the title caption to bold if its sorted.

See my attached code snipplet

I know how to create glyphs, and I know how to add the glyphs to my current resource file. I just need the code to draw the glyphs on the current sorted columns title header. Because I allow my users to change each columns title header properties (font, background color, ect) - the code should respect the current sorted columns properties.

THanks

procedure TfrmMain.grdMainTitleClick(Column: TColumn);
{$J+}
 const PreviousColumnIndex : integer = -1;
{$J-}
begin
  if grdMain.DataSource.DataSet is TCustomADODataSet then
  with TCustomADODataSet(grdMain.DataSource.DataSet) do
  begin
    try
     grdMain.Columns[PreviousColumnIndex].title.Font.Style := grdMain.Columns[PreviousColumnIndex].title.Font.Style - [fsBold];
    except
    end;
    Column.title.Font.Style := Column.title.Font.Style + [fsBold];
    PreviousColumnIndex := Column.Index;
    if (Pos(Column.Field.FieldName, Sort) = 1)
    and (Pos(' DESC', Sort)= 0) then
     Sort := Column.Field.FieldName + ' DESC'
    else
     Sort := Column.Field.FieldName + ' ASC';
  end;
end;

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gsak-screenshot.jpg

TheRealLoki

the standard DBGrid does not allow you to do such abilities
However, you can use a THeaderControl instead
it even goes so far as to allow you to do custom drawing of each header section

here's an example I whipped up for you to do the "sort" icons
you will need :-
a TImageList (callled imagelist1) with 2 images in it
place a TPanel on the form (called panel1)
place a THeaderControl (from the Win32 tab) inside panel1
move your dbgrid into panel1 below the header control

turn off the title in your dbgrid
dbgrid1.Options -> untick "rgTitle"

now use the folliowing code, putting the call to your sort routine in place of "Do_SortDataRoutine"

const
 sort_Reversed = 100;
 
...
  AttachHeaderToDBGrid(HeaderControl1, DBGrid1);
...
 
procedure TForm1.AttachHeaderToDBGrid(header: THeaderControl; grid: TDBGrid);
var
  newsection: THeaderSection;
  i: integer;
begin
  header.Tag := 0;
  header.Sections.Clear;
  if dgindicator in grid.Options then
  begin
    newsection := header.Sections.Add;
    newsection.Text := '';
    newsection.MinWidth := 16;
    newsection.MaxWidth := 16;
    newsection.Width := 16;
    newsection.AllowClick := false;
  end;
  for i := 0 to pred(grid.Columns.Count) do
  begin
    newsection := header.Sections.Add;
    newsection.Text := grid.Columns[i].Title.Caption;
    newsection.Width := grid.Columns[i].Width;
    newsection.AllowClick := true;
  end;
  header.Tag := integer(grid);
end;
 
procedure TForm1.HeaderControl1SectionResize(HeaderControl: THeaderControl; Section: THeaderSection);
var
  dbgridcolid: integer;
begin
  if HeaderControl.Tag = 0 then exit;
  dbgridcolid := Section.ID;
  if (dgindicator in TDBGrid(HeaderControl.Tag).Options) then
    dec(dbgridcolid);
  TDBGrid(HeaderControl.Tag).Columns[dbgridcolid].Field.DisplayWidth := Section.Width;
  TDBGrid(HeaderControl.Tag).Columns[dbgridcolid].Width := Section.Width;
 
end;
 
procedure TForm1.HeaderControl1SectionClick(HeaderControl: THeaderControl; Section: THeaderSection);
var
  dbgridcolid: integer;
  currentsortcol: integer;
  isreversed: boolean;
  i: integer;
begin
  if HeaderControl.Tag = 0 then exit;
  dbgridcolid := Section.ID;
  if (dgindicator in TDBGrid(HeaderControl.Tag).Options) then
    dec(dbgridcolid);
  currentsortcol := TDBGrid(HeaderControl.Tag).Tag;
  isreversed := false;
  if (currentsortcol >= sort_Reversed) then
  begin
    currentsortcol := currentsortcol - sort_Reversed;
    isreversed := true; // will toggle back to normal
  end;
  if (dbgridcolid = currentsortcol) then
  begin
    isreversed := not isreversed; // toggle direction
    if isreversed then
      TDBGrid(HeaderControl.Tag).Tag := dbgridcolid + sort_Reversed
    else
      TDBGrid(HeaderControl.Tag).Tag := dbgridcolid;
  end
  else
  begin
    TDBGrid(HeaderControl.Tag).Tag := dbgridcolid;
    isreversed := false;
  end;
  for i := 0 to pred(HeaderControl.Sections.Count) do
  begin
    if HeaderControl.Sections[i].ID <> Section.ID then
      HeaderControl.Sections[i].ImageIndex := -1
    else if isreversed then
      HeaderControl.Sections[i].ImageIndex := 1 // reversed order
    else
      HeaderControl.Sections[i].ImageIndex := 0; // normal order
  end
// place the call to your sorting here eg.
// Do_SortDataRoutine(dbgridcolid, isreversed);   //( dbgrid column, reversed? )
end;

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TheRealLoki

oh i forgot to mention, set HeaderControl1.Images to ImageList1

ASKER CERTIFIED SOLUTION