LmdGrid Column Chooser

Comments

• Eugene Balabuev (LMD)

  February 2022

  The link, provided by you, pointing to the compiled version of the demo, which does not include source code. Demo sources can be found in the corresponding demo folder of your installation.

  
  

  To access specific properties of a Chooser at run-time, you need to case the chooser to its exact class:

  
  

  (MyColumn.Chooser as TLMDGridPickListChooser).Items.Add('...');

  
  

  
  

  Additionally, if you need non-numeric values in the drop-down list of the numeric column, you can follow the way, shown in the demo:

  
  

  The demo contains TLMDGrid with a column of floating point mubers. The Chooser is set to PickList, Chooser.Items is set to a set of values, including nonnumeric values, like Pi or Exp:

  
  

  1

  3

  5

  7

  PI

  EXP

  
  

  To handle these values two event handlers are written:

  
  

  procedure TMainForm.LMDGridFloatColumn1FloatFormatEdit(Grid: TObject;
  

    Column: TLMDGridColumn; const Value: Variant;

    AIsNull: Boolean; var S: string);

  var

    d: Double;

  begin

    if not AIsNull then

    begin

      d := Value;

      if Abs(3.14 - d) <= 0.0001 then

        S := 'PI'

      else if Abs(2.76 - d) <= 0.0001 then

        S := 'EXP';

    end;

  end;

  
  

  procedure TMainForm.FloatColParse(Grid: TObject; Column: TLMDGridColumn;

    const S: string; var Value: Variant; var ParsedOk: Boolean;

    CanRaiseError: Boolean);

  begin

    if UpperCase(S) = 'PI' then

    begin

      Value := 3.14;

      ParsedOk := True;

    end

    else if UpperCase(S) = 'EXP' then

    begin

      Value := 2.76;

      ParsedOk := True;

    end

    else if not ParsedOk then

      raise Exception.Create('Only float values or "PI"/"EXP" constants allowed!');

  end;

  
  

  The first even handler is connected to OnFormatEdit and OnFormatPaint events, while the second - to OnParse event.
• lawefa

  February 2022

  Thanks for extensive examples and hints. This helps me a lot