How to detect user double click on x axis area or Y axis are

[Herman]

How to detect if user double click on x axis area or Y axis area?
Any event I can use?

Thank you

[Narcís]

Hi Herman,

You can use TChart's OnClickAxis event.

[Herman]

ummm but I want to detect it on double click event instead of just clicking.
And clickaxis seems to be work when i click precisely on the axis line, what if i click on area near the axis line (outside the axis for sure, not inside) but still have the same effect. Possible?

[Narcís]

Hi Herman,

ummm but I want to detect it on double click event instead of just clicking.

Yes, but it's easier with some events which already provide mouse coordinates on their arguments list.

And clickaxis seems to be work when i click precisely on the axis line, what if i click on area near the axis line (outside the axis for sure, not inside) but still have the same effect. Possible?

Yes, you can do something like:

Code: Select all

procedure TForm1.Chart1DblClick(Sender: TObject);
var
  Top,Bottom,Left,Right: Integer;
  MousePos: TPoint;
begin
  Top:=Chart1.Axes.Left.IStartPos;
  Bottom:=Chart1.Axes.Left.IEndPos;
  Left:=Chart1.Axes.Left.PosAxis-30;
  Right:=Chart1.Axes.Left.PosAxis;

  MousePos:=Chart1.GetCursorPos;

  if ((MousePos.X>=Left) and (MousePos.X<=Right) and
      (MousePos.Y>=Top) and (MousePos.Y<=Bottom)) then
    Chart1.Title.Text[0]:='Left Axis Clicked!'
  else Chart1.Title.Text[0]:= IntToStr(Top)+', ' +
                          IntToStr(Bottom)+', ' +
                          IntToStr(Left)+', ' +
                          IntToStr(Right);
end;

or

Code: Select all

procedure TForm1.Chart1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  Top,Bottom,Left,Right: Integer;
begin
  Top:=Chart1.Axes.Left.IStartPos;
  Bottom:=Chart1.Axes.Left.IEndPos;
  Left:=Chart1.Axes.Left.PosAxis-30;
  Right:=Chart1.Axes.Left.PosAxis;

  if ((X>=Left) and (X<=Right) and (Y>=Top) and (Y<=Bottom)) then
    Chart1.Title.Text[0]:='Left Axis Clicked!'
  else Chart1.Title.Text[0]:= IntToStr(Top)+', ' +
                          IntToStr(Bottom)+', ' +
                          IntToStr(Left)+', ' +
                          IntToStr(Right);
end;