How do I read mouse button state in a MouseMove eventt?

[741]

The MouseMove event appears to only get called if no buttons are pressed.

I am considering setting a global variable when the button is pressed, but that feels like bad style.

procedure TfrmMain.pbxGridMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
var
   aButton: Word;
begin
  //Decide which cell we are in
  cellX := X DIV gridSizX;
  cellY := (pbxFieldPro.Height - Y) DIV gridSizY; //Want 'Y' "going upwards"
  sbrImagZ.Panels[4].Text := Format('pbxField: (x:%d, y:%d) --> Cell = (%d, %d)', [X, Y, cellX, cellY]);

//PROBLEM: If mouse button is down we do not see the move event[?]. On release we see the move, but then the button is zero

  aButton := GetMouseButtons;
  sbrImagZ.Panels[0].Text := Format('Button = $%2X', [aButton]);

  if MouseLeftButton = GetMouseButtons then
  begin
//##############Never get here UNTIL button released#####################
     pbxFieldProMouseDown(pbxFieldPro, mbLeft, Shift, X, Y);
  end;//if
end;//pbxGridMouseMove

[jamie]

Mouse Move works for me no matter what button I hold down, it still gets called.

What widget are you on?

and btw..

is 741 anything to do with the LM741 op-amp ?

Jamie

[741]

Hi

"What widget are you on?".
Not sure how to find the answer to that (!) I will admit I am not a regular Lazarus user (I used to code with Delphi lots some years ago though).

Yes, the famous 741 op-amp 


Please can you post your code where MouseMove is seen, even when the left button is continually down?

Regards
Stephen

[Sieben]

With mouse events the Shift parameter also holds information about the mouse buttons: https://www.freepascal.org/docs-html/rtl/classes/tshiftstate.html

[741]

Very interesting - thank you