Make Timage move down and left 3 pixels when Mouse enters and return to original position when mouse leaves

Question

I have a form with about 168 Timage objects containing Icons that are user selectable.

I wish to make each Icon move Down and Right by 3 pixels when the mouse is over the Timage object. I want it to return to its original position when the mouse leaves the Timage. This will add a pleasing effect to the user interface.

I know I can do this in the OnMouseEnter and OnMouseLeave events and it works well - however I cannot help but think that there must be a more elegant / efficient method to produce this effect for all 168 Timage objects, rather than creating 168 OnMouseEnter procedures and 168 OnMouseLeave procedures.

Any help much appreciated ...

Answer 1

It is enough to create a single OnMouseEnter event handler procedure and assign it to every component (similar for OnMouseLeave).

If these components were created in design-time (hard to imagine), then you can select all 168 images in the Form Designer, and then go to the Object Inspector and assign the events in a single go, as Remy Lebeau wrote in comments. Alternative way - use existing list of components (assuming that owner is form and there is no other TImages on the form):

for i := 0 to Components.Count - 1 do
  if Components[i] is TImage then  //perhaps more conditions to separate needed images
     TImage(Components[i]).OnMouseEnter := EnterHandler;

If components were created in run-time and they are stored in array or list, handler assigning is simpler:

for i := 0 to Images.Length - 1 do
   Images[i].OnMouseEnter := EnterHandler;

---

Then you can work with each component using the event's Sender argument:

procedure TMyForm.EnterHandler(Sender: TObject);
begin
  TImage(Sender).Left := TImage(Sender).Left + 3;
  TImage(Sender).Top := TImage(Sender).Top + 3;
end;

procedure TMyForm.LeaveHandler(Sender: TObject);
begin
  TImage(Sender).Left := TImage(Sender).Left - 3;
  TImage(Sender).Top := TImage(Sender).Top - 3;
end;