dynamic button trouble

**Traveler** · 24-02-2006, 05:03 PM

I have a few problems with the buttons in my game.

Currently I have a class button that looks a bit like the following

Code:

TButton = class
  private
    &#40;..&#41;
    FOnClick  &#58; TNotifyEvent;
    procedure doClick; dynamic;
  public
    &#40;..&#41;
    property OnClick  &#58; TNotifyEvent read FOnClick write FOnClick;
  end;

I also have a list that hold these buttons.

At initialization I create an x number of buttons

Code:

buttonlist.addButton&#40;x, y, width, height, title&#41;;

What I need now, is to attach predesigned procedures or functions to these dynamically created buttons.

My first quess was to create a new class that holds all these procedures and then do something like

Code:

ButtonList&#91;1&#93;.OnClick &#58;= btnEvents.changeMouse;

but somehow thats not really working.

I was kinda hoping someone has any thoughts on how to solve this.

Thanks a bunch!

**savage** · 24-02-2006, 05:36 PM

Can you clarify what you mean by it does not work? Does it not work at compile-time or run-time?

**Nitrogen** · 24-02-2006, 06:16 PM

You've got a very 'OOP' way of making your buttons work there..

I'd go a more traditionalist route and use Function Pointers..

Just define:

Code:

Type
       ClickProc = procedure&#40;x,y&#58; integer&#41;;

Or something like that..
Then inside your class:

Code:

   OnClick&#58; ClickProc

Then you just write a procedure that conforms to the procedure(x,y) format and set it equal to ClickProc... (IIRC of course!)

**savage** · 24-02-2006, 06:23 PM

Originally Posted by Nitrogen

You've got a very 'OOP' way of making your buttons work there..
I'd go a more traditionalist route and use Function Pointers..

Events are essentially just fancy function pointers the only difference being that you qualify them as being "of object" when you declare them.

**Traveler** · 24-02-2006, 07:59 PM

Originally Posted by savage

Can you clarify what you mean by it does not work? Does it not work at compile-time or run-time?

Well, everything does compile. However the moment I click a button, any button, the game simply ends. I went through the code, but there's nothing that should end the game just like that. Weird thing is I'm not getting any errors too.

From your reply I take it I am on the right path though, so at least I'm not doing anything odd, in a oo way that is.

Nitrogen, thanks for the suggestion. Going to give that a try as well.