Re: [DUG]: [Q] Event Hooking.....

[Phil Middlemiss]

Reading back, I realised I missed a step. You would have to be working with your own inherited version of TButton. Do you have that much control over it or is this someone elses control?   Phil. ----- Original Message ----- From: Phil Middlemiss To: Multiple recipients of list delphi Sent: Thursday, November 21, 2002 1:55 PM Subject: Re: [DUG]: [Q] Event Hooking..... I've successfully used this method myself at times. eg:   TMyClass = class(TAnAncestor) private     FAnEventHandler : TMyEvent; protected     procedure SetAnEvent(UsersEvent : TMyEvent);     function GetAnEvent: TMyEvent;     procedure TheRealButtonEvent(Sender : TObject); public     property OnAnEvent : TMyEvent read GetAnEvent write SetAnEvent; end;   then...   procedure TMyClass.SetAnEvent(UsersEvent : TMyEvent); begin     FAnEventHandler := UsersEvent; end;   function TMyClass.GetAnEvent: TMyEvent; begin     result := FAnEventHandler; end;   procedure TMyClass.TheRealButtonEvent(Sender : TObject); begin     //do my stuff here (or after)     if Assigned(FAnEventHandler) then         FAnEventHandler(Sender); end;   now the user never even reaches the real event handler field and you are free to do what you need to.   Phil. ----- Original Message ----- From: Phil Middlemiss To: Multiple recipients of list delphi Sent: Thursday, November 21, 2002 12:43 PM Subject: Re: [DUG]: [Q] Event Hooking..... You could handle that by having a Set procedure for your event field that holds on the users handler.   Phil. ----- Original Message ----- From: Donovan J. Edye To: Multiple recipients of list delphi Sent: Thursday, November 21, 2002 11:57 AM Subject: Re: [DUG]: [Q] Event Hooking..... P, And what happens when the user has no event assigned when the app starts and then during program operation sets an event handler in code? At 11:54 21/11/2002 +1300, you wrote: At runtime, you can check to see if the user has assigned an event handler to the button and then internally store their handler and call after your code.   Phil. ----- Original Message ----- From: Donovan J. Edye To: Multiple recipients of list delphi Sent: Thursday, November 21, 2002 11:42 AM Subject: [DUG]: [Q] Event Hooking..... G'Day, I was just curious about some approaches to achieve responding to the event of an embedded component in my component. Clear as mud? An example: Lets say I have a component MyComponent that has a published property MyButton : TButton. Now I want to take some action when the user clicks the button assigned to MyButton. However any code that they have assigned to the click event for the button must also be fired. So basically I want to transparently hook the OnClick event. The only way I can think of doing this is by responding to the apropriate CN_*, CM_* message. Is there another way to do this? If not what messages should I be looking at responding to? -- Donovan ---------------------------------------------------------------------- Donovan J. Edye [www.edye.wattle.id.au] Namadgi Systems [www.namsys.com.au] Voice: +61 2 6285-3460 Fax: +61 2 6285-3459 TVisualBasic = Class(None); Heard just before the 'Big Bang': "...Uh Oh...." ---------------------------------------------------------------------- GXExplorer [http://www.gxexplorer.org] Freeware Windows Explorer replacement. Also includes freeware delphi windows explorer components. ---------------------------------------------------------------------- -- Donovan ---------------------------------------------------------------------- Donovan J. Edye [www.edye.wattle.id.au] Namadgi Systems [www.namsys.com.au] Voice: +61 2 6285-3460 Fax: +61 2 6285-3459 TVisualBasic = Class(None); Heard just before the 'Big Bang': "...Uh Oh...." ---------------------------------------------------------------------- GXExplorer [http://www.gxexplorer.org] Freeware Windows Explorer replacement. Also includes freeware delphi windows explorer components. ----------------------------------------------------------------------