Is it possible to visually design a custom component at design time?

Question

I am venturing into making my own components in Delphi. I'm having difficulty getting started with component development.

I want to make a composite control ie a control made up of several other controls, eg like an address form or something like that.

I am descending from TWinControl. Would that be considered to be the correct choice?

The main thing is, I cannot see a way to visually design the component in D2010. Is this possible? eg drop some text boxes onto your component, as you would with a form. I'm hoping I don't have to hand code all the visual aspects to my own components..

Also any good links on delphi component dev would be very much appreciated - esp for composite controls. The docs are not A1, its a struggle. I searched a lot already, I'm still going nowhere fast.

Answer 1

If you're making something with multiple controls such as an address form, you might consider making it a frame instead of a control. Frames can be designed like windows, and re-used.

Answer 2

You'll have to describe it in code to compile, but you can use a trick to design the component visually at first.

Put a TPanel on the form, and let that stand for the base control. Arrange your sub-controls, then get the properties from text view. GExperts adds a menu option that will convert controls on a form to code to generate them automatically, making this step a lot easier.

Answer 3

Read my bog article on using Frames as Visual Components - don't forget your spring.
It is very easy: put everything on your Frame, register it as a component, register the sprig, and don't forget that at design time 'Visible=False' is being ignored.

I just explained this yesterday during my preconference workshop at the DelphiLive! conference :-)

--jeroen