Deleting and disabling properties in designer for custom plugins...

**wysota** · 23rd March 2007, 21:55

You know, I wanted to say that right in the beginning - why do you want to hide a property in Designer? This won't stop anyone from using it in code anyway, so what's the point? If you want to disable all the properties (only in Designer!) then the proper way to go is to implement a QDesignerPropertySheetExtension for your widget - this will substitute the default property browser with yours. You can specify your own properties there and handle them the way you want. Of course it won't stop anyone from calling the property methods (or QObject::setProperty()) directly from code.

**thawkins** · 24th March 2007, 02:42

Originally Posted by wysota

You know, I wanted to say that right in the beginning - why do you want to hide a property in Designer? This won't stop anyone from using it in code anyway, so what's the point? If you want to disable all the properties (only in Designer!) then the proper way to go is to implement a QDesignerPropertySheetExtension for your widget - this will substitute the default property browser with yours. You can specify your own properties there and handle them the way you want. Of course it won't stop anyone from calling the property methods (or QObject::setProperty()) directly from code.

I'm generating a library of custom plugins that will be used by another group (non-programmers) to lay out GUI screens. I'm not real concerned about somebody doing what you said because the intended audience will be non-programming UI designers. I really wish there was a way to add more slots that can be seen in designer, but we can't have everything.

**wysota** · 24th March 2007, 09:12

Originally Posted by thawkins

I really wish there was a way to add more slots that can be seen in designer, but we can't have everything.

You mean without subclassing? What would it give a non-programmer? Anyway, you might want to take a look at this:
QDesignerMemberSheetExtension

**thawkins** · 24th March 2007, 17:51

Originally Posted by wysota

You mean without subclassing? What would it give a non-programmer? Anyway, you might want to take a look at this:
QDesignerMemberSheetExtension

I briefly took a look at that. I guess I got somewhat discouraged because I've searched this and a couple other forums and everyones says the same thing, that you can't have custom slots from within designer. I'm still working on getting the property sheet stuff working with QDesignerPropertySheetExtension. I'll play around with that next to see if some type of custom slots are possible by implementing my own QDesignerMemberSheetExtension.

**wysota** · 24th March 2007, 19:49

Why would you want to allow an ui designer (the person) to create custom slots if he/she can't implement them? The problem is people treat Qt Designer as an IDE, but it's not one - it's a layout editor, you shouldn't implement any logic there. To be honest I'm surprised why Trolltech implemented writing scripts in QtScript in Designer (since 4.3), as it clearly violates their own rule of removing the editor part from Designer.

**thawkins** · 24th March 2007, 21:04

Originally Posted by wysota

Why would you want to allow an ui designer (the person) to create custom slots if he/she can't implement them? The problem is people treat Qt Designer as an IDE, but it's not one - it's a layout editor, you shouldn't implement any logic there. To be honest I'm surprised why Trolltech implemented writing scripts in QtScript in Designer (since 4.3), as it clearly violates their own rule of removing the editor part from Designer.

I don't think you understand, or maybe I'm not saying it right. I don't want a user to be able to create and modify a slot from scratch in Qt, merely to have slots that were defined in code visible in the slot editor in designer. I think if they went through the trouble of exposing properties and such with Q_PROPERTY(), Q_ENUM, etc, why is there no equivalent for slots and signals? That wouldn't seem to violate their rules and in fact would make designer more useful as a layout tool. As it stands now, when you develop a plugin you still have to programmatically attach any of the slots that you wrote. This takes away from the usefulness of designer for anything accept the layout of built in widgets as anything else requires further coding to work.

**wysota** · 24th March 2007, 22:35

Originally Posted by thawkins

I don't think you understand, or maybe I'm not saying it right. I don't want a user to be able to create and modify a slot from scratch in Qt, merely to have slots that were defined in code visible in the slot editor in designer. I think if they went through the trouble of exposing properties and such with Q_PROPERTY(), Q_ENUM, etc, why is there no equivalent for slots and signals?

I think you had to make some mistake, as my custom slots are perfectly visible in Designer (screenshot attached).

**thawkins** · 25th March 2007, 03:40

Originally Posted by wysota

I think you had to make some mistake, as my custom slots are perfectly visible in Designer (screenshot attached).

And so it is. Mine appear to show up as well. I never looked before because I hadn't gotten a chance to play with that feature in my custom plugins and I've read so much about not having custom slots show up in designer. Oh well, just goes to show you can't take everything at face value.