Resize button when using layout

[Macok]

I have listWidget on my form and I had problem with it, becouse when user was resizing window so it couldn't hold all listWidget's items - scrollbar wasn't appearing.
I solved it by marking "Lay out vertically" option, but now i can't resize button which is on the same form.

So is there way to change size of button when Vertical Layout is specified?
Or is it possible to force scrollbar to appear when form is too small?

Thanks in advance and sorry for bad english.

[wysota]

Why would you want to manually resize the button?

You should apply a layout (as you did by clicking on "Lay out vertically"). If it doesn't satisfy you, you can manipulate its contents by using spacers and size policies of widgets (or apply a different layout - like the grid layout). At a last resort you can set the exact size of each widget by setting its minimum and maximum size but this has many disadvantages and is almost never needed.

[Macok]

Why would you want to manually resize the button?

I'm new to Qt, and I'm only learning it now.

I see that it's almost impossible to change button size when using layouts.
So I'll put another question:
When you are creating your gui in Qt Designer, are you always using layouts?
Should I use it or not?

[wysota]

I'm new to Qt, and I'm only learning it now.

I see that it's almost impossible to change button size when using layouts.

Again, why would you want to do that? The button knows how big it should be. If you want to force your own size, you can do it in many ways - more or less gracefully. If you want to resize the button, the easiest way is to put it in a layout where its cell size is what you want your button to be. The cell size is determined based on all widgets occupying a particular column or row of the layout. If that's not enough for you, you can use spacers. If that's not enough - use size policies. If again this is not enough, use layout constraints and/or set minimum/maximum size of the widget manually. But never try to move the widget with a mouse after placing it in a layout (unless you want to drag it to another cell size) - it doesn't make any sense as the widget wouldn't know what to "dock" itself to and how to control its size.

When you are creating your gui in Qt Designer, are you always using layouts?
Should I use it or not?

Yes, always. Treat it as a rule and don't try to avoid it unless you have a very wacky usecase and you are sure you shouldn't use a layout in this particular situation. Your current situation is certainly not one of those.