PyQT how to change layouts size

Question

I am trying to make a GUI that is very similar to Spotify using PyQT I've already designed the main window and I am struggling with applying the design to QT Creator. This is what I want it to look like

But I'm trying to use Layouts in order to organize every widget. For example Image of the main window, split into 3 parts like in the sketch I've made the software will be split into 3 parts, left bar, mid which is where the explore title is and right bar.

The problem I have is that I can't control the layouts size and the size of what's below them for example in the sketch the mid bar is wider than the right bar and the right bar is wider than the left bar but in the QTCreator I've no idea how to change the width and height of objects inside Layouts.

Answer 1

The first option (which I personally prefer) is to fill your layout with it's contents first (buttons, labels, etc.). This will already start to scale your layout, if there are more buttons in the middle bar than on the other bars. If your layout still isn't what you want it to be, you can use Spacers. They can push and pull puttons and position the in relation to other parts of the layout, as well as to the layout itself. The scaling will be adjusted automatically according to the spacers position. This option has the advantage, that your application will be correctly scaled and not completely chaotic when it is run on a device with a display aspect ratio which is not the same as the one of the machine your developing it on.

There is, however, also a minimumSize and maximumSize attribute to the layouts, which provide a much more straightforward possibility, but sometimes cause your layouts to become very weird when adding or removing a button, or changing the text of a label. More on this option can be found in the Qt docs: https://doc.qt.io/qt-5/qlayout.html