firstly look at https://imgur.com/a/1r6sK31
I have a project where I wanna show a Table with some data. it show the data but the panels dont fill verticaly and horizontaly. I use the GridLayoutManager from com.intellij.uiDesigner.core
The table has its own panel and class where it gets its data the class below the table is just a baseClass with all buttons (so i dont need to rewrite the class all the time) and a panel for the table, where it should be filled, and the mainView where i wanna add the tableView and fill it in the panel where it should be added. View first Image
Edit:
i add all panels with mainPanel.add(panelToAdd,new GridConstraints());