This option specifies what kind of output the GUI Designer generates for the visual forms you create.
The available settings are:
Binary class files. This is the default option. When selected, no Java source code is generated for GUI forms and components. When the project compiles, IntelliJ IDEA creates the necessary compiled runtime classes.
Java source files .If this option is selected, the GUI Designer writes Java source code for the form and its components to the source file of the class to which the form is bound, on compiling, running or debugging. During compilation, two blocks of code are added to the form's class:
A private method $$$setupUI$$$() that contains the GUI initializer code for the bound form and its components.
A call to the $$$setupUI$$$() method.
Automatically copy form runtime classes to the output directory
If this option is checked, the classes from the package com.intellij.uiDesigner.core package are copied to the configured output directory, when the project is compiled. These classes are used when working with the GridLayoutManager(IntelliJ), or when there are components with mnemonics, specified by the & character.
Default Layout Manager
Set the default layout manager for new components placed into forms. The selection here appears as the setting for the Layout Manager property whenever a new component is placed on a form.
BorderLayout: Design-time behavior in forms emulates Java's Border layout manager.
CardLayout: Design-time behavior in forms emulates Java's Card layout manager.
FlowLayout: Design-time behavior in forms emulates Java's Flow layout manager.
FormLayout (JGoodies): Design-time behavior in forms emulates JGoodies Forms layout manager. (For more information, see https://jgoodies.dev.java.net/)
GridBagLayout: Design-time behavior in forms emulates Java's Grid Bag layout manager.
GridLayoutManager (IntelliJ): Design-time behavior in forms is controlled by this custom layout manager. It's basically a simple grid layout scheme that's sufficient for many uses. It is the default layout manager in new IntelliJ IDEA installations.
Default accessibility for UI-bound fields
Use this option, if you want to change the default accessibility for UI-bound fields from private to something else, like public.
Resize column and row headers with mouse
This checkbox enables/disables resizing in captions. If this checkbox is selected, IntelliJ IDEA allows you to resize column and rows using mouse. When pointing to a column or a row, the mouse pointer changes its shape to the double arrow.