What is the Horizontal and Vertical spacer in the IntelliJ Swing form?

Question

Every time I drag a component to the JPanel , it will automatically add the horizontal spacer and vertical spacer, I don't know what it is.

What is the Horizontal and Vertical spacer in the IntelliJ Swing form?

Answer 1

The spacers are added so that the component does not take the entire space of the form. The IntelliJ IDEA UI designer uses the grid layout by default, and each component occupies the entirety of one or more grid cells. Without the spacers, there would be only one grid cell, and the component would occupy all of it, which is usually not what you want.

If you have multiple components that together need to occupy the entire space of the form, you can delete the spacers.