GridPanel
A JPanel under a GridLayout: the panel is divided into equally sized cells and the children fill them one per cell, row by row in the panel's reading order.
A zero rows means as many rows as the children need, and a zero cols as many columns; one of the two may be zero, never both.
Parameters
the SwingModifier applied to the panel
the number of rows, or 0 for as many as the children need; the default 1 puts every child in one row
the number of columns, or 0 for as many as the children need; a non-zero rows takes precedence, and the column count then follows from the row count and the number of children
the horizontal gap between components; 0 by default, so columns touch
the vertical gap between components; 0 by default, so rows touch
the composable content of the panel; empty by default