define and declaration of BoxLayout, CardLayout, GridbagLayout in java

Layout, layo, becomes that layout manager for container p (a JPanel or Container) with the following.

   p.setLayout(layo);

Layouts (BoxLayout, CardLayout, GridbagLayout)
BoxLayout, Box - Lays out components in single row or col. Add "glue" and rigid areas to control spacing.
boxl =	new BoxLayout(p, dir);	Creates layout for container p. dir is BoxLayout.X_AXIS BoxLayout.Y_AXIS. Note: must have already created p.
box =	new Box(dir);	Creates a Container with vertical or horizontal layout.
	p.add(widget);	Adds widget to the next position.
	These static Box methods create useful spacing components, which can be used in other layouts.
	Box.createVerticalStrut(n)	Creates a vertical spacer n pixels high.
	Box.createHorizontalStrut(n)	Creates a horizontal spacer n pixels wide.
	Box.createRigidArea(dim)	Spacer with width and height. dim is Dimension object, eg, new Dimension(10, 0).
	Box.createHorizontalGlue()	Creates expandable horizontal space.
	Box.createVerticalGlue()	Creates expandable vertical space.
	new Box.Filler(mn,prf,mx)	Creates a Box.Filler with min, preferred, and max sizes, each is Dimension object.
CardLayout - Panels are placed on top of each other like stack of cards -- only one visible at a time.
	Used to produce installer or wizard style interface as steps in process, or to select palette. Use JTabbedPanel if user should have control.
crdMgr =	new CardLayout();	Sets layout to CardLayout.
crdMgr =	new CardLayout(h, v));	Also can specify horizontal and vertical padding.
	p.add(cardPanel);	Adds next card to panel.
	p.add(cardPanel, name);	Adds next card to panel. Use String name to select it later.
	crdMgr.first(p);	Panel p displays the first card in the layout of p.
	crdMgr.next(p);	Panel p displays the next card in the layout of p.
	crdMgr.previous(p);	Panel p displays the previous card in the layout of p.
	crdMgr.last(p);	Panel p displays the last card in the layout of p.
	crdMgr.show(p, name);	Panel p displays card with String name name in panel p.
GridBagLayout - Panel divided into rows&cols of possibly unequal size. Overall best, but difficult.
gbag =	new GridBagLayout();	Creates GridBagLayout.
	Must add with GridBagConstraints object (gbc below). Can (carefully) reuse same gbc object.
gbc =	new GridBagConstraints();	Creates a new GridBagConsraints object.
	gbc.gridx = i;	Column, counting from 0. Always start at 0. Don't use default (RELATIVE).
	gbc.gridy = i;	Column, counting from 0. Always start at 0. Don't use default (RELATIVE)..
	gbc.gridwidth = i;	Number of columns wide (default 1).
	gbc.gridheight = i;	Number of rows high (default 1).
	gbc.weightx = d;	Relative horizontal space to allocate if container expands. Default 0.0.
	gbc.weighty = d;	Relative vertical space to allocate if container expands. Default 0.0.
	gbc.fill = fill;	How to expand comp if space larger than preferred size. fill can be GridBagConstraints.NONE, GridBagConstraints.VERTICAL, GridBagConstraints.HORIZONTAL, GridBagConstraints.BOTH.
	gbc.anchor = anch;	If component doesn't fill the space, tells how it should be aligned. anch can be one of these GridBagConstraints constants: CENTER (default), NORTH, SOUTH, NORTHEAST, SOUTHWEST, EAST, WEST, SOUTHEAST, NORTHWEST
	gbc.insets = ins;	Space around component. Eg, gbc.insets = new Insets(10,5,5,10);
	gbc.ipadx = i;	Horizontal padding internal to component. Can be negative!
	gbc.ipady = i;	Vertical padding internal to component. Can be negative!