javax.swing

Class SpringLayout

public class SpringLayout extends Object implements LayoutManager2

A very flexible layout manager. Components are laid out by defining the relationships between them. The relationships are expressed as {@link Spring}s. You can attach a Spring for each edge of a component and link it to an edge of a different component. For example, you can say, the northern edge of component A should be attached to the southern edge of component B, and the space between them should be something between x and y pixels, and preferably z pixels.

While quite simple, this layout manager can be used to emulate most other layout managers, and can also be used to solve some layout problems, which would be hard to solve with other layout managers.

Nested Class Summary
static class	SpringLayout.Constraints The constraints that define the relationships between components.

Field Summary
static String	EAST The right edge of a component.
static String	NORTH The top edge of a component.
static String	SOUTH The bottom edge of a component.
static String	WEST The left edge of a component.

Constructor Summary
	SpringLayout() Creates a new SpringLayout.

Method Summary
void	addLayoutComponent(Component component, Object constraint) Adds a layout component and a constraint object to this layout.
void	addLayoutComponent(String name, Component c) Adds a layout component and a constraint object to this layout.
Spring	getConstraint(String edgeName, Component c) Returns the constraint of the edge named by `edgeName`.
SpringLayout.Constraints	getConstraints(Component c) Returns the {@link Constraints} object associated with the specified component.
float	getLayoutAlignmentX(Container p) Returns the X alignment of the Container `p`.
float	getLayoutAlignmentY(Container p) Returns the Y alignment of the Container `p`.
void	invalidateLayout(Container p) Recalculate a possibly cached layout.
void	layoutContainer(Container p) Lays out the container `p`.
Dimension	maximumLayoutSize(Container p) Calculates the maximum size of the layed out container.
Dimension	minimumLayoutSize(Container p) Calculates the minimum size of the layed out container.
Dimension	preferredLayoutSize(Container p) Calculates the preferred size of the layed out container.
void	putConstraint(String e1, Component c1, int pad, String e2, Component c2) Attaches the edge `e1` of component `c1` to the edge `e2` of component `c2` width the fixed strut `pad`.
void	putConstraint(String e1, Component c1, Spring s, String e2, Component c2) Attaches the edge `e1` of component `c1` to the edge `e2` of component `c2` width the {@link Spring} `s`.
void	removeLayoutComponent(Component c) Removes a layout component.

Field Detail

EAST

public static final String EAST

The right edge of a component.

NORTH

public static final String NORTH

The top edge of a component.

SOUTH

public static final String SOUTH

The bottom edge of a component.

WEST

public static final String WEST

The left edge of a component.

Constructor Detail

SpringLayout

public SpringLayout()

Creates a new SpringLayout.

Method Detail

addLayoutComponent

public void addLayoutComponent(Component component, Object constraint)

Adds a layout component and a constraint object to this layout. This method is usually only called by a {@link java.awt.Container}s add method.

Parameters: component the component to be added. constraint the constraint to be set.

addLayoutComponent

public void addLayoutComponent(String name, Component c)

Adds a layout component and a constraint object to this layout. This method is usually only called by a {@link java.awt.Container}s add method. This method does nothing, since SpringLayout does not manage String-indexed components.

Parameters: name the name. c the component to be added.

getConstraint

public Spring getConstraint(String edgeName, Component c)

Returns the constraint of the edge named by edgeName.

Parameters: c the component from which to get the constraint. edgeName the name of the edge, one of {@link #EAST}, {@link #WEST}, {@link #NORTH} or {@link #SOUTH}.

Returns: the constraint of the edge edgeName of the component c.

getConstraints

public SpringLayout.Constraints getConstraints(Component c)

Returns the {@link Constraints} object associated with the specified component.

Parameters: c the component for which to determine the constraint.

Returns: the {@link Constraints} object associated with the specified component.

getLayoutAlignmentX

public float getLayoutAlignmentX(Container p)

Returns the X alignment of the Container p.

Parameters: p the {@link java.awt.Container} for which to determine the X alignment.

Returns: always 0.0

getLayoutAlignmentY

public float getLayoutAlignmentY(Container p)

Returns the Y alignment of the Container p.

Parameters: p the {@link java.awt.Container} for which to determine the Y alignment.

Returns: always 0.0

invalidateLayout

public void invalidateLayout(Container p)

Recalculate a possibly cached layout.

layoutContainer

public void layoutContainer(Container p)

Lays out the container p.

Parameters: p the container to be laid out.

maximumLayoutSize

public Dimension maximumLayoutSize(Container p)

Calculates the maximum size of the layed out container. This respects the maximum sizes of all contained components.

Parameters: p the container to be laid out.

Returns: the maximum size of the container.

minimumLayoutSize

public Dimension minimumLayoutSize(Container p)

Calculates the minimum size of the layed out container. This respects the minimum sizes of all contained components.

Parameters: p the container to be laid out.

Returns: the minimum size of the container.

preferredLayoutSize

public Dimension preferredLayoutSize(Container p)

Calculates the preferred size of the layed out container. This respects the preferred sizes of all contained components.

Parameters: p the container to be laid out.

Returns: the preferred size of the container.

putConstraint

public void putConstraint(String e1, Component c1, int pad, String e2, Component c2)

Attaches the edge e1 of component c1 to the edge e2 of component c2 width the fixed strut pad.

Parameters: e1 the edge of component 1. c1 the component 1. pad the space between the components in pixels. e2 the edge of component 2. c2 the component 2.

putConstraint

public void putConstraint(String e1, Component c1, Spring s, String e2, Component c2)

Attaches the edge e1 of component c1 to the edge e2 of component c2 width the {@link Spring} s.

Parameters: e1 the edge of component 1. c1 the component 1. s the space between the components as a {@link Spring} object. e2 the edge of component 2. c2 the component 2.

removeLayoutComponent

public void removeLayoutComponent(Component c)

Removes a layout component.

Parameters: c the layout component to remove.