javax.swing

Class SpringLayout

java.lang.Object

javax.swing.SpringLayout

All Implemented Interfaces:

java.awt.LayoutManager, java.awt.LayoutManager2

public class SpringLayout
extends java.lang.Object
implements java.awt.LayoutManager2

A very flexible layout manager. Components are laid out by defining the relationships between them. The relationships are expressed as Springs. 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

Nested Classes

Modifier and Type	Class and Description
static class	SpringLayout.Constraints The constraints that define the relationships between components.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	EAST The right edge of a component.
static java.lang.String	NORTH The top edge of a component.
static java.lang.String	SOUTH The bottom edge of a component.
static java.lang.String	WEST The left edge of a component.

Constructor Summary

Constructors

Constructor and Description
SpringLayout() Creates a new SpringLayout.

Method Summary

Methods

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

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

EAST

public static final java.lang.String EAST

The right edge of a component.

See Also:

Constant Field Values

NORTH

public static final java.lang.String NORTH

The top edge of a component.

See Also:

Constant Field Values

SOUTH

public static final java.lang.String SOUTH

The bottom edge of a component.

See Also:

Constant Field Values

WEST

public static final java.lang.String WEST

The left edge of a component.

See Also:

Constant Field Values

Constructor Detail

SpringLayout

public SpringLayout()

Creates a new SpringLayout.

Method Detail

addLayoutComponent

public void addLayoutComponent(java.awt.Component component,
                      java.lang.Object constraint)

Adds a layout component and a constraint object to this layout. This method is usually only called by a Containers add method.

Specified by:

addLayoutComponent in interface java.awt.LayoutManager2

Parameters:

component - the component to be added.

constraint - the constraint to be set.

addLayoutComponent

public void addLayoutComponent(java.lang.String name,
                      java.awt.Component c)

Adds a layout component and a constraint object to this layout. This method is usually only called by a Containers add method. This method does nothing, since SpringLayout does not manage String-indexed components.

Specified by:

addLayoutComponent in interface java.awt.LayoutManager

Parameters:

name - the name.

c - the component to be added.

getConstraint

public Spring getConstraint(java.lang.String edgeName,
                   java.awt.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 EAST, WEST, NORTH or SOUTH.

Returns:

the constraint of the edge edgeName of the component c.

getConstraints

public SpringLayout.Constraints getConstraints(java.awt.Component c)

Returns the SpringLayout.Constraints object associated with the specified component.

Parameters:

c - the component for which to determine the constraint.

Returns:

the SpringLayout.Constraints object associated with the specified component.

getLayoutAlignmentX

public float getLayoutAlignmentX(java.awt.Container p)

Returns the X alignment of the Container p.

Specified by:

getLayoutAlignmentX in interface java.awt.LayoutManager2

Parameters:

p - the Container for which to determine the X alignment.

Returns:

always 0.0

getLayoutAlignmentY

public float getLayoutAlignmentY(java.awt.Container p)

Returns the Y alignment of the Container p.

Specified by:

getLayoutAlignmentY in interface java.awt.LayoutManager2

Parameters:

p - the Container for which to determine the Y alignment.

Returns:

always 0.0

invalidateLayout

public void invalidateLayout(java.awt.Container p)

Recalculate a possibly cached layout.

Specified by:

invalidateLayout in interface java.awt.LayoutManager2

Parameters:

p - the target container

layoutContainer

public void layoutContainer(java.awt.Container p)

Lays out the container p.

Specified by:

layoutContainer in interface java.awt.LayoutManager

Parameters:

p - the container to be laid out.

maximumLayoutSize

public java.awt.Dimension maximumLayoutSize(java.awt.Container p)

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

Specified by:

maximumLayoutSize in interface java.awt.LayoutManager2

Parameters:

p - the container to be laid out.

Returns:

the maximum size of the container.

See Also:

Component.getMaximumSize()

minimumLayoutSize

public java.awt.Dimension minimumLayoutSize(java.awt.Container p)

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

Specified by:

minimumLayoutSize in interface java.awt.LayoutManager

Parameters:

p - the container to be laid out.

Returns:

the minimum size of the container.

See Also:

LayoutManager.preferredLayoutSize(Container)

preferredLayoutSize

public java.awt.Dimension preferredLayoutSize(java.awt.Container p)

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

Specified by:

preferredLayoutSize in interface java.awt.LayoutManager

Parameters:

p - the container to be laid out.

Returns:

the preferred size of the container.

See Also:

LayoutManager.minimumLayoutSize(Container)

putConstraint

public void putConstraint(java.lang.String e1,
                 java.awt.Component c1,
                 int pad,
                 java.lang.String e2,
                 java.awt.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(java.lang.String e1,
                 java.awt.Component c1,
                 Spring s,
                 java.lang.String e2,
                 java.awt.Component c2)

Attaches the edge e1 of component c1 to the edge e2 of component c2 width the Spring s.

Parameters:

e1 - the edge of component 1.

c1 - the component 1.

s - the space between the components as a Spring object.

e2 - the edge of component 2.

c2 - the component 2.

removeLayoutComponent

public void removeLayoutComponent(java.awt.Component c)

Removes a layout component.

Specified by:

removeLayoutComponent in interface java.awt.LayoutManager

Parameters:

c - the layout component to remove.