public class LayoutStyle

  1. Object
  2. LayoutStyle

LayoutStyle is used to determine how much space to place between components during layout. LayoutStyle can be obtained for two components, or for a component relative to an edge of a parent container. The amount of space can vary depending upon whether or not the components are logically grouped together (RELATED).

This class is primarily useful for JREs prior to 1.6. In 1.6 API for this was added to Swing. When run on a JRE of 1.6 or greater this will call into the appropriate methods in Swing.

Fields

public static final int RELATED = 0Possible argument to getPreferredGap.
public static final int UNRELATED = 1Possible argument to getPreferredGap.
public static final int INDENT = 3Possible argument to getPreferredGap.

Constructors

public LayoutStyle()

Methods

public static LayoutStyle getSharedInstance()Factory methods for obtaining the current LayoutStyle object appropriate for the current look and feel.
public static void setSharedInstance(LayoutStyle layout)Sets the LayoutStyle instance to use for this look and feel.
public int getPreferredGap(Component component1, Component component2, int type, int position, Container parent)Returns the amount of space to use between two components.
public int getContainerGap(Component component, int position, Container parent)Returns the amount of space to position a component inside its parent.

Inherited methods

From Object

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

Field details

UNRELATED

public static final int UNRELATED = 1
Possible argument to getPreferredGap. Used to indicate the two components are not grouped together.

INDENT

public static final int INDENT = 3
Possible argument to getPreferredGap. Used to indicate the distance to indent a component is being requested. To visually indicate a set of related components they will often times be horizontally indented, the INDENT constant for this. For example, to indent a check box relative to a label use this constant to getPreferredGap.

Constructor details

LayoutStyle

public LayoutStyle()

Method details

getSharedInstance

public static LayoutStyle getSharedInstance()
Factory methods for obtaining the current LayoutStyle object appropriate for the current look and feel.

Returns

the current LayoutStyle instance

setSharedInstance

public static void setSharedInstance(LayoutStyle layout)
Sets the LayoutStyle instance to use for this look and feel. You generally don’t need to invoke this, instead use the getter which will return the LayoutStyle appropriate for the current look and feel.

Parameters

layout LayoutStyle
the LayoutStyle to use; a value of null indicates the default should be used

getPreferredGap

public int getPreferredGap(Component component1, Component component2, int type, int position, Container parent)

Returns the amount of space to use between two components. The return value indicates the distance to place component2 relative to component1. For example, the following returns the amount of space to place between component2 and component1 when component2 is placed vertically above component1:

  int gap = getPreferredGap(component1, component2,
                            LayoutStyle.RELATED,
                            SwingConstants.NORTH, parent);

The type parameter indicates the type of gap being requested. It can be one of the following values:

RELATED If the two components will be contained in the same parent and are showing similar logically related items, use RELATED. UNRELATED If the two components will be contained in the same parent but show logically unrelated items use UNRELATED. INDENT Used to obtain the preferred distance to indent a component relative to another. For example, if you want to horizontally indent a JCheckBox relative to a JLabel use INDENT. This is only useful for the horizontal axis.

It’s important to note that some look and feels may not distinguish between RELATED and UNRELATED.

The return value is not intended to take into account the current size and position of component2 or component1. The return value may take into consideration various properties of the components. For example, the space may vary based on font size, or the preferred size of the component.

Parameters

component1 Component
the JComponent component2 is being placed relative to
component2 Component
the JComponent being placed
type int
how the two components are being placed
position int
the position component2 is being placed relative to component1; one of SwingConstants.NORTH, SwingConstants.SOUTH, SwingConstants.EAST or SwingConstants.WEST
parent Container
the parent of component2; this may differ from the actual parent and may be null

Returns

the amount of space to place between the two components

Throws

IllegalArgumentException
if position is not one of SwingConstants.NORTH, SwingConstants.SOUTH, SwingConstants.EAST or SwingConstants.WEST; type not one of INDENT, RELATED or UNRELATED; or component1 or component2 is null

getContainerGap

public int getContainerGap(Component component, int position, Container parent)
Returns the amount of space to position a component inside its parent.

Parameters

component Component
the Component being positioned
position int
the position component is being placed relative to its parent; one of SwingConstants.NORTH, SwingConstants.SOUTH, SwingConstants.EAST or SwingConstants.WEST
parent Container
the parent of component; this may differ from the actual parent and may be null

Returns

the amount of space to place between the component and specified edge

Throws

IllegalArgumentException
if position is not one of SwingConstants.NORTH, SwingConstants.SOUTH, SwingConstants.EAST or SwingConstants.WEST; or component is null