org.jdesktop.layout

Class LayoutStyle

public class LayoutStyle extends Object

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.

Field Summary
static intINDENT
Possible argument to getPreferredGap.
static intRELATED
Possible argument to getPreferredGap.
static intUNRELATED
Possible argument to getPreferredGap.
Method Summary
intgetContainerGap(JComponent component, int position, Container parent)
Returns the amount of space to position a component inside its parent.
intgetPreferredGap(JComponent component1, JComponent component2, int type, int position, Container parent)
Returns the amount of space to use between two components.
static LayoutStylegetSharedInstance()
Factory methods for obtaining the current LayoutStyle object appropriate for the current look and feel.
static voidsetSharedInstance(LayoutStyle layoutStyle)
Sets the LayoutStyle instance to use for this look and feel.

Field Detail

INDENT

public static final int INDENT
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.

RELATED

public static final int RELATED
Possible argument to getPreferredGap. Used to indicate the two componets are grouped together.

UNRELATED

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

Method Detail

getContainerGap

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

Parameters: component the Component being positioned position the position component is being placed relative to its parent; one of SwingConstants.NORTH, SwingConstants.SOUTH, SwingConstants.EAST or SwingConstants.WEST parent 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

getPreferredGap

public int getPreferredGap(JComponent component1, JComponent 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 the JComponent component2 is being placed relative to component2 the JComponent being placed type how the two components are being placed position the position component2 is being placed relative to component1; one of SwingConstants.NORTH, SwingConstants.SOUTH, SwingConstants.EAST or SwingConstants.WEST parent 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

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 layoutStyle)
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: layoutStyle the LayoutStyle to use; a value of null indicates the default should be used