FlowLayout (Java 2 Platform SE v1.4.1)

java.awt
Class FlowLayout
java.lang.Object
  |
  +--java.awt.FlowLayout
All Implemented Interfaces:
LayoutManager, Serializable

public class FlowLayout
extends Object
implements LayoutManager, Serializable

A flow layout arranges components in a left-to-right flow, much like lines of text in a paragraph. Flow layouts are typically used to arrange buttons in a panel. It will arrange buttons left to right until no more buttons fit on the same line. Each line is centered.
For example, the following picture shows an applet using the flow layout manager (its default layout manager) to position three buttons:

Here is the code for this applet:
 import java.awt.*;
 import java.applet.Applet;

 public class myButtons extends Applet {
     Button button1, button2, button3;
     public void init() {
         button1 = new Button("Ok");
         button2 = new Button("Open");
         button3 = new Button("Close");
         add(button1);
         add(button2);
         add(button3);
     }
 }
 
A flow layout lets each component assume its natural (preferred) size.

Since:

JDK1.0

See Also:
Serialized Form

Field Summary
static int CENTER
    This value indicates that each row of components should be centered.
static int LEADING
    This value indicates that each row of components should be justified to the leading edge of the container's orientation, for example, to the left in left-to-right orientations.
static int LEFT
    This value indicates that each row of components should be left-justified.
static int RIGHT
    This value indicates that each row of components should be right-justified.
static int TRAILING
    This value indicates that each row of components should be justified to the trailing edge of the container's orientation, for example, to the right in left-to-right orientations.

Constructor Summary
FlowLayout()
    Constructs a new FlowLayout with a centered alignment and a default 5-unit horizontal and vertical gap.
FlowLayout(int align)
    Constructs a new FlowLayout with the specified alignment and a default 5-unit horizontal and vertical gap.
FlowLayout(int align, int hgap, int vgap)
    Creates a new flow layout manager with the indicated alignment and the indicated horizontal and vertical gaps.

Method Summary
void addLayoutComponent(String name, Component comp)
    Adds the specified component to the layout.
int getAlignment()
    Gets the alignment for this layout.
int getHgap()
    Gets the horizontal gap between components.
int getVgap()
    Gets the vertical gap between components.
void layoutContainer(Container target)
    Lays out the container.
Dimension minimumLayoutSize(Container target)
    Returns the minimum dimensions needed to layout the visible components contained in the specified target container.
Dimension preferredLayoutSize(Container target)
    Returns the preferred dimensions for this layout given the visible components in the specified target container.
void removeLayoutComponent(Component comp)
    Removes the specified component from the layout.
void setAlignment(int align)
    Sets the alignment for this layout.
void setHgap(int hgap)
    Sets the horizontal gap between components.
void setVgap(int vgap)
    Sets the vertical gap between components.
String toString()
    Returns a string representation of this FlowLayout object and its values.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

LEFT
public static final int LEFT
This value indicates that each row of components should be left-justified.

See Also:
Constant Field Values

CENTER
public static final int CENTER
This value indicates that each row of components should be centered.

See Also:
Constant Field Values

RIGHT
public static final int RIGHT
This value indicates that each row of components should be right-justified.

See Also:
Constant Field Values

LEADING
public static final int LEADING
This value indicates that each row of components should be justified to the leading edge of the container's orientation, for example, to the left in left-to-right orientations.

Since:

1.2 Package-private pending API change approval

See Also:
Component.getComponentOrientation(), ComponentOrientation, Constant Field Values

TRAILING
public static final int TRAILING
This value indicates that each row of components should be justified to the trailing edge of the container's orientation, for example, to the right in left-to-right orientations.

Since:

1.2 Package-private pending API change approval

See Also:
Component.getComponentOrientation(), ComponentOrientation, Constant Field Values

Constructor Detail

FlowLayout
public FlowLayout()
Constructs a new FlowLayout with a centered alignment and a default 5-unit horizontal and vertical gap.

FlowLayout
public FlowLayout(int align)
Constructs a new FlowLayout with the specified alignment and a default 5-unit horizontal and vertical gap. The value of the alignment argument must be one of FlowLayout.LEFT, FlowLayout.RIGHT, or FlowLayout.CENTER.

Parameters:
align - the alignment value

FlowLayout
public FlowLayout(int align,
                  int hgap,
                  int vgap)
Creates a new flow layout manager with the indicated alignment and the indicated horizontal and vertical gaps.
The value of the alignment argument must be one of FlowLayout.LEFT, FlowLayout.RIGHT, or FlowLayout.CENTER.

Parameters:
align - the alignment value
hgap - the horizontal gap between components
vgap - the vertical gap between components

Method Detail

getAlignment
public int getAlignment()
Gets the alignment for this layout. Possible values are FlowLayout.LEFT, FlowLayout.RIGHT, FlowLayout.CENTER, FlowLayout.LEADING, or FlowLayout.TRAILING.

Returns:
the alignment value for this layout
Since:

JDK1.1

See Also:
setAlignment(int)

setAlignment
public void setAlignment(int align)
Sets the alignment for this layout. Possible values are

FlowLayout.LEFT
FlowLayout.RIGHT
FlowLayout.CENTER
FlowLayout.LEADING
FlowLayout.TRAILING

Parameters:
align - one of the alignment values shown above
Since:

JDK1.1

See Also:
getAlignment()

getHgap
public int getHgap()
Gets the horizontal gap between components.

Returns:
the horizontal gap between components
Since:

JDK1.1

See Also:
setHgap(int)

setHgap
public void setHgap(int hgap)
Sets the horizontal gap between components.

Parameters:
hgap - the horizontal gap between components
Since:

JDK1.1

See Also:
getHgap()

getVgap
public int getVgap()
Gets the vertical gap between components.

Returns:
the vertical gap between components
Since:

JDK1.1

See Also:
setVgap(int)

setVgap
public void setVgap(int vgap)
Sets the vertical gap between components.

Parameters:
vgap - the vertical gap between components
Since:

JDK1.1

See Also:
getVgap()

addLayoutComponent
public void addLayoutComponent(String name,
                               Component comp)
Adds the specified component to the layout. Not used by this class.

Specified by:
addLayoutComponent in interface LayoutManager

Parameters:
name - the name of the component
comp - the component to be added

removeLayoutComponent
public void removeLayoutComponent(Component comp)
Removes the specified component from the layout. Not used by this class.

Specified by:
removeLayoutComponent in interface LayoutManager

Parameters:
comp - the component to remove
See Also:
Container.removeAll()

preferredLayoutSize
public Dimension preferredLayoutSize(Container target)
Returns the preferred dimensions for this layout given the visible components in the specified target container.

Specified by:
preferredLayoutSize in interface LayoutManager

Parameters:
target - the component which needs to be laid out
Returns:
the preferred dimensions to lay out the subcomponents of the specified container
See Also:
Container, minimumLayoutSize(java.awt.Container), Container.getPreferredSize()

minimumLayoutSize
public Dimension minimumLayoutSize(Container target)
Returns the minimum dimensions needed to layout the visible components contained in the specified target container.

Specified by:
minimumLayoutSize in interface LayoutManager

Parameters:
target - the component which needs to be laid out
Returns:
the minimum dimensions to lay out the subcomponents of the specified container
See Also:
preferredLayoutSize(java.awt.Container), Container, Container.doLayout()

layoutContainer
public void layoutContainer(Container target)
Lays out the container. This method lets each component take its preferred size by reshaping the components in the target container in order to satisfy the alignment of this FlowLayout object.

Specified by:
layoutContainer in interface LayoutManager

Parameters:
target - the specified component being laid out
See Also:
Container, Container.doLayout()

toString
public String toString()
Returns a string representation of this FlowLayout object and its values.

Overrides:
toString in class Object

Returns:
a string representation of this layout

Field Summary
static int	CENTER This value indicates that each row of components should be centered.
static int	LEADING This value indicates that each row of components should be justified to the leading edge of the container's orientation, for example, to the left in left-to-right orientations.
static int	LEFT This value indicates that each row of components should be left-justified.
static int	RIGHT This value indicates that each row of components should be right-justified.
static int	TRAILING This value indicates that each row of components should be justified to the trailing edge of the container's orientation, for example, to the right in left-to-right orientations.

Method Summary
void	addLayoutComponent(String name, Component comp) Adds the specified component to the layout.
int	getAlignment() Gets the alignment for this layout.
int	getHgap() Gets the horizontal gap between components.
int	getVgap() Gets the vertical gap between components.
void	layoutContainer(Container target) Lays out the container.
Dimension	minimumLayoutSize(Container target) Returns the minimum dimensions needed to layout the visible components contained in the specified target container.
Dimension	preferredLayoutSize(Container target) Returns the preferred dimensions for this layout given the visible components in the specified target container.
void	removeLayoutComponent(Component comp) Removes the specified component from the layout.
void	setAlignment(int align) Sets the alignment for this layout.
void	setHgap(int hgap) Sets the horizontal gap between components.
void	setVgap(int vgap) Sets the vertical gap between components.
String	toString() Returns a string representation of this FlowLayout object and its values.

java.awt Class FlowLayout

Field Summary

Constructor Summary

Method Summary

Field Detail

LEFT

CENTER

RIGHT

LEADING

TRAILING

Constructor Detail

FlowLayout

FlowLayout

FlowLayout

Method Detail

getAlignment

setAlignment

getHgap

setHgap

getVgap

setVgap

addLayoutComponent

removeLayoutComponent

preferredLayoutSize

minimumLayoutSize

layoutContainer

toString

java.awt
Class FlowLayout