Java java.awt Class FlowLayout（JDK8）

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Java™ Platform
Standard Ed. 8

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Method

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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 directional flow, much like lines of text in a paragraph. The flow direction is determined by the container's componentOrientation property and may be one of two values:
- ComponentOrientation.LEFT_TO_RIGHT
- ComponentOrientation.RIGHT_TO_LEFT
Flow layouts are typically used to arrange buttons in a panel. It arranges buttons horizontally until no more buttons fit on the same line. The line alignment is determined by the align property. The possible values are:
- LEFT
- RIGHT
- CENTER
- LEADING
- TRAILING
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:

ComponentOrientation, Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`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

Constructors
Constructor and Description
`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

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addLayoutComponent(String name, Component comp)` Adds the specified component to the layout.
`int`	`getAlignment()` Gets the alignment for this layout.
`boolean`	`getAlignOnBaseline()` Returns true if components are to be vertically aligned along their baseline.
`int`	`getHgap()` Gets the horizontal gap between components and between the components and the borders of the `Container`
`int`	`getVgap()` Gets the vertical gap between components and between the components and the borders of the `Container`.
`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`	`setAlignOnBaseline(boolean alignOnBaseline)` Sets whether or not components should be vertically aligned along their baseline.
`void`	`setHgap(int hgap)` Sets the horizontal gap between components and between the components and the borders of the `Container`.
`void`	`setVgap(int vgap)` Sets the vertical gap between components and between the components and the borders of the `Container`.
`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
    
    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
    
    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, FlowLayout.CENTER, FlowLayout.LEADING, or FlowLayout.TRAILING.
    
    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, FlowLayout.CENTER, FlowLayout.LEADING, or FlowLayout.TRAILING.
    
    Parameters:
    
    align - the alignment value
    
    hgap - the horizontal gap between components and between the components and the borders of the Container
    
    vgap - the vertical gap between components and between the components and the borders of the Container
- 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 and between the components and the borders of the Container
    
    Returns:
    
    the horizontal gap between components and between the components and the borders of the Container
    
    Since:
    
    JDK1.1
    
    See Also:
    
    setHgap(int)
  - setHgap
```
public void setHgap(int hgap)
```
    Sets the horizontal gap between components and between the components and the borders of the Container.
    
    Parameters:
    
    hgap - the horizontal gap between components and between the components and the borders of the Container
    
    Since:
    
    JDK1.1
    
    See Also:
    
    getHgap()
  - getVgap
```
public int getVgap()
```
    Gets the vertical gap between components and between the components and the borders of the Container.
    
    Returns:
    
    the vertical gap between components and between the components and the borders of the Container
    
    Since:
    
    JDK1.1
    
    See Also:
    
    setVgap(int)
  - setVgap
```
public void setVgap(int vgap)
```
    Sets the vertical gap between components and between the components and the borders of the Container.
    
    Parameters:
    
    vgap - the vertical gap between components and between the components and the borders of the Container
    
    Since:
    
    JDK1.1
    
    See Also:
    
    getVgap()
  - setAlignOnBaseline
```
public void setAlignOnBaseline(boolean alignOnBaseline)
```
    Sets whether or not components should be vertically aligned along their baseline. Components that do not have a baseline will be centered. The default is false.
    
    Parameters:
    
    alignOnBaseline - whether or not components should be vertically aligned on their baseline
    
    Since:
    
    1.6
  - getAlignOnBaseline
```
public boolean getAlignOnBaseline()
```
    Returns true if components are to be vertically aligned along their baseline. The default is false.
    
    Returns:
    
    true if components are to be vertically aligned along their baseline
    
    Since:
    
    1.6
  - 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 container that 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 container that 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 visible 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

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Java™ Platform
Standard Ed. 8

All Classes

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Detail:
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Java java.awt Class FlowLayout（JDK8）

Class FlowLayout

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

LEFT

CENTER

RIGHT

LEADING

TRAILING

Constructor Detail

FlowLayout

FlowLayout

FlowLayout

Method Detail

getAlignment

setAlignment

getHgap

setHgap

getVgap

setVgap

setAlignOnBaseline

getAlignOnBaseline

addLayoutComponent

removeLayoutComponent

preferredLayoutSize

minimumLayoutSize

layoutContainer

toString