FlowLayout (Java 2 Platform SE 5.0) (original) (raw)

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 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

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

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 ofFlowLayout.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 ofFlowLayout.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

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 theContainer.

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 theContainer.

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()

addLayoutComponent

public void addLayoutComponent(String name, Component comp)

Adds the specified component to the layout. Not used by this class.

Specified by:

[addLayoutComponent](../../java/awt/LayoutManager.html#addLayoutComponent%28java.lang.String, java.awt.Component%29) in interface [LayoutManager](../../java/awt/LayoutManager.html "interface in java.awt")

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](../../java/awt/LayoutManager.html#removeLayoutComponent%28java.awt.Component%29) in interface [LayoutManager](../../java/awt/LayoutManager.html "interface in java.awt")

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](../../java/awt/LayoutManager.html#preferredLayoutSize%28java.awt.Container%29) in interface [LayoutManager](../../java/awt/LayoutManager.html "interface in java.awt")

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](../../java/awt/LayoutManager.html#minimumLayoutSize%28java.awt.Container%29) in interface [LayoutManager](../../java/awt/LayoutManager.html "interface in java.awt")

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](../../java/awt/LayoutManager.html#layoutContainer%28java.awt.Container%29) in interface [LayoutManager](../../java/awt/LayoutManager.html "interface in java.awt")

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](../../java/lang/Object.html#toString%28%29) in class [Object](../../java/lang/Object.html "class in java.lang")

Returns:

a string representation of this layout

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For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

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