OpenJDK 27 · java.awt.GridLayout · APIdia, the JavaDoc alternative

The GridLayout class is a layout manager that lays out a container's components in a rectangular grid. The container is divided into equal-sized rectangles, and one component is placed in each rectangle. For example, the following is a window that lays out six buttons into three rows and two columns:

import java.awt.Button;
import java.awt.EventQueue;
import java.awt.Frame;
import java.awt.GridLayout;

public class GridLayoutExample {

    public static void main(String[] args) throws Exception {
        EventQueue.invokeAndWait(() -> {
            Frame frame = new Frame("GridLayout");
            frame.setLayout(new GridLayout(3, 2));
            frame.add(new Button("1"));
            frame.add(new Button("2"));
            frame.add(new Button("3"));
            frame.add(new Button("4"));
            frame.add(new Button("5"));
            frame.add(new Button("6"));
            frame.setSize(200, 200);
            frame.setVisible(true);
        });
    }
}

If the container's ComponentOrientation property is horizontal and left-to-right, the above example produces the output shown in Figure 1. If the container's ComponentOrientation property is horizontal and right-to-left, the example produces the output shown in Figure 2.

Shows 6 buttons in rows of 2. Row 1 shows buttons 1 then 2.
Row 2 shows buttons 3 then 4. Row 3 shows buttons 5 then 6.

Figure 1: Horizontal, Left-to-Right

Shows 6 buttons in rows of 2. Row 1 shows buttons 2 then 1.
Row 2 shows buttons 4 then 3. Row 3 shows buttons 6 then 5.

Figure 2: Horizontal, Right-to-Left

When both the number of rows and the number of columns have been set to non-zero values, either by a constructor or by the setRows and setColumns methods, the number of columns specified is ignored. Instead, the number of columns is determined from the specified number of rows and the total number of components in the layout. So, for example, if three rows and two columns have been specified and nine components are added to the layout, they will be displayed as three rows of three columns. Specifying the number of columns affects the layout only when the number of rows is set to zero.

Modifier and Type	Field and Description
pack-priv int	cols This is the number of columns specified for the grid.
pack-priv int	hgap This is the horizontal gap (in pixels) which specifies the space between columns.
pack-priv int	rows This is the number of rows specified for the grid.
private static final long	serialVersionUID Use serialVersionUID from JDK 1.6 for interoperability.
pack-priv int	vgap This is the vertical gap (in pixels) which specifies the space between rows.

Constructor Summary

Access	Constructor and Description
public	GridLayout() Creates a grid layout with a default of one column per component, in a single row.
public	GridLayout(int the rows, with the value zero meaning any number of rows. rows, int the columns, with the value zero meaning any number of columns. cols) Creates a grid layout with the specified number of rows and columns.
public	GridLayout(int the rows, with the value zero meaning any number of rows rows, int the columns, with the value zero meaning any number of columns cols, int the horizontal gap hgap, int the vertical gap vgap) Creates a grid layout with the specified number of rows and columns.

Method Summary

Modifier and Type	Method and Description
public void	addLayoutComponent(String the name of the component name, Component the component to be added comp) Implements java.awt.LayoutManager.addLayoutComponent. Adds the specified component with the specified name to the layout.
public int	Returns: the number of columns in this layout getColumns() Gets the number of columns in this layout.
public int	Returns: the horizontal gap between components getHgap() Gets the horizontal gap between components.
public int	Returns: the number of rows in this layout getRows() Gets the number of rows in this layout.
public int	Returns: the vertical gap between components getVgap() Gets the vertical gap between components.
public void	layoutContainer(Container the container in which to do the layout parent) Implements java.awt.LayoutManager.layoutContainer. Lays out the specified container using this layout.
public Dimension	Returns: the minimum dimensions needed to lay out the subcomponents of the specified container minimumLayoutSize(Container the container in which to do the layout parent) Implements java.awt.LayoutManager.minimumLayoutSize. Determines the minimum size of the container argument using this grid layout.
public Dimension	Returns: the preferred dimensions to lay out the subcomponents of the specified container preferredLayoutSize(Container the container in which to do the layout parent) Implements java.awt.LayoutManager.preferredLayoutSize. Determines the preferred size of the container argument using this grid layout.
public void	removeLayoutComponent(Component the component to be removed comp) Implements java.awt.LayoutManager.removeLayoutComponent. Removes the specified component from the layout.
public void	setColumns(int the number of columns in this layout cols) Sets the number of columns in this layout to the specified value.
public void	setHgap(int the horizontal gap between components hgap) Sets the horizontal gap between components to the specified value.
public void	setRows(int the number of rows in this layout rows) Sets the number of rows in this layout to the specified value.
public void	setVgap(int the vertical gap between components vgap) Sets the vertical gap between components to the specified value.
public String	Returns: a string representation of this grid layout toString() Overrides java.lang.Object.toString. Returns the string representation of this grid layout's values.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll wait wait wait

Field Detail

cols back to summary

cols	back to summary
pack-priv int cols This is the number of columns specified for the grid. The number of columns can be changed at any time. This should be a non negative integer, where '0' means 'any number' meaning that the number of Columns in that dimension depends on the other dimension. See Also `getColumns()`, `setColumns(int)`

pack-priv int cols

This is the number of columns specified for the grid. The number of columns can be changed at any time. This should be a non negative integer, where '0' means 'any number' meaning that the number of Columns in that dimension depends on the other dimension.

See Also: getColumns(), setColumns(int)

hgap back to summary

hgap	back to summary
pack-priv int hgap This is the horizontal gap (in pixels) which specifies the space between columns. They can be changed at any time. This should be a non-negative integer. See Also `getHgap()`, `setHgap(int)`

pack-priv int hgap

This is the horizontal gap (in pixels) which specifies the space between columns. They can be changed at any time. This should be a non-negative integer.

See Also: getHgap(), setHgap(int)

rows back to summary

rows	back to summary
pack-priv int rows This is the number of rows specified for the grid. The number of rows can be changed at any time. This should be a non negative integer, where '0' means 'any number' meaning that the number of Rows in that dimension depends on the other dimension. See Also `getRows()`, `setRows(int)`

pack-priv int rows

This is the number of rows specified for the grid. The number of rows can be changed at any time. This should be a non negative integer, where '0' means 'any number' meaning that the number of Rows in that dimension depends on the other dimension.

See Also: getRows(), setRows(int)

serialVersionUID	back to summary
private static final long serialVersionUID Use serialVersionUID from JDK 1.6 for interoperability. Annotations @Serial

vgap back to summary

vgap	back to summary
pack-priv int vgap This is the vertical gap (in pixels) which specifies the space between rows. They can be changed at any time. This should be a non negative integer. See Also `getVgap()`, `setVgap(int)`

pack-priv int vgap

This is the vertical gap (in pixels) which specifies the space between rows. They can be changed at any time. This should be a non negative integer.

See Also: getVgap(), setVgap(int)

Constructor Detail

GridLayout	back to summary
public GridLayout() Creates a grid layout with a default of one column per component, in a single row. Since 1.1

GridLayout

back to summary

public GridLayout()

Creates a grid layout with a default of one column per component, in a single row.

Since: 1.1

GridLayout back to summary

GridLayout	back to summary
public GridLayout(int rows, int cols) Creates a grid layout with the specified number of rows and columns. All components in the layout are given equal size. One, but not both, of `rows` and `cols` can be zero, which means that any number of objects can be placed in a row or in a column. Parameters rows:int the rows, with the value zero meaning any number of rows. cols:int the columns, with the value zero meaning any number of columns.

public GridLayout(int rows, int cols)

Creates a grid layout with the specified number of rows and columns. All components in the layout are given equal size.

One, but not both, of rows and cols can be zero, which means that any number of objects can be placed in a row or in a column.

Parameters

rows:int: the rows, with the value zero meaning any number of rows.
cols:int: the columns, with the value zero meaning any number of columns.

GridLayout back to summary

GridLayout	back to summary
public GridLayout(int rows, int cols, int hgap, int vgap) Creates a grid layout with the specified number of rows and columns. All components in the layout are given equal size. In addition, the horizontal and vertical gaps are set to the specified values. Horizontal gaps are placed between each of the columns. Vertical gaps are placed between each of the rows. One, but not both, of `rows` and `cols` can be zero, which means that any number of objects can be placed in a row or in a column. All `GridLayout` constructors defer to this one. Parameters rows:int the rows, with the value zero meaning any number of rows cols:int the columns, with the value zero meaning any number of columns hgap:int the horizontal gap vgap:int the vertical gap Exceptions IllegalArgumentException: if the value of both `rows` and `cols` is set to zero

public GridLayout(int rows, int cols, int hgap, int vgap)

Creates a grid layout with the specified number of rows and columns. All components in the layout are given equal size.

In addition, the horizontal and vertical gaps are set to the specified values. Horizontal gaps are placed between each of the columns. Vertical gaps are placed between each of the rows.

One, but not both, of rows and cols can be zero, which means that any number of objects can be placed in a row or in a column.

All GridLayout constructors defer to this one.

Parameters

rows:int: the rows, with the value zero meaning any number of rows
cols:int: the columns, with the value zero meaning any number of columns
hgap:int: the horizontal gap
vgap:int: the vertical gap

Exceptions

IllegalArgumentException:: if the value of both rows and cols is set to zero

Method Detail

addLayoutComponent	back to summary
public void addLayoutComponent(String name, Component comp) Implements java.awt.LayoutManager.addLayoutComponent. Adds the specified component with the specified name to the layout. Parameters name:String the name of the component comp:Component the component to be added

addLayoutComponent

back to summary

public void addLayoutComponent(String name, Component comp)

Implements java.awt.LayoutManager.addLayoutComponent.

Adds the specified component with the specified name to the layout.

Parameters

name:String: the name of the component
comp:Component: the component to be added

getColumns	back to summary
public int getColumns() Gets the number of columns in this layout. Returns:int the number of columns in this layout Since 1.1

getColumns

back to summary

public int getColumns()

Gets the number of columns in this layout.

Returns:int: the number of columns in this layout
Since: 1.1

getHgap	back to summary
public int getHgap() Gets the horizontal gap between components. Returns:int the horizontal gap between components Since 1.1

getHgap

back to summary

public int getHgap()

Gets the horizontal gap between components.

Returns:int: the horizontal gap between components
Since: 1.1

getRows	back to summary
public int getRows() Gets the number of rows in this layout. Returns:int the number of rows in this layout Since 1.1

getRows

back to summary

public int getRows()

Gets the number of rows in this layout.

Returns:int: the number of rows in this layout
Since: 1.1

getVgap	back to summary
public int getVgap() Gets the vertical gap between components. Returns:int the vertical gap between components Since 1.1

getVgap

back to summary

public int getVgap()

Gets the vertical gap between components.

Returns:int: the vertical gap between components
Since: 1.1

layoutContainer back to summary

layoutContainer	back to summary
public void layoutContainer(Container parent) Implements java.awt.LayoutManager.layoutContainer. Lays out the specified container using this layout. This method reshapes the components in the specified target container in order to satisfy the constraints of the `GridLayout` object. The grid layout manager determines the size of individual components by dividing the free space in the container into equal-sized portions according to the number of rows and columns in the layout. The container's free space equals the container's size minus any insets and any specified horizontal or vertical gap. All components in a grid layout are given the same size. Parameters parent:Container the container in which to do the layout See Also `java.awt.Container`, `java.awt.Container#doLayout`

public void layoutContainer(Container parent)

Implements java.awt.LayoutManager.layoutContainer.

Lays out the specified container using this layout.

This method reshapes the components in the specified target container in order to satisfy the constraints of the GridLayout object.

The grid layout manager determines the size of individual components by dividing the free space in the container into equal-sized portions according to the number of rows and columns in the layout. The container's free space equals the container's size minus any insets and any specified horizontal or vertical gap. All components in a grid layout are given the same size.

Parameters

parent:Container: the container in which to do the layout

minimumLayoutSize back to summary

minimumLayoutSize	back to summary
public Dimension minimumLayoutSize(Container parent) Implements java.awt.LayoutManager.minimumLayoutSize. Determines the minimum size of the container argument using this grid layout. The minimum width of a grid layout is the largest minimum width of all of the components in the container times the number of columns, plus the horizontal padding times the number of columns minus one, plus the left and right insets of the target container. The minimum height of a grid layout is the largest minimum height of all of the components in the container times the number of rows, plus the vertical padding times the number of rows minus one, plus the top and bottom insets of the target container. Parameters parent:Container the container in which to do the layout Returns:Dimension the minimum dimensions needed to lay out the subcomponents of the specified container See Also `java.awt.GridLayout#preferredLayoutSize`, `java.awt.Container#doLayout`

public Dimension minimumLayoutSize(Container parent)

Implements java.awt.LayoutManager.minimumLayoutSize.

Determines the minimum size of the container argument using this grid layout.

The minimum width of a grid layout is the largest minimum width of all of the components in the container times the number of columns, plus the horizontal padding times the number of columns minus one, plus the left and right insets of the target container.

The minimum height of a grid layout is the largest minimum height of all of the components in the container times the number of rows, plus the vertical padding times the number of rows minus one, plus the top and bottom insets of the target container.

Parameters

parent:Container: the container in which to do the layout

Returns:Dimension

the minimum dimensions needed to lay out the subcomponents of the specified container

preferredLayoutSize back to summary

preferredLayoutSize	back to summary
public Dimension preferredLayoutSize(Container parent) Implements java.awt.LayoutManager.preferredLayoutSize. Determines the preferred size of the container argument using this grid layout. The preferred width of a grid layout is the largest preferred width of all of the components in the container times the number of columns, plus the horizontal padding times the number of columns minus one, plus the left and right insets of the target container. The preferred height of a grid layout is the largest preferred height of all of the components in the container times the number of rows, plus the vertical padding times the number of rows minus one, plus the top and bottom insets of the target container. Parameters parent:Container the container in which to do the layout Returns:Dimension the preferred dimensions to lay out the subcomponents of the specified container See Also `java.awt.GridLayout#minimumLayoutSize`, `java.awt.Container#getPreferredSize()`

public Dimension preferredLayoutSize(Container parent)

Implements java.awt.LayoutManager.preferredLayoutSize.

Determines the preferred size of the container argument using this grid layout.

The preferred width of a grid layout is the largest preferred width of all of the components in the container times the number of columns, plus the horizontal padding times the number of columns minus one, plus the left and right insets of the target container.

The preferred height of a grid layout is the largest preferred height of all of the components in the container times the number of rows, plus the vertical padding times the number of rows minus one, plus the top and bottom insets of the target container.

Parameters

parent:Container: the container in which to do the layout

Returns:Dimension

the preferred dimensions to lay out the subcomponents of the specified container

removeLayoutComponent	back to summary
public void removeLayoutComponent(Component comp) Implements java.awt.LayoutManager.removeLayoutComponent. Removes the specified component from the layout. Parameters comp:Component the component to be removed

removeLayoutComponent

back to summary

public void removeLayoutComponent(Component comp)

Implements java.awt.LayoutManager.removeLayoutComponent.

Removes the specified component from the layout.

Parameters

comp:Component: the component to be removed

setColumns back to summary

setColumns	back to summary
public void setColumns(int cols) Sets the number of columns in this layout to the specified value. Setting the number of columns has no effect on the layout if the number of rows specified by a constructor or by the `setRows` method is non-zero. In that case, the number of columns displayed in the layout is determined by the total number of components and the number of rows specified. Parameters cols:int the number of columns in this layout Exceptions IllegalArgumentException: if the value of both `rows` and `cols` is set to zero Since 1.1

public void setColumns(int cols)

Sets the number of columns in this layout to the specified value. Setting the number of columns has no effect on the layout if the number of rows specified by a constructor or by the setRows method is non-zero. In that case, the number of columns displayed in the layout is determined by the total number of components and the number of rows specified.

Parameters

cols:int: the number of columns in this layout

Exceptions

IllegalArgumentException:: if the value of both rows and cols is set to zero

Since

1.1

setHgap	back to summary
public void setHgap(int hgap) Sets the horizontal gap between components to the specified value. Parameters hgap:int the horizontal gap between components Since 1.1

setHgap

back to summary

public void setHgap(int hgap)

Sets the horizontal gap between components to the specified value.

Parameters

hgap:int: the horizontal gap between components

Since

1.1

setRows back to summary

setRows	back to summary
public void setRows(int rows) Sets the number of rows in this layout to the specified value. Parameters rows:int the number of rows in this layout Exceptions IllegalArgumentException: if the value of both `rows` and `cols` is set to zero Since 1.1

public void setRows(int rows)

Sets the number of rows in this layout to the specified value.

Parameters

rows:int: the number of rows in this layout

Exceptions

IllegalArgumentException:: if the value of both rows and cols is set to zero

Since

1.1

setVgap	back to summary
public void setVgap(int vgap) Sets the vertical gap between components to the specified value. Parameters vgap:int the vertical gap between components Since 1.1

setVgap

back to summary

public void setVgap(int vgap)

Sets the vertical gap between components to the specified value.

Parameters

vgap:int: the vertical gap between components

Since

1.1

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Returns the string representation of this grid layout's values. Returns:String a string representation of this grid layout

toString

back to summary

public String toString()

Overrides java.lang.Object.toString.

Returns the string representation of this grid layout's values.

Returns:String: a string representation of this grid layout

public Class GridLayout

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail