This document discusses layout managers in AWT. It describes four common layout managers: FlowLayout, which arranges components horizontally from left to right; GridLayout, which divides a container into a grid of equal rows and columns; BorderLayout, which divides a container into five regions (north, south, east, west, center); and BoxLayout, which arranges components vertically or horizontally within a container. It provides code examples of using each layout manager.

1. GRAPHICAL USERGRAPHICAL USER
INTERFACEINTERFACE
1.4 USE LAYOUT1.4 USE LAYOUT
MANAGERMANAGER

2. Learning Outcomes
 By the end of the class, student should be
able to:
 Define the use of layout manager in AWT
 Use layout manager in AWT:
 FlowLayout
 GridLayout
 BorderLayout
 BoxLayout
 Write java program using layout manager

3. USE OF LAYOUT
MANAGERS
 The UI components are placed in
containers.
 Each container has a layout manager to
arrange the GUI components within
the container.

4. LAYOUT MANAGERS
 FlowLayout
 GridLayout
 BorderLayout
 BoxLayout

5. SYNTAXTO SET LAYOUT
MANAGER
container.setLayout(new
SpecificLayout());
container.setLayout(new
SpecificLayout());
setLayout(new SpecificLayout());setLayout(new SpecificLayout());
Set the layout manager
here
Set the layout manager
here
AWT
SWING

6. FlowLayout
 Simplest and most basic layout manager
 Components arranged in container from left to
right in the order in which they were added
 When edge of container reached, continues
on next line
 Can determine the gap between components
in pixels.

7.  Three constant (alignment):
 FlowLayout.RIGHT
 FlowLayout.LEFT
 FlowLayout.CENTER

8. FlowLayout.CENTER
FlowLayout.RIGHT
FlowLayout.LEFT

9. FlowLayout CONSTRUCTOR
 public FlowLayout(int align, int hGap,
int vGap)
Constructs a new FlowLayout with a specified alignment,
horizontal gap and vertical gap. The g aps are the distances
in
pixel between components.
 public FlowLayout(int alignment)
Constructs a new FlowLayout with a specified alignment
and a default gap of 5 pixels for both horizontal and vertical.
 public FlowLayout()
Constructs a new FlowLayout with a default center
alignment and a default gap of 5 pixels for both horizontal
and vertical.

10. import java.awt.*;
import javax.swing.*;
public class TestFlowLayout extends JFrame
{
public TestFlowLayout()
{
super(“Create FlowLayout");
Container c = getContentPane();
c.setLayout(new FlowLayout(FlowLayout.LEFT,20,10));
for (int i=1; i<9;i++)
c.add(new Button("button "+i));
setSize(350,200);
setVisible(true);
}
public static void main(String[] arg)
{
TestFlowLayout s = new TestFlowLayout();
s.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
10
20

11. GridLayout
 Divides container into a grid
 Components placed in rows and columns
 All components have same width and height
 Added starting from top left, then from left to right
 When row full, continues on next row, left to right

12. GridLayout CONSTRUCTOR
 public GridLayout()
Construct a new GridLayout with one column
in a single row.
 public GridLayout(int rows,
int columns)
Constructs a new GridLayout with the
specified number of rows and columns.

13. GridLayout CONSTRUCTOR
 public GridLayout(int rows, int
columns, int hGap, int vGap)
Constructs a new GridLayout with the
specified number of rows and columns,
along with specified horizontal and vertical
gaps between components.

14. import java.awt.*;
import javax.swing.*;
public class TestGridLayout extends JFrame
{
public TestGridLayout()
{
super(“Create GridLayout");
Container s = getContentPane();
s.setLayout(new GridLayout(3,2,20,10));
for (int i=1; i<7;i++)
s.add(new Button("button "+i));
setSize(350,200);
setVisible(true);
}
public static void main(String[] arg)
{
TestGridLayout t = new TestGridLayout();
t.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}

15. BorderLayout
 Divides the window into 5 areas:
 BorderLayout.NORTH - North
 BorderLayout. SOUTH - South
 BorderLayout. EAST - East
 BorderLayout. WEST - West
 BorderLayout. CENTER - Center

16. BorderLayout CONSTRUCTOR
 public BorderLayout()
Construct a new BorderLayout without
horizontal or vertical gaps
 public BorderLayout(int hGap,
int vGap)
Constructs a new BorderLayout with the
specified horizontal and vertical gaps
between the components.

17. import java.awt.*;
import javax.swing.*;
public class TestBorderLayout extends JFrame
{
public TestBorderLayout()
{
super(“Create BorderLayout");
Container s = getContentPane();
s.setLayout(new BorderLayout(20,10));
Button bNorth = new Button(“North");
Button bSouth = new Button(“South");
Button bEast = new Button(“East");
Button bWest = new Button(“West");
Button bCenter = new Button(“Center");
s.add(bNorth,BorderLayout.NORTH);
s.add(bSouth,BorderLayout.SOUTH);
s.add(bEast,BorderLayout.EAST);
s.add(bWest,BorderLayout.WEST);
s.add(bCenter,BorderLayout.CENTER);
setSize(350,200);
setVisible(true);
}
public static void main(String[] arg)
{
TestBorderLayout t = new TestBorderLayout();
t.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}

18. import java.awt.*;
import javax.swing.*;
public class TestBorderLayout extends JFrame
{
public TestBorderLayout()
{
super(“Create BorderLayout");
Container s = getContentPane();
s.setLayout(new BorderLayout(20,10));
Button bNorth = new Button(“North");
Button bSouth = new Button(“South");
Button bEast = new Button(“East");
Button bWest = new Button(“West");
Button bCenter = new Button(“Center");
//s.add(bNorth,BorderLayout.NORTH);
s.add(bSouth,BorderLayout.SOUTH);
s.add(bEast,BorderLayout.EAST);
s.add(bWest,BorderLayout.WEST);
s.add(bCenter,BorderLayout.CENTER);
setSize(350,200);
setVisible(true);
}
public static void main(String[] arg)
{
TestBorderLayout t = new TestBorderLayout();
t.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}

19. import java.awt.*;
import javax.swing.*;
public class TestBorderLayout extends JFrame
{
public TestBorderLayout()
{
super(“Create BorderLayout");
Container s = getContentPane();
s.setLayout(new BorderLayout(20,10));
Button bNorth = new Button(“North");
Button bSouth = new Button(“South");
Button bEast = new Button(“East");
Button bWest = new Button(“West");
Button bCenter = new Button(“Center");
s.add(bNorth,BorderLayout.NORTH);
s.add(bSouth,BorderLayout.SOUTH);
//s.add(bEast,BorderLayout.EAST);
s.add(bWest,BorderLayout.WEST);
s.add(bCenter,BorderLayout.CENTER);
setSize(350,200);
setVisible(true);
}
public static void main(String[] arg)
{
TestBorderLayout t = new TestBorderLayout();
t.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}

20. import java.awt.*;
import javax.swing.*;
public class TestBorderLayout extends JFrame
{
public TestBorderLayout()
{
super(“Create BorderLayout");
Container s = getContentPane();
s.setLayout(new BorderLayout(20,10));
Button bNorth = new Button(“North");
Button bSouth = new Button(“South");
Button bEast = new Button(“East");
Button bWest = new Button(“West");
Button bCenter = new Button(“Center");
//s.add(bNorth,BorderLayout.NORTH);
s.add(bSouth,BorderLayout.SOUTH);
//s.add(bEast,BorderLayout.EAST);
//s.add(bWest,BorderLayout.WEST);
s.add(bCenter,BorderLayout.CENTER);
setSize(350,200);
setVisible(true);
}
public static void main(String[] arg)
{
TestBorderLayout t = new TestBorderLayout();
t.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}

21. import java.awt.*;
import javax.swing.*;
public class TestBorderLayout extends JFrame
{
public TestBorderLayout()
{
super(“Create BorderLayout");
Container s = getContentPane();
s.setLayout(new BorderLayout(20,10));
Button bNorth = new Button(“North");
Button bSouth = new Button(“South");
Button bEast = new Button(“East");
Button bWest = new Button(“West");
Button bCenter = new Button(“Center");
s.add(bNorth,BorderLayout.NORTH);
s.add(bSouth,BorderLayout.SOUTH);
s.add(bEast,BorderLayout.EAST);
s.add(bWest,BorderLayout.WEST);
//s.add(bCenter,BorderLayout.CENTER);
setSize(350,200);
setVisible(true);
}
public static void main(String[] arg)
{
TestBorderLayout t = new TestBorderLayout();
t.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}

22. BoxLayout
 A layout manager that allows multiple
components to be laid out either vertically
or horizontally.
 The value of axis can be one of the
following:
 BoxLayout.X_AXIS
 BoxLayout.Y_AXIS
 BoxLayout.LINE_AXIS
 BoxLayout.PAGE_AXIS

23.  BoxLayout has a single constructor:
public Bo xLayo ut(Co ntaine r targ e t, int axis)
 public BoxLayout(Container target, int axis)
 The first argument is the container
 The second is the layout direction.

24. Summary
 4 layout manager: FlowLayout, BorderLayout,
GridLayout and BoxLayout.