The document discusses 4 common layout managers in AWT: FlowLayout, GridLayout, BorderLayout, and BoxLayout. It provides details on how each layout manager arranges and positions components within a container. Code examples are given to demonstrate implementing each layout manager. The document is intended to help students understand how to define and use layout managers to structure the UI design of an AWT application.

1. 1.4 USE LAYOUT1.4 USE LAYOUT
MANAGERMANAGER

2.  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.  The UI components are placed in
containers.
 Each container has a layout manager to
arrange the GUI components within
the container.

4.  FlowLayout
 GridLayout
 BorderLayout
 BoxLayout

5. 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.  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.  public FlowLayout(int align, int hGap, int vGap)
Constructs a new FlowLayout with a specified alignment,
horizontal gap and vertical gap. The gaps 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.  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.  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.  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.  Divides the window into 5 areas:
◦ BorderLayout.NORTH - North
◦ BorderLayout. SOUTH - South
◦ BorderLayout. EAST - East
◦ BorderLayout. WEST - West
◦ BorderLayout. CENTER - Center

16.  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.  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.  4 layout manager: FlowLayout, BorderLayout,
GridLayout and BoxLayout.