chapter 11.3

LAYOUT MANAGERChapter 11.3:

Layout Managers The layout manager determines how the GUI

components are added to the container (such as the content pane of a frame)

Layout managers are set in containers using the

setLayout(LayoutManager) method in a container

FlowLayout

In using this layout, GUI components are placed in left-to-right order. When the component does not fit on the

same line, left-to-right placement continues on the next line.

As a default, components on each line are centered.

When the frame containing the component is resized, the placement of components is adjusted accordingly.

FlowLayout Sample

This shows the placement of five buttons by using FlowLayout.

FlowLayout The components are arranged

in the container from left to right in the order in which they were added.

When one row becomes filled, a new row is started.

FlowLayout can be aligned in 3 ways:

FlowLayout.LEFT – left alignedFlowLayout.RIGHT – right alignedFlowLayout.CENTER – center aligned

FlowLayout Constructors 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 inpixel between components.

public FlowLayout(int alignment)Constructs a new FlowLayout with a specified alignment and a default gap of five pixels for both horizontal and vertical.

public FlowLayout()Constructs a new FlowLayout with a default center alignment and a default gap of five pixels for both horizontal and vertical.

import java.awt.*;import javax.swing.*;//import java.awt.event.*;

public class TestFlowLayout extends JFrame{ public TestFlowLayout() { super(“Using flowLayout"); Container cpane = getContentPane(); cpane.setLayout(new FlowLayout(FlowLayout.LEFT,20,10)); for (int i=1; i<7;i++) cpane.add(new JButton("button "+i)); setSize(300,200); setVisible(true); } public static void main(String[] arg) { TestFlowLayout teks = new TestFlowLayout(); teks.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); }

}

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BorderLayout This layout manager divides the container into five

regions: center, north, south, east, and west. The north and south regions expand or shrink in

width only The east and west regions expand or shrink in

height only The center region expands or shrinks on both

height and width. Not all regions have to be occupied.

BorderLayout Sample

GridLayout This layout manager placesGUI components on

equal-size N by M grids. Components are placed in top-to-bottom, left-to-

right order. The number of rows and columns remains the

same after the frame is resized, but the width and height of each region will change.

GridLayout Sample

Using Panels as Containers Panels act as smaller containers for grouping user

interface components.

It is recommended that you place the user interface components in panels and place the panels in a frame. You can also place panels in a panel.

To add a component to JFrame, you actually add it to the content pane of JFrame. To add a component to a panel, you add it directly to the panel using the add method.

Create a JPanel

example :

Container cpane = getContentPane();

JPanel pan = new JPanel(); // create a panel

pan.add(new JButton(“Click”)); // add a button in the panel

cpane.add(pan) // add the panel in the container

label TextField

Text Area

button button

There are 3 panels : top panel – has 2 components that are label, textfield - 2 components are arranged with flowLayout

middle panel – has a component: text area. It is arranged with Gridlayout

bottom panel – has 2 components that are buttons - 2components are arranged with Flowlayout All panels are arrranged with borderlayout top panel –north middle panel –center bottom panel –South

Toppanel

Middlepanel

Bottompanel

import java.awt.*;import javax.swing.*;

public class UjiPanel extends JFrame{ public UjiPanel() { super("Membuat BorderLayout"); Container bekas = getContentPane(); bekas.setLayout(new BorderLayout());

JPanel panelAtas = new JPanel(); bekas.add(panelAtas,BorderLayout.NORTH); JLabel label = new JLabel("Nama"); JTextField txtField = new JTextField(10); panelAtas.setLayout(new FlowLayout()); panelAtas.add(label); panelAtas.add(txtField);

JPanel panelTengah = new JPanel(); bekas.add(panelTengah,BorderLayout.CENTER); JTextArea txtArea = new JTextArea(); panelTengah.setLayout(new GridLayout()); panelTengah.add(txtArea); JPanel panelBawah = new JPanel(); bekas.add(panelBawah,BorderLayout.SOUTH); JButton btg1 = new JButton("Hantar"); JButton btg2 = new JButton("Batal"); btg2.setMnemonic('B'); panelBawah.setLayout(new FlowLayout()); panelBawah.add(btg1); panelBawah.add(btg2);

setSize(300,200); setVisible(true); } // konstruktor

public static void main(String[] arg) { UjiPanel teks = new UjiPanel(); teks.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); }}

Step in Creating Panel Set a layout manager for a container (frame). Create a panel Set a layout for the panel. Add the panel in the container (frame) Create a component that to be added in the panel Add the component in the panel