SWING: FlowLayout Class Cheat Sheet - A quick cheatsheet for beginners, with examples

Following is the declaration for java.awt.FlowLayout class −

public class FlowLayout
   extends Object
      implements LayoutManager, Serializable

# Field

Following are the fields for java.awt.BorderLayout class

static int CENTER − This value indicates that each row of components should be centered.
static 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.
static int LEFT − This value indicates that each row of components should be left-justified.
static int RIGHT − This value indicates that each row of components should be right-justified.
static 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.

# Constructors

`FlowLayout()`	Constructs a new FlowLayout with a centered alignment and a default 5-unit horizontal and vertical gap.
`FlowLayout(int align)`	Constructs a new FlowLayout with the specified alignment and a default 5-unit horizontal and vertical gap.
`FlowLayout(int align, int hgap, int vgap)`	Creates a new flow layout manager with the indicated alignment and the indicated horizontal and vertical gaps.

# Methods

`void addLayoutComponent(String name, Component comp)`	Adds the specified component to the layout.
`int getAlignment()`	Gets the alignment for this layout.
`int getHgap()`	Gets the horizontal gap between the components.
`int getVgap()`	Gets the vertical gap between the components.
`void layoutContainer(Container target)`	Lays out the container.
`Dimension minimumLayoutSize(Container target)`	Returns the minimum dimensions needed to layout the visible components contained in the specified target container.
`Dimension preferredLayoutSize(Container target)`	Returns the preferred dimensions for this layout given the visible components in the specified target container.
`void removeLayoutComponent(Component comp)`	Removes the specified component from the layout.
`void setAlignment(int align)`	Sets the alignment for this layout.
`void setHgap(int hgap)`	Sets the horizontal gap between the components.
`void setVgap(int vgap)`	Sets the vertical gap between the components.
`String toString()`	Returns a string representation of this FlowLayout object and its values.

# Methods Inherited

java.lang.Object

# FlowLayout Example

SwingLayoutDemo.java

package com.simplecheatsheet.gui;

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

public class SwingLayoutDemo {
   private JFrame mainFrame;
   private JLabel headerLabel;
   private JLabel statusLabel;
   private JPanel controlPanel;
   private JLabel msglabel;

   public SwingLayoutDemo(){
      prepareGUI();
   }
   public static void main(String[] args){
      SwingLayoutDemo swingLayoutDemo = new SwingLayoutDemo();  
      swingLayoutDemo.showFlowLayoutDemo();       
   }
   private void prepareGUI(){
      mainFrame = new JFrame("Java SWING Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));

      headerLabel = new JLabel("",JLabel.CENTER );
      statusLabel = new JLabel("",JLabel.CENTER);        
      statusLabel.setSize(350,100);
      
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }        
      });    
      controlPanel = new JPanel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }
   private void showFlowLayoutDemo(){
      headerLabel.setText("Layout in action: FlowLayout");      

      JPanel panel = new JPanel();
      panel.setBackground(Color.darkGray);
      panel.setSize(200,200);
      FlowLayout layout = new FlowLayout();
      layout.setHgap(10);              
      layout.setVgap(10);
      
      panel.setLayout(layout);        
      panel.add(new JButton("OK"));
      panel.add(new JButton("Cancel"));       
      controlPanel.add(panel);
      mainFrame.setVisible(true);  
   }
}

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