We Keep Coding

Java Layout with Component always in Top Right

The primary GUI of my application is composed of a JDesktopPane at the CENTER of a frame's content pane using a BorderLayout. I am hoping to have a component placed in the top right of the screen that still allows the user to drag JInternalFrames within the space to the left and and bottom of this component.
Setting the component to the NORTH or EAST of the BorderLayout seems to fill the entire space. I am thinking BorderLayout may not be the best layout manager for what I am trying to accomplish? Any suggestions on a better approach?

Check out the OverlayLayout. It allows you to stack components on top of one another.
You need to manipulate the setAlignmentX(..) and setAlignmentY(...)` methods to get the layout you want. It is not always intuitive how these alignments work together but setting the component to the top/left is relatively easy.
Here is a little demo for you to play with:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
public class OverlayLayoutTest extends JPanel
implements ActionListener
{
JPanel green;
JPanel red;
JLabel greenLabel;
JLabel redLabel;
JComboBox greenAlignmentX;
JComboBox greenAlignmentY;
JComboBox redAlignmentX;
JComboBox redAlignmentY;
public OverlayLayoutTest()
{
setLayout( new BorderLayout(10, 10) );
add(createNorthPanel(), BorderLayout.NORTH);
add(createCenterPanel(), BorderLayout.CENTER);
add(createSouthPanel(), BorderLayout.SOUTH);
}
private JPanel createNorthPanel()
{
JPanel panel = new JPanel();
panel.add( new JLabel("Green:") );
greenLabel = new JLabel();
panel.add( greenLabel );
panel.add( new JLabel("Red:") );
redLabel = new JLabel();
panel.add( redLabel );
return panel;
}
private JPanel createCenterPanel()
{
JPanel panel = new JPanel();
panel.setLayout( new OverlayLayout(panel) );
panel.setBackground( Color.ORANGE );
panel.setPreferredSize( new Dimension(200, 200) );
red = new JPanel();
red.setBackground( Color.RED );
red.setPreferredSize( new Dimension(50, 50) );
red.setMaximumSize( red.getPreferredSize() );
red.setMinimumSize( red.getPreferredSize() );
panel.add( red );
green = new JPanel();
green.setBackground( Color.GREEN );
green.setPreferredSize( new Dimension(100, 100) );
green.setMaximumSize( green.getPreferredSize() );
green.setMinimumSize( green.getPreferredSize() );
panel.add( green );
JPanel wrap = new JPanel();
wrap.add( panel );
return wrap;
}
private JPanel createSouthPanel()
{
JPanel panel = new JPanel( new GridLayout(1, 0, 10, 10) );
JPanel green = new JPanel(new GridLayout(0, 2, 5, 5) );
green.setBorder( new TitledBorder("Green Alignment") );
green.add( new JLabel("X Alignment:") );
greenAlignmentX = createComboBox();
green.add( greenAlignmentX );
green.add( new JLabel("Y Alignment:") );
greenAlignmentY = createComboBox();
green.add( greenAlignmentY );
panel.add( green );
JPanel red = new JPanel(new GridLayout(0, 2, 5, 5) );
red.setBorder( new TitledBorder("Red Alignment") );
red.add( new JLabel("X Alignment:") );
redAlignmentX = createComboBox();
red.add( redAlignmentX );
red.add( new JLabel("Y Alignment:") );
redAlignmentY = createComboBox();
red.add( redAlignmentY );
panel.add( red );
JButton reset = new JButton("Reset Alignment");
reset.addActionListener( this );
panel.add( reset );
return panel;
}
public void actionPerformed(ActionEvent e)
{
green.setAlignmentX( ((Float)greenAlignmentX.getSelectedItem()) );
green.setAlignmentY( ((Float)greenAlignmentY.getSelectedItem()) );
red.setAlignmentX( ((Float)redAlignmentX.getSelectedItem()) );
red.setAlignmentY( ((Float)redAlignmentY.getSelectedItem()) );
JPanel parent = (JPanel)green.getParent();
parent.revalidate();
/*
System.out.print(green.getAlignmentX() + " : ");
System.out.print(green.getAlignmentY() + " : ");
System.out.print(red.getAlignmentX() + " : ");
System.out.print(red.getAlignmentY() + " : ");
System.out.println();
*/
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
greenLabel.setText( green.getLocation().toString() );
redLabel.setText( red.getLocation().toString() );
}
});
}
private JComboBox createComboBox()
{
JComboBox<Float> comboBox = new JComboBox<Float>();
comboBox.addItem( new Float(0f) );
comboBox.addItem( new Float(0.25f) );
comboBox.addItem( new Float(0.5f) );
comboBox.addItem( new Float(0.75f) );
comboBox.addItem( new Float(1.0f) );
comboBox.setSelectedItem(0.5f);
return comboBox;
}
private static void createAndShowUI()
{
JFrame frame = new JFrame("OverlayLayoutTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( new OverlayLayoutTest() );
frame.pack();
frame.setLocationByPlatform( true );
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
set the alignment X values to 1.0 for both components
set the alignment Y values to 0.0 for both components
and you should get the layout you want.
Edit:
Missed the part about dragging a JInternalFrame. So this imples you are using a JDesktopPane to support the dragging. A JDesktopPane uses a null layout to allow you to drag components around.
There is no reason you can't add another component (other than a JInternalFrame) to the desktop. You just need to set the size/location of this component to be displayed at the top right of the desktop. You would then need to add a ComponentListener to the desktop pane to listen for the componentResized event. When this event is fired you would need to recalucate the location of the component to reset it to the top right.

Custom Swing layout

I'm creating a game and to set up the frame the way I want it, I need to some how create a costume layout. I have tried creating multiple panels with different layouts such as Flow and Border and adding panels on the main panel but I still don't get the desired outcome. What I desire is shown in the attached picture. Please tell me if any code segments would help.
Questions:
1. Is it possible to get such layout? (I want it to be fixed.)
Under the "button" there is the JLabel you see in the picture. I want its text to start from left, go down the column, and start on the middle, and then to the right column. Is that possible?

There is a slight variation, as to what I wrote in comments, since BoxLayout is somethingy, that I never use, since I am not good in it :-)
Though what I did to overcome, this shortcoming of mine, is to take 2 JPanels, one each for JTextField and JButton and the rest is the same, as shown in this example:
import java.awt.*;
import javax.swing.*;
public class LayoutExample {
private static final int GAP = 5;
private static final int TOTAL_LABELS = 18;
private JTextField tField;
private JButton button;
private JLabel[] labels;
private void displayGUI () {
JFrame frame = new JFrame ( "Layout Example" );
frame.setDefaultCloseOperation ( JFrame.DISPOSE_ON_CLOSE );
JPanel contentPane = getPanel ();
contentPane.setLayout ( new BorderLayout ( GAP, GAP ) );
JPanel headerPanel = getPanel ();
headerPanel.setLayout ( new GridLayout ( 0, 1, GAP, GAP ) );
JPanel textFieldPanel = getPanel ();
tField = new JTextField ( 10 );
textFieldPanel.add ( tField );
JPanel buttonPanel = getPanel ();
button = new JButton ( "Button" );
buttonPanel.add ( button );
headerPanel.add ( textFieldPanel );
headerPanel.add ( buttonPanel );
contentPane.add (headerPanel, BorderLayout.PAGE_START );
JPanel centerPanel = getPanel ();
centerPanel.setLayout ( new GridLayout ( 0, 3, GAP, GAP ) );
labels = new JLabel [ TOTAL_LABELS ];
for ( int i = 0; i < labels.length; ++i ) {
labels [ i ] = new JLabel ( String.valueOf ( i ), JLabel.CENTER );
centerPanel.add ( labels [ i ] );
}
contentPane.add ( centerPanel, BorderLayout.CENTER );
frame.setContentPane ( contentPane );
frame.pack ();
frame.setLocationByPlatform ( true );
frame.setVisible ( true );
}
private JPanel getPanel () {
JPanel panel = new JPanel ();
panel.setOpaque ( true );
panel.setBorder ( BorderFactory.createEmptyBorder ( GAP, GAP, GAP, GAP ) );
return panel;
}
public static void main ( String[] args ) {
Runnable runnable = new Runnable () {
#Override
public void run () {
new LayoutExample ().displayGUI ();
}
};
EventQueue.invokeLater ( runnable );
}
}
OUTPUT:

ActionListener java swing

i have being trying to create a window using swing ad i have to put the buttons on the right side that's why i used boxlayout but i can't find a way to use ActionListener on the button that i have. that's the program i am working on:
public class Fenetre2 extends JFrame {
private JSplitPane splitPan=null;
public Fenetre2 (){
JPanel pan = new JPanel ();
// CARACTERISTIQUE FENETRE
this.setTitle("Gestion Employe");
this.setSize(800, 400);
this.setLocationRelativeTo(null);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pan.setBackground(Color.white);
this.setContentPane(pan);
// ADD BUTTON
Container c = getContentPane();
c.setLayout( new BorderLayout( 30, 30 ) );
Box boxes[] = new Box[ 4 ];
boxes[ 0 ] = Box.createHorizontalBox();
boxes[ 1 ] = Box.createVerticalBox();
boxes[ 2 ] = Box.createHorizontalBox();
boxes[ 3 ] = Box.createVerticalBox();
// create strut and add buttons to boxes[ 1 ]
boxes[ 1 ].add( new JButton( "ajouter" ) );
boxes[ 1 ].add( new JButton( "suprimer" ) );
boxes[ 1 ].add( new JButton( "afficher" ) );
c.add( boxes[ 1 ], BorderLayout.EAST );
//TREE
DefaultMutableTreeNode root = new DefaultMutableTreeNode("STRUCTURE EMPLOYE");
//create the child nodes
DefaultMutableTreeNode PDGNode = new DefaultMutableTreeNode("PDG");
DefaultMutableTreeNode departement1Node = new DefaultMutableTreeNode("departement 1");
departement1Node.add(new DefaultMutableTreeNode("CHEF DEPARTEMENT"));
departement1Node.add(new DefaultMutableTreeNode("EMPLOYEE1"));
departement1Node.add(new DefaultMutableTreeNode("EMPLOYEE2"));
departement1Node.add(new DefaultMutableTreeNode("EMPLOYEE3"));
//add the child nodes to the root node
root.add(PDGNode);
PDGNode.add(departement1Node);
JTree tree = new JTree(root);
this.add(tree);
JScrollPane scroll=new JScrollPane(tree);
splitPan=new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,scroll,new JLabel("aaaaa"));
splitPan.setSize(this.getMaximumSize());
add(splitPan);
this.setVisible(true);
}
public static void main (String args []){
Fenetre2 fen = new Fenetre2();
}
}

You should not add the buttons directly into the panel but instead instantiate them and then add an ActionListener to them or whatever else you want to do with them. Example:
JButton ajouterButton = new JButton("ajouter");
ajouterButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent event) {
// code goes here
}
});
Then you can add the button to your array:
boxes[1].add(ajouterButton);
Then do the same thing to all your buttons.

The button instance you are looking for is stored in boxes[1], so you can simply do boxes[1].addActionListener(...);.

Miglayout, baseline and JTextAreas

I am using MigLayout (and I really like it). But I have a problem with Labels in front of a JTextArea.
I have read about the "baseline" keyword. But that does not work in combination with "grow".
Here is an example that shows the problem.
I expected the label to be aligned at the top (at the same location as the first line of the JTextArea).
Any ideas?
public class MigRunner {
public static void main( String[] args ) {
SwingUtilities.invokeLater( new Runnable() {
#Override
public void run() {
new MigRunner().run();
}
} );
}
#UiThread
private void run() {
JFrame frame = new JFrame();
Container contentPane = frame.getContentPane();
contentPane.setLayout( new MigLayout("wrap 2, fill, debug", "[][grow]", "[grow]") );
{
JLabel name = new JLabel( "Description" );
contentPane.add( name, "baseline" );
JTextArea textArea = new JTextArea();
JScrollPane scrollPane = new JScrollPane( textArea );
contentPane.add( scrollPane, "grow, baseline" );
name.setLabelFor( textArea );
}
frame.setDefaultCloseOperation( WindowConstants.DISPOSE_ON_CLOSE );
frame.setSize( 400, 300 );
frame.setLocationRelativeTo( null );
frame.setVisible( true );
}
}

Maybe you need the align contraint:
JLabel name = new JLabel("Description");
contentPane.add(name, "aligny top");
I didn't saw the 3 pixel gap between the baselines of the texts until Jeremias' comment. Well I don't have a nice solution for this, but here is an additional idea to Jeremias "gaptop 3" solution:
JTextArea name = new JTextArea("Description");
name.setEditable(false);
contentPane.add(new JScrollPane(name), "aligny top");

Using two JPanels in one JFrame

I'm attempting to create a program that allows the user to click a button to place something in the JPanel and allowing them to move this item around. I have already found a good layout to use to allow the moving components (see this link). However, I'm just curious the best way to create a layout like this? My hope is to have something like this:
How can I accomplish this? Would I want to use two JPanel's or something else?

The main panel (or the window content pane) would have to have a BorderLayout as the layout manager.
Then, the buttons panel would be added to BorderLayout.WEST and the drag panel to BorderLayout.CENTER.
There is a Visual Guide to swing layout managers.

Try to use JSplitPane:
Here is a code example:
class SplitPane extends JFrame {
private JSplitPane splitPaneV;
private JSplitPane splitPaneH;
private JPanel panel1;
private JPanel panel2;
private JPanel panel3;
public SplitPane(){
setTitle( "Split Pane Application" );
setBackground( Color.gray );
JPanel topPanel = new JPanel();
topPanel.setLayout( new BorderLayout() );
getContentPane().add( topPanel );
// Create the panels
createPanel1();
createPanel2();
createPanel3();
// Create a splitter pane
splitPaneV = new JSplitPane( JSplitPane.VERTICAL_SPLIT );
topPanel.add( splitPaneV, BorderLayout.CENTER );
splitPaneH = new JSplitPane( JSplitPane.HORIZONTAL_SPLIT );
splitPaneH.setLeftComponent( panel1 );
splitPaneH.setRightComponent( panel2 );
splitPaneV.setLeftComponent( splitPaneH );
splitPaneV.setRightComponent( panel3 );
}
public void createPanel1(){
panel1 = new JPanel();
panel1.setLayout( new BorderLayout() );
// Add some buttons
panel1.add( new JButton( "North" ), BorderLayout.NORTH );
panel1.add( new JButton( "South" ), BorderLayout.SOUTH );
panel1.add( new JButton( "East" ), BorderLayout.EAST );
panel1.add( new JButton( "West" ), BorderLayout.WEST );
panel1.add( new JButton( "Center" ), BorderLayout.CENTER );
}
public void createPanel2(){
panel2 = new JPanel();
panel2.setLayout( new FlowLayout() );
panel2.add( new JButton( "Button 1" ) );
panel2.add( new JButton( "Button 2" ) );
panel2.add( new JButton( "Button 3" ) );
}
public void createPanel3(){
panel3 = new JPanel();
panel3.setLayout( new BorderLayout() );
panel3.setPreferredSize( new Dimension( 400, 100 ) );
panel3.setMinimumSize( new Dimension( 100, 50 ) );
panel3.add( new JLabel( "Notes:" ), BorderLayout.NORTH );
panel3.add( new JTextArea(), BorderLayout.CENTER );
}
public static void main( String args[] ){
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
// Create an instance of the test application
SplitPane mainFrame = new SplitPane();
mainFrame.pack();
mainFrame.setVisible( true );
}
}
You can play with splitPaneH.setOneTouchExpandable true/false
You can confugure divider location for both like:
Toolkit tk = Toolkit.getDefaultToolkit();
Dimension d = tk.getScreenSize();
int width = d.width;
int height = d.height;
spane.setDividerLocation((width*3)/4);
spanex.setDividerLocation(width/4);