Develop Reference

Cannot set the location for java widget

The problem is that I can't position the button where I want to. So I wrote this code to set again the location:
button.setLocation(new Point(100, 60));
import javax.swing.*;
import java.awt.*;
public class gui {
public static void main(String [] args){
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.setBackground(Color.ORANGE);
frame.add(panel);
JButton button = new JButton("Button");
button.setPreferredSize(new Dimension(200,25));
button.setLocation(new Point(100, 60));
panel.add(button);
frame.setSize(new Dimension(500,400));
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("GUI App");
frame.setResizable(false);
frame.setVisible(true);
}
}

You have to use the method setBounds()! This method requires 4 parameters: The x & y coordinate and the width and height your button should have. Also you have to set the Layout to null... So try this:
button.setBounds(100, 60, 100, 50) //just an example
frame.setLayout(null)

add below to your component:
//JPanel layout
panel.setLayout(null);
// postioning
button.setLocation(100,60);
As panel.setLayout(null) set your content panel to use absolute layout. Which you'd always have to set your component's bounds explicitly by using setBounds method.
Better to choose here the most suitable layout than using absolute layout.
ex:panel.setLayout(new FlowLayout());

BoxLayout only showing last component added

Looked at some previous posts pertaining to my subject but too no avail.
Trying to align components using BoxLayout but I cannot get it to work. I have tinkered with it for some time now with different results but I can't figure it out. I have used the default FlowLayout with no problems, I am trying to learn and expand my knowledge and BoxLayout will be better for my program. I want everything to stay in alignment if the User resizes their application window. I've adjusted all the sizes this way after just trying to get it to work and failing.
package GUI;
import javax.swing.*;
import java.awt.*;
/**
* Created by Thunderfoot on 7/31/2016. Keep Growing!
* Graphical User Interface
* Needs 3 JPanels(Text area + scroll pane)(2 Buttons) (1 Button), a JTextArea, JScrollPane, and 3 JButtons
*/
public class PrimaryFrame extends JFrame {
//Class variables
private static JPanel panel1, panel2, panel3;
public static JTextArea output;
//Constructor
public PrimaryFrame() {
//Frame component attributes
final Dimension FRAME_SIZE = new Dimension(400, 400);
final Dimension PANEL1_SIZE = new Dimension(400, 250);
final Dimension PANEL2_SIZE = new Dimension(400, 40);
final Dimension PANEL3_SIZE = new Dimension(400, 40);
//JFrame is PrimaryFrame
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setPreferredSize(FRAME_SIZE);
setMaximumSize(FRAME_SIZE);
setTitle("Fighting Game");
//JPanel for Text
panel1 = new JPanel();
panel1.setLayout(new BoxLayout(panel1, BoxLayout.PAGE_AXIS));
panel1.setMinimumSize(PANEL1_SIZE);
panel1.setPreferredSize(PANEL1_SIZE);
panel1.setMaximumSize(PANEL1_SIZE);
panel1.setBackground(Color.BLACK);
//JPanel for Attack and Kick Buttons
panel2 = new JPanel();
panel2.setLayout(new BoxLayout(panel2, BoxLayout.LINE_AXIS));
panel2.setMinimumSize(PANEL2_SIZE);
panel2.setPreferredSize(PANEL2_SIZE);
panel2.setMaximumSize(PANEL2_SIZE);
panel2.setBackground(Color.BLUE);
//JPanel for Power Attack Button
panel3 = new JPanel();
panel3.setLayout(new BoxLayout(panel3, BoxLayout.PAGE_AXIS));
panel3.setMinimumSize(PANEL3_SIZE);
panel3.setPreferredSize(PANEL3_SIZE);
panel3.setMaximumSize(PANEL3_SIZE);
panel3.setBackground(Color.ORANGE);
panel3.add(Box.createHorizontalGlue());
panel3.add(Box.createVerticalGlue());
//JTextArea & JScrollPane
output = new JTextArea();
output.setEditable(false);
JScrollPane outputScroller = new JScrollPane(output, ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED, ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
outputScroller.setMaximumSize(new Dimension(375, 250));
outputScroller.setBorder(BorderFactory.createLineBorder(Color.RED));
panel1.add(outputScroller);
panel1.add(Box.createHorizontalGlue());
panel1.add(Box.createVerticalGlue());
//Attack Button
JButton attackButton = new JButton(" ATTACK ");
attackButton.setMaximumSize(new Dimension(75, 30));
attackButton.setBorderPainted(true);
//Kick Button
JButton kickButton = new JButton(" KICK ");
kickButton.setMaximumSize(new Dimension(75, 30));
kickButton.setBorderPainted(true);
//Add components
panel2.add(attackButton);
panel2.add(Box.createHorizontalGlue());
panel2.add(Box.createVerticalGlue());
panel2.add(kickButton);
panel2.add(Box.createHorizontalGlue());
panel2.add(Box.createVerticalGlue());
//Power Attack Button
JButton powAttButton = new JButton(" POWER ATTACK ");
powAttButton.setMaximumSize(new Dimension(150, 30));
powAttButton.setBorderPainted(true);
panel3.add(powAttButton);
panel3.add(Box.createHorizontalGlue());
}
public void buildGUI() {
//Add components and build GUI Frame
this.add(panel3);
this.add(panel2);
this.add(panel1);
//Set attributes
//Pack components together inside of frame
pack();
//Center of screen
setLocationRelativeTo(null);
//Make frame visible
setVisible(true);
}
}

You have to set the Layout of your PrimaryFrame.
I suggest you add an additional line to your buildGUI() method:
public void buildGUI() {
//defines the Layout for the main Frame
this.setLayout(new GridLayout(3,1)) //its up to you wich Layout you use
//Add components and build GUI Frame
this.add(panel3);
this.add(panel2);
this.add(panel1);
//Set attributes
//Pack components together inside of frame
pack();
//Center of screen
setLocationRelativeTo(null);
//Make frame visible
setVisible(true);
}
Notice GridLayout(3,1) will generate a layout with three rows and one column

JPanel with null layout in JScrollPane - don't see elements

I want to set every element location with .setLocation(x, y)
I need a JPanel in a JScrollPane. But when I add components to JPanel, only buttons are showing. But not JLabel.
Method below is calling in JFrame constructor:
private void initGUI_test() {
this.setSize(950, 700);
this.setResizable(false);
this.getContentPane().setLayout(null);
JScrollPane mainScroll = new JScrollPane(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
JPanel container = new JPanel();
mainScroll.setSize(900,500);
mainScroll.setLocation(0,100);
mainScroll.setBorder(BorderFactory.createLineBorder(Color.blue));
mainScroll.add(container);
container.setLayout(null);
container.setLocation(0, 0);
container.setSize(900, 500);
JLabel rowA = new JLabel();
rowA.setSize(180, 26);
rowA.setLocation(10, 100);
rowA.setText("Row A");
JButton loadButton = new JButton();
loadButton.setSize(180, 34);
loadButton.setLocation(290, 110);
loadButton.setText("Load file");
container.add(rowA);
container.add(loadButton);
this.getContentPane().add(mainScroll);
}

Although I agree completely with #Frakcool about null layout, the problem you are facing has a different source. You should not add components directly into JScrollPane, but into JScrollPane's ViewPort.
The line mainScroll.add(container); should be mainScroll.getViewport().add(container);

Creating JTabbedPane in a JDialog and making the frame available

I'm working with GUI in Java and I've made several JDialogs opening one above the other.
I tried to create a JTabbedPane and I have succeed. However, I have to make the JTabbedPane in a JFrame. I've tried but the JPanel opens all blank.
Second of all when I use JFrame (so the new JTabbedPane became operational) that same frame appears behind the previous one.
So my questions are:
How can I create the tabbed pane in a JDialog ?
How do I make the JTabbedPane appear in front of all other frames, if I use JFrame ?
Here's my code, this JFrame opened when I click on a JButton from a previous JDialog
public class AddComponents extends JDialog {
private String[] arr = {"House", "Microgrid", "CSP", "VPP"};
public AddComponents(JDialog pai, String titulo)
{
super(pai, titulo);
frame = new JFrame(titulo);
// Display the window.
frame.setSize(500, 300);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// set grid layout for the frame
frame.getContentPane().setLayout(new GridLayout(1, 1));
tabbedPane = new JTabbedPane(JTabbedPane.TOP);
pack();
for (int i = 0; i < arr.length; i++) {
String tmp = arr[i];
tabbedPane.addTab(tmp, makePanel(tmp));
}
frame.getContentPane().add(tabbedPane);
frame.setMinimumSize(new Dimension(getWidth(), getHeight()));
frame.setLocation(pai.getX() + 85, pai.getY() + 25);
frame.setEnabled(true);
}
private JPanel makePanel(String text) {
JPanel p = new JPanel();
//p.setLayout(new GridLayout(0,1));
JPanel p1 = new JPanel();
JPanel p2 = new JPanel();
if(text.equals("House"))
{ //CADA UM DOS ifs chama a class correspondente para criar o interface
p1.setLayout(new GridLayout(4, 2));
idLabel = new JLabel("Component ID:");
idText = new JTextField("");
p1.add(idLabel);
p1.add(idText);
maxUsageLabel = new JLabel("Max usage per hour:");
maxUsageText = new JTextField("");
p1.add(maxUsageLabel);
p1.add(maxUsageText);
minUsageLabel = new JLabel("Min usage per hour:");
minUsageText = new JTextField("");
p1.add(minUsageLabel);
p1.add(minUsageText);
averageUsageLabel = new JLabel("Average usage per hour:");
averageUsageText = new JTextField("");
p1.add(averageUsageLabel);
p1.add(averageUsageText);
// emptyLabel = new JLabel("");
saveButton = new JButton("Save");
// p.add(emptyLabel);
p2.add(saveButton);
p.add(p1);
p.add(p2);
}
if(text.equals("Microgrid"))
{
p.setLayout(new GridLayout(5, 2));
outroLabel = new JLabel(" Microgrid");
p.add(outroLabel);
}
if(text.equals("VPP"))
{
p.setLayout(new GridLayout(5, 2));
outroLabel = new JLabel(" VPP");
p.add(outroLabel);
}
if(text.equals("CSP"))
{
p.setLayout(new GridLayout(5, 2));
outroLabel = new JLabel(" CSP");
p.add(outroLabel);
}
return p;
}
}

"How can I create the tabbed pane in a JDialog ?"
same as you would if you added it to a JFrame. There is essentially no difference here whatsoever.
"How do I make the JTabbedPane appear in front of all other frames, if I use JFrame ?"
you don't. You use a JDialog if you want to display a window above other windows.

For creating the JDialog use:
final JDialog dialog = new JDialog();
dialog.add(tabbedPane);
dialog.setVisible(true);
Java applications normally have only one JFrame, so nobody worries about the Z-order. If you like them, you can use JInternalFrame. Here is the tutorial. You can, however, use dialogs instead.

Adding components into JPanel inside a JFrame

Since im a beginner and i don't want to get involved with the layout managers, i was simply adding a JPanel into my main JFrame and giving spesific location to each component in the panel. But somehow the output appears way too wrong..
frame = new JFrame(email + " (Offline)");
frame.setSize(400, 400);
frame.setLocation(0, 0);
frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
frame.setLayout(new FlowLayout());
frame.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
// out.println("BYE");
// out.flush();
frame.dispose();
thread.stop();
}
});
panel = new JPanel();
frame.add(panel);
chat = new JTextArea();
chat.setSize(400, 200);
chat.setLocation(0, 0);
chat.setEditable(false);
panel.add(chat);
panel.validate();
JLabel you = new JLabel("You:");
you.setSize(you.getPreferredSize());
you.setLocation(0, 210);
panel.add(you);
panel.validate();
input = new JTextArea();
input.setSize(200, 200);
input.setLocation(0, 220 + chat.getSize().height);
panel.add(input);
panel.validate();
send = new JButton("Send");
send.setSize(send.getPreferredSize());
send.setLocation(210, 220 + chat.getSize().height);
panel.add(send);
panel.validate();
frame.setVisible(true);
The outcome of this frame is that text areas are invisible, a You: label in the middle and next to the right of it the button.. What am i missing here?

Again, don't use null layout since it makes updating and maintaining your GUI much more difficult than it should be, and can lead to ugly GUI's if you plan on having them run on multiple platforms. Instead
Use several JPanels, each one holding a core group of components and each using its best layout manager
Nest these JPanels in other JPanels that use the best layout manager to display them
and that will allow your GUI to be resizeable without need of extra code.
Put your JTextAreas in JScrollPanes so that you can see all text even if it goes beyond the text area.
Never set the size of the JTextArea as that will not allow it to scroll. Instead set its columns and rows.
As a very simple example, run this to see what I mean:
import java.awt.*;
import javax.swing.*;
public class FooSwing2 {
public static void main(String[] args) {
JTextArea chatArea = new JTextArea(8, 40);
chatArea.setEditable(false);
chatArea.setFocusable(false);
JScrollPane chatScroll = new JScrollPane(chatArea);
JPanel chatPanel = new JPanel(new BorderLayout());
chatPanel.add(new JLabel("Chat:", SwingConstants.LEFT), BorderLayout.PAGE_START);
chatPanel.add(chatScroll);
JTextField inputField = new JTextField(40);
JButton sendBtn = new JButton("Send");
JPanel inputPanel = new JPanel();
inputPanel.setLayout(new BoxLayout(inputPanel, BoxLayout.LINE_AXIS));
inputPanel.add(inputField);
inputPanel.add(sendBtn);
JPanel youLabelPanel = new JPanel(new FlowLayout(FlowLayout.LEFT, 0, 0));
youLabelPanel.add(new JLabel("You:"));
JPanel mainPanel = new JPanel();
mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.PAGE_AXIS));
mainPanel.add(chatPanel);
mainPanel.add(Box.createVerticalStrut(10));
mainPanel.add(youLabelPanel);
mainPanel.add(inputPanel);
JFrame frame = new JFrame("Foo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
This would result in a simple (non-functioning) GUI that looked like this:
Now say you want to change this and add another button, an "exit" JButton to the right of the send JButton. If you used null layout, you'd have to resize your GUI, you'd have to move the send button over to the left and make sure that your math was without error, etc. If you used layout managers, you'd need just two new lines of code (to change the display, not the functionality of course):
JTextField inputField = new JTextField(40);
JButton sendBtn = new JButton("Send");
JButton exitBtn = new JButton("Exit"); // ***** added
JPanel inputPanel = new JPanel();
inputPanel.setLayout(new BoxLayout(inputPanel, BoxLayout.LINE_AXIS));
inputPanel.add(inputField);
inputPanel.add(sendBtn);
inputPanel.add(exitBtn); // ***** added
That's it, and this would display: