For some reason i am having problems centering my panel vertically that is located inside another panel. I do exactly as the examples i studied but still no luck.
Down there is my code. Despite using setAlignmentY(0.5f) on my container panel, it still wont center when i resize the window.
Also the components inside container panel wont center either, despite setAligenmentX(0.5f).
I wonder if there is a solution for this, I pretty much tried everything out there but couldnt find a solution.
JLabel idLabel;
JLabel passLabel;
JTextField id;
JTextField pass;
JButton enter;
JPanel container;
public JournalLogin()
{
//setLayout(new FlowLayout());
//setPreferredSize(new Dimension(500, 500));
//setBorder(BorderFactory.createEmptyBorder(100, 100, 100, 100));
container = new JPanel();
container.setLayout(new MigLayout());
container.setAlignmentX(0.5f);
container.setAlignmentY(0.5f);
container.setPreferredSize(new Dimension(300, 300));
container.setBorder(BorderFactory.createTitledBorder("Login"));
add(container);
idLabel = new JLabel("ID:");
idLabel.setAlignmentX(0.5f);
container.add(idLabel);
id = new JTextField();
id.setText("id");
id.setAlignmentX(0.5f);
id.setPreferredSize(new Dimension(80, 20));
container.add(id, "wrap");
setAlignmentX and Y are not the way to go about doing this. One way to center a component in a container is to have the container use GridBagLayout and to add the component without using any GridBagConstraints, a so-called default addition. There are other ways as well.
For example to alter Nick Rippe's example (1+ to him):
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridBagLayout;
import javax.swing.*;
public class UpdatePane2 extends JPanel {
private static final int PREF_W = 300;
private static final int PREF_H = 200;
public UpdatePane2() {
JPanel innerPanel = new JPanel();
innerPanel.setLayout(new BorderLayout());
innerPanel.add(new JLabel("Hi Mom", SwingConstants.CENTER),
BorderLayout.NORTH);
innerPanel.add(new JButton("Click Me"), BorderLayout.CENTER);
setLayout(new GridBagLayout());
add(innerPanel);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
private static void createAndShowGui() {
JFrame frame = new JFrame("UpdatePane2");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new UpdatePane2());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Alignments tend to be pretty picky in Swing - they do [usually] work... but if all you're looking for is a panel that's centered, I'd recommend using Boxes in the BoxLayout (My personal favorite LayoutManager). Here's an example to get you started:
import java.awt.Dimension;
import javax.swing.*;
public class UpdatePane extends JPanel{
public static void main(String... args) {
SwingUtilities.invokeLater(new Runnable(){
#Override
public void run() {
//Create Buffers
Box verticalBuffer = Box.createVerticalBox();
Box horizontalBuffer = Box.createHorizontalBox();
verticalBuffer.add(Box.createVerticalGlue()); //Top vertical buffer
verticalBuffer.add(horizontalBuffer);
horizontalBuffer.add(Box.createHorizontalGlue()); //Left horizontal buffer
//Add all your content here
Box mainContent = Box.createVerticalBox();
mainContent.add(new JLabel("Hi Mom!"));
mainContent.add(new JButton("Click me"));
horizontalBuffer.add(mainContent);
horizontalBuffer.add(Box.createHorizontalGlue()); //Right horizontal buffer
verticalBuffer.add(Box.createVerticalGlue()); //Bottom vertical buffer
// Other stuff for making the GUI
verticalBuffer.setPreferredSize(new Dimension(300,200));
JFrame frame = new JFrame();
frame.add(verticalBuffer);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
});
}
}
You will need to get the LayoutManager to center the layout for you. Currently it looks like the implementation of "MigLayout" does not honor the Alignment. Try changing it or creating a subclass.
Related
Why does my Inner JPanel not display my JLabel text?
I have an outer JPanel, and an inner JPanel to display some text with the right dimensions. However I don't understand why it won't show?
JPanel jp = new JPanel();
jp.setBackground(Color.decode("#ffffff"));
jp.setBounds(0, 35, 400, 315);
JPanel mostInner = new JPanel();
mostInner.setForeground(Color.black);
mostInner.setBounds(207, 5, 190, 240);
jp.add(mostInner);
JLabel jltxt = new JLabel();
jltxt.setText("Test");
mostInner.add(jltxt);
Again, much better to avoid using null layouts and setBounds(...). While null layouts and setBounds() might seem to Swing newbies like the easiest and best way to create complex GUI's, the more Swing GUI'S you create the more serious difficulties you will run into when using them. They won't re-size your components when the GUI resizes, they are a royal witch to enhance or maintain, they fail completely when placed in scrollpanes, they look gawd-awful when viewed on all platforms or screen resolutions that are different from the original one.
For example, the following code creates this GUI:
This uses a GridLayout to place a JPanel in the right hand side of another JPanel. If I wanted to add more components in different relative locations, it would be easy to do by simply nesting JPanels, each using its own layout.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.*;
public class WorkWithLayouts extends JPanel {
private static final long serialVersionUID = 1L;
private static final int PREF_W = 400;
private static final int PREF_H = 315;
private static final String BG = "#ffffff";
public WorkWithLayouts() {
JPanel mostInner = new JPanel();
mostInner.setForeground(Color.black);
mostInner.setOpaque(false); // if you want the backing jpanel's background to show through
// add title temporarily just to show where mostInner panel is
mostInner.setBorder(BorderFactory.createTitledBorder("most inner")); // TODO: delete this
JLabel jltxt = new JLabel();
jltxt.setText("Test");
mostInner.add(jltxt);
setBackground(Color.decode(BG));
setLayout(new GridLayout(1, 2));
add(new JLabel()); // empty label
add(mostInner);
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
} else {
return new Dimension(PREF_W, PREF_H);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
createAndShowGui();
});
}
private static void createAndShowGui() {
WorkWithLayouts mainPanel = new WorkWithLayouts();
JFrame frame = new JFrame("Work With Layouts");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
}
As already mentioned by Hovercraft Full Of Eels, you can help us to help you by adding a small program to your question that shows your problem (see https://stackoverflow.com/help/mcve for more information). Then people can try to reproduce and solve the issue.
When I created a small program myself, it seemed to work fine:
import java.awt.*;
import javax.swing.*;
public class LabelNotVisible {
public static void main(String[] arguments) {
SwingUtilities.invokeLater(() -> new LabelNotVisible().createAndShowGui());
}
private void createAndShowGui() {
JFrame frame = new JFrame("Stack Overflow");
frame.setBounds(100, 100, 800, 200);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
JPanel jp = new JPanel();
jp.setBackground(Color.decode("#ffffff"));
//jp.setBounds(0, 35, 400, 315);
JPanel mostInner = new JPanel();
mostInner.setForeground(Color.black);
//mostInner.setBounds(207, 5, 190, 240);
jp.add(mostInner);
JLabel jltxt = new JLabel();
jltxt.setText("Test");
mostInner.add(jltxt);
frame.getContentPane().add(jp);
frame.setVisible(true);
}
}
I've made a GUI using swing with a BorderLayout and GridLayout in the center. I want to add a triangle I've made in another class to the JPanel east in my BorderLayout but cant get it to show.
When I set a bgcolor for said JPanel I got a weird little result, if you like you can have a look at the code: gistlink
I have a feeling the issue is in the TriGoButton constructor but I'm not sure how to test further. I've tried different variations of paint() but have never been able to see the green triangle.
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
#SuppressWarnings("serial")
public class TestGUI extends JFrame implements ActionListener {
private JPanel content;
private JTextField placeTxtField;
public static void main(String[] args) {
TestGUI frame = new TestGUI();
frame.pack();
frame.setVisible(true);
}
#SuppressWarnings("rawtypes")
public TestGUI() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
content = new JPanel();
content.setLayout(new BorderLayout());
setContentPane(content);
// issue
JPanel rightPanel = new JPanel();
content.add(rightPanel, BorderLayout.EAST);
rightPanel.add(new TriGoButton());
// issue?
JPanel leftPanel = new JPanel();
content.add(leftPanel, BorderLayout.WEST);
JPanel centerPanel = new JPanel();
content.add(centerPanel, BorderLayout.CENTER);
centerPanel.setLayout(new GridLayout(3, 3, 0, 20));
JLabel countyLbl = new JLabel("County");
centerPanel.add(countyLbl);
JComboBox countyDropDown = new JComboBox();
centerPanel.add(countyDropDown);
JLabel muniLbl = new JLabel("Munipalicity");
centerPanel.add(muniLbl);
JComboBox muniDropDown = new JComboBox();
centerPanel.add(muniDropDown);
JLabel placeLbl = new JLabel("City or place");
placeLbl.setToolTipText("search");
centerPanel.add(placeLbl);
placeTxtField = new JTextField();
centerPanel.add(placeTxtField);
placeTxtField.setColumns(15);
placeTxtField.setToolTipText("enter w/e");
JPanel bottomPanel = new JPanel();
content.add(bottomPanel, BorderLayout.SOUTH);
JButton goBtn = new JButton("Clicky");
bottomPanel.add(goBtn);
goBtn.setToolTipText("Please click.");
goBtn.addActionListener(this);
JPanel topPanel = new JPanel();
content.add(topPanel, BorderLayout.NORTH);
JLabel headlineLbl = new JLabel("headline");
topPanel.add(headlineLbl);
}
#Override
public void actionPerformed(ActionEvent e) {
}
}
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class TriGoButton extends JPanel {
public TriGoButton() {
add(new JPanel(), BorderLayout.EAST);
setBackground(new Color(100,100,250)); //blue //wtf
}
public void paint(Graphics g) {
super.paint(g);
int[]x={90,90,300};
int[]y={150,0,90};
g.setColor(new Color(23,201,10)); //green
g.fillPolygon(x,y,3);
}
}
EDIT:
////////////
I don't know why you are adding a JPanel to your TriGoButton class, but this is going to cause you issues.
It's not recommended that you override paint, this can cause no end of issues, as the parent container isn't always included in updates when it's children are painted. See Painting in AWT and Swing and Performing Custom Painting for more details.
BorderLayout will use the component's preferredSize tomake decisions about how it should sized. Your TriGoButton class should override the getPreferredSize method and return an appropriate default size..
I've added your code. I think that your issue is that your TriGoPanel doesn't override getPreferredSize, and so it may be sizing itself quite small. Consider adding to the class something like:
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
where you have int constants, PREF_W, PREF_H, for your width and height dimensions.
__________________________________________________
Edit: and I strongly second everything that MadProgrammer recommended!
I am working on the editor. I am using Java swing for it. I have embedded a JTextArea with JScrollPane. i want to position the jtextarea of particular size at the middle of JScrollPane. To do this I used setLocation function. But this is not working?
public class ScrollPaneTest extends JFrame {
private Container myCP;
private JTextArea resultsTA;
private JScrollPane scrollPane;
private JPanel jpanel;
public ScrollPaneTest() {
resultsTA = new JTextArea(50,50);
resultsTA.setLocation(100,100);
jpanel=new JPanel(new BorderLayout());
jpanel.add(resultsTA,BorderLayout.CENTER);
scrollPane = new JScrollPane(jpanel,JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
scrollPane.setPreferredSize(new Dimension(800, 800));
scrollPane.setBounds(0, 0, 800, 800);
setSize(800, 800);
setLocation(0, 0);
myCP = this.getContentPane();
myCP.setLayout(new BorderLayout());
myCP.add(scrollPane);
setVisible(true);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
}
public static void main(String[] args) {
new ScrollPaneTest();
}
}
You simply have to add the JTextArea to the JScrollPane, and add it to the CENTER of the JPanel having BorderLayout.
Don't use AbsolutePositioning. Add a proper LayoutManager, and let LayoutManager do the rest for positioning and sizing your components on the screen.
In order to use the setBounds(...) method you have to use a null Layout for your component, which is not worth using, provided the perspective, as mentioned in the first paragraph of the AbsolutePositioning. Though in the code example provided by you, you are doing both the thingies together i.e. using Layout and using AbsolutePositioning, which is wrong in every way. My advice STOP DOING IT :-)
In the example provided the ROWS and COLUMNS provided by you are sufficient to size the JTextArea by the Layout concern.
Code Example :
import java.awt.*;
import javax.swing.*;
public class Example
{
private JTextArea tarea;
private void displayGUI()
{
JFrame frame = new JFrame("JScrollPane Example");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
JPanel contentPane = new JPanel();
contentPane.setLayout(new BorderLayout(5, 5));
JScrollPane textScroller = new JScrollPane();
tarea = new JTextArea(30, 30);
textScroller.setViewportView(tarea);
contentPane.add(textScroller);
frame.setContentPane(contentPane);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String... args)
{
EventQueue.invokeLater(new Runnable()
{
#Override
public void run()
{
new Example().displayGUI();
}
});
}
}
I have this app, but, when I resize the window, the element JTextArea inside, it doesn't resize with the window. Why?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ExampleGUI {
private JTextArea text_area;
private JScrollPane scroll_bar;
private JFrame frame;
private JPanel panel;
public ExampleGUI(){
frame = new JFrame("Example GUI");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
text_area = new JTextArea();
scroll_bar = new JScrollPane(text_area);
panel = new JPanel();
panel.add(scroll_bar);
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable(){public void run(){new ExampleGUI();}});
}
}
You need to set your GridBagConstraint x and y weights (weightx and weighty -- the 5th and 6th parameters in the GridBagConstraint constructor) to a positive value other than 0.0. You should read tutorials on GridBagLayout if you're going to use it as it is fairly complex. Some have had great success nesting simpler layouts or using 3rd party layouts such as MigLayout.
Your frame layout is a FlowLayout. This does not resize children. From the docs:
A flow layout lets each component assume its natural (preferred) size.
You will be better off using a BorderLayout and putting the pane in the CENTER.
Replace this:
frame.setLayout(new FlowLayout());
frame.add(pane);
with this:
frame.setLayout(new BorderLayout());
frame.add(pane, BorderLayout.CENTER);
Also, as Hovercraft points out, if you need the individual components to resize when the pane resizes, then you need to have non-zero weights in the GridBagConstraints.
This takes into account the advice of Hovercraft Full Of Eels & Ted Hopp with a few other tweaks.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.Collection;
public class AziendaGUI implements ActionListener {
private JButton view_list;
private JButton save_list;
private JTextArea text_area;
private JScrollPane scrollpane;
private JPanel pane;
private JFrame frame;
private GridBagLayout grid;
public AziendaGUI() {
frame = new JFrame("Immobiliari s.p.a");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
view_list = new JButton("View Property");
view_list.setActionCommand("view_list");
view_list.addActionListener(this);
save_list = new JButton("Save List");
save_list.setActionCommand("save_list");
save_list.addActionListener(this);
text_area = new JTextArea(10,22);
text_area.setEditable(false);
scrollpane = new JScrollPane(text_area);
grid = new GridBagLayout();
pane = new JPanel();
pane.setLayout(grid);
/* Set Constraints view_list button */
grid.setConstraints(view_list, new GridBagConstraints(0,0,1,1,0.0,0.0,GridBagConstraints.WEST,GridBagConstraints.NONE,new Insets(5,5,5,5),0,0));
pane.add(view_list);
/* Set Constraints save_list button */
grid.setConstraints(save_list,new GridBagConstraints(1,0,1,1,0.1,0.1,GridBagConstraints.EAST,GridBagConstraints.NONE,new Insets(5,5,5,5),0,0));
pane.add(save_list);
frame.add(scrollpane);
frame.add(pane, BorderLayout.NORTH);
frame.pack();
frame.setVisible(true);
}
private void store(){
String file_name = JOptionPane.showInputDialog("Inserisci il nome del file");
}
#Override
public void actionPerformed(ActionEvent e){
String s = e.getActionCommand();
if(s.equals("view_list")){
}
if(s.equals("save_list")){
store();
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable(){#Override
public void run(){new AziendaGUI();}});
}
}
Hi all!
I'm trying to solve an -apparently- simple problem, but I cannot fix it.
I'm working on a sample application with Java/Swing libraries;
I have a JFrame and a JPanel.
I just want to achieve the following objectives:
JPanel MUST be centered inside the JFrame.
JPanel MUST have ALWAYS the size that is specified with
setPreferredSize() method. It MUST NOT be resized under this size.
I tried by using a GridBagLayout: it's the ONLY way I can do it.
See the sample below:
/* file StackSample01.java */
import java.awt.*;
import javax.swing.*;
public class StackSample01 {
public static void main(String [] args) {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.setPreferredSize(new Dimension(100, 100));
panel.setBackground(Color.RED);
frame.setLayout(new GridBagLayout());
frame.add(panel, new GridBagConstraints());
frame.setSize(new Dimension(200, 200));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
Here a screenshot:
I would not use a GridBagLayout to do a thing too simple.
I tried a simplest solution, by using a Box, but this does not work:
Sample code:
/* file StackSample02.java */
import java.awt.*;
import javax.swing.*;
public class StackSample02 {
public static void main(String [] args) {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.setPreferredSize(new Dimension(100, 100));
panel.setBackground(Color.RED); // for debug
panel.setAlignmentX(JComponent.CENTER_ALIGNMENT); // have no effect
Box box = new Box(BoxLayout.Y_AXIS);
box.add(Box.createVerticalGlue());
box.add(panel);
box.add(Box.createVerticalGlue()); // causes a deformation
frame.add(box);
frame.setSize(new Dimension(200, 200));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
Here a screenshot,
Any ideas? Thanks to all :-)
BoxLayout can pretty to hold your setXxxSize(), then just add panel.setMaximumSize(new Dimension(100, 100));
and your output would be
Removed by setMinimumSize(notice if Container has greater size as ... )
import java.awt.*;
import javax.swing.*;
public class CustomComponent12 extends JFrame {
private static final long serialVersionUID = 1L;
public CustomComponent12() {
Box box = new Box(BoxLayout.Y_AXIS);
box.setAlignmentX(JComponent.CENTER_ALIGNMENT);
box.add(Box.createVerticalGlue());
box.add(new CustomComponents12());
box.add(Box.createVerticalGlue());
add(box);
pack();
setTitle("Custom Component Test / BoxLayout");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setMaximumSize(getMinimumSize());
setMinimumSize(getMinimumSize());
setPreferredSize(getPreferredSize());
setLocation(150, 150);
setVisible(true);
}
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
CustomComponent12 main = new CustomComponent12();
}
};
javax.swing.SwingUtilities.invokeLater(r);
}
}
class CustomComponents12 extends JPanel {
private static final long serialVersionUID = 1L;
#Override
public Dimension getMinimumSize() {
return new Dimension(100, 100);
}
#Override
public Dimension getMaximumSize() {
return new Dimension(100, 100);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(100, 100);
}
#Override
public void paintComponent(Graphics g) {
int margin = 10;
Dimension dim = getSize();
super.paintComponent(g);
g.setColor(Color.red);
g.fillRect(margin, margin, dim.width - margin * 2, dim.height - margin * 2);
}
}
First of all, thanks to all.
I reply another time to my own question, to show everyone the choice I have made.
See the sample code below;
As you can see, I have included only minimal steps which are absolutely necessary to achieve the goal.
/* file StackResponse.java */
import java.awt.*;
import javax.swing.*;
public class StackResponse {
public static void main(String [] args) {
JPanel panel = new JPanel();
Dimension expectedDimension = new Dimension(100, 100);
panel.setPreferredSize(expectedDimension);
panel.setMaximumSize(expectedDimension);
panel.setMinimumSize(expectedDimension);
panel.setBackground(Color.RED); // for debug only
Box box = new Box(BoxLayout.Y_AXIS);
box.add(Box.createVerticalGlue());
box.add(panel);
box.add(Box.createVerticalGlue());
JFrame frame = new JFrame();
frame.add(box);
frame.setSize(new Dimension(200, 200));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setMinimumSize(frame.getMinimumSize()); // cannot be resized-
frame.setVisible(true);
}
}
Here you can see a screenshot.
Problem solved.
Many thanks again to all.
IT
create a panel by name "FixedPanel" with GridBagLayout and set preferred size to frame size
then add your frame into FixedPanel.
Frame = new JFrame("CenterFrame");
Frame.setLocation(0, 0);
Frame.setSize(new Dimension(400,400));//dim
JPanel FixedPanel = new JPanel(new GridBagLayout());
FixedPanel.setPreferredSize(Frame.getSize());
JPanel myPanel = new JPanel();
myPanel.setPreferredSize(new Dimension(100,100));
myPanel.setBackground(Color.BLACK);
FixedPanel.add(myPanel);
Frame.add(FixedPanel);
Frame.setVisible(true);
You can do this. I had to make a chess game, and I wanted the chess piece piece to always go in the center of a cell which was a JlayeredPane:
private void formMouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
if (jl != null)
{
jl.setLocation(evt.getX()+10, evt.getY()+10);
Component com = findComponentAt(evt.getPoint());
if (com instanceof JPanel)
{
// System.out.println("Yes, it's a jpanel");
((JPanel)com).add(jl);
((JPanel)com).validate();
}
}
}
Its Just Having
jPanel.setBounds(x, y, 1046, 503);
Where x is space for right side and y is space for left side.
you have to calculate the space from both side according to screen height and width
use
panel.setMaximumSize(new Dimension(200,200));
panel.setResizable(false)
instead?