I have the problem of a non displaying swing component. Here is how I have structured my code:
Thats my SelectionComponents class:
public void init() {
placeSelectionWithButtons();
}
private void placeSelectionWithButtons() {
JPanel selectionArea = new JPanel(new FlowLayout(FlowLayout.CENTER));
marketList = new JComboBox();
countryList = new JComboBox();
selectionArea.add(marketList);
selectionArea.add(countryList);
repaint();
}
With the init function I am initializing the method to Place the Buttons and Comboboxes.
Furthermore I want to put everything together in my MainPanel class:
I am just initializing this one method(will initialize more later!!!):
public void init(){
log.info("enterMainTabPanel init method");
selectionPanel.init();
}
Finally I am adding it to the method, when I created the TabBar:
public void createTabBar() {
log.info("add Tab Bar");
tabbedPane = new JTabbedPane();
//sets the first Tab
mainTabPanel.init();
tabbedPane.addTab("Main", mainTabPanel);
tabbedPane.setMnemonicAt(0, KeyEvent.VK_1);
...
My problem is that my TabBar gets created and all methods are callen(have viewed the log entries). However nothing displays inside the Tab Content?
Any recommendations what I should change or add?
I appreciate your answer!
The component hierarchy is not clear from your example code.
First check if you have added the TabBar to the content pane of your frame. Then verify that you have added the selectionArea to your TabBar.
Related
I have a simple swing App, that can manage a specific type of project with multiple JButton and that print the project tree on the bottom, see the screenshoot bellow when a project is opened in the App :
App screenshoot with project opened
The thing is when no project is opened I get something like this :
App screenshoot without project opened
The HMI is simple and looks like this :
public class Desktop extends JFrame implements ActionListener {
public Desktop() {
JButton newProject, generate, quit, bAddToClassPath, openProject, saveProject;
JPanel mainPanel;
JScrollPane jscrollpane;
super("MainWindow");
setLookAndFeel();
setSize(330, 440);
ParamMainPanel();
setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new Desktop();
}
});
}
public static void ParamMainPanel() {
mainPanel = new JPanel(new FlowLayout());
// BUTTONS PARAM
newProject = new JButton("Nouveau projet");
generate = new JButton("Générer...");
quit = new JButton("Quitter");
openProject = new JButton ("Ouvrir projet");
saveProject = new JButton ("Sauvegarder");
bAddToClassPath = UIUtil.iconButton();
bAddToClassPath.setActionCommand("setCP");
bAddToClassPath.addActionListener(this);
mainPanel.add(bAddToClassPath);
newProject.addActionListener(this);
newProject.setActionCommand("newP");
generate.addActionListener(this);
generate.setActionCommand("gen");
quit.addActionListener(this);
quit.setActionCommand("qui");
openProject.addActionListener(this);
openProject.setActionCommand("openP");
saveProject.addActionListener(this);
saveProject.setActionCommand("save");
mainPanel.add(newProject);
mainPanel.add(generate);
mainPanel.add(openProject);
mainPanel.add(saveProject);
mainPanel.add(quit);
// PROJECT TREE
jscrollpane = new JScrollPane(new JTree());
jscrollpane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
jscrollpane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED);
jscrollpane.setMinimumSize(new Dimension(50, 50));
jscrollpane.setLocation(4,61);
jscrollpane.setSize(306,322);
mainPanel.add(jscrollpane);
}
}
So what I want is at the App launch, instead of having the bad looking display JTree (into the jscrollpane) without project opened, having the same display with a project opened (white bloc) but without the project tree inside.
I can't figure how to do it, any ideas ?
Here the answer I found to resolve this display problem :
The FlowLayout used on my main panel somehow was preventing me from resizing my jscrollpane directly using setSize()
So I decided to have a secondary panel on my MainFrame secondMainPanel without specific layout using new JPanel(null);
I did add jscrollpaneon it, then I could resize it without problems to have a correct display.
I think there might be better way to fix it, but this one works.
Good afternoon,
As a personal project intended to help me practice using JPanels and subclasses, I am coding a professional web portfolio containing my education, work and volunteer experience, and other notable works using JApplets.
I have the layout set to BorderLayout with the JButtons aligned WEST. When a button is clicked, the JPanels in the CENTER are supposed to switch out with the appropriate panel. However, I am not that far yet.
As of now, I only have a JLabel onto my Home JPanel that says "Home," because I'd like to make sure the method from the Home JPanel class is working before doing anything more. The issue is that the JPanel isn't displaying on the applet.
The thing is, when I move all the code into from the JPanel's class onto the main class, it displays just fine. So I know the problem is with either how I'm constructing the method, or with how I constructed my JPanel's class.
I've tried setting it to visible-- that didn't work. I've tried setting the LayoutManager as a parameter for the class constructor, I've tried adding paintComponent and super.paint(g), I tried using this.home.addHomePanel-- but nothing worked.
I know I'm missing a few things. It would be appreciated if someone could give me a hand. Please let me know if you need more information. Thank you for reading.
Main Class:
public class myWebFolio extends JApplet implements ActionListener
{
JButton[ ] menu =
{
new JButton("Home"),
new JButton("Education"),
new JButton("Work Experience"),
new JButton("Programming Projects"),
new JButton("Other")
};
//adds panel to memory
private JPanel buttonPanel = new JPanel();
private Home home;
public void init()
{
setLayout (new BorderLayout( ) ); //changes the layout of the appl
home = new Home();
buttonPanel.setLayout(new BoxLayout(buttonPanel, BoxLayout.Y_AXIS));
/*
* Adds an ActionListener to each button
* and then adds the button to the buttonPanel.
* Also adds an invisible componenet to give the buttons
* spacing.
*/
for (int i=0; i<menu.length; i++)
{
menu[i].addActionListener(this);
buttonPanel.add(Box.createVerticalStrut(100));
buttonPanel.add(menu[i]);
}
add(buttonPanel,BorderLayout.WEST);
home.addHomePanel();
}
public void actionPerformed(ActionEvent event)
{
}
public void paintComponent(Graphics g)
{
super.paint(g);
}
}
Home Panel's Class:
public class Home extends JPanel
{
JPanel homePanel = new JPanel(new FlowLayout());
JLabel label = new JLabel("Home");
/**
* Constructor for objects of class Home
*/
public Home()
{
}
public void addHomePanel()
{
homePanel.add(label, FlowLayout.LEFT);
homePanel.setVisible(true);
add(homePanel, BorderLayout.CENTER);
}
public void paintComponent(Graphics g)
{
super.paint(g);
}
}
I am trying to open a GUI from my main GUI by pressing a button. When the button is pressed, this is executed:
WorkloadFactor wf = new WorkloadFactor();
wf.setVisible(true);
This doesn't open the WorkloadFactor GUI. I am confused by this because I have other GUIs that open this way without issue.
WorkloadFactor class works fine when I run it by itself but won't open when it is called by my main GUI. Below is my class without imports and stuff:
public class WorkloadFactor extends JPanel {
public WorkloadFactor() {
setLayout(new BorderLayout());
JTabbedPane tabbedPane = new JTabbedPane();
String[] tabnames = { "Zero", "One", "Two", "Three", "Four" };
for (int i = 0; i < tabnames.length; i++) {
tabbedPane.addTab(tabnames[i], createPane(tabnames[i]));
}
tabbedPane.setSelectedIndex(0);
JButton submit = new JButton("Submit All");
submit.setForeground(Color.RED);
add(tabbedPane, BorderLayout.CENTER);
add(submit, BorderLayout.SOUTH);
}
public JPanel createPane(final String t) {
JPanel contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
//setContentPane(contentPane); I think this might be it?
contentPane.setLayout(null);
setBounds(100, 100, 531, 347);
//***** all the components I am including then add them like so
//******contentPane.add(checkbox1);
//****** contentpane.add(label1);
return contentPane;
}
public static void main(String[] args) {
JFrame frame = new JFrame("Set Workload Factor Information");
frame.getContentPane().add(new WorkloadFactor());
frame.setBounds(100, 100, 531, 347);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
}
}
I have tried arranging things in so many ways, putting everything in the constructor and other changes but can't seem to find a reason why instantiating this WorkloadFactor class elsewhere and setting it visible won't work.
Does it have something to do with setContentPane(contentPane) vs contentPane.add(xxxx) and returning it?
Thank you for reading!
WorkloadFactor wf = new WorkloadFactor();
wf.setVisible(true);
To be blunt, this won't display anything. Please understand that WorkloadFactor extends JPanel and like all non-top level components must be placed into a container that is ultimately held by a top-level window in order to be displayed. Look at how you display it in your main method -- you first put it into a JFrame, and then display that JFrame. You must do the same thing if you want to display it on button press -- you need to put it into a JPanel or other container that is held by a JFrame or JDialog, or JOptionPane.
Make sure that you have properly registered the button on your main GUI which opens WorkLoadFactor GUI to an action listener.
Since you have not included code from your main GUI I can't confirm this is the issue. However it is a commonly overlooked issue.
Heres some suggestions from the Java documentation tutorials:
"Problem: I'm trying to handle certain events from a component, but the component isn't generating the events it should.
First, make sure you registered the right kind of listener to detect the events. See whether another kind of listener might detect the kind of events you need.
Make sure you registered the listener on the right object.
Did you implement the event handler correctly? For example, if you extended an adapter class, then make sure you used the right method signature. Make sure each event-handling method is public void, that the name spelled right and that the argument is of the right type."
source: Solving Common Event-Handling Problems
Make a JFrame and add a JButton in it than add action listener in button and add this code in it like this:
This code makes a frame with a button and when button is pressed new window is opened.
public class Example extends JFrame {
public Example() {
super("Title");
setLayout(new FlowLayout());
JButton b = new JButton("Open new Frame");
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
newWindow nw = new newWindow();
}
});
add(b);
}
}
newWindow Code:
public class newWindow extends JFrame {
newWindow() {
super("title");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400,400);
setVisible(true);
}
}
I'm working on a project, and have run into a little bit of a logic error, hopefully one of you can clear this up.
I'm building an application that will display a SQL database (among other things). Currently, the way I have things set up, I have a JTabbedPane inside a Container (BorderLayout.CENTER) not that this is really pertinent information.
Anywho, I would like to add a tab once the user has connected to a database (and eventually selected which 'table' to see. For now however, there is only one table to be displayed.
So, when the user hits 'Connect', ideally the connection will be successful, at which point in time a JTable is populated with the database information.
Once this table is initialized and ready to go, add it to a new JPanel, and add that panel to the JTabbedPane.
This is where the error comes in. I 'believe' my logic thus far is correct, and I don't get any compiler/runtime errors, the new tab just isn't shown (and if I click where it should be) nothing happens.
Below is some of my code, if anything needs clarified please don't hesitate to ask!
This is the Table_Builder Class code (I will clean it up once it is working properly!)
public class Table_Builder extends Framework
{
private DefaultTableModel updated_table_model;
private JTable updated_table;
private JScrollPane table;
public Table_Builder()
{
// no implemention needed
}
public Table_Builder(Vector rows, Vector columns)
{
updated_table_model = new DefaultTableModel(rows, columns);
updated_table = new JTable(updated_table_model);
updated_table.setCellSelectionEnabled(true);
updated_table.setFillsViewportHeight(false);
table = new JScrollPane(updated_table);
JPanel tab2 = new JPanel();
tab2.add(table);
tab2.setVisible(true);
center.add("Table Viewer", tab2);
// I'm thinking some sort of listener needs to be active, so it knows I'm adding a new
// tab, but I'm not sure how this actually works.
center.addPropertyChangeListener("foregroud", null);
center.repaint();
// center has already been added to container so i don't think that needs to be done again?
}
Framework
protected void center_panel()
{
JPanel tab1 = new JPanel();
tab1.add(//emitted);
center.setPreferredSize(new Dimension(1340, 950));
center.setBackground(new Color(90, 90, 90));
center.addTab("Tab1", tab1);
container.add(center, BorderLayout.CENTER);
}
Best Regards,
Mike
UPDATE:
Framework has these variables I am using to build the 'Frame'
Framework is a borderlayout (east, west, north, south, center)
protected JTabbedPane center // this is the center panel
protected Container container // this will house all panels to be added
As seen above, I am currently adding tabs by
1.) creating a new JPanel
2.) adding (whatever needs to be displayed) to the jpanel
3.) adding that jpanel to the JTabbedPane
this is done by
center.addTab("Tab name here", panel to be added);
The javadoc for this says
center.addTab("String title", Component component);
This works as intended, the problem I am encountering, is that this is done prior to server connection. After the user connects to the server, I would like to add a new tab, which is being done from Table_Builder, which inherits from Framework (which is why center and container are protected and not private).
Your code for adding a tab in the constructor is the following:
JPanel tab2 = new JPanel();
tab2.add(table);
tab2.setVisible(true);
center.add("Table Viewer", tab2);
// I'm thinking some sort of listener needs to be active, so it knows I'm adding a new
// tab, but I'm not sure how this actually works.
center.addPropertyChangeListener("foregroud", null);
center.repaint();
There are 2 errors and a lot of unnecessary lines. The errors are:
center.add("Table Viewer", tab2); is using the add function of the Container class. When you wanted to use center.addTab("Table Viewer", tab2);.
Just to clear up what #peeskillet was pointing out, there is not a "foregroud" property, nor a "forground" (as per your comment), but a "foreground" property.
Now what you need to do is just the following:
JPanel tab2 = buildTableViewerTab();
center.addTab("Table Viewer", tab2);
Where buildTableViewerTab() (returning a JPanel) is the code necessary to create the JPanel that you desire. Just create the component and add it to the tabbedPane properly.
To show how this code works here is a simple executable application demonstrating this functionality. Again, what #peeskillet was asking you in his second comment is to do this same example but in your own way and with your code demonstrating the errors you were encountering. Although doing this you probably would have found them.
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.SwingUtilities;
public class AddTabsExample
{
public static final void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new AddTabsExample();
}
});
}
public AddTabsExample()
{
JFrame frame = new JFrame("Tab adder frame");
final JTabbedPane tabbedPane = new JTabbedPane();
frame.add(tabbedPane);
JButton addButton = new JButton("Add tab");
addButton.addActionListener(new ActionListener()
{
#Override
public void actionPerformed(ActionEvent arg0)
{
JPanel newTabComponent = new JPanel();
int tabCount = tabbedPane.getTabCount();
newTabComponent.add(new JLabel("I'm tab " + tabCount));
tabbedPane.addTab("Tab " +tabCount, newTabComponent);
}
});
frame.add(addButton, BorderLayout.SOUTH);
addButton.doClick(); //add the first tab
frame.setSize(800, 300);//frame.pack();
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setVisible(true);
}
}
Execution result:
call revalidate() on your center, then repaint.
I`m planning to use a panel as a view controler container.
//variables
CustomerSearch cs;
CardLayout cl;
string BUTTONPANEL="Page1";
Setup of variables
private void InitViews(){
cl = new CardLayout();
cs = new CustomerSearch();
cl.addLayoutComponent(cs, BUTTONPANEL);
ViewPanel.setLayout(cl);
//cl.show(ViewPanel, BUTTONPANEL);
}
the button click for updating the view:
private void SearchBtnActionPerformed(java.awt.event.ActionEvent evt) {
cl.show(ViewPanel, BUTTONPANEL);
cs.repaint();
ViewPanel.repaint();
}
But when the event is fired, nothing happens?
Can anyone tell me what I'm doing wrong?
Normally you do not add the components to the layout. They are added to the parent component, the one using the layout:
private void initViews() {
cl = new CardLayout();
viewPanel.setLayout(cl);
cs = new CustomerSearch();
viewPanel.add(cs, BUTTONPANEL);
}
This tutorial should help: How to Use CardLayout
It also is convention that variables, fields and methods are named starting with a lowercase. Classes and Interfaces start with uppercase.
EDIT
repaint is not needed in this case, the following listener should do:
private void SearchBtnActionPerformed(java.awt.event.ActionEvent evt) {
cl.show(viewPanel, BUTTONPANEL);
}