I'd like to use a JScrollPane for a panel which has an arbitrary list of labels in it using box layout. I'm trying to get it so that the scrollbar would appear if there were too many items (labels) to display.
I tried adding a JScrollPane to the panel and then add the labels but then I don't see any scroll bar.
Any ideas?
TIA
For this kind of thing, you'd normally use a JList or JTable (if you need custom rendering).
Make sure that you call validate() or revalidate() on the JScrollPane after adding an item, to force the preferred size of the panel to be recalculated.
Here's how I did it.
JPanel midPanel = new JPanel();
midPanel.setLayout(new BoxLayout(midPanel, BoxLayout.Y_AXIS));
midPanel.add(new JLabel("<html><u>Label</u>"));
Box box = Box.createVerticalBox();
for (Item item : data.getInventory()) {
inventory.add(box.add(new JLabel(item.getName())));
}
JScrollPane jscrlpBox = new JScrollPane(box);
midPanel.add(jscrlpBox);
add(midPanel, BorderLayout.CENTER);
From:
http://www.java2s.com/Code/Java/Swing-JFC/JScrollPanetoholdscrollablecomponent.htm
Did you remember to set the preferred size of the content panel?
final JFrame frame = new JFrame("Scroll Demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
final Box textArea = Box.createVerticalBox();
final JScrollPane textAreaScroll = new JScrollPane(textArea);
textAreaScroll.setPreferredSize(new Dimension(80,150)); /* essential! */
JButton addButton = new JButton("ADD");
addButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
textArea.add(new JLabel("abc"));
textArea.revalidate();
}
});
frame.getContentPane().add(textAreaScroll, BorderLayout.SOUTH);
frame.getContentPane().add(Box.createRigidArea(new Dimension(10,10)), BorderLayout.CENTER);
frame.getContentPane().add(addButton, BorderLayout.NORTH);
frame.pack();
frame.setVisible(true);
In this example, the scroll bar works correctly, but if you remove the line marked as "essential", it will not work anymore.
Related
I try to program a GUI like this. When a button clicked every time a new button is created and placed at specific position but after adding some buttons in jscrollpane, scrollbar not activated, so I unable to see all created buttons.
My code is here:
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Test{
private JFrame frame;
private JPanel panel1,panel2;
private JScrollPane pane;
private JButton button;
int i = 1, y = 10;
public Test()
{
panel2 = new JPanel(null);
panel2.setBounds(0,0,280,300);
button = new JButton("Add Button");
button.setBounds(90,10,120,30);
pane = new JScrollPane();
pane.setBounds(10,50,280,300);
panel1 = new JPanel(null);
panel1.setPreferredSize(new Dimension(300,400));
panel1.setBackground(Color.WHITE);
frame = new JFrame("Test");
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(panel1);
frame.pack();
panel1.add(pane);
panel1.add(button);
pane.add(panel2);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
panel2.add(new JButton("Button "+i)).setBounds(80,y,120,30);
i += 1;
y += 35;
}
});
}
public static void main(String[] args) {
new Test();
}
}
Don't use a null layout. Don't use setBounds().
The scrollbars will only appear automatically when the preferred size of the panel is greater that the size of the scroll pane.
It is the job of the layout manager to:
set the location of a component
set the size of a component
calculate the preferred size of the panel.
So the solution is to use the appropriate layout manager on your panel.
So for example you can use a BoxLayout:
//panel2 = new JPanel(null);
panel2 = new JPanel();
panel2.setLayout( new BoxLayout(panel2, BoxLayout.Y_AXIS) );
And then when you add components to a visible frame you need to revalidate() the panel to invoke the layout manager:
//panel2.add(new JButton("Button "+i)).setBounds(80,y,120,30);
panel2.add(new JButton("Button "+i));
panel2.revalidate();
There is no need for panel1. Just add the components to the frame:
//panel1.add(pane);
//panel1.add(button);
frame.add(button, BorderLayout.PAGE_START);
frame.add(pane, BorderLayout.CENTER);
But there are other issues:
pane = new JScrollPane();
You actually need to add the panel to the scroll pane. So the code should be:
pane = new JScrollPane(panel2);
Since a component can only have a single parent, you need to remove:
pane.add(panel2);
Since the panel2 has been added to the scroll pane.
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(panel1);
frame.pack();
The above logic is wrong.
You should only invoked pack() and setVisible( true ) AFTER all the component have been added to the frame.
So most of the code posted is wrong.
Start by reading the section from the Swing turtorial on Layout Managers. Download the working demo code and learn how to better structure your code. The modify the code for your specific example.
I have been working on this for hours. I honestly cannot figure it out. I have JTextArea's inside a JSplitPane which is inside a JPanel with a JButton and all that is put in my JFrame. I am using Layout managers. I have tried using pack(). I have tried using preferred sizes. Without the JPanel my button does not display in the proper location or switch buttons in other Tabs. With the JPanel it cuts off all my text, stops the scroll function(yes I have tried setting the TextAreas to always have horizontal and vertical scroll bars...does not solve the problem where text just stops wrapping for no apparent reason).
public static void main(String[] args) throws IOException
{
JFrame frame = new JFrame();
Deck blackjack = new Deck(Deck.TYPE[0]);
JTextArea textBlackjackUnshuffled = new JTextArea();
JTextArea textBlackjackShuffle = new JTextArea();
JButton shuffleButtonBlackjack = new JButton(new ImageIcon(ImageIO.read(new File("res/shuffle.png"))));
JToolBar toolBarBlackjack = new JToolBar("Blackjack");
JSplitPane splitPaneBlackjack = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT);
JPanel panel = new JPanel();
JTabbedPane tabbedPaneBlackJack = new JTabbedPane();
JTabbedPane tabbedPaneCanasta = new JTabbedPane();
JTabbedPane tabbedPanePinochle = new JTabbedPane();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
textBlackjackUnshuffled.setColumns(10);
textBlackjackUnshuffled.setLineWrap(true);
textBlackjackUnshuffled.setWrapStyleWord(true);
textBlackjackUnshuffled.setEditable(false);
textBlackjackUnshuffled.setFont(new Font("DejaVu Sans", Font.PLAIN, 100));
textBlackjackUnshuffled.append(blackjack.toString());
textBlackjackShuffle.setColumns(10);
textBlackjackShuffle.setLineWrap(true);
textBlackjackShuffle.setWrapStyleWord(true);
textBlackjackShuffle.setEditable(false);
textBlackjackShuffle.setFont(new Font("DejaVu Sans", Font.PLAIN, 100));
textBlackjackShuffle.append(blackjack.toString());
shuffleButtonBlackjack.setBorderPainted(false);
shuffleButtonBlackjack.setFocusPainted(false);
shuffleButtonBlackjack.setContentAreaFilled(false);
splitPaneBlackjack.add(new JScrollPane(textBlackjackUnshuffled));
splitPaneBlackjack.add(new JScrollPane(textBlackjackShuffle));
panel.add(splitPaneBlackjack, BorderLayout.CENTER);
panel.add(shuffleButtonBlackjack, BorderLayout.PAGE_END);
tabbedPaneBlackJack.addTab("Blackjack", panel);
frame.add(tabbedPaneBlackJack);
frame.setSize(new Dimension(Toolkit.getDefaultToolkit().getScreenSize()));
frame.setVisible(true);
}
You're adding the JScrollPanes to the panel in BorderLayout positions, but have not set the layout manager of panel to BorderLayout. In this situation, panel will be using JPanel's default layout manager, FlowLayout, a manager which is not smart enough to respect the scroll pane's preferred sizes.
Your code needs:
panel.setLayout(new BorderLayout());
I have a JFrame with three areas:
A scrollpane with a list of objects
A panel with labels and textfields
A scrollpane with a panel potentially having multiple labels
When you click the item on the list, the textfields on the panel are filled and the labels on the second scroll are created. I have two problems with my code:
For some reason the scrollpane at the botom of the screen does not fill the whole borderlayout's south area, only half of it.
the scrollpane does not show anything when the item on the list is selected.
Here I tried to make an example:
private void jMenuItem1ActionPerformed(java.awt.event.ActionEvent evt) {
JPanel geral = new JPanel();
JPanel lista = new JPanel();
JPanel dados = new JPanel();
JPanel paneHist = new JPanel();
JPanel historico = new JPanel();
GridLayout gridLay = new GridLayout(0, 2, 5, 10);
geral.setLayout(gridLay);
dados.setLayout(gridLay);
historico.setLayout(new BorderLayout());
lista.setLayout(new BorderLayout());
paneHist.setLayout(gridLay);
this.setLayout(new BorderLayout());
this.add(geral);
geral.add(lista, BorderLayout.WEST);
geral.add(dados, BorderLayout.EAST);
geral.add(historico, BorderLayout.SOUTH);
DefaultListModel listModel = new DefaultListModel();
listModel.addElement("just testing");
final JList list = new JList(listModel);
list.setLayoutOrientation(JList.VERTICAL);
list.setVisible(true);
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
JScrollPane scroll = new JScrollPane(list);
scroll.setPreferredSize(new Dimension(100, 500));
lista.add(scroll, BorderLayout.CENTER);
JTextField jtf = new JTextField();
dados.add(new JLabel("test:"));
dados.add(jtf);
list.addListSelectionListener(new ListSelectionListener() {
#Override
public void valueChanged(ListSelectionEvent lse) {
jtf.setText("clicked");
paneHist.add(new JLabel("texttexttext"));
paneHist.add(new JLabel("texttexttext"));
}}
);
JScrollPane scrollHist = new JScrollPane(paneHist);
scrollHist.setPreferredSize(new Dimension(500, 100));
historico.add(new JLabel("Historico:"), BorderLayout.NORTH);
historico.add(scrollHist, BorderLayout.EAST);
//list.setCellRenderer(new CellRenderer());
this.validate();
this.repaint();
}
Can't really tell what you are doing from the posted code.
Some general comments:
Don't use setPreferredSize(). Let each component determined its preferred size. In the case of a JList you can use the setVisibleRowCount(...) method so the JList can calculate a reasonable size.
In your ListSelectionListener, when you add/remove components from a visible GUI you need to revalidate() and repaint() the panel.
I'm trying to build a Java GUI where among other things there will be several tabs.
In one of the tabs I want to have both a scrollable JTextArea, and also some buttons at the top/bottom that interacts with the JTextArea. I can't figure out how to get both into the same tab, I'm either getting the buttons and a non-scrollable jtextarea, or just the scrollable jtextarea. I also don't want to display the button in the other tabs. Here is my code:
private final JTextArea music = new JTextArea();
private final JTextArea button = new JTextArea();
private final JTextArea test = new JTextArea();
private final JTabbedPane tab = new JTabbedPane();
private JTable table;
music.append(newPlaylist.toString());
JFrame frame = new JFrame("GUI");
frame.setTitle("Music File Organiser");
JPanel panel = new JPanel();
panel.setLayout(new FlowLayout(FlowLayout.CENTER));
JButton button1 = new JButton("Hello");
JButton button2 = new JButton("Sort by Album Title");
JButton button3 = new JButton("Sort by Track Title");
button1.addActionListener(new ActionListener() {code};
button2.addActionListener(new ActionListener() {code};
button3.addActionListener(new ActionListener() {code};
panel.add(music);
panel.add(button1);
panel.add(button2);
panel.add(button3);
JScrollPane scroll = new JScrollPane(panel);
JScrollPane scroll2 = new JScrollPane(table);
tab.add("Music Files", scroll);
tab.add("Table", scroll2);
this.add(tab);
frame.setLocationRelativeTo(null);
this.setSize(1200, 1000);
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
The tab in mind is the first one. How do I add buttons to "scroll"? The way I'm trying it here is to add the JTextArea "music" into panel, then adding the buttons to the same panel, then adding the panel to a JScrollPane, and then adding the JScrollPane to tab. Any help would really be appreciated.
Encapsulate your visual elements into child Panels.
JPanel buttonPanel = new JPanel(); //panel for buttons.
buttonPanel.add(button1);
buttonPanel.add(button2);
buttonPanel.add(button3);
JScrollPane scroll = new JScrollPane(music); //scrollable pane for JTextArea
panel.add(buttonPanel);
panel.add(scroll); //add sub-components to panel for tab
/*here you would add some layout code to fit the panel and scroll into the associated spaces */
tab.add("Music Files", panel); //add panel to tab
You can do something like this:
JPanel tab = new JPanel()
JPanel tabWithButtons = new JPanel()
JPanel tabWithScrollPanel = new JPanel()
tab.add(tabWithScrollPanel)
tab.add(tabWithButtons)
IMO this is better way, because I assume that buttons shouldn't be included in JScrollPane and they should be visible all the time
Of course, you have to add all elements to proper JPanels.
Also, you can try with width/height settings of panel which contains all your elements, maybe ScrollArea panel is to big?
As you see the code, I would like to implement the 2nd tab with a text area, scrolling, and a button down there. This (JScrollPane scr = new JScrollPane(secondTab(panel2));) code was in the function, private static JTextArea secondTab(JPanel panel) before but I took it out of the function and put that back to MainFrame. Because the scroll and text area didn't show up. Now that I moved the code to mainframe the tex tarea and scroll are visible, but I'm struggling with making the button showing up in the 2nd tab. Do you guys have any idea?
public MainFrame(String username)
{
JTabbedPane tab = new JTabbedPane();
mainFrame.add(tab, BorderLayout.CENTER);
JPanel panel1 = new JPanel();
firstTab(panel1);
tab.add("babababa", panel1);
JPanel panel2 = new JPanel();
JScrollPane scr = new JScrollPane(secondTab(panel2));
JButton saveButton = new JButton("Save");
panel2.add(saveButton);
saveButton.setBounds(190, 280, 80, 40);
tab.add("hahaha", panel2.add(scr));
mainFrame.setBounds(200,200,500,400);
mainFrame.setVisible(true);
}
private static JTextArea secondTab(JPanel panel) {
panel.setLayout(null);
final JTextArea nameTextArea=new JTextArea();
nameTextArea.setBounds(10,10,440,270);
nameTextArea.setLineWrap(true);
return nameTextArea;
}
}
You should avoid use of null layout as this makes for very inflexible GUI's that while they might look good on one platform look terrible on most other platforms or screen resolutions and that are very difficult to update and maintain. Not only that, JScrollPanes do not work well when the viewport view (the component that you display inside of the JScrollPane) uses null layout. Not only that, if you set the bounds or even the preferred size of a JTextArea, it will not expand inside the JScrollPane and you won't see scrollbars.
Solution:
Avoid using null layouts like the plague.
Learn and use the layout managers: The Swing Layout Manager Tutorials
Never set a JTextArea's size or preferredSize. Instead consider setting its columns and rows.
For example:
import java.awt.BorderLayout;
import javax.swing.*;
public class MainFrame2 extends JPanel {
private JTabbedPane tabbedPane = new JTabbedPane();
private JTextArea textArea = new JTextArea(20, 40);
public MainFrame2() {
tabbedPane.add("Bahahahaha", new JPanel());
tabbedPane.add("TextArea Info", createTextAreaPane());
setLayout(new BorderLayout());
add(tabbedPane, BorderLayout.CENTER);
}
private JComponent createTextAreaPane() {
JPanel btnPanel = new JPanel();
btnPanel.add(new JButton("Save"));
JPanel textAreaPane = new JPanel(new BorderLayout());
textAreaPane.add(new JScrollPane(textArea), BorderLayout.CENTER);
textAreaPane.add(btnPanel, BorderLayout.SOUTH);
return textAreaPane;
}
private static void createAndShowGui() {
MainFrame2 mainPanel = new MainFrame2();
JFrame frame = new JFrame("Main Frame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
It's better to build each tab panel in each method.
private JPanel buildFirstTab() {
// create new panel
// add components to the panel
// return the panel
}
private JPanel buildSecondTab() {
// create new panel
// create JScrollPane
// create JTextArea
// add text area to scrollpane by calling scrollpane.setViewPort method
// add scrollpane to the panel
// create button
// add button to the panel
// return the panel
}
public MainFrame(String username) {
JTabbedPane tab = new JTabbedPane();
mainFrame.add(tab, BorderLayout.CENTER);
tab.add("1st tab", buildFirstTab());
tab.add("2nd tab", buildSecondTab());
mainFrame.setBounds(200,200,500,400);
mainFrame.setVisible(true);
}
Adding to the previous answer, try to use the simple layout like BoxLayout (adds components on top of each other), or FlowLayout (adds components next to previous component), then learn more complex layout like GridBagLayout (so far, this is the best layout for me, most of the time).