I understand some parts of BorderLayout -- e.g., the EAST/WEST (or BEGINNING_OF_LINE/END_OF_LINE) panel component stays one width and its length is stretched with the length of the window.
I want to put a panel on the WEST side that itself has multiple components - a panel of buttons and a JList of things the buttons control, in this case. I would like to allocate a minimum width for the strings in that JList, but something (probably BorderLayout) prevents me from setting a minimum or preferred width.
When I run the code below, the list in the left panel is wide enough for "LongNameGame 3", but only because I added the string before rendering the list. I would like to set the width of that JList to accommodate strings of the width of my choice. Later I'll put it in a ScrollPane for strings wider than that, but that's a different problem.
My question is not answered by referring me to other layout managers -- I want to know how to do this with BorderLayout, if possible.
package comm;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.util.Vector;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.border.Border;
public class BLPlay
{
public static void main(String ... arguments)
{
JFrame frame = buildLoungeFrame();
frame.setVisible(true);
}
private static JFrame buildLoungeFrame()
{
JFrame loungeFrame = new JFrame("BLPlay");
loungeFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
loungeFrame.setLayout(new BorderLayout(10,10));
// left panel is another BorderLayout panel with buttons and a list of games
JPanel gameListControlPanel = new JPanel(new BorderLayout());
Border innerBorder = BorderFactory.createLineBorder(Color.BLACK, 2);
Border outerBorder = BorderFactory.createEmptyBorder(3,3,3,3);
gameListControlPanel.setBorder(BorderFactory.createCompoundBorder(outerBorder, innerBorder));
String[] gamePanelButtonLabels = { "New", "Join", "Leave", "End" };
JPanel gamePanelButtons = new JPanel(new GridLayout(gamePanelButtonLabels.length,1));
addButtons(gamePanelButtons, gamePanelButtonLabels);
JPanel gamePanelButtonsContainerPanel = new JPanel();
gamePanelButtonsContainerPanel.add(gamePanelButtons);
gameListControlPanel.add(gamePanelButtonsContainerPanel, BorderLayout.WEST);
Vector<String> gameList = new Vector<>();
gameList.add("Game 1");
gameList.add("Game 2");
gameList.add("LongNameGame 3");
JList<String> gameJList = new JList<>(gameList);
JPanel gameListPanel = new JPanel(new FlowLayout());
gameListPanel.setMinimumSize(new Dimension(600,600)); // <-- has no effect
gameListPanel.add(gameJList);
gameListControlPanel.add(gameListPanel, BorderLayout.EAST);
loungeFrame.add(gameListControlPanel, BorderLayout.WEST);
// center panel in the lounge is for chat messages; it has a separate border layout,
// center for accumulated messages, bottom for entering messages
JPanel chatMessagePanel = new JPanel(new BorderLayout());
// Border chatMessagePanelBorder = BorderFactory.createEmptyBorder(7,7,7,7);
// chatMessagePanel.setBorder(chatMessagePanelBorder);
JTextArea chatMessages = new JTextArea();
chatMessagePanel.add(chatMessages, BorderLayout.CENTER);
// debug
chatMessages.append("message one\n");
chatMessages.append("message two\n");
chatMessages.append("message three\n");
// and lower panel is for entering one's own chat messages
JPanel chatMessageEntryPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
JTextField chatMessageEntryField = new JTextField(35);
JButton chatMessageEntryButton = new JButton("Enter");
chatMessageEntryPanel.add(chatMessageEntryField);
chatMessageEntryPanel.add(chatMessageEntryButton);
chatMessagePanel.add(chatMessageEntryPanel, BorderLayout.SOUTH);
loungeFrame.add(chatMessagePanel, BorderLayout.CENTER);
loungeFrame.pack();
return loungeFrame;
}
private static void addButtons(JPanel panel, String ... labels)
{
for (String label : labels)
{
JButton button = new JButton(label);
panel.add(button);
}
}
}
Give the JList a prototype cell value that is wide enough to display what you need. e.g.,
gameJList.setPrototypeCellValue("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
The prototype value (here a String because the list has been declared as a JList<String>) is used to set the list's preferred size, but is not displayed in the JList. You can use as large or small a list as you need. Also be sure to set visible row count for the same purpose in the horizontal dimension:
gameJList.setVisibleRowCount(20); // for example
Related
So I have been trying to come up with a good layout manager that will enable me to put multiple components in a scrollable panel with different sizes. The only one I found was gridlayout, but it forces the same size.
here is the current code I have:
package main;
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Main {
public static void main(String[] args) {
// Create and set up a frame window
JFrame frame = new JFrame("Layout");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Define the panel to hold the components
JPanel panel = new JPanel(new GridLayout(0, 1, 0, 0));
panel.setPreferredSize(new Dimension(500, 800));
for (int i = 0; i < 20; i++) {
JButton button = new JButton("Button " + i);
button.setPreferredSize(new Dimension(50, 100 + (i * 10)));
panel.add(button);
}
// Add the panel and set the window to be visible
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
}
I also do know about GridBagLayout, but I do want a layout that wouldn't require me to enter the numbers manually.
I also do know about GridBagLayout, but I do want a layout that wouldn't require me to enter the numbers manually.
You can specify:
constraint.gridWidth = GridBagConstraints.REMAINDER;
and each component will be placed on a new row.
Or you can use a BoxLayout, as I suggested in my comment, and not worry about constraints.
Read the tutorial. The constraints for the GridBagLayout are explained in more detail.
Hello StackExchange community,
I'm at my wits end about this JSplitPane I'm trying to put into my frame, it is sitting on the right side of my frame instead of filling it up or atleast sitting on the left.
If anyone could help me with this issue I'd be very thankful.
See below an image of my problem and the code
The problem area is the pane with "tab1" and "tab2", the divider and the pane on the right side of that divider:
I've tried setting setAlignmentX(Component.LEFT_ALIGNMENT) on all the individual parts of the JSplitPane. I've also tried making a JPanel to hold it and aligning that. All to no avail.
Furthermore, existing information I've been able to find hasn't been relevant, mostly people discussing how to align the contents of the JSplitPane.
The code below is all that is needed to make this frame, if any of you need it to help me out feel free.
package test;
import java.awt.Color;
import java.awt.Component;
import java.util.ArrayList;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTextField;
import javax.swing.ListSelectionModel;
public class FrameMaker {
public int x = 0;
private ArrayList<String> mpLabels;
private JFrame theFrame;
public void MakeFrame() {
theFrame = new JFrame("title");
theFrame.getContentPane().setLayout(new BoxLayout(theFrame.getContentPane(), BoxLayout.Y_AXIS));
mpLabels = new ArrayList<String>();
//label1
JPanel bgSwitches = new JPanel();
JLabel calcsLabel = new JLabel("top label, broadened with lines to exaggerate problem-------------------------------------------");
bgSwitches.add(calcsLabel);
//label2
JPanel topLevel = new JPanel();
JLabel textinfo = new JLabel("label below that");
topLevel.add(textinfo);
//splitpane tabs
mpLabels.add("tab1");
mpLabels.add("tab2");
String[] mpLabelsAr = new String[mpLabels.size()];
JList<String> posL = new JList<String>(mpLabels.toArray(mpLabels.toArray(mpLabelsAr)));
posL.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
//panel inside the right splitpane pane, this is needed for something later.
JPanel RPanel = new JPanel();
RPanel.setLayout(new BoxLayout(RPanel, BoxLayout.Y_AXIS));
JScrollPane scrollPos = new JScrollPane(posL);
JScrollPane scrollROI = new JScrollPane(RPanel);
JSplitPane posPanel = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,scrollPos,scrollROI);
posPanel.setOneTouchExpandable(false);
posPanel.setDividerLocation(75);
//label and textfield
JLabel msLabel = new JLabel("another label");
JTextField msField = new JTextField("textfield");
JPanel buttonPanel = new JPanel();
buttonPanel.add(msLabel);
buttonPanel.add(msField);
bgSwitches.setBackground(new Color(0,0,255));
theFrame.add(bgSwitches);
topLevel.setBackground(new Color(0,255,0));
theFrame.add(topLevel);
posPanel.setAlignmentX(Component.LEFT_ALIGNMENT);
posPanel.setBackground(new Color(0,255,255));
theFrame.add(posPanel);
buttonPanel.setBackground(new Color(255,0,0));
theFrame.add(buttonPanel);
theFrame.pack();
theFrame.setVisible(true);
}
}
You need to align all of your other elements to the left as well.
bgSwitches.setAlignmentX(Component.LEFT_ALIGNMENT);
topLevel.setAlignmentX(Component.LEFT_ALIGNMENT);
buttonPanel.setAlignmentX(Component.LEFT_ALIGNMENT);
You can also add posPanel.setResizeWeight(VALUE BETWEEN 0 AND 1); to specify what percent of the space the JSplitPane should occupy and it will resize with your window.
I'm trying to align a JLabel to the right in a JPanel. I'm adding a JTabbedPane, a JPanel which contains my JLabel and JTextArea to a main JPanel.
I have searched SO and tried some methods like setAlignmentX, setHorizontalAlignment(SwingConstants.LEFT) and nested containers to no avail.
Here's my code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class LabelProblem
{
public static void main(String[] args)
{
JFrame frame = new JFrame("Label Problem");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel Main = new JPanel();
Main.setLayout(new BoxLayout(Main, BoxLayout.Y_AXIS));
JPanel ComponentPanel = new JPanel();
JLabel label = new JLabel("Sample Text");
label.setHorizontalAlignment(SwingConstants.LEFT);
label.setBorder(BorderFactory.createLineBorder(Color.BLACK));
label.setAlignmentX(Component.RIGHT_ALIGNMENT);
ComponentPanel.add(label);
JTabbedPane Tab = new JTabbedPane();
Tab.add("Document 1", new JPanel());
Main.add(Tab);
Main.add(ComponentPanel);
JTextArea Area = new JTextArea(10,10);
JScrollPane Scroll = new JScrollPane(Area);
frame.add(Main);
frame.add(Scroll, BorderLayout.SOUTH);
frame.setSize(450,450);
frame.setVisible(true);
}
}
How can I align my JLabel to the right?
Thanks!
So, the place of that label is determined by the layout of ComponentPanel. Since you didn't specify any layout it is using the default FlowLayout with a CENTER alignment. Assuming that you are ok with a FlowLayout it is a mere question of setting the alignment of the LEFT since this is possible with this layout.
Here's the code with the fix, however I suspect that as you put more elements to the ComponentPanel you will want to use another layout since FlowLayout is more adequate for menus and the like and not for displaying the main content.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTabbedPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
class LabelProblem
{
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
initGUI();
}
});
}
public static void initGUI()
{
JFrame frame = new JFrame("Label Problem");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel main = new JPanel();
main.setLayout(new BoxLayout(main, BoxLayout.Y_AXIS));
JPanel componentPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
JLabel label = new JLabel("Sample Text");
label.setBorder(BorderFactory.createLineBorder(Color.BLACK));
componentPanel.add(label);
JTabbedPane Tab = new JTabbedPane();
Tab.add("Document 1", new JPanel());
main.add(Tab);
main.add(componentPanel);
JTextArea area = new JTextArea(10, 10);
JScrollPane scroll = new JScrollPane(area);
frame.add(main);
frame.add(scroll, BorderLayout.SOUTH);
frame.setSize(450, 450);
frame.setVisible(true);
}
}
Result:
Note: I also changed the variable names to follow the java style convention: variable names should start with lower case to differenciate them from clases names, starting in upper case.
One simple approach is to set the label's horizontalAlignment to JLabel.RIGHT in the constructor.
import java.awt.*;
import javax.swing.*;
class LabelProblem {
public static void main(String[] args) {
JFrame frame = new JFrame("Label Problem");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridLayout(0, 1));
JTabbedPane tab = new JTabbedPane();
tab.add("Document 1", new JPanel());
frame.add(tab);
JLabel label = new JLabel("Sample Text", JLabel.RIGHT);
frame.add(label);
JTextArea area = new JTextArea(10, 10);
JScrollPane scroll = new JScrollPane(area);
frame.add(scroll);
frame.pack();
frame.setSize(450, 450);
frame.setVisible(true);
}
}
I think it may be a matter of you not actually setting layouts where you imagine you're setting layouts.
You have a JPanel with a vertically oriented BoxLayout (Main) enclosing another JPanel with default layout (ComponentPanel), finally enclosing your label. The reason why your label can't be pushed to the right is because is already is pushed to the right within it's enclosing container. If you set a colored border around ComponentPanel, you'll see what I mean -- it only occupies the same amount of space as the JLabel, giving the JLabel nowhere to move.
You need to set a layout and constraints for your intermediate ComponentPanel, allowing it to horizontally fill its parent container so that the label has someplace to go.
You haven't really specified how your layout is supposed to look, but if you change the layout on Main to X_AXIS, your label will pop over to the left (as will its parent container). Without knowing what you're really trying to do, I can't say much more.
I would however, suggest you throw your BoxLayout away entirely and look into using GridBagLayout, which gives you a high level control over your UI. GridBagLayout isn't the most concise construct, but that's the price of control.
I have this incredibly easy task of wanting a nice centered JPanel inside another JPanel. The parent is set to 900, 550, and the child should be approximately 200,400 or so.
To do this, I thought giving the parent a BorderLayout and then setting the setPreferredSize(200, 400) of the child. This child would be in the CENTER. Two empty JPanels would be on the EAST and WEST. Of course this did not work. Giving the two sidepanels a setPreferredSize() of course DID work. Problem with this is that narrowing the Frame causes the center pane to go away.
Here's some sample code that should give show the issue:
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Component;
import java.awt.Dimension;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Temporary {
public static Temporary myObj = null;
private JFrame mainFrame;
public void go(){
mainFrame = new JFrame("Swing");
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainFrame.setPreferredSize(new Dimension(900,550));
JPanel mainCards = new JPanel(new CardLayout());
mainCards.add(loginLayer(), "Login");
mainFrame.setContentPane(mainCards);
mainFrame.pack();
mainFrame.setLocationRelativeTo(null);
mainFrame.setVisible(true);
}
public JPanel loginLayer(){
JPanel masterPane = new JPanel(new BorderLayout());
JPanel centerPane = new JPanel();
centerPane.setLayout(new BoxLayout(centerPane, BoxLayout.Y_AXIS));
centerPane.setPreferredSize(new Dimension(100,200));
JLabel label = new JLabel("Swing is overly");
label.setAlignmentX(Component.CENTER_ALIGNMENT);
centerPane.add(label);
JButton button = new JButton("complicated");
button.setAlignmentX(Component.CENTER_ALIGNMENT);
centerPane.add(button);
JTextField textField = new JTextField(10);
centerPane.add(textField);
JPanel filler = new JPanel();
JPanel filler2 = new JPanel();
masterPane.add(filler, BorderLayout.WEST);
masterPane.add(centerPane, BorderLayout.CENTER);
masterPane.add(filler2, BorderLayout.EAST);
return masterPane;
}
public static void main(String[] args){
myObj = new Temporary();
myObj.go();
}
}
BorderLayout will, by it's nature, give as much of the available space as it can to the CENTER component. This is how it's designed.
If you want the component to be centered within the parent container, BUT maintain it's preferred size, you should consider using a GridBagLayout instead. Without any additional constraints, this should achieve the result you're after
For example...
public JPanel loginLayer(){
JPanel masterPane = new JPanel(new GridBagLayout);
JPanel centerPane = new JPanel();
centerPane.setLayout(new BoxLayout(centerPane, BoxLayout.Y_AXIS));
JLabel label = new JLabel("Swing is overly");
label.setAlignmentX(Component.CENTER_ALIGNMENT);
centerPane.add(label);
JButton button = new JButton("complicated");
button.setAlignmentX(Component.CENTER_ALIGNMENT);
centerPane.add(button);
JTextField textField = new JTextField(10);
centerPane.add(textField);
masterPane.add(centerPane);
// Add additional borders to providing padding around the center pane
// as you need
return masterPane;
}
I would also avoid actively setting the preferred size of component in this way, as it's possible that the components you're adding to it will exceed your expectations, instead, make use of things like EmptyBorder (for example) to add additional white space arouond the component and it's contents
In Java Swing, you generally want to avoid creating a bunch of statically positioned items with preferred sizes and absolute positions, because things get weird with resizing (as you've noticed). Instead you want to rely on the fluid LayoutManagers. There is an excellent tutorial here. Or, if you want to supply a mock-up of some sort to show the actual UI you are trying to create, I could provide some more feedback.
I have a JScrollPane (with both scrollbars optional (should not cause the problem)
Inside of the ScrollPane is a panel with BoxLayout and X_Axis - align. (it contains arbitrary number of Panels with fixed (prefference)Size.
The Problem is that the ScrollPane will be much wider than necessary (Horizontal Scrollbar scrolls through "grey screen").
With Y_Axis align it works as it should.
Relevant code:
final JPanel forSpecific = new JPanel();
final JScrollPane scrollSpecific = new JScrollPane(forSpecific,
ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,
ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
forSpecific.setLayout(new BoxLayout(forSpecific,BoxLayout.X_AXIS));
I have no idea whats the poblem and did not find any solution...
EDITED: sry it took some time. The original code was to complex to extract some sscce.. i wrote a test-class. This example works coorect.. but i dont know whats different.. package getdata;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class Sscce {
public static void gui(){
final JFrame rootframe = new JFrame("Time Series Mining");
final JPanel mainPanel = new JPanel(new BorderLayout());
rootframe.setSize(new Dimension(400,400));
rootframe.setContentPane(mainPanel);
mainPanel.setLayout(new BorderLayout());
JPanel center=new JPanel(new GridLayout(2,1));
JPanel forSpecific=new JPanel();
forSpecific.setLayout(new BoxLayout(forSpecific, BoxLayout.X_AXIS));
JPanel test1 = new JPanel();
test1.setPreferredSize(new Dimension(1000,1000));
forSpecific.add(test1);
test1.setBackground(Color.white);
final JScrollPane scrollSpecific = new JScrollPane(forSpecific);
center.add(scrollSpecific);
rootframe.add(center, BorderLayout.CENTER);
rootframe.setVisible(true);
}
}
//final JScrollPane scrollSpecific = new JScrollPane(forSpecific,
// ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,
// ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
final JScrollPane scrollSpecific = new JScrollPane(forSpecific);
Not the problem but the "scrollbar as needed" is the default. You don't need to specify this.
Inside of the ScrollPane is a panel with BoxLayout and X_Axis - align. (it contains arbitrary number of Panels with fixed (prefference)Size.
What is a fixed size?
the "main" panel added to the scrollpane
the "child" panels added to the main panel
In any case the size should not be fixed, the layout manager should determine the preferred size. Or if you are creating a custom component then you should override the getPreferredSize() method to return the proper size so the layout manager can do its job.