JEditorPane filling all available space in JScrollPane - java

I'm using a JEditorPane inside a JPanel which I've called my contentPane in the example below. The content pane is inside a JScrollPane. I would like the editor pane to fill as little space as possible (to just contain it's text) and the rest of the space available in the content pane be left empty to the bottom, and on either side. If the text gets too large, the editor pane will grow, and eventually the scroll pane will create scroll bars to browse through all of the content. However, instead of the editor pane only taking up its preferred size (which is the size of the text it contains) it fills up the entire content pane which fills the entire view port of the scroll pane. Here's some example code to demonstrate my problem:
import java.awt.BorderLayout;
import java.awt.Color;
import javax.swing.BoxLayout;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
#SuppressWarnings("serial")
public class ScrollPaneExample extends JFrame {
public static void main(String[] args) {
new ScrollPaneExample();
}
public ScrollPaneExample() {
super("ScrollPaneExample");
setSize(400, 400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new BorderLayout());
JEditorPane editorPane = new JEditorPane("text/plain", "");
editorPane.setBackground(Color.YELLOW);
for (int i = 0; i < 5; i++)
editorPane.setText(editorPane.getText() + "Hello World\n");
JPanel contentPane = new JPanel();
contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.Y_AXIS));
contentPane.setBackground(Color.BLUE);
contentPane.add(editorPane);
JScrollPane scrollPane = new JScrollPane(contentPane);
add(scrollPane, BorderLayout.CENTER);
setVisible(true);
}
}
When run, this is what the window looks like:
By the yellow background, we can see that the editor pane is taking up all the space. Here is a (Photoshopped) example of what I want the layout to look like:
The blue background represents the content pane, and the yellow represents the editor pane.
Edit: In my working program, there is more than just an editor pane in the contentPane. This is why I am using a BoxLayout instead of a FlowLayout for the contentPane; because the vertical page-flow layout is desired.

Just use a FlowLayout for the content pane. BorderLayout won't respect preferred size and will stretch the component to fit. See more about layout managers at Laying out Components Withing a Container
If you want to set an initial size for the editor pane, just like with any other component that is Scollable, you can override getPreferredScrollableViewportSize() to set the size for the scroll pane view (when the component is added)
Also you should be adding the editor to the scroll pane, not the panel. Doing the latter, the editor will not be scrollable in the scroll pane.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
#SuppressWarnings("serial")
public class ScrollPaneDemo extends JFrame {
public static void main(String[] args) {
new ScrollPaneDemo();
}
public ScrollPaneDemo() {
super("ScrollPaneExample");
setSize(400, 400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new FlowLayout());
JEditorPane editorPane = new JEditorPane("text/plain", "") {
#Override
public Dimension getPreferredScrollableViewportSize() {
return new Dimension(200, 200);
}
};
editorPane.setBackground(Color.YELLOW);
for (int i = 0; i < 50; i++) {
editorPane.setText(editorPane.getText()
+ "Hello World Hello World\n");
}
JScrollPane scrollPane = new JScrollPane(editorPane);
add(scrollPane);
setVisible(true);
}
}
UPDATE
In my working program, there is more than just an editor pane in the contentPane. This is why I am using a BoxLayout instead of a FlowLayout for the contentPane; because the vertical page-flow layout is desired.
The BoxLayout is the problem. You need to set a maximum size for the editor pane. Or just get rid of the BoxLayout all together. FlowLayout or GridBagLayout will respect the preferred size
UPDATE 2
Here is an example using GridBagLayout that may more suitable for your "expanding" editor.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.Timer;
#SuppressWarnings("serial")
public class ScrollPaneExample extends JFrame {
public static void main(String[] args) {
new ScrollPaneExample();
}
public ScrollPaneExample() {
super("ScrollPaneExample");
setSize(400, 400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new BorderLayout());
//getContentPane().setBackground(Color.BLUE);
final JEditorPane editorPane = new JEditorPane("text/plain", "") {
};
editorPane.setBackground(Color.YELLOW);
for (int i = 0; i < 5; i++)
editorPane.setText(editorPane.getText() + "Hello World\n");
JPanel contentPane = new JPanel();
contentPane.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.weighty = 1;
contentPane.setBackground(Color.BLUE);
contentPane.add(editorPane, gbc);
gbc.gridy++;
contentPane.add(new JButton("Button"), gbc);
gbc.gridy++;
contentPane.add(new JButton("Button"), gbc);
JPanel panel = new JPanel();
panel.add(contentPane);
JScrollPane scrollPane = new JScrollPane(panel);
add(scrollPane);
setVisible(true);
Timer timer = new Timer(1000, new ActionListener(){
public void actionPerformed(ActionEvent e) {
editorPane.setText(editorPane.getText() + "Hello World\n");
setVisible(true);
}
});
timer.start();
}
}

Related

Prevent JPanel within JScrollPane from growing horizontally

I have a JPanel with FlowLayout that I'm dynamically filling with identical components (JButtons in the MWE). The JPanel is inside a JScrollPane. As I add components, I'd like them to fill left to right, kicking down to the next row once the top row would become wider than the JScrollPane.
My problem is that FlowLayout is instead widening the JPanel ad nauseum, to which the JScrollPane responds by adding a horizontal scroll. How do I prevent this?
Edit: I've seen WrapLayout; I was hoping for a solution within standard Java since I'm using NetBeans GUI Builder for my application.
MWE based on this answer:
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JPanel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.*;
import javax.swing.JScrollPane;
public class MWE extends JFrame implements ActionListener {
JPanel panel;
JScrollPane pane;
public MWE() {
super("Add component on JFrame at runtime");
setLayout(new BorderLayout());
this.panel = new JPanel();
this.pane = new JScrollPane();
this.panel.setLayout(new FlowLayout(FlowLayout.LEFT));
this.pane.setViewportView(this.panel);
add(pane, BorderLayout.CENTER);
JButton button = new JButton("CLICK HERE");
add(button, BorderLayout.SOUTH);
button.addActionListener(this);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(500, 500);
setVisible(true);
}
public void actionPerformed(ActionEvent evt) {
this.panel.add(new JButton("Button"));
this.panel.revalidate();
validate();
}
public static void main(String[] args) {
MWE mwe = new MWE();
}
}
Try setting a preferred size for the panel :
this.panel.setPreferredSize(new Dimension(500, 500));

BorderLayout doesn't honor maximumsize

I have a problem using BorderLayout, but first of all, here is my GUI setup:
As you can see, I have 3 different components inside my JFrame. Adding the JMenu and JList works fine. But my JPanel should have a fixed size so I want to prevent my BorderLayout from stretching the panel. I tried everything, setPreferredSize() setMinimumSize() setMaximumSize() setSize() but again the layout stretches my panel to fit to the frame. (The panel is added to the frame using BorderLayout.CENTER).
Is there any way to prevent this or do you have other suggestions to manage the problem?
I'm pretty sure you mean BorderLayout, not BoxLayout, because there is no BoxLayout.CENTER and it looks like you use a BorderLayout to place the components.
I think the problem here is that you only set the preferred size of the panel that you add to BorderLayout.CENTER. This doesn't have any effect. Instead you need nested layouts.
In this example I added the JPanel called centerPanel, which is using a standard GridBagLayout (to center the added component), to BorderLayout.CENTER. Then I added the additional JPanel called panel, which has a custom preferrdSize, to centerPanel. This way panel won't get stretched.
Code:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.DefaultListModel;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JPanel;
public class Example {
public Example() {
JMenuBar menuBar = new JMenuBar();
menuBar.setBorder(BorderFactory.createMatteBorder(0, 0, 1, 0, Color.BLACK));
DefaultListModel<String> listModel = new DefaultListModel<String>();
JList<String> list = new JList<String>(listModel);
list.setBorder(BorderFactory.createMatteBorder(0, 0, 0, 1, Color.BLACK));
JPanel panel = new JPanel() {
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
// Uncomment the following lines if you also want to prevent the
// 'wrapping' of the panel.
/*
* #Override public Dimension getMinimumSize() { return new
* Dimension(400, 400); }
*/
};
panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
panel.setBorder(BorderFactory.createLineBorder(Color.BLUE));
for (int i = 1; i <= 5; i++) {
menuBar.add(new JMenu("Menu " + i));
listModel.addElement("Element " + i);
panel.add(new JLabel("Label " + i));
}
JPanel centerPanel = new JPanel(new GridBagLayout());
centerPanel.add(panel);
JPanel contentPanel = new JPanel(new BorderLayout());
contentPanel.add(menuBar, BorderLayout.NORTH);
contentPanel.add(list, BorderLayout.WEST);
contentPanel.add(centerPanel);
JFrame frame = new JFrame();
frame.setContentPane(contentPanel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(800, 600);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new Example();
}
});
}
}
Add your existing JPanel to a JPanel having Flowlayout, the default, or having GridBagLayout with default constraints. Add this panel to the frame's center, BorderLayout.CENTER by default.
Panel centerPane = new Panel(new GridBagLayout())`;
centerPane.add(yourJPanel);
frame.add(centerPane, BorderLayout.CENTER);
Also consider using Box, rather than a JPanel having BoxLayout.
Also consider using the frame's setJMenuBar(), rather than add(BorderLayout.PAGE_START).

JScrollPane for a JPanel inside a JPanel

After reading this answer, I came to using getPreferredSize instead of setPreferredSize. But I still can't use the #Override getPreferredSize, but that's not the main problem I'm facing right now.
I have a CardLayout application which calls a class called HiraganaData
HiraganaData is a class which extends a JPanel so it can be used by the CardLayout, but it also has 2 more JPanels on it, one for a "back" button and one for the rest of buttons, before using this idea I was using a JTable, but faced problems on making cells as buttons, so I dropped the idea and came with this new one using GridLayout. Some of the buttons will be disabled, anyway I can do that and won't include that code since it's not relevant.
So my actual question or problem is:
How can I add a JScrollPane only to buttonsPanel, did my best
trying to add it even to the whole "global" pane w/o success.
This is the most aproximate GUI I can do with the same code of my class I just added a JFrame to it.
Not sure if relevant, but I'm using a CardLayout with different sizes, in the way #MadProgrammer suggested on this answer.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.*;
import javax.swing.table.TableCellRenderer;
import javax.swing.DefaultCellEditor;
import java.awt.Dimension;
public class HiraganaPage extends JPanel {
JFrame frame = new JFrame("Hello");
JButton kanas[][] = new JButton[26][5];
JButton backButton = new JButton("back");
JPanel backPanel = new JPanel();
JPanel buttonsPanel = new JPanel();
public static void main(String args[]) {
new HiraganaPage();
}
public HiraganaPage() {
JPanel pane = new JPanel();
backPanel.add(backButton);
buttonsPanel.setLayout(new GridLayout(0, 5));
pane.setLayout(new BoxLayout(pane, BoxLayout.Y_AXIS));
pane.add(backPanel);
//pane.setPreferredSize(new Dimension(500, 500));
for (int i = 0; i < 26; i++) {
for (int j = 0; j < 5; j++) {
kanas[i][j] = new JButton("1");
buttonsPanel.add(kanas[i][j]);
}
}
JScrollPane scroll = new JScrollPane(buttonsPanel);
pane.add(buttonsPanel);
this.add(pane, BorderLayout.CENTER);
frame.add(this);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocation(50, 50);
frame.setSize(300, 300);
}
}
This is how it looks like in my complete application
And this is how it looks like in the MCVE.
The main problem you've facing is the fact that you removing the buttonsPane from the scroll pane when you add it to the pane...
JScrollPane scroll = new JScrollPane(buttonsPanel);
pane.add(buttonsPanel);
this.add(pane, BorderLayout.CENTER);
And the fact that you never actually add the scroll pane to anything doesn't help either.
A component may only have a single parent, so when you add buttonsPane to pane, it is effectively removed from the scroll pane
Instead, set the layout manager of the HiraganaPage to BorderLayout, add the buttonsPanel to the scroll pane and add the scroll pane to the CENTER position of the HiraganaPage then add the pane to the NORTH position of the HiraganaPage
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridLayout;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TestScrollPane {
public static void main(String[] args) {
new TestScrollPane();
}
public TestScrollPane() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new HiraganaPage());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class HiraganaPage extends JPanel {
JFrame frame = new JFrame("Hello");
JButton kanas[][] = new JButton[26][5];
JButton backButton = new JButton("back");
JPanel backPanel = new JPanel();
JPanel buttonsPanel = new JPanel();
public HiraganaPage() {
setLayout(new BorderLayout());
JPanel pane = new JPanel();
backPanel.add(backButton);
buttonsPanel.setLayout(new GridLayout(0, 5));
pane.setLayout(new BoxLayout(pane, BoxLayout.Y_AXIS));
pane.add(backPanel);
// pane.setPreferredSize(new Dimension(500, 500));
for (int i = 0; i < 26; i++) {
for (int j = 0; j < 5; j++) {
kanas[i][j] = new JButton("1");
buttonsPanel.add(kanas[i][j]);
}
}
add(pane, BorderLayout.NORTH);
add(new JScrollPane(buttonsPanel));
}
#Override
public Dimension getPreferredSize() {
return new Dimension(500, 500);
}
}
}

How to create vertical TitledBorder in JPanel (javax swing)

I'm trying to figure out how to create a vertical TitledBorder in a JPanel.
I've got this situation:
I'd like to have "Actuators st..." placed vertically, so user can read it.
Is there a way to do it, or should I implement my own customized JPanel & TitledBorder?
maybe crazy idea but is possible with JSeparator too :-)
required proper LayoutManager, maybe GridBagLayout (JComponent placed without GBC can take PreferrredSize from JComponent, but isn't resiziable), not GridLayout
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSeparator;
import javax.swing.SwingUtilities;
public class NestedLayout {
private JFrame frame = new JFrame();
private JPanel leftPanel = new JPanel();
private JSeparator sep = new JSeparator();
private JLabel label = new JLabel("<html> L<br>a<br>b<br>e<br>l<br></html>");
public NestedLayout() {
label.setOpaque(true);
sep.setOrientation(JSeparator.VERTICAL);
sep.setLayout(new GridLayout(3, 1));
sep.add(new JLabel());
sep.add(label);
sep.add(new JLabel());
leftPanel.setLayout(new BorderLayout());
leftPanel.setBorder(BorderFactory.createEmptyBorder(
10, //top
10, //left
10, //bottom
10)); //right
leftPanel.add(sep, BorderLayout.CENTER);
leftPanel.setPreferredSize(new Dimension(40, 220));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(leftPanel, BorderLayout.WEST);
//frame.add(label);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
NestedLayout nestedLayout = new NestedLayout();
}
});
}
}
As shown in How to Use Borders, you can create a compound border using an empty border and a titled border.
Addendum: As an alternative, you can use the border's getMinimumSize() method to ensure that the title is visible. See also this related Q&A.
f.add(createPanel("Actuator status"), BorderLayout.WEST);
f.add(createPanel("Indicator result"), BorderLayout.EAST);
...
private Box createPanel(String s) {
Box box = new Box(BoxLayout.Y_AXIS);
TitledBorder title = BorderFactory.createTitledBorder(null, s,
TitledBorder.CENTER, TitledBorder.DEFAULT_POSITION);
box.setBorder(title);
for (int i = 0; i < 6; i++) {
JButton b = new JButton(null, UIManager.getIcon("html.pendingImage"));
b.setAlignmentX(JButton.CENTER_ALIGNMENT);
box.add(b);
}
box.validate();
Dimension db = box.getPreferredSize();
int max = Math.max(title.getMinimumSize(box).width, db.width);
box.setPreferredSize(new Dimension(max, db.height));
return box;
}

How to make JTextArea Stick to the window

Hello I would like to make this TextArea stick to the windows size whene I resize it by mouse, the same way as lower buttons does. This is the code it is perfectly working no bugs, please have a glance at it.
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.LayoutManager;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class Rozklady extends JFrame {
public Rozklady() {
super();
}
public void createGUI(){
setPreferredSize(new Dimension(400,150));
JPanel jp = new JPanel();
// jp.setLayout(new BoxLayout(jp, BoxLayout.Y_AXIS));
jp.setLayout(new GridLayout(0,1));
JPanel gora = new JPanel();
JPanel dol = new JPanel();
pack();
JTextArea jt1 = new JTextArea("JF1");
gora.add(jt1);
jt1.setPreferredSize(new Dimension(getWidth(),getHeight()/2));
dol.setLayout(new BorderLayout());
JPanel lewo = new JPanel();
JPanel prawo = new JPanel();
JPanel srodek = new JPanel();
dol.add(lewo, BorderLayout.EAST);
dol.add(prawo,BorderLayout.WEST);
dol.add(srodek, BorderLayout.CENTER);
lewo.setLayout(new GridLayout(2,2));
prawo.setLayout(new GridLayout(2,2));
srodek.setLayout(new GridLayout(0,1));
for(int i = 0; i < 4; i++){
lewo.add(new JButton(i+""));
prawo.add(new JButton(i+""));
if(i < 3){
srodek.add(new JTextField("JF"+i));
}
}
jp.add(gora);
jp.add(dol);
add(jp);
setVisible(true);
pack();
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new Rozklady().createGUI();
}
});
}
}
Use BorderLayout for you gora panel. Put text area to the center:
gora.setLayout(new BorderLayout());
gora.add(jt1, BorderLayout.CENTER);
// declare a GridLayout in constructor, one component will 'fill the container'
JPanel gora = new JPanel(new GridLayout());
JPanel dol = new JPanel();
// this should be called after all components are added! BNI
pack();
JTextArea jt1 = new JTextArea("JF1");
// be sure to use a scroll pane for multi-line text components
gora.add(new JScrollPane(jt1));
// ..
Stretching a single component to fill the available space can be achieved various was. Two common ways are using either BorderLayout as mentioned by AlexR or GridLayout. See this answer for sample code. I prefer GridLayout because it is shorter (less typing). ;)

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