I have a text editor with Netbeans where i load a text to a JtextPane. If text is too big u can read it with the help of an horizontal scroll.Is there any way to split the text into pages of 24 lines for example so that every page is visible without scrolling and use a next page button for changing page (like eBooks do)?
It is easier to use a JTextArea to do this because you can easily specify the number of lines to display each time you scroll to a new page.
The basic solution is to add a text area to a scroll pane than then hide the scrollbars. You can then use the defaults Actions of the vertical scrollbar to do the scrolling for you. The code below uses code from the Action Map Action blog entry to easily create an Action that you can add to a JButton:
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
public class TextAreaScroll extends JPanel
{
private JTextArea textArea;
public TextAreaScroll()
{
setLayout( new BorderLayout() );
textArea = new JTextArea(10, 80);
textArea.setEditable( false );
JScrollPane scrollPane = new JScrollPane( textArea );
scrollPane.setVerticalScrollBarPolicy( JScrollPane.VERTICAL_SCROLLBAR_NEVER );
add(scrollPane);
JButton load = new JButton("Load TextAreaScroll.java");
load.addActionListener( new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
try
{
FileReader reader = new FileReader( "TextAreaScroll.java" );
BufferedReader br = new BufferedReader(reader);
textArea.read( br, null );
br.close();
}
catch(Exception e2) { System.out.println(e2); }
}
});
add(load, BorderLayout.NORTH);
// Add buttons to do the scrolling
JScrollBar vertical = scrollPane.getVerticalScrollBar();
Action nextPage = new ActionMapAction("Next Page", vertical, "positiveBlockIncrement");
nextPage.putValue(AbstractAction.MNEMONIC_KEY, KeyEvent.VK_N);
JButton nextButton = new JButton(nextPage);
Action previousPage = new ActionMapAction("Previous Page", vertical, "negativeBlockIncrement");
previousPage.putValue(AbstractAction.MNEMONIC_KEY, KeyEvent.VK_N);
JButton previousButton = new JButton(previousPage);
JPanel south = new JPanel();
add(south, BorderLayout.SOUTH);
south.add( previousButton );
south.add( nextButton );
}
private static void createAndShowUI()
{
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TextAreaScroll());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
Related
i have problem with my JTextArea i java. When i print output in the text area, it doesn't automatically scroll to the bottom. And when it reaches the bottom of text area i cannot scroll it with scroll panel. Here is my GUI Code:
public void initializeWindow()
{
JPanel pan;
JPanel colorBox;
JPanel consolePanel;
JLabel panText;
JFrame frame = new JFrame();
JScrollPane scroll;
gridPanels = new JPanel[sizeX][sizeY];
boardPanel = new JPanel();
legend = new JPanel();
consolePanel = new JPanel();
consoleOutput = new JTextArea(25,20);
consoleOutput.setEditable(false);
consoleOutput.setPreferredSize(new Dimension( 200,300));
consoleOutput.setAutoscrolls(true);
scroll = new JScrollPane(this.consoleOutput, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
consolePanel.setBorder(BorderFactory.createLineBorder(Color.black));
consolePanel.add(consoleOutput);
consolePanel.add(scroll);
boardPanel.setBorder(BorderFactory.createEmptyBorder(30,30,10,30));
boardPanel.setLayout(new GridLayout(sizeX,sizeY));
legend.setBorder(BorderFactory.createEmptyBorder(30,30,10,30));
legend.setPreferredSize( new Dimension(300,boardPanel.getHeight()));
PrintStream printStream = new PrintStream(new CustomOutputStream(consoleOutput));
for (Organizm org: legendOrgs)
{
pan = new JPanel();
colorBox = new JPanel();
panText = new JLabel();
pan.setMaximumSize(new Dimension(100,70));
pan.setAlignmentX(Component.LEFT_ALIGNMENT);
pan.setLayout(new FlowLayout(FlowLayout.LEADING));
colorBox.setBackground(org.getOrgColor());
colorBox.setAlignmentX(Component.LEFT_ALIGNMENT);
colorBox.setPreferredSize(new Dimension(30,30));
colorBox.setMaximumSize(new Dimension(30,30));
panText.setPreferredSize(new Dimension(100,15));
panText.setText(" - " + org.getName());
panText.setAlignmentX(Component.RIGHT_ALIGNMENT);
pan.add(colorBox);
pan.add(panText);
legend.add(pan);
}
legend.add(consolePanel);
for(int i=0; i<sizeY; i++)
{
for(int j=0; j<sizeX; j++)
{
gridPanels[i][j] = new JPanel();
if(organizmy[i][j]!=null)
gridPanels[i][j].setBackground(organizmy[i][j].getOrgColor());
else gridPanels[i][j].setBackground(Color.white);
boardPanel.add(gridPanels[i][j]);
}
}
System.setOut(printStream);
System.setErr(printStream);
frame.add(boardPanel);
frame.add(legend,BorderLayout.EAST);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Wirtualny świat");
frame.pack();
frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.setVisible(true);
worldFrame = frame;
}
And here is my Custom output Stream class which is used to print everything i print via System.out.println to my text Area:
public class CustomOutputStream extends OutputStream
{
private final JTextArea textArea;
public CustomOutputStream(JTextArea textArea)
{
this.textArea = textArea;
}
#Override
public void write(int b)
{
textArea.append(String.valueOf((char)b));
textArea.setCaretPosition(textArea.getDocument().getLength());
}
}
Here is link to image what it looks like in GUI:
You need to remove this line from your code:
consoleOutput.setPreferredSize(new Dimension( 200,300));
Unfortunately, it prevents your JTextArea from being scrollable because you set static size to that element.
P.S. Stay away from Swing - there are better options in Java
It works for me.
import javax.swing.*;
public class Scrollin{
public static void main(String[] args){
JFrame frame = new JFrame("scrolling");
JTextArea area = new JTextArea(20, 20);
frame.add(new JScrollPane(area));
frame.setVisible(true);
frame.pack();
Timer t = new Timer( 150, evt->{
area.setCaretPosition( area.getDocument().getLength() );
area.append("word is born\n");
});
t.start();
}
}
As text is added, the window will scroll to the end provided the cursor is at the end of the document.
Maybe you can start with something as short as this to demonstrate your issue?
I am trying to set my JTextArea to take up the max horz length of the screen, so that the next thing, in this case a button, will start on a new line, but I have no clue how to do it. I have messed around by setting the size of the JTextArea to change from, say, 20 to 1000 but that does not do anything.
How can I get my textarea to take up the entire first row and then have the next item that I add to begin on the following row? Here is what I have so far...
MyFrame(){//constructor
super("Simple Calculator");
p = new JPanel();
grid = new GridLayout(4, 4, 3, 3);
p.setLayout(grid);
setSize(400, 500);
setResizable(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setUpTextScreen();
//create buttons
for(int i = 0; i < buttonValues.length; i++){
p.add(new JButton(buttonValues[i]));
}
add(p);
setVisible(true);
}
private void setUpTextScreen() {
textOnScreen = new JTextArea(7, 1000);
textOnScreen.setText("0");//default
textOnScreen.setEditable(false);
p.add(textOnScreen);
}
How can I get my textarea to take up the entire first row and then have the next item that I add to begin on the following row?
Break your layout up into logical pieces. Start with your main panel using a BorderLayout.
First I would use a JTextField for the calculator display, not a JTextArea. Then you can add the text field using: mainPanel.add(textField, BorderLayout.PAGE_START);
Then you create a JPanel using a GridLayout for the buttons. Then you add the buttons to the button panel and use: maonPanel.add(buttonPanel, BorderLayout.CENTER);
For example:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
public class CalculatorPanel extends JPanel
{
private JTextField display;
public CalculatorPanel()
{
Action numberAction = new AbstractAction()
{
#Override
public void actionPerformed(ActionEvent e)
{
// display.setCaretPosition( display.getDocument().getLength() );
display.replaceSelection(e.getActionCommand());
}
};
setLayout( new BorderLayout() );
display = new JTextField();
display.setEditable( false );
display.setHorizontalAlignment(JTextField.RIGHT);
add(display, BorderLayout.NORTH);
JPanel buttonPanel = new JPanel();
buttonPanel.setLayout( new GridLayout(0, 5) );
add(buttonPanel, BorderLayout.CENTER);
for (int i = 0; i < 10; i++)
{
String text = String.valueOf(i);
JButton button = new JButton( text );
button.addActionListener( numberAction );
button.setBorder( new LineBorder(Color.BLACK) );
button.setPreferredSize( new Dimension(30, 30) );
buttonPanel.add( button );
InputMap inputMap = button.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
inputMap.put(KeyStroke.getKeyStroke(text), text);
inputMap.put(KeyStroke.getKeyStroke("NUMPAD" + text), text);
button.getActionMap().put(text, numberAction);
}
}
private static void createAndShowUI()
{
JFrame frame = new JFrame("Calculator Panel");
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
frame.add( new CalculatorPanel() );
frame.pack();
frame.setLocationRelativeTo( null );
frame.setVisible(true);
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
Hava a look at Nested layouts, you can add one panel with a BorderLayout (there are other options too though) and add the textarea to it. Then you only need one more panel with a GridLayout that displays the buttons. This is an example: (Note that a few lines are unnecessary in this code, but they help understand layouts)
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.border.LineBorder;
public class Example extends JFrame {
Example() {//
super("Simple Calculator");
// The Main Panel where the 2 other panels will be on
JPanel mainPanel = new JPanel(new BorderLayout());
// The textarea will be inside this panel
JPanel areaPanel = new JPanel(new BorderLayout());
JTextArea area = new JTextArea(
"This is a JTextArea -Long text to show it works -Long text to show it works- -Long text to show it works- -Long text to show it works- -Long text to show it works- -Long text to show it works-");
area.setBorder(new LineBorder(Color.BLACK));
area.setWrapStyleWord(true);
area.setLineWrap(true);
// Fill the whole space of the panel with the area
areaPanel.add(area, BorderLayout.CENTER);
// The buttons will be inside this panel
JPanel buttonPanel = new JPanel(new GridLayout(4, 4, 3, 3));
for (int i = 0; i < 16; i++) { // Adding buttons
buttonPanel.add(new JButton("Button" + i));
}
// The textarea-panel should be on top of the main panel
mainPanel.add(areaPanel, BorderLayout.NORTH);
// The panel with the buttons should fill the remaining space
mainPanel.add(buttonPanel, BorderLayout.CENTER);
getContentPane().add(mainPanel);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(500, 500);
setVisible(true);
}
public static void main(String[] args) {
new Example();
}
}
You can also use html tags like:
JButton button = new JButton("<html><b><u>T</u>wo</b><br>lines</html>");
Or in any other JComponent like you got.
So you can use <BR> tag you achieve your need.
I want to create a Jtextarea in the first half of the below panel under tab2. I want to iterate and write the contents present in the test.txt file into this newly created Jtext area. The text.txt file is present in the location (C:\test.txt). Can someone suggest me how to achieve this for the below code.(Note: The below code is a JPane with three tabs tab1,tab2,tab3) and the tab 2 has been splited into two halves.)
I am new to the Jtextarea concept so it will be nice from understanding viewpoint if anyone can provide some suggestion code for my below code:
text.txt contents in my local disk is as below
username:test1
Password:test1
DataBasename: testDB
CODE:
import javax.swing.*;
import java.awt.*;
public class SplitPaneExp {
public static void main(String[] args){
Runnable r = new Runnable() {
public void run() {
JFrame frame = new JFrame("WELCOME");
// A better close operation..
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
JTabbedPane tab = new JTabbedPane();
frame.add(tab, BorderLayout.CENTER);
JButton button = new JButton("1");
tab.add("tab1", button);
// this GridLayout will create a single row of components,
// with equal space for each component
JPanel tab2Panel = new JPanel(new GridLayout(0,1));
button = new JButton("2");
tab2Panel.add(button);
tab2Panel.add(new JButton("Second window"));
// add the panel containing two buttons to the tab
tab.add("tab2", tab2Panel);
button = new JButton("3");
tab.add("tab3", button);
// a better sizing method..
//frame.setSize(400,400);
frame.pack();
frame.setVisible(true);
}
};
SwingUtilities.invokeLater(r);
}
}
import javax.swing.*;
import java.awt.*;
import java.io.*;
public class SplitPaneExp {
public static void main(String[] args) {
Runnable r = new Runnable() {
public void run() {
JFrame frame = new JFrame("WELCOME");
// A better close operation..
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
JTabbedPane tab = new JTabbedPane();
frame.add(tab, BorderLayout.CENTER);
JButton button = new JButton("1");
tab.add("tab1", button);
// this GridLayout will create a single row of components,
// with equal space for each component
JPanel tab2Panel = new JPanel(new GridLayout(0, 1));
// button = new JButton("2");
//Hi, I added a few things here!
String output = "";
try {
BufferedReader br = new BufferedReader(new FileReader(new File("C:\test.txt")));
String line = br.readLine();
while(line != null) {
if(output.length() > 0) {
output = output + "\n";
}
output = output + line;
line = br.readLine();
}
} catch (Exception e) {
e.printStackTrace();
}
JTextArea jta = new JTextArea(output);
tab2Panel.add(jta);
// Done.
// tab2Panel.add(button);
tab2Panel.add(new JButton("Second window"));
// add the panel containing two buttons to the tab
tab.add("tab2", tab2Panel);
button = new JButton("3");
tab.add("tab3", button);
// a better sizing method..
//frame.setSize(400,400);
frame.pack();
frame.setVisible(true);
}
};
SwingUtilities.invokeLater(r);
}
}
Hope it helps.
I want to create scrollpane like on this picture:
With arrows on component sides and with no scrollbar visible. Only horizontal scrolling is needed. Can It be done with JScrollPane?
You can make you own component by using a scrollpane and by creating your own buttons that will use the Actions of the scrollbar:
import java.awt.*;
import javax.swing.*;
import javax.swing.plaf.basic.*;
public class ScrollPaneSSCCE extends JPanel
{
public ScrollPaneSSCCE()
{
setLayout( new BorderLayout() );
JTextArea textArea = new JTextArea(1, 80);
textArea.setText("Hopefully this will answer your question");
JScrollPane scrollPane = new JScrollPane( textArea );
scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
add(scrollPane);
JScrollBar horizontal = scrollPane.getHorizontalScrollBar();
BasicArrowButton west = new BasicArrowButton(BasicArrowButton.WEST);
west.setAction( new ActionMapAction("", horizontal, "negativeUnitIncrement") );
add(west, BorderLayout.WEST);
BasicArrowButton east = new BasicArrowButton(BasicArrowButton.EAST);
east.setAction( new ActionMapAction("", horizontal, "positiveUnitIncrement") );
add(east, BorderLayout.EAST);
}
private static void createAndShowUI()
{
JFrame frame = new JFrame("ScrollPaneSSCCE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new ScrollPaneSSCCE(), BorderLayout.NORTH);
frame.setSize(100, 100);
frame.setLocationByPlatform( true );
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
You will also need to use the Action Map Action class.
I am working on a project for my college course. I was just wondering if anyone knew how to add a scrollBar to a JTextArea. At present I have the GUI laid out correctly, the only thing missing is the scroll bar.
This is what the GUI looks like. As you can see on the second TextArea I would like to add the Scrollbar.
This is my code where I create the pane. But nothing seems to happen... t2 is the JTextArea I want to add it to.
scroll = new JScrollPane(t2);
scroll.setBounds(10,60,780,500);
scroll.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
Any help would be great, thanks!
The Scroll Bar comes when your text goes beyond the bounds of your view area. Don't use Absolute Positioning, for such a small talk at hand, always prefer Layout Managers, do read the first para of the first link, to know the advantage of using a Layout Manager.
What you simply need to do is use this thingy :
JTextArea msgArea = new JTextArea(10, 10);
msgArea.setWrapStyleWord(true);
msgArea.setLineWrap(true);
JScrollPane msgScroller = new JScrollPane();
msgScroller.setBorder(
BorderFactory.createTitledBorder("Messages"));
msgScroller.setViewportView(msgArea);
panelObject.add(msgScroller);
Here is a small program for your understanding :
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class JTextAreaScroller
{
private JTextArea msgArea;
private JScrollPane msgScroller;
private JTextArea logArea;
private JScrollPane logScroller;
private JButton sendButton;
private JButton terminateButton;
private Timer timer;
private int counter = 0;
private String[] messages = {
"Hello there\n",
"How you doing ?\n",
"This is a very long text that might won't fit in a single line :-)\n",
"Okay just to occupy more space, it's another line.\n",
"Don't read too much of the messages, instead work on the solution.\n",
"Byee byee :-)\n",
"Cheers\n"
};
private ActionListener timerAction = new ActionListener()
{
#Override
public void actionPerformed(ActionEvent ae)
{
if (counter < messages.length)
msgArea.append(messages[counter++]);
else
counter = 0;
}
};
private void displayGUI()
{
JFrame frame = new JFrame("Chat Messenger Dummy");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel contentPane = new JPanel();
contentPane.setLayout(new BorderLayout(5, 5));
JPanel centerPanel = new JPanel();
centerPanel.setLayout(new GridLayout(0, 1, 5, 5));
logArea = new JTextArea(10, 10);
logArea.setWrapStyleWord(true);
logArea.setLineWrap(true);
logScroller = new JScrollPane();
logScroller.setBorder(
BorderFactory.createTitledBorder("Chat Log"));
logScroller.setViewportView(logArea);
msgArea = new JTextArea(10, 10);
msgArea.setWrapStyleWord(true);
msgArea.setLineWrap(true);
msgScroller = new JScrollPane();
msgScroller.setBorder(
BorderFactory.createTitledBorder("Messages"));
msgScroller.setViewportView(msgArea);
centerPanel.add(logScroller);
centerPanel.add(msgScroller);
JPanel bottomPanel = new JPanel();
terminateButton = new JButton("Terminate Session");
terminateButton.addActionListener(new ActionListener()
{
#Override
public void actionPerformed(ActionEvent ae)
{
if (timer.isRunning())
timer.stop();
else
timer.start();
}
});
sendButton = new JButton("Send");
bottomPanel.add(terminateButton);
bottomPanel.add(sendButton);
contentPane.add(centerPanel, BorderLayout.CENTER);
contentPane.add(bottomPanel, BorderLayout.PAGE_END);
frame.setContentPane(contentPane);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
timer = new Timer(1000, timerAction);
timer.start();
}
public static void main(String... args)
{
EventQueue.invokeLater(new Runnable()
{
#Override
public void run()
{
new JTextAreaScroller().displayGUI();
}
});
}
}
Here is the outcome of the same :
The scroll bar by default will only be shown when the content overfills the available viewable area
You can change this via the JScrollPane#setVerticalScrollBarPolicy method, passing it ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS