How to start something on a new line in Java SWING? - java

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.

Related

Adding a JLabel to a JFrame that is using BoxLayout

I am creating a JFrame that contains a JPanel with a grid of buttons. Everything works fine but I then want to add a JLabel above the panel of buttons but the label never appears. It does appear if I don't use BoxLayout, though. Any help is appreciated.
The first code part below is my JFrame class:
import java.awt.Dimension;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class Frame extends JFrame {
private static final long serialVersionUID = 1L;
Panel panel = new Panel();
Dimension frameDim = new Dimension(1000, 1000);
Dimension labelDim = new Dimension(100, 20);
Box box = new Box(BoxLayout.Y_AXIS);
JLabel label = new JLabel("Tic Tac Toe");
JPanel pane = new JPanel();
public Frame() {
pane.add(label);
pane.setPreferredSize(labelDim);
pane.setMinimumSize(labelDim);
add(pane);
box.add(Box.createVerticalGlue());
box.add(panel);
box.add(Box.createVerticalGlue());
add(box);
setTitle("Tic Tac Toe");
setSize(frameDim);
setMinimumSize(frameDim);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setVisible(true);
}
}
The code below is my JPanel class with buttons:
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JPanel;
public class Panel extends JPanel {
private static final long serialVersionUID = 2L;
private int i;
JButton[] button = new JButton[9];
GridLayout layout = new GridLayout(3, 3);
Dimension dim = new Dimension(500, 500);
public Panel() {
for (i = 0; i<9; i++) {
button[i] = new JButton();
add(button[i]);
}
setPreferredSize(dim);
setMinimumSize(dim);
setMaximumSize(dim);
setLayout(layout);
}
}
The last code part below is the Main class:
public class RunGame {
public static void main(String[] args) {
new Frame();
}
}
add(box);
This is adding the label direct to the JFrame, the content pane of which is laid out using a BorderLayout. The default when adding to a component to a border layout without any constraint is the CENTER, which can only display a single component. To fix it use:
pane.add(box);
you can use the BorderLayout when adding your label into Pane into the Frame and remove that box thing as below
public Frame()
{
//create label and add it to the frame
JLabel label = new JLabel("Tic Tac Toe");
label.setHorizontalAlignment( JLabel.CENTER );
add(label, BorderLayout.NORTH);
//create buttonsPanel and add it to the frame
JPanel buttons = new JPanel();
buttons.setLayout( new GridLayout(3, 3));
for (int i = 0; i < 9; i++)
{
buttons.add(new JButton(""+i));
}
add(buttons, BorderLayout.CENTER);
//setup the title, other properties for the frame etc..
setTitle("Tic Tac Toe");
setSize(1000, 1000);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setVisible(true);
}
hope this helps better :)

PictureCount does not change

the code is used to create an application which shows picture and if your anwser is correct your supposed to see the next picture but the pictureCount does not go up. all of the variables ar declared after the main class and i created an Actionlistener to check if the awnser is correct.
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Main {
public static void main(String[] args) {new Main().test();}
public int pictureCount = 1;
JFrame frame = new JFrame();
JButton button1 = new JButton("Submit");
JTextField text = new JTextField();
JPanel panel1 = new JPanel();
JPanel panel2 = new JPanel();
JPanel panel3 = new JPanel();
JLabel label = new JLabel(new ImageIcon("C:\\Users\\Admin\\Desktop\\practicum 3\\" + pictureCount + ".jpg"));
void test(){
button1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
if(text.getText().equals("5")){
pictureCount++;
new Main().test();
}
}
});
panel1.add(button1);
panel2.add(text);
panel3.add(label);
text.setPreferredSize(new Dimension(100,50));
panel1.setPreferredSize(new Dimension(1000, 200));
panel2.setPreferredSize(new Dimension(1000, 100));
panel3.setPreferredSize(new Dimension(1000, 450));
frame.getContentPane().add(BorderLayout.SOUTH, panel1);
frame.getContentPane().add(BorderLayout.CENTER, panel2);
frame.getContentPane().add(BorderLayout.NORTH, panel3);
frame.setSize(1000,750);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Operation Screen");
frame.setLocationRelativeTo(null);
}
}
You need to read in all the pictures as ImageIcons into an array or ArrayList, say called imageIconArray and then display imageIconArray[0] in your JLabel when you start.
When the button is pressed, increment pictureCount, and then reset the JLabel's icon via its setIcon(...) method:
// in the ActionListener code:
pictureCount++;
label.setIcon(imageIconArray[pictureCount];
Whatever you do, don't create a new Main object, despite what others might say. Why create a new GUI when all you need to do is swap displayed images?

Keep BoxLayout From Expanding Children

I want to stack some JComponents vertically inside a JPanel so they stack at the top and any extra space is at the bottom. I'm using a BoxLayout. The components will each contain a JTextArea that should allow the text to wrap if necessary. So, basically, I want the height of each of these components to be the minimum necessary for displaying the (possibly wrapped) text.
Here's a contained code example of what I'm doing:
import javax.swing.*;
import java.awt.*;
public class TextAreaTester {
public static void main(String[] args){
new TextAreaTester();
}
public TextAreaTester(){
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.setLayout(new BoxLayout(panel,BoxLayout.PAGE_AXIS));
panel.setPreferredSize(new Dimension(100,400));
for(int i = 0; i<3; i++){
JPanel item = new JPanel(new BorderLayout());
JTextArea textarea = new JTextArea("this is a line of text I want to wrap if necessary");
textarea.setWrapStyleWord(true);
textarea.setLineWrap(true);
textarea.setMaximumSize( textarea.getPreferredSize() );
item.add(textarea,BorderLayout.NORTH);
panel.add(item);
}
panel.add(Box.createGlue());
frame.add(panel);
frame.setVisible(true);
frame.pack();
}
}
The child JPanels are expanding to fill the vertical space. I tried using glue because I thought that's what glue was for, but it seems to do nothing at all. Any help?
Note: I have found questions that look almost identical, but none with answers I can apply.
One solution: nest JPanels with the outer JPanel using Borderlayout and adding the BoxLayout using JPanel to this one BorderLayout.NORTH, also known as BorderLayout.PAGE_START:
Edit for Kleopatra:
import javax.swing.*;
import java.awt.*;
public class TextAreaTester {
public static void main(String[] args) {
new TextAreaTester();
}
public TextAreaTester() {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS));
// panel.setPreferredSize(new Dimension(100,400));
for (int i = 0; i < 3; i++) {
JPanel item = new JPanel(new BorderLayout());
// item.setLayout(new BoxLayout(item,BoxLayout.LINE_AXIS));
JTextArea textarea = new JTextArea(
"this is a line of text I want to wrap if necessary", 3, 35);
textarea.setWrapStyleWord(true);
textarea.setLineWrap(true);
// textarea.setMaximumSize(textarea.getPreferredSize());
// item.setMaximumSize( item.getPreferredSize() );
item.add(new JScrollPane(textarea), BorderLayout.NORTH);
panel.add(item);
}
panel.add(Box.createGlue());
JPanel mainPanel = new JPanel(new BorderLayout()) {
private final int prefW = 100;
private final int prefH = 400;
#Override
public Dimension getPreferredSize() {
return new Dimension(prefW, prefH);
}
};
// mainPanel.setPreferredSize(new Dimension(100, 400));
mainPanel.add(panel, BorderLayout.PAGE_START);
frame.add(mainPanel);
frame.setVisible(true);
// frame.getContentPane().add(jp);
frame.pack();
}
}
Alternatively, you can use Box.Filler. Just replace your call to panel.add(Box.createGlue()) with
panel.add(new Box.Filler(new Dimension(0, 0),
new Dimension(0, Short.MAX_VALUE),
new Dimension(0, Short.MAX_VALUE)));
If you want to achieve the same for a horizontal layout, just use Short.MAX_VALUE for width instead of height in the Dimension call.

Make a JtextPane looks like eBook

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();
}
});
}
}

Make JTextPane adjust height to content

I'm trying to get a JTextPane to adjust its height according to whatever content I feed it. All I can do is to set a fixed height in pixels using Dimension.
How do I make the JTextPane collapse/expand so it will fit to contents?
I might add that I use this in a GridBagLayout'ed JPanel that has been added to a JScrollPane.
I don't know any direct way to do it, but this may give you some ideas:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
public class TextPanePerfectSize extends JFrame
{
JTextField textField;
JTextPane textPane;
public TextPanePerfectSize()
{
textField = new JTextField(20);
textField.setText("add text");
getContentPane().add(textField, BorderLayout.NORTH );
textField.addActionListener( new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
try
{
Document doc = textPane.getDocument();
doc.insertString(doc.getLength(), " " + textField.getText(), null);
textField.setText("");
Dimension d = textPane.getPreferredSize();
Rectangle r = textPane.modelToView( textPane.getDocument().getLength() );
d.height = r.y + r.height;
textPane.setPreferredSize( d );
getContentPane().validate();
// pack();
}
catch(Exception e2) {}
}
});
JLabel label = new JLabel("Hit Enter to Add Text to Text Pane");
getContentPane().add(label);
JPanel south = new JPanel();
textPane = new JTextPane();
textPane.setText("Some text");
textPane.setEditable( false );
textPane.setPreferredSize( new Dimension(120, 23) );
south.add( textPane );
getContentPane().add(south, BorderLayout.SOUTH);
}
public static void main(String[] args)
{
JFrame frame = new TextPanePerfectSize();
frame.setSize(200, 200);
frame.setLocationRelativeTo( null );
frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
JTextPane tp = new JTextPane();
setLayout(new BorderLayout()); // set layout on parent
add(tp, BorderLayout.CENTER);
This works for me.

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