package Rainbow;
import javax.swing.*;
import java.awt.*;
public class Entry
{
public static void main(String[] Q)
{
JFrame R = new JFrame();
JPanel P = new JPanel()
{
public Dimension getMaximumSize()
{ return new Dimension(Integer.MAX_VALUE,getMinimumSize().height); }
};
P.setLayout(new BoxLayout(P,BoxLayout.Y_AXIS));
JTextArea A = new JTextArea(
"VERYLONGLONGLONGLONGLONGLONGLONGLONGLONGLONGLONGLONGLONGLONGLONGLONGLONGLONGLONGLONG");
A.setEditable(false);
A.setLineWrap(true);
P.add(new Label("Text"));
P.add(A);
JScrollPane S = new JScrollPane(P);
R.add(S);
R.setSize(300,300);
R.setLocationRelativeTo(null);
R.setVisible(true);
}
}
It is how it looks on startup.
StartUp
After reducing the Frame's size.
Reduce
The JTextArea inside would not reduce its size.
I'm using JTextArea here because it seems to be the easiest way to do line wrap on a component. So how to solve it? Or is there an alternate way to do the same thing?
You need to resize TextArrea too. Here are some related examples for your question: Java JTextArea that auto-resizes and scrolls.
Example described where JPanel is used and how we can do it:
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout()); //give your JPanel a BorderLayout
JTextArea text = new JTextArea();
JScrollPane scroll = new JScrollPane(text); //place the JTextArea in a scroll pane
panel.add(scroll, BorderLayout.CENTER); //add the JScrollPane to the panel
// CENTER will use up all available space
Related
I want to add JPanel containers to a JScrollPane and add this scroll pane to a JFrame. But when I add multiple panels to the scroll pane this happens. The gap between the scroll pane and the top bar increases. I use BoxLayout as layout manager for all the components that I use.
Here is my take on laying out this GUI. Some notes:
Rather than use a BoxLayout in the JScrollPane it puts a GridLayout in the PAGE_START of a BorderLayout. This is fine for when it's OK to stretch the elements in the scroll pane to the full width of the GUI. Stick to a BoxLayout (which I rarely use) or a GridBagLayout if it's necessary to keep the elements at their preferred size.
This strategy of layout is basically 'divide and conquer' in that it starts with the smallest sub-divisions of the GUI (e.g. the FlowLayout for the buttons) and then adds those containers to larger containers with different layouts and constraints (e.g. adding that button panel to the LINE_END of a BorderLayout - to push I to the right of the GUI) as needed for the overall effect.
I'd also consider using a JList (using a panel for the renderer) in the scroll pane. It depends on the use as to whether that makes sense.
Note that this code is an MRE. An MRE should have everything that's needed (including imports, a class structure and the main method) for another person to compile and run the code.
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.ActionEvent;
// ref: https://stackoverflow.com/a/70934802/418556
public class ScrollPaneTestGUI {
int elementCount = 1;
JPanel elementsPanel = new JPanel(new GridLayout(0,1,2,2));
public ScrollPaneTestGUI() {
initGUI();
}
private void initGUI() {
// this will become the content pane of the frame
JPanel gui = new JPanel(new BorderLayout(4,4));
gui.setBorder(new EmptyBorder(4,4,4,4));
JPanel pageStartPanel = new JPanel(new BorderLayout(2,2));
gui.add(pageStartPanel, BorderLayout.PAGE_START);
pageStartPanel.add(new JLabel("LINE START label"), BorderLayout.LINE_START);
// default flow layout is good for this one
JPanel buttonPanel = new JPanel();
pageStartPanel.add(buttonPanel, BorderLayout.LINE_END);
buttonPanel.add(new JButton("Does Nothing"));
Action addToScrollAction = new AbstractAction("Add to scrollPane") {
#Override
public void actionPerformed(ActionEvent e) {
elementsPanel.add(getPanelForScroll());
elementsPanel.revalidate();
}
};
JButton addToScrollButton = new JButton(addToScrollAction);
buttonPanel.add(addToScrollButton);
JPanel scrollPanel = new JPanel(new BorderLayout());
scrollPanel.add(elementsPanel, BorderLayout.PAGE_START);
gui.add(new JScrollPane(scrollPanel,
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
JScrollPane.HORIZONTAL_SCROLLBAR_NEVER)
);
for (int ii=0; ii<2; ii++) {
elementsPanel.add(getPanelForScroll());
}
JFrame frame = new JFrame("ScrollPane GUI");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setContentPane(gui);
frame.pack(); // sets the GUI to the exact size needed
frame.setMinimumSize(frame.getSize());
frame.setVisible(true);
}
private JPanel getPanelForScroll() {
JPanel p = new JPanel();
p.add(new JLabel("Panel " + elementCount++));
p.setBorder(new EmptyBorder(10,200,10,200));
p.setBackground(Color.GREEN);
return p;
}
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
new ScrollPaneTestGUI();
}
};
SwingUtilities.invokeLater(r);
}
}
I am creating a GUI using GridLayout to arrange multiple panels that are using FlowLayout. I am using pack to determine the size of the frame. If I have only a TextArea then it sizes correctly. If I have only other components it sizes correctly. But if I use both p1 and p2 in the code below the panel with the buttons does not size properly. The test code I am using is below. If I use only p1 or p2 it sizes properly, but not with both: Here is the image I am getting. I don't want all that extra space between the buttons and the textarea.
If I do textarea alone it sizes properly.:
public class GUIPractice extends JFrame
{
//declare GUI objects
JPanel panel;
JPanel p1, p2;
JButton btnAdd, btnShow;
JScrollPane js;
JTextArea taOutput;
//constructor
public GUIPractice()
{
//give frame a title
setTitle("GUI Practice");
panel =new JPanel(new GridLayout(0, 1));
btnAdd = new JButton("Add");
btnShow = new JButton("Show");
taOutput = new JTextArea(10, 20);
js = new JScrollPane(taOutput, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED,
JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
p1 = new JPanel();
p1.add(btnAdd);
p1.add(btnShow);
p2 = new JPanel();
p2.add(js);
panel.add(p1);
panel.add(p2);
//add the panel to the frame
add(panel);
}
public static void main(String[] args)
{
GUIPractice frame = new GUIPractice();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
}
It sizes correctly. The GridLayout means that all cells will be the same size. Since the text area is bigger than the buttons, you see extra space in the panel containing the buttons.
I would suggest you just use the default BorderLayout of the frame.
There is no need for your "panel" using the GridLayout.
You just use:
add(p1, BorderLayout.PAGE_START);
add(p2, BorderLayout.CENTER);
Now the p1 and p2 will be the proper height.
Also, there really is no need for "p2". You can just add the scroll pane directly to the frame.
I need to add about 600 Images to a Scrollpane, but all the Images are arranged side-by-side
public CollectionPanel(Controller controller)
this.setBackground(Color.white);
this.setLayout(new BorderLayout());
JPanel content = new JPanel();
content.setLayout(new FlowLayout());
JScrollPane scrollPane = new JScrollPane(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
for(int i = 0; i < 100; ++i){
content.add(new Sticker(i+1));
}
scrollPane.setViewportView(content);
this.add(scrollPane, BorderLayout.CENTER);
}
How is it possible to arrange them to make a "linebreak" when they reached the end of the screen?
Have a look at Rob Camick's WrapLayout.
You can resize the frame, and all your components will be reformatted for you. Here's an example usage
import java.awt.*;
import javax.swing.*;
public class TestWrapLayout {
public TestWrapLayout () {
ImageIcon icon = new ImageIcon(getClass().getResource("/resources/stackoverflow2.png"));
JPanel panel = new JPanel(new WrapLayout());
for (int i = 1; i <= 250; i++) {
JLabel iconlabel = new JLabel(icon);
iconlabel.setLayout(new BorderLayout());
JLabel textlabel = new JLabel(String.valueOf(i));
textlabel.setHorizontalAlignment(JLabel.CENTER);
textlabel.setForeground(Color.WHITE);
textlabel.setFont(new Font("impact", Font.PLAIN,20));
iconlabel.add(textlabel);
panel.add(iconlabel);
}
JFrame frame = new JFrame();
frame.add(new JScrollPane(panel));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300, 300);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable(){
public void run() {
new TestWrapLayout();
}
});
}
}
Use GridLayout instead of FlowLayout that fits the components side by side.
JPanel content = new JPanel();
content.setLayout(new GridLayout(rows,1));
//pass no of rows with just one column
You can try with BoxLayout as well.
JPanel content = new JPanel();
content.setLayout(new BoxLayout(content, BoxLayout.PAGE_AXIS));
Please have a look at Using Layout Managers & A Visual Guide to Layout Managers for more info with working sample codes.
Myself, I would try to keep things as simple as possible by putting images, ImageIcons actually, into a JList which can handle ImageIcons quite well. Give it a horizontal wrap set its visible row count to 0, plop it into a JScrollPane, and there you go.
I'm trying to draw a gui like shown in the figure, but somehow I'm not able to place the objects in right place (I guess that the problem is with the layout) the textArea is suppose to go in the middle... but is not showing at all
package Chapter22Collections;
import javax.swing.*;
import java.awt.*;
public class Exercise226 extends JFrame {
private JButton jbSort;
private JButton jbReverse;
private JButton jbAdd;
private JButton jbShuffle;
private JLabel jlAddnum;
private JTextArea jTextDisplay;
private JTextField jTextAdd;
public Exercise226() {
jbSort = new JButton("Sort");
jbReverse = new JButton("Reverse");
jbShuffle = new JButton("Shuffle");
jbAdd = new JButton("Add");
jlAddnum = new JLabel("Add number here: ");
jTextDisplay = new JTextArea();
jTextAdd = new JTextField(8);
setLayout(new BorderLayout());
JPanel p1 = new JPanel(new GridLayout(1,3));
p1.add(jlAddnum);
p1.add(jTextAdd);
p1.add(jbAdd);
JPanel p2 = new JPanel(new GridLayout(1,3));
p2.add(jbSort);
p2.add(jbReverse);
p2.add(jbShuffle);
add(p1, BorderLayout.NORTH);
add(jTextDisplay, BorderLayout.CENTER);
add(p2, BorderLayout.SOUTH);
}
public static void main(String... args) {
Exercise226 gui = new Exercise226();
gui.setTitle("Numbers");
gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
gui.setSize(300, 200);
gui.setLocationRelativeTo(null);
gui.setVisible(true);
}
}
The JTextArea is actually where you expect it to be but has no outline border. It is usual to place the component in a JScrollPane which will give this effect:
add(new JScrollPane(jTextDisplay), BorderLayout.CENTER);
or simply
add(new JScrollPane(jTextDisplay));
To make the textArea re-size with the window, try BoxLayout. Box is "A lightweight container that uses a BoxLayout object as its layout manager."
Box p1 = new Box(BoxLayout.X_AXIS);
How could I add spacing/padding between the elements in the frame? So the text area is more visible and centered.
Borders and padding. E.G.
Compared with:
import javax.swing.*;
import java.awt.*;
import javax.swing.border.EmptyBorder;
import javax.swing.border.TitledBorder;
public class Exercise226 {
private JButton jbSort;
private JButton jbReverse;
private JButton jbAdd;
private JButton jbShuffle;
private JLabel jlAddnum;
private JTextArea jTextDisplay;
private JTextField jTextAdd;
private JPanel gui;
public Exercise226() {
gui = new JPanel(new BorderLayout(5,5));
jbSort = new JButton("Sort");
jbReverse = new JButton("Reverse");
jbShuffle = new JButton("Shuffle");
jbAdd = new JButton("Add");
jlAddnum = new JLabel("Add number here: ");
// set the size constraints using columns/rows
jTextDisplay = new JTextArea("Here I am!", 6,20);
jTextAdd = new JTextField(8);
JPanel p1 = new JPanel(new GridLayout(1,3,3,3));
p1.add(jlAddnum);
p1.add(jTextAdd);
p1.add(jbAdd);
JPanel p2 = new JPanel(new GridLayout(1,3,3,3));
p2.add(jbSort);
p2.add(jbReverse);
p2.add(jbShuffle);
JPanel textAreaContainer = new JPanel(new GridLayout());
textAreaContainer.add(new JScrollPane(jTextDisplay));
textAreaContainer.setBorder(new TitledBorder("Text Area Here"));
gui.add(p1, BorderLayout.PAGE_START);
gui.add(textAreaContainer, BorderLayout.CENTER);
gui.add(p2, BorderLayout.PAGE_END);
gui.setBorder(new EmptyBorder(4,4,4,4));
}
public Container getGui() {
return gui;
}
public static void main(String... args) {
JFrame f = new JFrame();
Exercise226 gui = new Exercise226();
f.setContentPane(gui.getGui());
f.setTitle("Numbers");
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.pack();
f.setLocationByPlatform(true);
f.setVisible(true);
}
}
This code:
Primarily provides 'white space' in the GUI using different constructors for the layouts that accept 2 int arguments for horizontal & vertical spacing.
Also adds 2 borders:
An empty border around the entire GUI to provide some spacing between it and the frame decorations.
A titled border around the text area, to make it very obvious.
Does implement a change for one unnecessary part of the original code. Instead of extending frame, it simply retains an instance of one.
Uses the JScrollPane container for the text area, as suggested by #Reimeus. It adds a nice beveled border of its own to an element that needs no scroll bars.
Creates a textAreaContainer specifically so that we can set a titled border to surround the scroll pane - without interfering with its existing border. It is possible to use a CompoundBorder for the scroll pane that consists of the existing border (scroll.getBorder()) & the titled border. However that gets complicated with buttons & other elements that might change borders on selection or action. So to set an 'outermost border' for a screen element (like the text area here) - I generally prefer to wrap the entire component in another container first.
Does not create and show the GUI on the EDT. Swing GUIs should be created and modified on the EDT. Left as an exercise for the user. See Concurrency in Swing for more details.
Old Code
The original code on this answer that provides the 'comparison GUI image' seen above. IT is closely based on the original code but with the text area wrapped in a scroll pane (and gaining a beveled border because of that) & given some text to display.
import javax.swing.*;
import java.awt.*;
public class Exercise226 extends JFrame {
private JButton jbSort;
private JButton jbReverse;
private JButton jbAdd;
private JButton jbShuffle;
private JLabel jlAddnum;
private JTextArea jTextDisplay;
private JTextField jTextAdd;
public Exercise226() {
jbSort = new JButton("Sort");
jbReverse = new JButton("Reverse");
jbShuffle = new JButton("Shuffle");
jbAdd = new JButton("Add");
jlAddnum = new JLabel("Add number here: ");
// set the size constraints using columns/rows
jTextDisplay = new JTextArea("Here I am!", 6,20);
jTextAdd = new JTextField(8);
setLayout(new BorderLayout());
JPanel p1 = new JPanel(new GridLayout(1,3));
p1.add(jlAddnum);
p1.add(jTextAdd);
p1.add(jbAdd);
JPanel p2 = new JPanel(new GridLayout(1,3));
p2.add(jbSort);
p2.add(jbReverse);
p2.add(jbShuffle);
add(p1, BorderLayout.NORTH);
add(new JScrollPane(jTextDisplay), BorderLayout.CENTER);
add(p2, BorderLayout.SOUTH);
}
public static void main(String... args) {
Exercise226 gui = new Exercise226();
gui.setTitle("Numbers");
gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//gui.setSize(300, 200);
gui.pack();
//gui.setLocationRelativeTo(null);
gui.setLocationByPlatform(true);
gui.setVisible(true);
}
}
I would like the following lay out...
JButtons on top along side eachother.
The JTextArea should be under the buttons.
The JTextArea should also have a scrollbar.
...for the code below.
JPanel jp = new JPanel();
One = new JButton("One");
Two = new JButton("Two");
TestOutput = new JTextArea();
jp.add(One);
jp.add(Two);
jp.add(TestOutput);
Use a nested layout: To a JPanel having BorderLayout,
add a JPanel having FlowLayout for the buttons to the NORTH
and a JScrollPane for the JTextArea to the CENTER.
The keyword is layering - having JPanel on JPanel.
Use a GridBagLayout
See this for more help : How to Use GridBagLayout
Now note that the JTextarea to have a scrollbar have nothing to do with layouts.
See this for more help in that context : How to Use Scroll Panes
The FlowLayout in a JPanel for the JButton instances is one way to go. You might also use a JToolBar for the buttons.
import java.awt.*;
import javax.swing.*;
class ButtonsAndTextAreaLayout {
ButtonsAndTextAreaLayout() {
JPanel gui = new JPanel(new BorderLayout(5,5));
// use a toolbar for the buttons
JToolBar tools = new JToolBar();
// use firstWordLowerCase for attribute/method names.
JButton one = new JButton("One");
JButton two = new JButton("Two");
tools.add(one);
tools.add(two);
// provide hints as to how large the text area should be
JTextArea testOutput = new JTextArea(5,20);
gui.add(tools, BorderLayout.NORTH);
gui.add(new JScrollPane(testOutput), BorderLayout.CENTER);
JOptionPane.showMessageDialog(null, gui);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new ButtonsAndTextAreaLayout();
}
});
}
}
You can either use a GridBagLayout as suggested, or nest multiple layout managers such as:
JFrame frame = new JFrame();
frame.setLayout(new BorderLayout());
JPanel buttonPanel = new JPanel();
JButton oneButton = new JButton("One");
JButton twoButton = new JButton("Two");
buttonPanel.add(oneButton);
buttonPanel.add(twoButton);
JTextArea output = new JTextArea();
JScrollPane scrollPane = new JScrollPane(output);
frame.add(buttonPanel, BorderLayout.NORTH);
frame.add(scrollPane);
frame.pack();
frame.setVisible(true);