May I know why my jPanel does not appear in the jFrame? I want to make 5 blue jPanel appear in the jFrame but why only 1 blue jPanel appear in my jFrame? Thanks for helping!
public class NewJFrame2 extends javax.swing.JFrame {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
/**
* Creates new form NewJFrame2
*/
public NewJFrame2() {
initComponents();
JPanel[] panelArray = new JPanel[5];
JButton btnArray[] = new JButton[5];
for(int i = 0; i<5;i++)
{
panelArray[i] = new JPanel();
//panelArray[i].setVisible(true);
System.out.println(panelArray[i]);
javax.swing.border.Border border = BorderFactory.createLineBorder(Color.BLUE, 5);
panelArray[i].setBackground(Color.YELLOW);
panelArray[i].setBorder(border);
frame.getContentPane().add(panelArray[i]);
}
frame.setSize(new Dimension(500, 400));
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("A Simple JFrame");
frame.setVisible(true);
}
As mentioned in the comments you want a LayoutManager.
The current issue is that you are adding all five panels to the exact same space on your frame. To solve this issue you need to provide a structure for the frame to associate different coordinates with different areas.
This answer contains a good jumping off point for you to start to play with layouts in Java.
Using a container JPanel with a BoxLayout -- see comments below for further info :
initComponents();
JPanel[] panelArray = new JPanel[5];
JButton btnArray[] = new JButton[5];
JPanel container = new JPanel(); // Container JPanel
container.setLayout(new BoxLayout(container, BoxLayout.X_AXIS)); // With a BoxLayout
for (int i = 0; i < 5; i++) {
panelArray[i] = new JPanel();
//panelArray[i].setVisible(true);
System.out.println(panelArray[i]);
javax.swing.border.Border border = BorderFactory.createLineBorder(Color.BLUE, 5);
panelArray[i].setBackground(Color.YELLOW);
panelArray[i].setBorder(border);
container.add(panelArray[i]); // Adding 5 JPanels to container JPanel
}
frame.getContentPane().add(container); // Adding container JPanel to JFrame
frame.setSize(new Dimension(500, 400));
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("A Simple JFrame");
frame.setVisible(true);
Related
I have a parent JPanel with child components which are stacked on another. However they do not resize as I'd like to:
This is how it should be
This is what I get
Code:
public class LayoutTest extends JFrame {
public LayoutTest() {
setVisible(true);
setSize(new Dimension(500, 500));
getContentPane().setLayout(new BoxLayout(getContentPane(), BoxLayout.PAGE_AXIS));
for (int i = 0; i < 2; i++) {
JPanel panel = new JPanel();
panel.setPreferredSize(new Dimension(500, 50));
panel.setBorder(BorderFactory.createLineBorder(Color.BLACK));
panel.setBackground(Color.red);
getContentPane().add(panel);
}
}
public static void main(String[] args) {
LayoutTest layoutTest = new LayoutTest();
}
}
The problem mainly is that the components resize vertically when they should not. I'd like them to keep their vertical dimension, but they won't. I've tried multiple layouts e.g. GridBagLayout, FlowLayout, BoxLayout, but none of them worked.
My best try has been with BoxLayout:
Simply: container.setLayout(new BoxLayout(container, BoxLayout.PAGE_AXIS);
and then container.add(component1)...
Any help is appreciated.
Working solution by camickr:
public class LayoutTest extends JFrame {
public LayoutTest() {
setVisible(true);
setSize(new Dimension(500, 500));
JPanel container = new JPanel();
container.setLayout(new BoxLayout(container, BoxLayout.PAGE_AXIS));
for (int i = 0; i < 2; i++) {
JPanel panel = new JPanel();
panel.setPreferredSize(new Dimension(500, 50));
panel.setBorder(BorderFactory.createLineBorder(Color.BLACK));
panel.setBackground(Color.red);
container.add(panel, BorderLayout.PAGE_START);
}
getContentPane().add(container, BorderLayout.NORTH);
}
public static void main(String[] args) {
LayoutTest layoutTest = new LayoutTest();
}
}
A BoxLayout will grow components up to there maximum size when space is available.
When you add your panel to the frame, instead of adding it to the CENTER, which would allow the panel to grow, you add it to the PAGE_START which will respect the height:
JPanel north = new JPanel();
north.setLayout( new BoxLayout(north, BoxLayout.PAGE_AXIS) );
// add loop to add panels to the "north" panel
add(north, BorderLayout.PAGE_START);
Another solution is to wrap the panel using a box layout into another panel.
JPanel panel = new JPanel();
panel.setLayout( new BoxLayout(panel. BoxLayout.PAGE_AXIS) );
// create your loop to add child panels
JPanel wrapper = new JPanel(); // uses FlowLayout by default which respects the preferred size.
wrapper.add( panel );
frame.add( wrapper );
public static void main(String[] args) {
JTextField text = new JTextField();
JFrame frame = new JFrame();
frame.setLayout(new BorderLayout());
JPanel panel = new JPanel();
panel.setLayout(new GridLayout(5, 4));
JPanel panel2 = new JPanel();
panel2.setLayout(new FlowLayout());
JLabel imgLabel1 = new JLabel(new ImageIcon("C:\\Users\\Arthur\\Downloads\\abs.jpg"));
JLabel imgLabel2 = new JLabel(new ImageIcon("C:\\Users\\Arthur\\Downloads\\abss.jpg"));
imgLabel1.setPreferredSize(new Dimension(100,100));
imgLabel2.setPreferredSize(new Dimension(100,100));
panel2.add(imgLabel1);
panel2.add(imgLabel2);
for(int i=0; i<20; i++){
panel.add(panel2);
}
frame.add(text, BorderLayout.NORTH);
frame.add(panel, BorderLayout.CENTER);
frame.setPreferredSize(new Dimension(1280,700));
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
I want to make a memory game, I need to put two images in each cell of the JPanel of 4x5. For this I created a JPanel 1x2 with two images inside and put it in the JPanel of 4x5. But the result is:
Result:
So, if understand correctly, you're problem is, you're not seeing 20 new panels, only one.
The problem is, a component can only reside in a single container, once, so doing something like...
for (int i = 0; i < 20; i++) {
panel.add(panel2);
}
is the equivalent of doing something like...
panel.add(panel2);
You actually need to create a new instance of the component on each iteration of the loop
What I would suggest you do is create a "wrapper" or "card" panel which can contain the two images. In my testing I just used coloured panels, but you get the idea...
public class WrapperPane extends JPanel {
public WrapperPane() {
setLayout(new FlowLayout());
add(makePanel(Color.RED));
add(makePanel(Color.GREEN));
// This is just for demonstration purposes
setBorder(new LineBorder(Color.DARK_GRAY));
}
protected JPanel makePanel(Color background) {
JPanel panel = new JPanel();
panel.setBackground(background);
panel.setPreferredSize(new Dimension(100, 100));
return panel;
}
}
The you'd just have to do something like...
JTextField text = new JTextField();
JFrame frame = new JFrame();
frame.setLayout(new BorderLayout());
JPanel panel = new JPanel();
panel.setLayout(new GridLayout(5, 4));
for (int i = 0; i < 20; i++) {
panel.add(new WrapperPane());
}
frame.add(text, BorderLayout.NORTH);
frame.add(panel, BorderLayout.CENTER);
// Don't do this, just let the content make it's own
// calculations
//frame.setPreferredSize(new Dimension(1280, 700));
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
And you'd end up with something like...
Hello im trying to create a grid in java and paint each cell but I dont kown what im doing wrong. Each cell is a JPanel and I add each cell to the to the mazePanel. After that the mazePanel is added to the frame. But only get the result shown in the next image:
public void printFrame() {
JFrame frame;
JPanel mazePanel = new JPanel();
frame = new JFrame("The Maze");
frame.setSize(600, 600);
mazePanel.setLayout(new GridLayout(2, 2));
mazePanel.setBackground(Color.cyan);
JPanel cell = new JPanel();
cell.setBackground(Color.gray);
mazePanel.add(cell);
cell.setBackground(Color.BLACK);
mazePanel.add(cell);
cell.setBackground(Color.red);
mazePanel.add(cell);
cell.setBackground(Color.GREEN);
mazePanel.add(cell);
frame.add(mazePanel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
A Component cannot be added to a Container more than once (eg cannot have multiple parents). In this case, what you see is the result of the last addition of the variable 'cell' to its parent mazePanel (green - together with the background color of mazePanel (cyan) due to the layout). If you wish to add multiple 'cells', then create new JPanel's with the appropriate background color and add them to the mazePanel
JFrame frame;
JPanel mazePanel = new JPanel();
frame = new JFrame("The Maze");
frame.setSize(600, 600);
mazePanel.setLayout(new GridLayout(2, 2));
mazePanel.setBackground(Color.cyan);
JPanel cell = new JPanel();
JPanel cell2 = new JPanel();
JPanel cell3 = new JPanel();
JPanel cell4 = new JPanel();
cell.setBackground(Color.gray);
mazePanel.add(cell);
cell2.setBackground(Color.BLACK);
mazePanel.add(cell2);
cell3.setBackground(Color.red);
mazePanel.add(cell3);
cell4.setBackground(Color.GREEN);
mazePanel.add(cell4);
frame.add(mazePanel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
You have to create separate cell objects like mentioned above. I believe this gives you what you are looking for.
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.
How can I switch Panels with ScrollPanes in a Frame? I've tried many possible ways but cannot come up with a solution to.
Actually this is one of the Java Problems my professor gave me and I needed to accomplish this by not using other layouts (such as CardLayout) and I should use the null layout only. Additional classes are allowed as long as I maintain these three classes and the scroll pane.
public class MainDriver {
public static void main(String[] args) {
JFrame frame = new JFrame("Frame");
panel1 p1 = new panel1();
panel2 p2 = new panel2();
JScrollPane jsp = new JScrollPane(panel1.panel);
Container c = frame.getContentPane();
jsp.getVerticalScrollBar().setUnitIncrement(10);
c.add(jsp);
//codes for panel switching from panel1 to panel2 vice versa
frame.setDefaultCloseOperation(JFrame.exit_ON_CLOSE);
frame.setSize(1058, 600);
frame.setLocation(100, 50);
frame.setVisible(true);
}
}
---------------------------------------------
public class panel1{
public JPanel panel(){
JPanel fore = new JPanel();
fore.setLayout(null);
fore.setPreferredSize(new Dimension (1024, 600));
fore.setBackground(Color.decode("#004050"));
fore.setVisible(true);
JButton but = new JButton();
but.setLocation(425, 300);
but.setSize(100, 35);
//button action/mouse listener
fore.add(but);
return fore;
}
}
---------------------------------------------
public class panel2{
public JPanel panel(){
JPanel fore = new JPanel();
fore.setLayout(null);
fore.setPreferredSize(new Dimension (1024, 600));
fore.setBackground(Color.decode("#004050"));
fore.setVisible(true);
JButton but = new JButton();
but.setLocation(425, 300);
but.setSize(100, 35);
//button action/mouse listener
fore.add(but);
return fore;
}
}
How can I switch Panels with ScrollPanes in a Frame?
scrollPane.setViewportView( anotherPanel );