Why is my JPanel messing with other components on my JFrame? - java

So I have a JFrame which contains a JPanel that holds a JList component.
Then I have another JPanel for my paintComponent() which also returns a dimension.
But when I set the size for the dimension, it tries to relocate my other JPanel.
Here is my code for the paintComponent():
class drawOnPanel extends JPanel {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(Color.BLUE);
}
#Override
public Dimension getPreferredSize(){
return new Dimension(250, 250);
}
}
Then I have my JFrame which calls the drawOnPanel class:
public static void mainFrame() {
JFrame f = new MTGSAMPServerReference();
f.setTitle("MTG SAMP Server Reference Guide");
f.pack();
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new drawOnPanel());
f.setSize(330, 300);
f.setLocationRelativeTo(null);
}
And then I have my JList which is on my JPanel:
public void MainMenu() {
JPanel controls = new JPanel(new BorderLayout(5,5));
final CardLayout cl = new CardLayout();
final JPanel panel = new JPanel(cl);
controls.add(panel);
this.getContentPane().setLayout(new FlowLayout(FlowLayout.LEADING));
list = new JList<Object>(mainMenu);
list.setVisibleRowCount(7);
select = new JButton("Select");
exit = new JButton("Exit");
select.addActionListener(this);
exit.addActionListener(this);
controls.add(new JScrollPane(list));
JPanel basePanel = new JPanel(new GridLayout(0, 1));
basePanel.add(select);
basePanel.add(exit);
controls.add(basePanel, BorderLayout.PAGE_END);
add(controls);
refreshFrame();
}
When I try to draw on my paintComponent() JPanel, it draws, but the coordinates that I indicate are not correctly drawn.
Does anyone know why this is happening?
Thanks in advance!
EDIT: Here are some screenshots of my program.
This one is what my program looks like when I don't include drawOnPanel:
And this one is what my program looks like when I include drawOnPanel:
I just want it to draw on the right side of the JList, without moving the JList. As you can see, it adjusts the other JPanel.
Any and all help is appreciated!
EDIT: Here is my SSCCE.
EDIT: Here is my SSCCE code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public final class SSCCE1 extends JFrame implements ActionListener {
private static final long serialVersionUID = 1L;
JList list;
JButton select;
JButton exit;
Object[]mainMenu = {"Value 1", "Value 2", "Value 3", "Value 4"};
public SSCCE1() {
MainMenu();
}
public void MainMenu() {
JPanel controls = new JPanel(new BorderLayout(5,5));
final CardLayout cl = new CardLayout();
final JPanel panel = new JPanel(cl);
controls.add(panel);
this.getContentPane().setLayout(new FlowLayout(FlowLayout.LEADING));
list = new JList<Object>(mainMenu);
list.setVisibleRowCount(7);
select = new JButton("Select");
exit = new JButton("Exit");
controls.add(new JScrollPane(list));
JPanel basePanel = new JPanel(new GridLayout(0, 1));
basePanel.add(select);
basePanel.add(exit);
controls.add(basePanel, BorderLayout.PAGE_END);
add(controls);
revalidate();
repaint();
SSCCE1.this.repaint();
}
public void createAndShowGUI() {
mainFrame();
SSCCE1.this.repaint();
}
public static void mainFrame() {
JFrame f = new SSCCE1();
f.setTitle("My SSCCE");
f.pack();
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new drawOnPanel()); // When this is uncommented, it messes with the other JPanel, but when commented, it works fine, but does not allow drawing on the other JFrame.
f.setExtendedState(JFrame.MAXIMIZED_BOTH);
f.setLocationRelativeTo(null);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
SSCCE1 gui = new SSCCE1();
gui.createAndShowGUI();
}
});
}
#Override
public void actionPerformed(ActionEvent ae) {
}
}
class drawOnPanel extends JPanel {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(Color.BLUE);
}
#Override
public Dimension getPreferredSize(){
return new Dimension(250, 250);
}
}

Make setVisible() last, after a adding, packing and locating. Complete examples are seen here and here.
f.add(…);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
Addendum: Here's a variation on your example, without the invisible panel. Absent a compelling reason to extend JFrame, just create one and add your components.
import java.awt.*;
import javax.swing.*;
/** #see https://stackoverflow.com/a/18038765/230513 */
public class SSCCE2 {
private JList list;
private JButton select;
private JButton exit;
private Object[] mainMenu = {"Value 1", "Value 2", "Value 3", "Value 4"};
public JPanel mainMenu() {
JPanel controls = new JPanel(new BorderLayout(5, 5));
list = new JList(mainMenu);
list.setVisibleRowCount(7);
select = new JButton("Select");
exit = new JButton("Exit");
controls.add(new JScrollPane(list));
JPanel basePanel = new JPanel(new GridLayout(0, 1));
basePanel.add(select);
basePanel.add(exit);
controls.add(basePanel, BorderLayout.PAGE_END);
return controls;
}
public void createAndShowGUI() {
JFrame f = new JFrame("My SSCCE");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new DrawOnPanel());
f.add(mainMenu(), BorderLayout.WEST);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
SSCCE2 gui = new SSCCE2();
gui.createAndShowGUI();
}
});
}
private static class DrawOnPanel extends JPanel {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.BLUE);
g.fillRect(0, 0, getWidth(), getHeight());
}
#Override
public Dimension getPreferredSize() {
return new Dimension(250, 250);
}
}
}

Related

Java&Swing: why the componenet isn't added dynamically?

The following is my code.
I think click the button, at least, a Color.CYAN block will be added into MainPanel, but it doesn't.
Could you please tell me how to achieve that? Thanks.
public class TestFrame extends JFrame {
public static void main(String[] args) {
EventQueue.invokeLater(() -> {
final TestFrame mainFrame = new TestFrame();
mainFrame.setDefaultCloseOperation(EXIT_ON_CLOSE);
mainFrame.setVisible(true);
});
}
public TestFrame() throws HeadlessException {
setTitle("Frame");
setSize(new Dimension(1000, 800));
final JPanel mainPanel = new JPanel();
final JButton button = new JButton("Test");
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println(e.getActionCommand());
mainPanel.add(new Unit());
}
});
mainPanel.add(button);
mainPanel.revalidate();
add(mainPanel);
}
class Unit extends JComponent {
public Unit() {
setSize(new Dimension(100, 100));
setBackground(Color.CYAN);
}
#Override
protected void paintComponent(Graphics g) {
final Graphics2D g2D = (Graphics2D) g;
g2D.drawString("Hello World", 10, 10);
}
}
}
Your Unit JComponent is likely being added to mainPanel in the ActionListener and thus the GUI, but it has no preferred size and so per the FlowLayout used by JPanels, it will size to [0, 0]. FlowLayouts (and most layout managers) do not respect a component's size but rather its preferredSize. Also, revalidate() and repaint() need to be called on the container (mainPanel) after Unit has been added so that the layout managers can do their laying out of components and to allow the OS to clear dirty pixels.
To solve this, give it a preferred size, preferably by overriding public Dimension getPreferredSize() but by calling setPreferredSize(...) if you must, and by calling revalidate() and repaint() after adding the component to the container.
Better still, add the component to the container using a CardLayout tutorial, but hide it by also adding an empty JLabel, again using a CardLayout, and then display the hidden component by calling CardLayout.show(...) from within ActionListener.
Side note: don't forget the super method within your painting method:
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g); // add this ****
final Graphics2D g2D = (Graphics2D) g;
g2D.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
g2D.setFont(UNIT_FONT);
g2D.drawString("Hello World", textX, textY);
}
else you break the painting chain and may see unwanted artifacts or other problems
e.g.,
import java.awt.*;
import javax.swing.*;
#SuppressWarnings("serial")
public class TestFrame extends JFrame {
private CardLayout cardLayout = new CardLayout();
private JPanel cardPanel = new JPanel(cardLayout);
public static void main(String[] args) {
EventQueue.invokeLater(() -> {
final TestFrame mainFrame = new TestFrame();
mainFrame.setDefaultCloseOperation(EXIT_ON_CLOSE);
mainFrame.pack();
mainFrame.setLocationRelativeTo(null);
mainFrame.setVisible(true);
});
}
public TestFrame() throws HeadlessException {
setTitle("Frame");
setPreferredSize(new Dimension(1000, 800));
final JPanel mainPanel = new JPanel(new BorderLayout());
final JButton button = new JButton("Test");
button.addActionListener(e -> {
cardLayout.next(cardPanel);
});
JPanel btnPanel = new JPanel();
btnPanel.add(button);
mainPanel.add(btnPanel, BorderLayout.PAGE_END);
mainPanel.add(cardPanel);
add(mainPanel);
cardPanel.add(new JLabel(), "Foo");
cardPanel.add(new Unit(), Unit.class.getCanonicalName());
}
static class Unit extends JPanel {
private static final int PREF_W = 100;
private static final int PREF_H = 100;
private static final Font UNIT_FONT = new Font(Font.SANS_SERIF, Font.BOLD, 60);
public Unit() {
setBackground(Color.CYAN);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
final Graphics2D g2D = (Graphics2D) g;
g2D.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
g2D.setFont(UNIT_FONT);
g2D.drawString("Hello World", 360, 350);
}
}
}

Combinations of Classes

Hey everyone, I want to combine my classes and get it in
only one frame. Now I have 2 classes and I don't know how to group them.
The JSlider.
public class JSliderExample extends JFrame {
JSlider jsHorizontal;
JTextField jtf1;
public JSliderExample() {
jsHorizontal = new JSlider(JSlider.HORIZONTAL, 0, 100, 50);
jtf1 = new JTextField(15);
jtf1.setEditable(false);
jtf1.setText("Horizontal value is " + jsHorizontal.getValue());
JPanel panel = new JPanel();
panel.setBackground(Color.WHITE);
panel.add(jsHorizontal);
panel.setBackground(Color.WHITE);
panel.add(jtf1);
panel.setBackground(Color.WHITE);
getContentPane().add(panel, BorderLayout.CENTER);
getContentPane().add(panel, BorderLayout.SOUTH);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(300, 400, 400, 300);
setVisible(true);
setBackground(Color.WHITE);
}
class JSliderHandler implements ChangeListener {
public void stateChanged(ChangeEvent ce) {
jtf1.setText("value is " + jsHorizontal.getValue());
}
}
And there are my buttons
.
public void createGUI() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
panel.setLayout(new FlowLayout());
JButton button2 = new JButton("PLAY");
button2.setActionCommand("Button PLAY was pressed!");
panel.add(button2);
textField = new JTextField();
textField.setColumns(23);
panel.add(textField);
ActionListener actionListener = new TestActionListener();
button1.addActionListener(actionListener);
button2.addActionListener(actionListener);
button3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
textField.setText(e.getActionCommand());
}
});
getContentPane().add(panel);
setPreferredSize(new Dimension(320, 100));
}
public class TestActionListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
textField.setText(e.getActionCommand());
}
}
In the end of programm I see 2 frames that consist of 2 classes.
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
TestFrame frame = new TestFrame();
frame.pack();
JSliderExample frame1 = new JSliderExample();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
If you don't want to see 2 JFrames, then don't create 2 JFrames. Why not make JPanels with all your classes above and not JFrames, and then in your main method, add your JPanels to the JFrame created within main. Simple.
So for example, instead of having JSliderExample extend JFrame, change it's name to SliderPanel and have it extend JPanel, and likewise with your JButton program. Then your main method could look something like:
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
// your JSlider example class **that extends JPanel**
SliderPanel sliderPanel = new SliderPanel();
// your JButton example class **that extends JPanel**
ButtonPanel buttonPanel = new ButtonPanel():
JFrame frame = new JFrame("My GUI");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.add(sliderPanel, BorderLayout.PAGE_START);
frame.add(buttonPanel, BorderLayout.CENTER);
frame.pack();
frame.setLocationRelativeTo(null); // center GUI if you want
frame.setVisible(true);
}
});
}

Java JFrame Graphics dont show up

public class FrameTest extends JFrame {
private JPanel contentPane;
private JPanel spielPane;
private JPanel infoPane;
private JButton btnStart;
private JLabel lblRunde;
private Monster monster1;
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
FrameTest frame = new FrameTest();
frame.setVisible(true);
Monster m = new Monster();
frame.repaintSpielPanel();
}
catch (Exception e) {
e.printStackTrace();
}
}
});
}
public FrameTest() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 800, 600);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(null);
setContentPane(contentPane);
spielPane = new JPanel();
spielPane.setBounds(6, 6, 566, 566);
spielPane.setLayout(null);
spielPane.setBackground(Color.yellow);
contentPane.add(spielPane);
infoPane = new JPanel();
infoPane.setBounds(578, 6, 216, 566);
infoPane.setLayout(null);
infoPane.setBackground(Color.yellow);
contentPane.add(infoPane);
btnStart = new JButton("Start");
btnStart.setBounds(44, 6, 117, 29);
infoPane.add(btnStart);
lblRunde = new JLabel("Runde");
lblRunde.setBounds(77, 47, 61, 16);
infoPane.add(lblRunde);
monster1 = new Monster();
monster1.setVisible(true);
spielPane.add(monster1);
}
private class Monser extends JLabel {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.RED);
g.fillRect(0, 0, 10, 10);
}
}
public void repaintSpielPanel() {
spielPane.repaint();
}
}
I tried to put a Rectangle into my frame, but it isn't there. I'm just starting to program, so probably I just don't know how to get it onto the screen. Pls help!
Don't paint in a JLabel which isn't opaque. Instead do so in a JPanel.
Don't use null layouts and setBounds(...). While null layouts and setBounds() might seem to Swing newbies like the easiest and best way to create complex GUI's, the more Swing GUI'S you create the more serious difficulties you will run into when using them. They won't resize your components when the GUI resizes, they are a royal witch to enhance or maintain, they fail completely when placed in scrollpanes, they look gawd-awful when viewed on all platforms or screen resolutions that are different from the original one.
Most important, you never add an instance of your drawing component, here Monser, to anything. To see that this is true, search your code for any calls to new Monser(). If a constructor isn't being called, an instance isn't going to be created.
Also note that you're creating a Monster instance, and this is a class that you've not shown us.
You're adding it to a null layout using JPanel, and so since it has no size, it won't show at all. Again, don't use null layouts.
For example:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridLayout;
import javax.swing.*;
#SuppressWarnings("serial")
public class MyTest extends JPanel {
private static final Color BG = Color.yellow;
private static final int GAP = 8;
private JButton btnStart = new JButton("Start");
private JLabel lblRunde = new JLabel("Runde", SwingConstants.CENTER);
private MonsterPanel monsterPanel = new MonsterPanel(600, 600, BG);
public MyTest() {
JPanel buttonPanel = createButtonPanel();
buttonPanel.setBackground(BG);
setLayout(new BorderLayout(GAP, GAP));
setBorder(BorderFactory.createEmptyBorder(GAP, GAP, GAP, GAP));
add(monsterPanel, BorderLayout.CENTER);
add(buttonPanel, BorderLayout.LINE_END);
}
private JPanel createButtonPanel() {
JPanel btnPanel = new JPanel();
btnPanel.setBackground(BG);
JPanel gridPanel = new JPanel(new GridLayout(0, 1, 0, 5));
gridPanel.setOpaque(false);
gridPanel.add(btnStart);
gridPanel.add(lblRunde);
btnPanel.add(gridPanel);
return btnPanel;
}
private static void createAndShowGui() {
MyTest mainPanel = new MyTest();
JFrame frame = new JFrame("MyFrameTest");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
class MonsterPanel extends JPanel {
public static final int MONST_WIDTH = 10;
public static final Color MONST_COLOR = Color.red;
private int prefW;
private int prefH;
private int monstX = 0;
private int monstY = 0;
public MonsterPanel(int prefW, int prefH, Color bkgrnd) {
this.prefW = prefW;
this.prefH = prefH;
setBackground(bkgrnd);
}
public void setMonstXY(int x, int y) {
this.monstX = x;
this.monstY = y;
repaint();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(MONST_COLOR);
g.fillRect(monstX, monstY, MONST_WIDTH, MONST_WIDTH);
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(prefW, prefH);
}
}

How to draw a rectangle within a JPanel

I am attempting to draw a Rectangle within a JPanel that is within a JFrame. I am wanting to use the paintComponents(Graphics g) method and override it but for some reason the rectangle is not appearing within the JPanel as I would hope. Any help would be appreciated.
public class RectangleFrame extends JFrame implements ActionListener {
JPanel buttonPanel;
JButton saveImage;
JButton clearImage;
JCheckBox intersections;
JCheckBox union;
JPanel drawingArea;
public RectangleFrame()
{
super();
setTitle("Rectangles");
setSize(600,600);
setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
buttonPanel = new JPanel();
buttonPanel.setBorder(BorderFactory.createLineBorder(Color.black));
this.add(buttonPanel, BorderLayout.SOUTH);
intersections = new JCheckBox("Draw Intersections");
buttonPanel.add(intersections);
union = new JCheckBox("Draw Union");
buttonPanel.add(union);
saveImage = new JButton("Save Image");
saveImage.setMargin(new Insets(0,0,0,0));
buttonPanel.add(saveImage);
clearImage = new JButton("Clear Image");
clearImage.setMargin(new Insets(0,0,0,0));
buttonPanel.add(clearImage);
drawingArea = new JPanel();
drawingArea.setBorder(BorderFactory.createLineBorder(Color.blue));
this.add(drawingArea, BorderLayout.CENTER);
}
}
class RectanglePanel extends JPanel
{
public RectanglePanel()
{
super();
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.setColor(Color.BLUE);
g.fillRect(25,25,100,30);
}
}
Here is my main method that is in a separate class:
public class SwingRectangle
{
/**
* #param args
*/
public static void main(String[] args)
{
// TODO Auto-generated method stub
RectangleFrame frame = new RectangleFrame();
RectanglePanel panel = new RectanglePanel();
frame.setVisible(true);
}
}
You didnt add the RectanglePanel to your frame.
drawingArea = new JPanel();
should be
drawingArea = new RectanglePanel();
Other points:
You still need to override paintComponent rather than paintComponents as suggested by #David so +1 to him
The panel created in SwingRectangle is unused

JButton copied when repainting?

I have a JFrame with 2 JPanel in it: a PaintPanel (with a paint() method) and a ButtonPanel (with buttons). When I invoke the repaint() of the PaintPanel (but clicking the button) the button of the ButtonPanel is being painted in the PaintPanel! It isn't clickable or anything, it is just there.
I tried to recreate the problem with this code:
public class Main {
public static void main(String[] args) {
JFrame frame = new JFrame("frame");
frame.setSize(400,400);
frame.setLayout(new GridLayout(2,1));
PaintPanel paint = new PaintPanel();
ButtonPanel buttons = new ButtonPanel(paint);
frame.add(paint);
frame.add(buttons);
frame.setVisible(true);
}
}
public class PaintPanel extends JPanel{
public void paint(Graphics g){
g.drawRect(10, 10, 10, 10);
}
}
public class ButtonPanel extends JPanel implements ActionListener{
private PaintPanel paintPanel;
public ButtonPanel(PaintPanel paintPanel){
this.paintPanel=paintPanel;
JButton button = new JButton("button");
button.addActionListener(this);
add(button);
}
#Override
public void actionPerformed(ActionEvent arg0) {
paintPanel.repaint();
}
}
This sould recreate the problem I have (sorry for the odd code markings, can't seem to get it right).
I really hope one of you knows what is happening here because i don't...
First of all, you should override paintComponent() instead of paint(). It's part of the best practices in Swing when it comes to do some panel customization.
Secondly, here is the code that works for me (I don't know why yours doesn't though :S):
public class Main {
public static void main(String[] args) {
JFrame frame = new JFrame("frame");
frame.setSize(400, 400);
// frame.setLayout(new GridLayout(2, 1));
PaintPanel paint = new PaintPanel();
ButtonPanel buttons = new ButtonPanel(paint);
// frame.add(paint);
// frame.add(buttons);
frame.setVisible(true);
JPanel pan = new JPanel(new BorderLayout());
pan.add(paint);
pan.add(buttons, BorderLayout.SOUTH);
frame.add(pan);
}
}
class PaintPanel extends JPanel {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(new Color(new Random().nextInt()));
g.drawRect(10, 10, 10, 10);
}
}
class ButtonPanel extends JPanel implements ActionListener {
private final PaintPanel paintPanel;
public ButtonPanel(PaintPanel paintPanel) {
this.paintPanel = paintPanel;
JButton button = new JButton("button");
button.addActionListener(this);
add(button);
}
#Override
public void actionPerformed(ActionEvent arg0) {
if (getParent() != null) {
getParent().repaint();
}
}
}

Categories

Resources