I am in the early stages of trying to create a Java 2d graphics paint program. I'm using a flow layout, and I'm using three panels. The first two are rows of buttons, combo boxes, etc. and the third is meant to be a large, blank, white panel that will be used to paint on. The first two panels show up beautifully, but the paint panel appears as a small white box next to the second button panel. Any help would be appreciated.
public class DrawingApp extends JFrame
{
private final topButtonPanel topPanel = new topButtonPanel();
private final bottomButtonPanel bottomPanel = new bottomButtonPanel();
private final PaintPanel paintPanel = new PaintPanel();
public DrawingApp()
{
super("Java 2D Drawings");
setLayout(new FlowLayout());
add(topPanel);
add(bottomPanel);
add(paintPanel);
}
public static void main(String[] args)
{
DrawingApp frame = new DrawingApp();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(750,500);
frame.setVisible(true);
}
}
public class topButtonPanel extends JPanel
{
private final String[] names = {"Line", "Oval", "Rectangle"};
private final JButton undo = new JButton("Undo");
private final JButton clear = new JButton("Clear");
private final JLabel shape = new JLabel("Shape:");
private final JComboBox<String> shapesComboBox = new JComboBox(names);
private final JCheckBox filled = new JCheckBox("Filled");
public topButtonPanel()
{
super();
setLayout(new FlowLayout());
add(undo);
add(clear);
add(shape);
shapesComboBox.setMaximumRowCount(3);
add(shapesComboBox);
add(filled);
}
}
public class bottomButtonPanel extends JPanel
{
private final JCheckBox useGradient = new JCheckBox("Use Gradient");
private final JButton firstColor = new JButton("1st Color");
private final JButton secondColor = new JButton("2nd Color");
private final JLabel lineWidthLabel = new JLabel("Line Width:");
private final JLabel dashLengthLabel = new JLabel("Dash Length:");
private final JTextField lineWidthField = new JTextField(2);
private final JTextField dashLengthField = new JTextField(2);
private final JCheckBox filled = new JCheckBox("Dashed");
public bottomButtonPanel()
{
super();
setLayout(new FlowLayout());
add(useGradient);
add(firstColor);
add(secondColor);
add(lineWidthLabel);
add(lineWidthField);
add(dashLengthLabel);
add(dashLengthField);
add(filled);
}
}
public class PaintPanel extends JPanel
{
public PaintPanel()
{
super();
setBackground(Color.WHITE);
setSize(700,400);
}
}
Basically, it's a misunderstanding of how the Swing API works.
Swing relies (heavily) on the layout management API which is used to make decisions about how large components should be (and where they should be placed)
Using setSize is pointless, as the layout manager will make it's own decisions about what it thinks the size of your component should be and will adjust it accordingly.
You can make suggestions to the layout manager about how large you'd like the component to be using getPreferred/Minimum/MaximumSize, for example
public class PaintPanel extends JPanel
{
public PaintPanel()
{
super();
setBackground(Color.WHITE);
}
public Dimension getPreferredSize() {
return new Dimension(700, 400);
}
}
Just remember, layout managers are well within their right to ignore these values, so you need to have a better understanding of how these managers work
See Laying Out Components Within a Container for more details
Related
I am new to swing and am wondering why my login panel isn't appearing in the frame. I believe it should show on the left side of the frame, is this correct? What needs to be changed to make the panel appear. Thanks.
Here is the GUIFrame code
public class GUIFrame extends JFrame {
private static final long serialVersionUID = 1L;
public GUIFrame(){
Container container = getContentPane();
Toolkit toolkit = Toolkit.getDefaultToolkit();
Dimension screenDimension = toolkit.getScreenSize();
setSize(screenDimension.width/2, screenDimension.height/2);
setLocation(screenDimension.width/4,screenDimension.height/4);
setLayout(new GridLayout(1,2));
add(new Login(this));
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
}
Here is the panels code:
public class Login extends JPanel {
private JPanel panel = new JPanel();
private JButton cancel = new JButton("Cancel");
private JButton submit = new JButton("Submit");
private JLabel username_label = new JLabel("Username :");
private JLabel password_label = new JLabel("Password :");
private JTextField username_text = new JTextField();
private JPasswordField password_text = new JPasswordField();
private GUIFrame frame;
public Login(GUIFrame frame){
this.frame = frame;
setLayout(new GridLayout(3,2,20,40));
addComponents();
}
public void addComponents(){
panel.add(username_label);
panel.add(username_text);
panel.add(password_label);
panel.add(password_text);
panel.add(cancel);
panel.add(submit);
}
}
Here is the main method which displays the frame:
public class Project {
public static void main(String[] args){
Project project = new Project();
}
public Project() {
//Login login = new Login();
GUIFrame frame = new GUIFrame();
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
frame.setVisible(true);
}
});
}
}
panel.add(username_label);
panel.add(username_text);
panel.add(password_label);
panel.add(password_text);
panel.add(cancel);
panel.add(submit);
You create a separate JPanel and add the component to this panel, but you never add the panel to your Login panel.
Your Login panel already is a JPanel, so there is no need to create another JPanel.
The code should just be:
add(username_label);
add(username_text);
add(password_label);
add(password_text);
add(cancel);
add(submit);
There is also no reason to pass the JFrame as a parameter to your Login class.
Also, you are using the invokeLater() incorrectly. All Swing components should be created on the Event Dispatch Thread (EDT). So you should also include the new GuiFrame() inside the invokeLater().
Generally there is no need to have a separate JFrame class. The logic in your Project class should simply create an instance of the frame and add the Login panel to the frame. In other words don't extend JFrame.
I'm trying to add a small tornado graphic (upside down pyramid) to my Frame. I can get the tornado by adding it to the frame in the main method but when I do that all I see is the tornado graphic and not the GUI underneath it.
So, I'm now trying to add the Tornado graphic to the frame when its created in the createComponents method but it now doesn't appear at all. Instead all I can see it the GUI in the frame.
I' probably missing something easy but I can't seem to figure it out. I'm not sure what I need to to in order to get the GUI and the tornado graphic both to appear.
public class EFScaleViewer {
public static void main(String[] args) {
// TODO Auto-generated method stub
TornadoFrame frame = new TornadoFrame();
frame.setTitle("EF Scale");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
Here is where I create the frame and am trying to add the tornado:
public class TornadoFrame extends JFrame{
private JButton submit;
private JLabel label;
static JLabel errorLabel;
static JTextField textBox;
JPanel tornado = new TornadoComponent();
private static final int FRAME_WIDTH = 400;
private static final int FRAME_HEIGHT = 300;
//Constructor for the frame
public TornadoFrame() {
super();
setSize(FRAME_WIDTH, FRAME_HEIGHT);
createComponents();
}
private void createComponents()
{
textBox = new JTextField(" ");
submit = new JButton("Submit");
label = new JLabel("Please enter a windspeed:");
errorLabel = new JLabel("Error Message " );
JPanel panel = new JPanel();
panel.add(label);
panel.add(textBox);
panel.add(submit);
panel.add(errorLabel);
panel.add(tornado);
add(panel);
}
}
I know this is working but I may be missing something so here is where I create the tornado:
public class TornadoComponent extends JPanel {
public void paintComponent(Graphics g) {
int[] xPoints = {100,200,0};
int[] yPoints = {0,200,200};
int nPoints = 3;
g.drawPolygon(xPoints, yPoints, nPoints);
}
}
You have to set the JPanels size for it to be able to display Graphics.
static class TornadoComponent extends JPanel {
public TornadoComponent() {
setPreferredSize(new Dimension(500, 500));
}
#Override
public void paintComponent(Graphics g) {
//Whatever
}
}
And in order to trigger paintComponent(Graphics g) you have to add tornado.repaint(); at the end of your createComponents() function.
private void createComponents() {
//All your components
panel.add(tornado);
add(panel);
tornado.repaint();
}
Now the Polygon is shown but not at the right place (slightly off the image)
Therefore we have to arrange your JPanels a bit:
private void createComponents() {
textBox = new JTextField(" ");
submit = new JButton("Submit");
label = new JLabel("Please enter a windspeed:");
errorLabel = new JLabel("Error Message " );
JPanel upper = new JPanel();
upper.setLayout(new BoxLayout(upper,BoxLayout.X_AXIS));
upper.add(label);
upper.add(textBox);
upper.add(submit);
upper.add(errorLabel);
JPanel lower = new JPanel();
lower.setLayout(new BoxLayout(lower,BoxLayout.X_AXIS));
lower.add(tornado);
JPanel over = new JPanel();
over.setLayout(new BoxLayout(over,BoxLayout.Y_AXIS));
over.add(upper);
over.add(lower);
add(over);
tornado.repaint();
}
Basically I make some boxes...
Over
Upper
... your stuff with text
Lower
Our tornado
Now our tornado is the wrong way round...
int[] xPoints = {100,200,150};
int[] yPoints = {0,0,150};
And voilà:
We just created a very basic tornado that is not aiming at anything :)
If you want to change the tornados position later you just have to recall tornado.repaint(); and you are all set.
I have a problem with this nested class of mine. I can't add my JComponents to my panels for some reason in the constructor. It gives an error of
The method of add(JComponent, String) is undefined for the HomePanel.inputFrame
The HomePanel is the outer class while inputFrame is my inner class. My methods return JComponents and I am able to add it to my outer class but my inner class just doesn't allow it so I decided to just use add.(enterButton(), BorderLayout.SOUTH) which doesn't give any errors but when I try to use this inner class from mainWindow class, it says
The method add(JComponent) in the type container is not applicable for the arguments (HomePanel.inputFrame)
But the problem is I can use the outer class from mainWindow class which makes it confusing as to what went wrong. Is it due to it being an inner class or my order is wrong?
mainWindow class
public class mainWindow extends JFrame{
CardLayout cl = new CardLayout();
private JFrame mainPage = new JFrame("Food Expiry");
private JPanel mainPanel = new JPanel(cl);
private static final String homePage = "HomePage";
private static final String expiryDateEntry = "Expiry Date Entry";
private JPanel card1 = new JPanel();
public JPanel card2 = new JPanel();
HomePanel getGui = new HomePanel();
HomePanel.inputFrame nextPane = getGui.new inputFrame();
CardLayout cardLayout = (CardLayout) mainPanel.getLayout();
public mainWindow(){
mainPage.setSize(500, 300);
mainPage.setLocationRelativeTo(null);
mainPage.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainPage.add(mainPanel);
mainPage.setVisible(true);
}
protected void mainPanel(){
card1.add(getGui);
}
protected void getInput(){
card2.add(nextPane);
}
}
HomePanel
public class HomePanel extends JPanel{
private JButton inputButton, storeButton;
private JLabel label, itemLabel;
private JPanel textAreaPanel, buttonPanel, labelPanel;
private JTextField itemField, itemCategory, expiryDate;
public HomePanel(){
setLayout(new BorderLayout());
this.add(getLabelPanel("Home"), BorderLayout.NORTH);
this.add(getButtonPanel(), BorderLayout.CENTER);
}
protected JComponent getButtonPanel(){
//add some buttons to a buttonPanel
return buttonPanel;
}
protected JComponent getLabelPanel(String topText){
//labelPanel
return labelPanel;
}
class inputFrame {
private JLabel categoryLabel, expiryLabel;
private JButton enter, back;
protected JComponent getInputFrame(){
textAreaPanel = new JPanel();
textAreaPanel.setLayout(new BoxLayout(textAreaPanel,
BoxLayout.Y_AXIS));
itemLabel = new JLabel("Item Name: ");
itemField = new JTextField(15);
textAreaPanel.add(itemLabel);
textAreaPanel.add(itemField);
categoryLabel = new JLabel("Category Name: ");
itemCategory = new JTextField(33);
textAreaPanel.add(categoryLabel);
textAreaPanel.add(itemCategory);
expiryLabel = new JLabel("Expiry Date: ");
expiryDate = new JTextField(33);
textAreaPanel.add(expiryLabel);
textAreaPanel.add(expiryDate);
return textAreaPanel;
}
protected JComponent enterButton(){
buttonPanel = new JPanel();
enter = new JButton("Enter");
back = new JButton("Back");
enter.addActionListener(new getInput());
back.addActionListener(new previousFrame());
buttonPanel.add(back);
buttonPanel.add(enter);
return buttonPanel;
}
public inputFrame(){
setLayout(new BorderLayout());
add(getLabelPanel("Expiry Date Entry"),BorderLayout.NORTH);
add(getInputFrame(), BorderLayout.CENTER);
add(enterButton(), BorderLayout.SOUTH);
}
}
I couldn't find any duplicates on this question and if anyone is able to find any, please do link it in the comments or answer it. Thank you.
So, based on...
public class HomePanel extends JPanel{
//...
class inputFrame {
//...
}
}
inputFrame extends (by default) from Object, making it compatible with Container#add, which expects some class which extends from Component.
Based on the current implementation, inputFrame is actually modifying the state of the instance of HomePanel from which it was instantiated, rather then adding components to itself
Something like...
public class HomePanel extends JPanel{
//...
class inputFrame extends JPanel {
//...
}
}
should alleviate the most pressing issues
The problem seems simple, but I can't seem to get around it.
I am using GlassPane in my frame (also the ContentPane). So when I add JMenuBar to the frame it doesn't show up. If/when I am using GlassPane at other times, everything works absolutely fine. I did some research, what I understand is that JMenuBar is shown on RootPane and I believe GlassPane is somehow hiding it.
I need to know if there is any way to get JMenuBar while using glassPane?
Thanks
UPDATE:
I am setting glassPane.setOpaque(false)
UPDATE:
The actual lines of code are much more but here are the ones that are relative to the problem.
(mainPanel and notificationPanel are self constructed classes extending from JPanel)
public class Demo extends JFrame {
/////////////////////////////////////////////////////////////////////////
// JMenuBar
private final JMenuBar mainMenuBar;
private final JMenu fileMenu;
private final JMenuItem exitFileMenu;
/////////////////////////////////////////////////////////////////////////
// CONTENT PANE & COMPONENTS
private final JPanel contentPanel;
private final JPanel buttonPanel;
private final JButton button1;
/////////////////////////////////////////////////////////////////////////
// GLASSPANE AND COMPONENTS
private final JPanel glassPanel;
private final JPanel buttonPanel2;
private final JButton button2;
public Demo() {
super();
this.mainMenuBar = new JMenuBar();
this.fileMenu = new JMenu("File");
this.exitFileMenu = new JMenuItem("EXIT");
this.contentPanel = new JPanel(new BorderLayout());
this.buttonPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
this.button1 = new JButton("Button 1");
this.glassPanel = new JPanel(new BorderLayout());
this.buttonPanel2 = new JPanel(new FlowLayout(FlowLayout.RIGHT));
this.button2 = new JButton("Button 2");
}
public void initGUI() {
this.fileMenu.add(this.exitFileMenu);
this.mainMenuBar.add(this.fileMenu);
this.buttonPanel.add(this.button1);
this.contentPanel.add(this.buttonPanel, BorderLayout.NORTH);
this.buttonPanel2.add(this.button2);
this.glassPanel.add(this.buttonPanel2, BorderLayout.NORTH);
super.setContentPane(this.contentPanel);
super.setGlassPane(this.glassPanel);
this.glassPanel.setOpaque(false);
this.glassPanel.setVisible(true);
super.setExtendedState(JFrame.MAXIMIZED_BOTH);
super.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
super.setJMenuBar(mainMenuBar);
super.setVisible(true);
}
public static void main(String[] args) {
Demo obj = new Demo();
obj.initGUI();
}
}
You are using BorderLayout and the option BorderLayout.NORTH for your glassPanel. It takes the entire space in the north and it overlaps your entire menu. Therefore you don't see anything anymore. Change for example your panel creation into:
this.glassPanel = new JPanel();
Then your panel will be resized to only fit your button and you will see your menu behind. You can play around with some layouts and see which one fits. But just remember that the glass pane is always on top of everything. Just a little side note: When you add your button directly to 'glassPanel' (without using 'buttonPanel2') you can remove the little "borders". Otherwise you could resize it to perfectly fit your button. Both is possible, but if you only want to have a single component (like your button) then I would add it directly.
Alright guys I accidentally found the solution to the problem. It was in-fact simple, if you are using nested Panels within the 'glassPane' then simply set each nested panel's opacity to false. If you don't the nested panels will show its background to each of its bounds and overlap any underlying layer(s).
Here's the working code of the above Demo.
public class Demo extends JFrame {
/////////////////////////////////////////////////////////////////////////
// JMenuBar
private final JMenuBar mainMenuBar;
private final JMenu fileMenu;
private final JMenuItem exitFileMenu;
/////////////////////////////////////////////////////////////////////////
// CONTENT PANE & COMPONENTS
private final JPanel contentPanel;
private final JPanel buttonPanel;
private final JButton button1;
/////////////////////////////////////////////////////////////////////////
// GLASSPANE AND COMPONENTS
private final JPanel glassPanel;
private final JPanel buttonPanel2;
private final JButton button2;
public Demo() {
super();
this.mainMenuBar = new JMenuBar();
this.fileMenu = new JMenu("File");
this.exitFileMenu = new JMenuItem("EXIT");
this.contentPanel = new JPanel(new BorderLayout());
this.buttonPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
this.button1 = new JButton("Button 1");
this.glassPanel = new JPanel(new BorderLayout());
this.buttonPanel2 = new JPanel(new FlowLayout(FlowLayout.RIGHT));
this.button2 = new JButton("Button 2");
}
public void initGUI() {
this.fileMenu.add(this.exitFileMenu);
this.mainMenuBar.add(this.fileMenu);
this.buttonPanel.add(this.button1);
this.contentPanel.add(this.buttonPanel, BorderLayout.NORTH);
this.buttonPanel2.add(this.button2);
this.buttonPanel2.setOpaque(false);
this.glassPanel.add(this.buttonPanel2, BorderLayout.NORTH);
super.setContentPane(this.contentPanel);
super.setGlassPane(this.glassPanel);
this.glassPanel.setOpaque(false);
this.glassPanel.setVisible(true);
super.setExtendedState(JFrame.MAXIMIZED_BOTH);
super.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
super.setJMenuBar(mainMenuBar);
super.setVisible(true);
}
public static void main(String[] args) {
Demo obj = new Demo();
obj.initGUI();
}
}
Now Also remember always to set the glassPane's Opacity after you call 'setGlassPane(JPanel)' Otherwise the GlassPane remain Opaque. (The nested Panels you may set before or after calling the said method)
I'm trying to add a JList to a JPanel. Specifically, I have two JPanels, a right one and a left one. The right one has two buttons. On the left one I want the JList mySpriteOptions (see code below). Unfortunately, when I run my code, this JList never shows up. I'm no swing expert (in fact I'm a huge newb) so I can't figure out why this is.
Here is my code:
import java.awt.*;
import java.swing.*
public class SpriteEditorLauncher extends JFrame {
private JLabel mySearchBoxLabel;
private JList mySpriteOptions;
private JPanel myLeft;
private JPanel myRight;
private JScrollPane myScrollPane;
private JTextField mySearchBox;
private JButton myNewEditLauncher;
private JButton myEditLauncher;
private static final long serialVersionUID = 1L;
private static final String FONT_TYPE = "Times New Roman";
private static final int FONT_SIZE = 12;
private static final int FONT_STYLE = 1;
private static final Font FONT = new Font(FONT_TYPE, FONT_STYLE, FONT_SIZE);
private static final int NUMBER_OF_ROWS = 1;
private static final int NUMBER_OF_COLUMNS = 2;
private static final int FRAME_WIDTH = 600;
private static final int FRAME_HEIGHT = 400;
public SpriteEditorLauncher () {
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
initializeComponents();
createLayout();
}
private void initializeComponents () {
myLeft = new JPanel();
myRight = new JPanel();
myNewEditLauncher = new JButton();
myEditLauncher = new JButton();
myScrollPane = new JScrollPane();
mySpriteOptions = new JList();
mySearchBox = new JTextField();
mySearchBoxLabel = new JLabel();
}
private void setPanelBorder (JPanel toSetBorderFor) {
toSetBorderFor.setBorder(BorderFactory
.createTitledBorder(null, "Options", TitledBorder.DEFAULT_JUSTIFICATION,
TitledBorder.DEFAULT_POSITION, FONT));
}
private void setButtonLabel (JButton button, Font font, String label) {
button.setFont(font);
button.setText(label);
}
private void setFrameLayout () {
GridLayout myLayout = new GridLayout(NUMBER_OF_ROWS, NUMBER_OF_COLUMNS);
setLayout (myLayout);
setPreferredSize(new Dimension(FRAME_WIDTH, FRAME_HEIGHT));
setResizable(false);
}
private void addPanelsToFrame () {
add(myLeft);
add(myRight);
}
private void addButtonsToPanel (JPanel panel) {
panel.add(myNewEditLauncher);
panel.add(myEditLauncher);
}
private void createLayout () {
setFrameLayout();
setPanelBorder(myRight);
setButtonLabel(myNewEditLauncher, FONT, "New");
setButtonLabel(myEditLauncher, FONT, "Edit");
addPanelsToFrame();
addButtonsToPanel(myRight);
mySpriteOptions.setModel(new AbstractListModel() {
private static final long serialVersionUID = 1L;
String[] strings = { "Item 1", "Item 2"};
public int getSize () {
return strings.length;
}
public Object getElementAt (int i) {
return strings[i];
}
});
myLeft.add(mySpriteOptions);
myScrollPane.setViewportView(mySpriteOptions);
mySearchBox.addActionListener(new ActionListener() {
#Override
public void actionPerformed (ActionEvent arg0) {
// TODO Auto-generated method stub
}
});
mySearchBoxLabel.setFont(FONT);
mySearchBoxLabel.setLabelFor(mySearchBox);
mySearchBoxLabel.setText("Search:");
pack();
setVisible(true);
}
}
The default layout for a JPanel is FlowLayout.
FlowLayout likes to use the preferred size of it's components to layout them.
The default size a empty JList is probably 0x0, which means it never shows up.
Try creating the right panel with a BorderLayout (myRight = new JPanel(new BorderLayout());) and add the JList to it, wrapped in JScrollPane...
private void addPanelsToFrame () {
add(myLeft);
add(new JScrollPane(myRight));
}
Take a look at
Using Layout Managers
A Visual Guide to Layout Managers
For more information
You never add myScrollPane to the JPanel myLeft:
myLeft.add(myScrollPane);
Although you have added mySpriteOptions to myLeft, it is also set as the ViewportView of myScrollPane.
A component will only ever be painted on the last container to which it has been attached
—so will only appear in the JScrollPane, but this has not been added.
Now, this statement is not needed:
myLeft.add(mySpriteOptions);