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JFrame strange white stripe on top of background image

I have a strange white stripe (see below) appearing on top of my background image. The code is quite simple. How to get rid of the white stripe?
//Graphics side of the game
public class GUI extends JFrame {
private final int larghezza = 1280;
private final int altezza = 720;
private final String name = "Sette e Mezzo";
private final ImageIcon backgroundImage;
private JLabel bgImageLabel;
private JPanel backgroundPanel, borderLayoutPanel, topGridLayout, botGridLayout;
public GUI () {
backgroundImage = new ImageIcon ("assets/background.png");
bgImageLabel = new JLabel (backgroundImage);
//Panels
borderLayoutPanel = new JPanel (new BorderLayout ());
topGridLayout = new JPanel (new GridLayout (1, 3));
botGridLayout = new JPanel (new GridLayout (1, 3));
backgroundPanel = new JPanel ();
backgroundPanel.add (bgImageLabel);
//Frame
this.setName (name);
this.setPreferredSize (new Dimension(larghezza, altezza));
this.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
//Adding to frame and panels
borderLayoutPanel.add (topGridLayout, BorderLayout.NORTH);
borderLayoutPanel.add (botGridLayout, BorderLayout.SOUTH);
this.add (borderLayoutPanel);
this.add (backgroundPanel);
this.pack ();
this.setLocationRelativeTo (null);
this.setVisible (true);
}
}

Don't use setPreferredSize() when you really mean to override getPreferredSize(). In this case, the specified Dimension probably doesn't quite match the size of "assets/background.png". This allows some portion of another panel to show, perhaps backgroundPanel.
In the example below,
The default layout of JPanel is FlowLayout, which has a "default 5-unit horizontal and vertical gap." A touch of Color.blue makes the gap stand out; resize the enclosing frame to see the behavior.
As the default layout of JFrame is BorderLayout, you may not need borderLayoutPanel at all.
Because the two GridLayout panels have no content, they remain invisible. Add content to each or override getPreferredSize() in each to see the effect.
Construct and manipulate Swing GUI objects only on the event dispatch thread.
import java.awt.*;
import java.net.URL;
import javax.swing.*;
public class GUI {
private static final String TITLE = "Title";
private static ImageIcon IMAGE_ICON;
private void display() {
//Panels
JPanel topGridLayout = new JPanel(new GridLayout(1, 3));
JPanel botGridLayout = new JPanel(new GridLayout(1, 3));
JPanel backgroundPanel = new JPanel();
backgroundPanel.setBackground(Color.blue);
backgroundPanel.add(new JLabel(IMAGE_ICON));
//Frame
JFrame f = new JFrame(TITLE);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Add components
f.add(topGridLayout, BorderLayout.NORTH);
f.add(backgroundPanel);
f.add(botGridLayout, BorderLayout.SOUTH);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) throws Exception {
IMAGE_ICON = new ImageIcon(new URL("http://i.imgur.com/mowekvC.jpg"));
EventQueue.invokeLater(new GUI()::display);
}
}

How do I use nested panels in my GUI application?

I created a drawing application that lets a user choose pen colors but I have having trouble with the layout. I created multiple panels but when I run it, all the buttons are still in one panel. Is there a way to fix this?
public class DrawingGUI extends JPanel {
private JRadioButton penColor1, penColor2, penColor3, randomPenColor, eraser;
private JButton clearButton;
private static Color defaultColor = Color.BLACK;
private static boolean isRandomSelected = false;
private final static int DIAMETER = 12;
protected static boolean canDraw;
private ArrayList<PointTracker> points;
public DrawingGUI() {
setBackground(Color.WHITE);
points = new ArrayList<PointTracker>();
JPanel drawPanel = new JPanel();
JLabel instructions = new JLabel("Enter your information:");
JPanel instructionsPanel = new JPanel();
instructionsPanel.add(instructions);
drawPanel.add(instructionsPanel);
JPanel colorPanel1 = new JPanel();
penColor1 = new JRadioButton("Red");
drawPanel.add(penColor1);
penColor1.addActionListener(new ToolListener());
drawPanel.add(colorPanel1);
JPanel colorPanel2 = new JPanel();
penColor2 = new JRadioButton("Blue");
drawPanel.add(penColor2);
penColor2.addActionListener(new ToolListener());
drawPanel.add(colorPanel2);
JPanel colorPanel3 = new JPanel();
penColor3 = new JRadioButton("Yellow");
drawPanel.add(penColor3);
penColor3.addActionListener(new ToolListener());
drawPanel.add(colorPanel3);...(So on)

all the buttons are still in one panel
Why is that a problem. That is what I would expect to happen.
Why are you creating a separate panel for each button? The whole point of using panel is to logically group components.
So I would expect you should have something like:
JPanel buttonsPanel = new JPanel();
buttonsPanel.add( button1 );
buttonsPanel.add( button2 );
buttonsPanel.add( button3 );
JPanel drawPanel = new JPanel();
drawPanel.add( component1 );
drawPanel.add( component2 );
frame.add(drawPanel, BorderLayout.PAGE_START);
frame.add(buttonsPanel, BorderLayout.PAGE_END);
Above is a simple example of "nesting" two panels on a frame. Each of the panel can use a different layout manager as required.
For a working example of this approach you can check out Custom Painting Approaches. Both code examples show how you can "nest" a drawing panel and a buttons panel in a frame.

I'm trying to play a video using vlcj inside a JPanel

I'm trying to play a video using vlcj inside a JPanel but it doesn't work for me. The message exception I am getting is:
"java.lang.IllegalStateException: The video surface component must be displayable"
The code:
public class MediaPlayerPanel extends JPanel {
private static final long serialVersionUID = 1L;
MediaPlayerFactory mediaPlayerFactory = new MediaPlayerFactory();
EmbeddedMediaPlayer mediaPlayer = mediaPlayerFactory.newEmbeddedMediaPlayer();
Canvas c = new Canvas();
JPanel p = new JPanel();
public MediaPlayerPanel() {
c.setBackground(Color.black);
p.setLayout(new BorderLayout());
p.add(c, BorderLayout.CENTER);
mediaPlayer.setVideoSurface(mediaPlayerFactory.newVideoSurface(c));
c.setVisible(true);
p.setVisible(true);
}
public void play(String video) {
mediaPlayer.playMedia(video);
}
}
public class VideoPlayer {
public static void main(final String[] args) {
NativeLibrary.addSearchPath(RuntimeUtil.getLibVlcLibraryName(), "C:\\Program Files\\VideoLAN\\VLC");
Native.loadLibrary(RuntimeUtil.getLibVlcLibraryName(), LibVlc.class);
JFrame frame = new JFrame("Video Player");
MediaPlayerPanel mpp = new MediaPlayerPanel();
frame.setLocation(100, 100);
frame.setSize(1050, 600);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(mpp, BorderLayout.CENTER);
frame.setVisible(true);
mpp.play("E:\\Filmek\\Game.of.Thrones.S04E02.HDTV.x264-2HD\\game.of.thrones.s04e02.hdtv.x264-2hd.mp4");
}
}

That error message usually means that you tried to do mediaPlayer.play() before you showed (or pack()'ed) the application frame that contains the video surface.
In the code you posted, you are not adding your panel p to the MediaPlayerPanel panel that you create. So your video surface Canvas is not actually attached to any visible component hierarchy.
Your MediaPlayerPanel should set a BorderLayout on itself and add p to that.

Gridlayout button click then load under the buttons a form Java

I really didn't now how to form the question i have a gridlayout with 4 buttons. When the user press Add module i want under the buttons a form instead of a new windows if this is possible.
frame = new JFrame("ModuleViewer");
makeMenu(frame);
Container contentPane = frame.getContentPane();
// Specify the layout manager with nice spacing
contentPane.setLayout(new GridLayout(0, 2));
addModule = new JButton("Toevoegen Module");
contentPane.add(addModule);
overview = new JButton("Overzicht Modules");
contentPane.add(overview);
addSchoolweeks = new JButton("Aapassen schoolweken");
contentPane.add(addSchoolweeks);
weekheavy = new JButton("Weekbelasting");
contentPane.add(weekheavy);
frame.pack();
Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
frame.setLocation(d.width/2 - frame.getWidth()/2, d.height/2 - frame.getHeight()/2);
frame.setVisible(true);
I know that i first need to add een action method for the buttons i know how to do that so that isn't important. I only want to know how i could create a layout under the buttons so when a user clicks the layout will be draw.

Each panel can only have one layout, but you can use multiple panels for the desired effect: a top panel using GridLayout to hold your buttons, and a bottom panel using CardLayout to hold multiple other panels, one for each button click. Each of these panels can use whatever layout you want, depending on its contents.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class CardLayoutDemo implements Runnable
{
final static String CARD1 = "Red";
final static String CARD2 = "Green";
final static String CARD3 = "Blue";
JPanel cards;
CardLayout cardLayout;
public static void main(String[] args)
{
SwingUtilities.invokeLater(new CardLayoutDemo());
}
public void run()
{
JButton btnRed = createButton("Red");
JButton btnGreen = createButton("Green");
JButton btnBlue = createButton("Blue");
JPanel buttons = new JPanel(new GridLayout(1,3));
buttons.add(btnRed);
buttons.add(btnGreen);
buttons.add(btnBlue);
JPanel card1 = new JPanel();
card1.setBackground(Color.RED);
JPanel card2 = new JPanel();
card2.setBackground(Color.GREEN);
JPanel card3 = new JPanel();
card3.setBackground(Color.BLUE);
cardLayout = new CardLayout();
cards = new JPanel(cardLayout);
cards.add(card1, CARD1);
cards.add(card2, CARD2);
cards.add(card3, CARD3);
JFrame f = new JFrame("CardLayout Demo");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(buttons, BorderLayout.NORTH);
f.add(cards, BorderLayout.CENTER);
f.setSize(300, 200);
f.setLocationRelativeTo(null);
f.setVisible(true);
}
private JButton createButton(final String name)
{
JButton button = new JButton(name);
button.addActionListener(new ActionListener()
{
#Override
public void actionPerformed(ActionEvent e)
{
cardLayout.show(cards, name);
}
});
return button;
}
}

Resize JPanel to fit new JLabel icon

I'm trying to create an animation (spinning text) by repeatedly changing the icon on a JLabel. The issue is the images are not of the same size, and when they are bigger than the size of the first image, they are clipped.
One way around this is to setPreferredSize for the JLabel so that all images fit - but I imagine there must be a way dinamically resize the JPanel containing the JLabel?
In the code bellow I've also tried removing the JLabel alltogether, creating a new one and then adding the new one, but to the same effect.
public class AnimationPanelv2 extends JPanel{
private JButton start = new JButton("Start Animation");
private JLabel img = new JLabel();
private JTextField animSpeed = new JTextField(10);
private JTextField filePrefix = new JTextField(10);
private JTextField noOfImg = new JTextField(10);
private JTextField audioFile = new JTextField(10);
private Timer timer;
private AudioClip clip;
private ArrayList<ImageIcon> icon = new ArrayList<>();
private int step=0;
public AnimationPanelv2() {
//button is for starting the animation
start.addActionListener(new Animatie());
this.setLayout(new BorderLayout());
add(start, BorderLayout.NORTH);
//showing the label with the first frame
Class metaObj = this.getClass();
URL url = metaObj.getResource("/image/L1.gif");
img.setIcon(new ImageIcon(url));
// img.setPreferredSize(new Dimension(500,550));
add(img, BorderLayout.CENTER);
//control panel
JPanel controls = new JPanel(new GridLayout(4,2));
controls.setBorder(new TitledBorder("Enter information for animation"));
controls.add(new JLabel("Animation speed in ms"));
controls.add(animSpeed);
controls.add(new JLabel("Image file prefix"));
controls.add(filePrefix);
controls.add(new JLabel("Number of images"));
controls.add(noOfImg);
controls.add(new JLabel("Audio file"));
controls.add(audioFile);
//
add(controls, BorderLayout.SOUTH);
}
private class TimerAnimation implements ActionListener {
public void actionPerformed(ActionEvent e) {
remove(img);
img = new JLabel(icon.get(step++));
img.setVisible(true);
add(img, BorderLayout.CENTER);
// img.revalidate();
// img.repaint();
validate();
repaint();
updateUI();
if (step==Integer.parseInt(noOfImg.getText())) step=0;
}
}
private class Animatie implements ActionListener {
public void actionPerformed(ActionEvent e) {
//getting data from the text fields
int ms = Integer.parseInt(animSpeed.getText());
String s = filePrefix.getText();
int nr = Integer.parseInt(noOfImg.getText());
String audioFilePath = audioFile.getText();
// clip
Class metaObj = this.getClass();
URL url = metaObj.getResource("/audio/"+audioFilePath);
clip = Applet.newAudioClip(url);
//image loading
for (int i=1; i<=nr; i++){
url = metaObj.getResource("/image/"+s+i+".gif");
System.out.println("/image/"+s+i+".gif");
icon.add(new ImageIcon(url));
}
//timer
timer = new Timer(ms, new TimerAnimation());
timer.start();
clip.loop();
}
}
public static void main(String[] args) {
JFrame jf = new JFrame("This class test");
jf.setLocationRelativeTo(null);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jf.add(new AnimationPanelv2());
jf.pack();
jf.setVisible(true);
}
}
This whole panel will be used in an applet.
This is a screenshot: http://screencast.com/t/UmqQFZHJVy
The images that are supposed to be the frames, should be located in an /images/ sub-directory and if the user enters n for the number of frames and F for the image
prefix, then the files are F1, F2, and so on, to Fn (GIFs). The sound file should be in an /audio/ sub-directory, and the entire file name is given by the user.

You can try to create list of JLabels for each image, add them to a panel with CardLayout and swap cards.

Okay well a JLabel should size automatically to its given content, so to solve JPanel issue, simply override getPreferredSize() of JPanel containing the JLabel and return Dimensions according to the JLabel size.
public class MyPanel extends JPanel {
JLabel label=...;
#Override
public Dimension getPreferredSize() {
return new Dimension(label.getWidth(),label.getHeight());
}
}
also dont forget when you change Icon of JLabel call revalidate() and repaint() on JPanel instance in order for size changes to refelect.