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How to make my JFrame components dynamically scale when resizing the window, without hard-coding position and size values?

I'm learning java through university and I've been taught the basics of making a java program and designing GUIs. Maximizing a window after running my program makes all the JFrame components stay in place while grey fills the rest of the space. Here's an example of how it looks like:
JFrame window normally, Maximized window before "fix".
After failing to find a solution I came up with a band-aid solution which is to get the component locations and just move them with hard-coded values when the jframe is maximized. This was not an elegant solution and every jframe in my java course project increased in the number of elements on screen. Is there any piece of code to make my components move and resize automatically and dynamically?
Here's what I've tried so far:
First I obtained the positions of components through 2D points:
Point managementLoginBtnLocation, empLogLocation, logoLocation, customerBtnLocation, welcomeLblLocation, contactBtnLocation, aboutBtnLocation, mainMenuBtnLocation;
//Constructor and rest of code...
public final void getOriginalComponentLocations()
{
managementLoginBtnLocation = managementLoginBtn.getLocation();
empLogLocation = empLoginBtn.getLocation();
logoLocation = shopLogo.getLocation();
customerBtnLocation = customerBtn.getLocation();
welcomeLblLocation = welcomeLbl.getLocation();
contactBtnLocation = contactBtn.getLocation();
aboutBtnLocation = aboutBtn.getLocation();
mainMenuBtnLocation = mainMenuBtn.getLocation();
}
//This method is called within the constructor.
I implemented the ComponentListener Interface and added a component listener to my jframe. Then I made it so when the jframe's size changes, it changes the size of the jlabel used for background art. And if the label's width is greater than 800 (the default I used while designing) it moves the components and doubles their size and font size. When the jframe is minimized the label will go back to the default size so I made a method to revert the font sizes, because I found the component sizes and locations reset automatically.
public void componentResized(ComponentEvent e)
{
//Resizing the background label and setting its icon to a resized version of its current icon.
backgroundMainArt.setSize(this.getWidth() - 16, this.getHeight() - 21);
ImageIcon icon = new ImageIcon("C:\\Program Files\\OMOClothingStore\\Resources\\Main menu\\main menu background art.jpg");
Image img = icon.getImage();
Image newImage = img.getScaledInstance(backgroundMainArt.getWidth(), backgroundMainArt.getHeight(), Image.SCALE_FAST);
icon = new ImageIcon(newImage);
backgroundMainArt.setIcon(icon);
if(backgroundMainArt.getWidth() > 800) //When the size of the label is greater than default
{
//I move the components, enlarge the buttons and zoom the font size
moveComponents();
enlargeBtns();
zoomBtnsFontSize();
}
else //When the label is back to its original size
{
//I revert the font sizes as button sizes and positions reset automatically
revertBtnsFontSize();
setLogoIconAndBackgroundArtAndWelcomeLbl();
}
}
public void moveComponents()
{
moveLogo();
moveManagementLoginBtn();
moveEmployeeLoginBtn();
moveCustomerBtn();
moveWelcomeLbl();
moveContactInfoBtn();
moveAboutBtn();
moveMainMenuBtn();
}
public void moveLogo()
{
ImageIcon logoIcon = new ImageIcon("C:\\Program Files\\OMOClothingStore\\Resources\\Shared resources\\OMO Clothing Store logo.png");
Image logoImg = logoIcon.getImage();
Image newLogoImage = logoImg.getScaledInstance(250, 250, Image.SCALE_DEFAULT);
logoIcon = new ImageIcon(newLogoImage);
shopLogo.setIcon(logoIcon);
Point newLogoLocation = new Point();
newLogoLocation.x = (logoLocation.x * 2) + 200;
newLogoLocation.y = (logoLocation.y * 2) + 30;
shopLogo.setLocation(newLogoLocation);
}
//The rest of the "moveX" methods follow the same pattern as moveLogo()
public void enlargeBtns()
{
managementLoginBtn.setSize(410, 94);
empLoginBtn.setSize(410, 94);
customerBtn.setSize(410, 94);
}
public void zoomBtnsFontSize()
{
customerBtn.setFont(sizeBtn.getFont());
//sizeBtn is a JButton that has a font size of 24. I found that just creating a new Font object with bigger size here made the font way larger for some reason.
empLoginBtn.setFont(sizeBtn.getFont());
managementLoginBtn.setFont(sizeBtn.getFont());
}
public void revertBtnsFontSize()
{
empLoginBtn.setFont(new Font("Segoe UI", Font.PLAIN, 14));
managementLoginBtn.setFont(new Font("Segoe UI", Font.PLAIN, 14));
customerBtn.setFont(new Font("Segoe UI", Font.PLAIN, 14));
}
I split the moving of the components into many methods inside other methods because I found it easier to keep up with.
This worked. Here's how it looks like when running the JFrame: Maximized window after "fix". But moving on to other JFrames, they are more intricate and have many more components - extra buttons, panels with other components in them, menu bars, etc.
Is there a better approach to fixing this? Or do I just remove the ability to resize and move on?

Implement video files in JFrame

This time I got a really hard nut to crack. I was able to implement a slideshow-program which is able to display a number of random pictures after each other in a given time. The program also reacts on button presses.
Now I got the task to also make it able to display video files and it's wrecking my head. The tasks that need to be solved are the following:
The resolution of the file should be dependent on the actualy size of the screen. If an image or video has a greater resolution than the screen it is supposed to be scaled down (see the example code).
Images and videos are supposed to be implemented as JComponents in a JFrame which itself should be composed out of several elements like an area for the image/video, an area for text and for buttons etc - (I solved this for pictures).
After a certain amount of time, the slideshow is supposed to show the next picture/video. With pictures the time is fixed but when showing a video, the time should be dependent on the duration of the video itself (we wouldn't want the slideshow to jump to the next slide in the middle of the video)
For easier explanation let me first show how I solved the implementation of the pictures into the slideshow:
'''
public class DisplayImage extends JComponent {
private static final long serialVersionUID = 2613775805584208452L;
private static Image image;
public static Image displayImage(File f, Dimension screenSize) throws IOException {
//This method loads a file from the computer and resizes it in comparison to the size of the computer screen. The image is then returned for further processing.
BufferedImage img = ImageIO.read(f);
Image dimg;
double width = screenSize.getWidth()*0.75;
double z1 = (img.getWidth()/width);
double z2 = (img.getHeight()/screenSize.getHeight());
if (img.getHeight()/z1 <= width && img.getHeight()/z1 < screenSize.getHeight()) {
dimg = img.getScaledInstance((int)(img.getWidth()/z1), (int) (img.getHeight()/z1),Image.SCALE_SMOOTH);
} else {
dimg = img.getScaledInstance((int)(img.getWidth()/z2), (int)(img.getHeight()/z2),Image.SCALE_SMOOTH);
}
return dimg;
}
public void setImage(Image image1) {
//When an image is resized, it is given to this method.
//It replaces the global variable "image" with the new loaded image so the JFrame in the slideshow is actually reset and will display the new image.
image = image1;
repaint();
invalidate();
}}
'''
As you can see, I am completely fine for loading a new image and rewriting the image as well as the JComponent of the class with it.
Coming to a video file it get's messy instead. I was able to get video files to be loaded by another code taken from somewhere here using Maven but I didn't succeed in implementing it as a JComponent (I have been browsing stackoverflow as well as google already for days but couldn't find the solution for my problem). So far the only thing I can do is starting an extra player besides the slideshow as if they have nothing in common:
'''
public void playVideo(File f, Dimension screenSize) throws IOException, JCodecException {
Picture img = FrameGrab.getFrameAtSec(f, 1);
double width = screenSize.getWidth()*0.75;
double z1 = (img.getWidth()/width);
double z2 = (img.getHeight()/screenSize.getHeight());
NativeLibrary.addSearchPath(RuntimeUtil.getLibVlcLibraryName(), "C:\\Program Files\\VideoLAN\\VLC");
Native.loadLibrary(RuntimeUtil.getLibVlcLibraryName(), LibVlc.class);
JFrame frame = new JFrame("vlcj Tutorial");
MediaPlayerFactory mediaPlayerFactory = new MediaPlayerFactory();
Canvas c = new Canvas();
c.setBackground(Color.black);
JPanel p = new JPanel();
p.setLayout(new BorderLayout());
p.add(c, BorderLayout.CENTER);
frame.add(p, BorderLayout.CENTER);
EmbeddedMediaPlayer mediaPlayer = mediaPlayerFactory.newEmbeddedMediaPlayer();
mediaPlayer.setVideoSurface(mediaPlayerFactory.newVideoSurface(c));
if (img.getHeight()/z1 <= width && img.getHeight()/z1 < screenSize.getHeight()) {
frame.setSize((int)(img.getWidth()/z1), (int)(img.getHeight()/z1));
} else {
frame.setSize((int)(img.getWidth()/z2), (int)(img.getHeight()/z2));
}
frame.setSize(screenSize);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
mediaPlayer.playMedia(f.getPath());
}
'''
The mess starts already with me not being able to actually get the measurements of the video file itself (meaning width and height). I have been crushing my head over implementing different frameworks like JavaCV, Xuggle, MarvinFramework and much more but it was no good at all. The only thing I can do is to get a frame from the video as a Picture-type as shown in this example. But this doesn't work for me to give back either a JComponent or a BufferedImage (as with the pictures seen in the first method). Even worse: I have found no possible way to make the JFrame actually be reset when a video file is loaded leading for it to freeze dead as soon as a video is started in a new player. After that there is only the kill switch left.
So I'm lost here. Any help is greatly appreciated.

java jpanel synchronization with repaint() or: Is a Listener addable to swing's repaint?

I'm writing a plugin for a miscropy program and have problems with the repaint() method.
short question:
Is there any way to get informed as soon as the repaint of a JPanel was done or synchronize the code with it?
detailed version:
My program can plot a set of data in a xy-chart to a JPanel and show it using jfree.chart; In another part of the programm I have many datasets (~100) that I want to plot and save as images. I've also found a solution, but I really don't like it. The Problem can be reduced to a notification about the paint status of a JPanel.
In the part that shall save all images I have this solution:
PlotSpectrum spectrumWindow = getTheWindow(); //pseudo code...
// some stuff
ti = storage.getImage(channel, slice, frame, position);
spectrumWindow.plotData(false, andor.captureSpectrum(ti.pix), wave,
centerWave, fineGrating, exposureTime,
slitWidth, substractBackground);
spectrumWindow.repaint(); // probably not necessary
sleep(100); // this annoys me...
spectrumWindow.savePlot(path, true, config, null);
spectrumWindow is a JPanel that is also displayed in another window and it all works fine.
BUT I really don't like that sleep(100) in there... without it I'm asking for a repaint but it isn't done till I try to save a "snapshot" of (thats what savePlot is doing...). I know, other Thread and these damn synchronization problems...
With the sleeping I'm just making it unnecessary slow and if I wait not long enough the images are not completly drawn (eg lower half missing)
Is there any way to get informed as soon as the repaint was done? I probably would be also fine with a Listener, better would be a solution with a monitor or sth comparable or a method that is repainting NOW (doesn't exists as far I know?)
The main GUI (include the JPanel spectrumWindow) and the earlier pasted code are running in different Threads.
The probably also important parts of my code are following here. Please excuse if some brackets aren't matching or some variables aren't declared, I removed very much code.
thanks
schetefan24
class PlotSpectrum extends ApplicationFrame // that extends JFrame
{
public void plotData(boolean backgroundGiven, int[] spect, double[] wave_,
double centerWave, boolean fineGrating_, double exposureTime,
double slitWidth, boolean substractBackground)
{
//process data and store internally
replot();
}
private void replot()
{
XYSeries series = new XYSeries("Spectrum");
//add data to series
XYSeriesCollection collection = new XYSeriesCollection(series);
//setting up some labels and such stuff...
JFreeChart chart = ChartFactory.createXYLineChart(
title,
"Wavelength [nm]",
yLabel,
collection,
PlotOrientation.VERTICAL,
false,
false,
false
);
dataPanel.add(new ChartPanel(chart)); // this is contained in a Frame
}
public void savePlot(String path, boolean overWriteAll, HashMap<String,String> config, int[][] addData)
{
File output = new File(path);
//some more stuff, ask overwrite etc
if(image)
{
BufferedImage im = createImage();
String extension = path.substring(path.lastIndexOf(".")+1, path.length());
ImageIO.write(im, extension, output);
} else {
//that is an textexport, works fine
}
}
public BufferedImage createImage()
{
JPanel panel = (JPanel) flipChart.getSelectedComponent();
int w = panel.getWidth();
int h = panel.getHeight();
BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Graphics2D g = bi.createGraphics();
panel.paint(g);
return bi;
}
}

that I want to plot and save as images.
add the data to a non visible panel.
create a BufferedImage of the panel
create an ImageIcon using the Image from above
update a JLabel (that has already been added to the frame) using the setIcon(...) method
the above step should generate a PropertyChange event when the Icon changes. You can use a ProperChangeListener to listen for this event. When you receive the event you can repeat steps 1 - 4.
Check out Screen Image. It will help you create an image of a non-visible component.
Note, you don't really need steps 4-5. I just added them so you have a visual of the plots as they are being processed. If you don't want the visual then maybe you just display text on a JLabel indicating which plot is currently being converted.

Java Swing Icon not appearing

I'm trying to create a piece of code that displays either a smiley face or a sad face when a button is pressed, depending on some value, but it just won't display the image. I know that it's definitely getting past the if/else statements, so I really don't know what is going wrong.
try {
if(data[2] <= ((int) ChronoUnit.DAYS.between(localDate, RTS()))*MnHrs())
{
JLabel lblSmiley = new JLabel(new ImageIcon("C:\\. . .\\smileyface.jpeg"));
panel.add(lblSmiley);
}
else
{
JLabel lblSmiley = new JLabel(new ImageIcon("C:\\ . . . \\sadeface.png));
panel.add(lblSmiley);
}
} catch (Exception e1) {
e1.printStackTrace();
}

It looks like you're loading the icon and adding a new label each time. Instead, you can add the label once and call setIcon() like they show here.
Icon smile = new ImageIcon("C:\\…\\smileyface.jpeg");
Icon sad = new ImageIcon("C:\\…\\sadeface.png");
JLabel lblSmiley = new JLabel();
…
frame.add(lblSmiley);
…
if (…) {
lblSmiley.setIcon(smile);
} else {
lblSmiley.setIcon(sad);
}
Depending on your layout, you may need to change the labels preferred size or add an empty label before you pack() the window.

Probably, it is getting in the panel, but due to dimensions of panel it might be getting placed off screen. Check by modifying the panel dimensions and placing the smiley within that.

how to hide a text area in java swing form?

i used textarea1.setVisible(false); but still i can see the border of the text area at run time. i want the textarea to be completely invisible
Can anyone help in this issue?

It sounds like you have a Panel around your text area since setVisible(false) should definitely hide the entire component. If so, make the panel invisible. Care to post some code so we can examine and help?

You have to hide the scroll pane which your text area is sitting in. If for some reason you have no direct access to it here is the way to get it:
public static final JScrollPane getScrollPane( JComponent component ) {
Container p = component .getParent();
if (p instanceof JViewport) {
Container gp = p.getParent();
if (gp instanceof JScrollPane) {
return (JScrollPane)gp;
}
}
return null;
}

Find your textarea scrollpane, then set the visibility to false, like this:
jScrollPane4.setVisible(false);