I would like to know how to put a JLabel on top of another JLabel at a specific position, in a class that extends JPanel in Java. People have asked for help with this before but the solutions that I found do not satisfy me. I am using GridLayout, here is some of my code:
//imports
public class Game extends JPanel implements MouseListener {
Icon background = new ImageIcon(getClass().getResource("/background.jpg"));
Icon foreground = new ImageIcon(getClass().getResource("/foreground.jpg"));
JLabel backgr = new JLabel(background);
JLabel foregr = new JLabel(foreground);
JFrame frame = new JFrame("Game");
public Game() {
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridBagLayout());
backgr.addMouseListener(this);
frame.setLayout(new FlowLayout());
frame.setPreferredSize(new Dimension(200,200));
frame.pack();
frame.setVisible(true);
frame.addMouseListener(this);
backgr.setLayout(new BorderLayout());
frame.add(backgr);
backgr.add(foreground);
}
}
(I have a lot of other methods in this class, such as some mouse stuff, but I don't include them here since they are not relevant to this problem.)
Currently the code almost works as I want, the foreground picture is displayed on top of the background, right in the middle of it. But I would like the foreground picture to be displayed at specific coordinates on the background picture. I thought that if I wanted to display the foreground at coordinates (50, 50), I could say backgr.add(foreground, 50,50), this compiles but returns an error when I run the program. Any tips of what to do? It would be really appreciated.
Edit: I discovered that by saying backgr.setLayout(null), backgr.add(foregr) and then foregr.setLocation(50,50), we can do what I was looking for. But since not using a layout manager is discouraged, I am looking for better solutions, so that I can use the coordinates on the backgr Icon.
People have asked for help with this before but the solutions that I found do not satisfy with me since they require me to set the frame layout to null, but I am using GridBagLayout
The frame is using a GridBagLayout.
You are adding the foreground JLabel, so the background JLabel. The background label can use any layout (including null) that you wish.
the foreground picture is displayed on top of the background, right in the middle of it.
That is because you are using a BorderLayout and are adding the foreground to the CENTER, which is the default when you don't specify a constraint.
Related
So for my project I just wanted the backgound to have a gif play to make it look nicer, but every solution I found wouldnt work. A solution where I make the gif on a JLabel then add everything onto the JLabel didnt work, the project ran but nothing showed up on screen. I have the gif called as this
ImageIcon obj = new ImageIcon("assets/animate.gif");
My main looks like this
public static void main(String[] args0) {
JFrame frame = new JFrame("inferdle");
gamePanel window = new gamePanel();
frame.add(window);
frame.setSize(500,900);
frame.setVisible(true);
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
and I extend JPanel in the beggining. There are a bunch of box's that I add and those boxs have a bunch of JButtons
hBox.add(sMenu);
jBox.add(tMenu);
add(hBox, BorderLayout.NORTH);
add(jBox, BorderLayout.SOUTH);
add(textBox, BorderLayout.EAST);
Is this even possible?
It is definitely possible. You can use a JLayeredPane
Note though that there are questions you should be thinking with this: What happens if the JComponent is larger than your background? What if it's smaller? If you want to do tiling, you might want to look at the Paint class and Graphics2D.setPaint
I'm trying to create a transparent fullscreen overlay with a bunch of buttons.
I've used JFrame to create the overlay, however, but the button does not show.
package com.Flickr.firstApp;
import javax.swing.*;
import java.awt.*;
import java.util.Random;
public class MainClass {
public static void main(String... args) throws Exception {
Robot robot = new Robot();
Random random = new Random();
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
JFrame frame = new JFrame("Flow Layout");
frame.setUndecorated(true);
frame.setOpacity(0.2f);
frame.setSize(screenSize);
Panel panel = new Panel();
panel.setPreferredSize(new Dimension(100,100));
panel.setBackground(Color.MAGENTA);
JButton b1 = new JButton("hello");
panel.add(b1);
frame.add(panel);
frame.setVisible(true);
}
}
As a newbie, there's a few questions that would help deepen my understanding:
Why doesn't the button show?
Why does the Panel cover the whole frame even though I've set the size to 200x200? Does it attempt to fill the frame by default?
Does content have to go in a panel or can we put buttons, etc directly onto the frame?
If you could answer any one of these questions, or point me towards a resource that can, that would be awesome. Thanks!
The button shows for me. Its opacity makes it hard to see.
The default layout manager for the content pane of the frame is a BorderLayout. When you don't specify a constraint it is added the the CENTER. Any component in the CENTER is resized to fill the space available in the frame.
You can add any component to the frame. If you add the button directly, then it will be resized to fill the frame. You need to understand how layout managers work.
Don't use a Panel, that is an AWT component. Use a JPanel for Swing.
point me towards a resource
Read the Swing Tutorial for many Swing basics. There are sections on:
A Visual Guide to Layout Managers
How to Create Translucent and Shaped Windows
Along with other basic demo programs to get you started.
First, to get it out of the way, I absolutely NEED to use heavyweight AWT component with a swing application. I need features from both of them.
The task is simple - render a heavyweight AWT Canvas (or any other element), render OpenGL scene directly onto it, then display Swing buttons above it for the UI.
My problem is that it works half-way.
I don't seem to have problems with Z-ordering. I am using jLayeredPanes for it, and I can move Canvas between layers and it actually works, popping on top or below other elements.
The problems are with transparency.
The thing is, Swing elements have Opaque parameter, and when it's set to false (non-opaque) - it should basically be transparent and you should see the next element below it. In my case, however, the AWT Canvas gets ignored, and you instead only see the next underlying SWING element.
Here are a couple of screenshots. They are taken from a standalone test project of mine. The canvas is stretched to the size of the frame, and in the upper left there is a JLayeredPane dummy element that is a simplified version of the menu.
On the first screenshot, the JLayeredPane's Opaque setting is set to true, and you can see that it's background property is set to Blue color.
On the second screenshot, everything is exactly the same but Opaque is set to false. Instead of displaying whatever is on the Canvas - what gets drawn in empty grey jFrame background.
Lastly, on the third screenshot I have put Canvas into a jPanel instead of leaving it on its own. As you can see, the Panel's orange color is seen through the transparent jLayeredPane, but the Canvas is yet again hidden.
Here's the code for the Frame layout. I would not post my rendering/context code right now
frame = new JFrame("AWT test");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.setPreferredSize(new Dimension(width, height));
canvas = new Canvas();
canvas.setSize(width,height);
//this part exists only in the third example
JPanel p = new JPanel();
p.setSize(width,height);
p.setBackground(Color.orange);
p.add(canvas);
// third example end
JLayeredPane pane = new JLayeredPane();
JLayeredPane paneMenu = new JLayeredPane();
JButton button = new JButton();
button.setSize(20,20);
paneMenu.setSize(200,200);
paneMenu.add(button, new Integer(1));
paneMenu.setBackground(Color.BLUE);
paneMenu.setOpaque(false); //True for the first example
pane.add(p, new Integer(1)); // canvas for the first two examples
pane.add(paneMenu, new Integer(2));
pane.setOpaque(false);
frame.add(pane);
frame.pack();
frame.setVisible(true);
frame.transferFocus();
Could anyone please explain me what is going on and how to do what I need to do.
I will repeat again - I have to use heavyweight component as render target. I am aware of solutions like JOGL's GLPanel which is a lightweight Swing-compatible component. But I tried that method and the performance is really slow, because instead of directly rendering onto it as a context target - it reads FrameBuffer from memory, flips it, and then paints it as BufferedImage. This path is not fitting for the limited resources of an embedded system that I'll be running on.
c0der said: Please post minimal reproducible example
Errrrm.... Didn't I?
Here, you can have it in complete java class form if you want, but I literally changed some variables for constants.
import javax.swing.*;
import java.awt.*;
public class Main
{
public static void main(String[] args)
{
JFrame frame = new JFrame("AWT test");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.setPreferredSize(new Dimension(500, 500));
Canvas canvas = new Canvas();
canvas.setSize(500,500);
canvas.setBackground(Color.RED);
//this part exists only in the third example
JPanel p = new JPanel();
p.setSize(500,500);
p.setBackground(Color.orange);
p.add(canvas);
// third example end
JLayeredPane pane = new JLayeredPane();
JLayeredPane paneMenu = new JLayeredPane();
JButton button = new JButton();
button.setSize(20,20);
paneMenu.setSize(200,200);
paneMenu.add(button, new Integer(1));
paneMenu.setBackground(Color.BLUE);
paneMenu.setOpaque(false); //True for the first example
pane.add(p, new Integer(1)); // canvas for the first two examples
pane.add(paneMenu, new Integer(2));
pane.setOpaque(false);
frame.add(pane);
frame.pack();
frame.setVisible(true);
frame.transferFocus();
}
}
A little update:
I initially suspected that because Swing elements delegate all their drawing to the underlying heavyweight element (In my case JFrame), then what happens is that the frame generates a single frameBuffer for itself and then displays on top of Canvas. Canvas itself is not handled in this generation and thus the frame "covers" over the canvas.
That doesn't seem to be the case. I tried making the JFrame undecorated, all panels non-opaque, and display the picture. The result - canvas is still "cut", and through the hole you can see the underlying IDE menu.
This makes me think that somewhere during Drawing, the Canvas itself detects that it is obscured by another element, and that it doesn't need to draw that area. So it "optimizes" itself and doesn't update these pixels.
Maybe I'm wrong. But here's another screenshot. This is the same example as before, but I took out 3d rendering and simply trying to display Canvas with background set to Red.
Once again, going to reply to my own question.
It turned out that I need to do
setComponentMixingCutoutShape(paneMenu, new Rectangle());
for the menu pane that lies underneath the button. That essentially tells java not to cut out the element from the heavyweight underlying component.
I've been fruitlessly searching the internet and nothing that people suggest seems to have any effect for me.
I have a JFrame which I'm trying to put a JPanel in. That JPanel ideally would have a JLabel with an imageicon as the background and a set of buttons in its own Jpanel in the foreground. The issue is every type of layout manager I've seen suggested just does not work as advertised for me. The best I've gotten to work so far is this approach:
public MenuBackgroundPanel(AsteroidsFrame frame)
{
this.gameFrame = frame;
this.setLayout(new OverlayLayout(this));
ImageIcon image = new ImageIcon(getClass().getResource("/resources/background1.gif"));
imageLabel = new JLabel(image, JLabel.CENTER);
mp = new MainMenuPanel(gameFrame);
mp.setMaximumSize(new Dimension(300,200));
this.add(mp);
this.add(imageLabel);
this.setVisible(true);
}
Unfortunately, I'm getting really strange alignments and trying to set location on the background (to actually get it to start at the JFrame's (0,0) or moving the button panel just seems to have no effect. Printing the location of each object says they're both at (0,0) but the image I'll link shows this is just not the case. My point is, I've tried things like JLayeredPane or setting the JLabel as the contentpane of the Jframe and making it transparent but nothing seems to do anything. One or the other of the two objects just covers the other completely.
As you can see the objects are not at all aligned.
Could anyone help me with this?
That JPanel ideally would have a JLabel with an imageicon as the background and a set of buttons in its own Jpanel in the foreground
Easiest way for something like this when the child panel is fully contained in the label image is to just set the layout manager of the JLabel and then add your components to the label.
JLabel background = new JLabel( new ImageIcon(...) );
background.setLayout( new GridBagLayout() );
JPanel buttons = new JPanel();
buttons.setOpaque( false );
buttons.add(...);
background.add(buttons, new GridBagConstraints() );
Now the button panel will be centered on the label.
As you can see the objects are not at all aligned
If you want to use the OverlayLayout then you need to play with the alignmentX/Y properties of each component. You would probably want to set them both to .5. Check out: Java Layout with Component always in Top Right for an example of how changing these values can affect the layout.
I am attempting to place two panels over the top of another two panels, so the positions match exactly. This will allow me to then paint over the top of the previous(bottom) panels. The reason for doing this, is that I have implemented a "drag a rectangle" zoom function, so on the panel the user will drag the mouse to draw a rectangle, and then the panel will become filled with the contents of that rectangle. However, I have now decided I would like include a visual representation of the rectangle as the user drags it.
Since I (assume) I cannot draw the rectangle on the bottom panel, since it already has a complicated paint on it anyway, I figured I would be able to draw it onto another panel that I would place on top. (If there is any easier way please shout!)
I am happy I have been able to get the panels into the correct position, using a BorderLayout/GridLayout combo, without the need for absolute positing, however the setOpaque method is not working on any of the three panels I have added. Does anyone know why this is?
Many thanks in advance, code below:
public void initiate() {
JPanel panel1 = new JPanel();
mandPanel mandDisplay = new mandPanel();
juliaPanel juliaDisplay = new juliaPanel();
JPanel detailsPanel = new JPanel();
JPanel bottomDetails = new JPanel();
JPanel panelForDisplays = new JPanel();
JPanel listenerPanelHolder = new JPanel();
JPanel listenerPanel = new JPanel();
JPanel blankPanel = new JPanel();
panelForDisplays.setLayout(new GridLayout(1,2));
detailsPanel.setLayout(new FlowLayout());
bottomDetails.setLayout(new FlowLayout());
panel1.setLayout(new BorderLayout());
panelForDisplays.add(mandDisplay);
panelForDisplays.add(juliaDisplay);
listenerPanelHolder.setOpaque(false);
listenerPanel.setOpaque(false);
blankPanel.setOpaque(false);
listenerPanelHolder.setLayout(new GridLayout(1,2));
listenerPanelHolder.add(listenerPanel);
listenerPanelHolder.add(blankPanel);
panel1.add(detailsPanel,BorderLayout.NORTH);
panel1.add(panelForDisplays,BorderLayout.CENTER);
panel1.add(listenerPanel,BorderLayout.CENTER);
panel1.add(bottomDetails, BorderLayout.SOUTH);
setContentPane(panel1);
setSize(width*2, height);
setResizable(false);
this.addWindowListener(new onClose(savedJulias));
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
PS: A lot of code is omitted to avoid mess, but if anyone thinks they could solve with more code please say! Thanks :)
First off, adding two components at the BorderLayout.CENTER position replaces the first component with the 2nd, and so the 2nd doesn't cover the 1st, it displaces it. As per the BorderLayout API:
Each region may contain no more than one component,...
But having said that, as I understand your problem in greater detail, I think that your best solution is not to use JLayeredPane or to overlay two JPanels. The best solution is in fact to draw directly on the image-displaying JPanel. This is not hard to do, and shouldn't over complicate your code. For example.
You can use JLayeredPane to place one component to the top of the other. You can check this