In a project of mine I have been trying to add a JConsonle to a JPanel witch is contained by another JPanel.
The problem is that the JConsole keeps being set 5px from the top of the JPanel.At first I tought it was the container that wasent beeing set up right but after giving it a red background I realised that the console is being set 5px from the top.
I've also tried to use BorderLayout to set it in the NORTH or CENTER of the JPanel but that
dosent work either.
This is my code:
public class MonopolyPanel extends JPanel {
JPanel consoleP = new JPanel();
JConsole console = new JConsole();
MonopolyPanel(){
this.setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
console.setPreferredSize(new Dimension(530, 300));
consoleP.add(console);
this.add(consoleP);
}
}
The console is added to consoleP which has FlowLayout by default, which by default has a vertical and horizontal gap of 5px. Instantiating that with a FlowLayout with zero gaps should do the trick
consoleP == new JPanel(new FlowLayout(align, 0, 0));
From my experience, the best and most flexible layout is GridBagLayout.
99% of panels in Swing I make are GridBagLayout, otherwise its impossible to get it all right.
Because with that layout, you can set weights, exact padding and spacing parameters.
The other layoutmanagers are to limited and not very configurable.
Have you looked at Borders?
It's possible you need to set the JPanel's or the JConsole's border to an EmptyBorder, like so:
component.setBorder(BorderFactory.createEmptyBorder());
You might also look for something about insets in the Javadocs.
Related
I am extremely new to Java Swing, and I'm having quite a bit of issues getting a nice layout going. I have checked out google, and even other answers on this website, but no information I find seems to solve the issue. Here is the result of my efforts:
As you can see, the label, text field, and button are all out of alignment. It is my goal for all of them to have the same left-hand border, and for the button and text field to have the same right-hand border, with these left and right hand borders being each the same distance from the left and righthand sides of my window.
Here are the important parts of my code:
public void run()
{
JFrame frame = new JFrame("Arduino Server");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
InstancePanel = new ServerGUIPanel();
frame.getContentPane().add(InstancePanel);
frame.pack();
frame.setVisible(true);
}
And, in ServerGUIPanel.java:
public ServerGUIPanel()
{
setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
setPreferredSize(new Dimension(500, 500));
setBorder(new EmptyBorder(10, 10, 10, 10));
StatusLabel = new JLabel("STATUS: BOOTUP");
add(StatusLabel);
PortField = new JTextField();
PortField.setPreferredSize(new Dimension(5000, 20));
PortField.setMaximumSize(PortField.getPreferredSize());
PortField.setActionCommand("PortChanged");
add(PortField);
ConnectionButton = new JButton();
ConnectionButton.setPreferredSize(new Dimension(5000, 20));
ConnectionButton.setMaximumSize(ConnectionButton.getPreferredSize());
ConnectionButton.setActionCommand("ConnectionClicked");
add(ConnectionButton);
}
Does anyone have a simple solution to this? What am I doing wrong here?
Thank you very much!
--Georges Oates Larsen
Read the section from the Swing tutorial on How to Use BoxLayout for the basics of using a BoxLayout as well as a section on alignment issues.
Basically you need to make sure the alignmentX value of all components is set to be left aligned.
Also:
Don't use setPreferredSize() to set the size of a component. Each Swing component will determine its own preferred size.
Use Java naming conventions. Variable names should NOT start with an upper case character.
I would not recommend using setPreferredSize() AND setMaximumSize(). The latter will cause problems when stretching your main frame. [Your components will likely not want resize]
You should be using layout managers to handle all the alignments itself. I would stay away from using BoxLayout in this case, as different components want to size differently, and that will sway the alignment when added into your BoxLayout panel.
Moreover, you might want to give your main frame a layout as well.
Can you post how you used your GridBagLayout?
Colleagues.
I'm trying to construct simple GUI in Java, where JFrame has Border Layout. I want to put JScrollPane with JTable to CENTER, and JPanel without layout to NORTH.
The problem is that JPanel doesn't visible. There is simple examle of the problem:
JFrame frame = new JFrame("Test frame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JButton button = new JButton("Test button");
button.setBounds(10, 10, 40, 20);
JPanel panelN = new JPanel(null); // layout = null, panelN without layout
panelN.add(button);
frame.add(panelN, BorderLayout.NORTH);
JTable table = new JTable(new DefaultTableModel(4, 4));
JScrollPane scrollPane = new JScrollPane(table);
frame.add(scrollPane, BorderLayout.CENTER);
frame.setSize(400, 400);
frame.setVisible(true);
You have to use a LayoutManager. It's totally discouraged not using layoutManager, but if you want this you have to set panel.setBounds(..) to the panel too.
By default JPanel has FlowLayout so if you put
JPanel panelN = new JPanel(); // FlowLayout used
panelN.add(button);
frame.add(panelN, BorderLayout.NORTH);
So your frame will look like this.
Layout Managers determines the size and position of the components within a container. Although components can provide size and alignment hints, a container's layout manager has the final say on the size and position of the components within the container.
It's strongly recommended cause for example if you have to resizes components or show in differentes resolutions you delegate this work to layout managers
I don't know the expected behavior of a null layout, but without further requirements you might as well just instantiate with the zero-arg constructor:
new JPanel();
If you didn't set any layout to the panel, when adding components the panel don't know where to put the component, so baisicly the component don't show until you set a specific location for components one by one by component.setBounds(x,y,width,hieght) method.
Note that it's not a good practice to remove the layout manager because of the different platformes, suppose that your program working on Window and MacOS and Linux, you'v better to use the layout managers instead.
Take a look at this post also and see #Andrew Thompson's comment on my answer:
Java GUIs might have to work on a number of platforms, on different
screen resolutions & using different PLAFs. As such they are not
conducive to exact placement of components. For a robust GUI, instead
use layout managers, or combinations of them, along with layout
padding & borders for white space, to organize the components.
After all:
If you have a requirement or an assignment telling you you must use absolute layout, then use it, otherwise avoid it.
It is OK to use containers with no layout manager because you actually CAN set container's layout to NULL. And it's a nice idea to position your components with setBounds(). But in this case, you just have to consider your container. What size it need to be? A layout manager would calculate this for you, and if you don't have one, you have to set the size of your panel by yourself, according to components you have added to it.
As pointed by others here, the case it that the border-layout manager of your frame needs the preferred size of your NORTH panel (actually, the preferred height). And you have to set it, or values will be zeros and the container will become invisible. Note that for the CENTER panel this is not needed as it gets all space possible.
I had a problem like yours before and have written a fast function to resize a container according to bounds of a given component. It will be as large as needed to show this component, so dimension (w,h) and position (x,y) are considered. There's an "auto-resize" version that can be used once, after all components are added.
public static void updatePreferredSize(Container cont, Component comp) {
int w = cont.getPreferredSize().width;
int h = cont.getPreferredSize().height;
int W = comp.getBounds().x + comp.getBounds().width;
int H = comp.getBounds().y + comp.getBounds().height;
if (W>w||H>h) cont.setPreferredSize(new Dimension(W>w?W:w, H>h?H:h));
}
public static void autoPreferredSize(Container cont) {
for (Component comp : cont.getComponents())
updatePreferredSize(cont, comp);
}
You can use updatePreferredSize() after adding every component to a panel, or use autoPreferredSize() once, after all addings.
// [...]
panelN.add(button);
updatePreferredSize(panelN, button);
// [...]
// or...
// [...]
autoPreferredSize(panelN);
// [...]
frame.setVisible(true);
This way, if you do not set you north panel height with a fixed value, with help of these functions you can expect your button will be visible according the position you set it with setBounds().
I'm looking to wrap a JPanel when it reaches the 'edge' of the screen using MigLayout. At the moment I have a JScrollPane (which I only want to be enabled vertically). The JScrollPane contains any number of JPanels which are arranged horizontally - when a panel is added so that the JPanel would go off the edge I want it to add to the next line. Is this possible?
This is the code:
public void setupPanels(){
JScrollPane scrollPane = new JScrollPane();
JPanel mainPanel = new JPanel(new MigLayout("insets 2"));
for (Object object : objects){
JPanel subPanel = new JPanel(new MigLayout("insets 0"));
mainPanel.add(subPanel, "alignx left, gapx 2px 5px, gapy 2px 2px, top");
}
scrollPane.setViewportView(mainPanel);
}
Also, to add an extra factor, every time it reaches the edge I need to add a new/different panel (a timeline) - so is there a way of finding out when it is going to wrap onto a new line?
Thanks
MigLayout does not have such a feature. It is based on a grid and while you can use the nogrid option to flow components horizontally or vertically in a cell span, you cannot make them flow into the next row or column.
The java.awt.FlowLayout contained in the JDK wraps the contained components automatically:
JPanel mainPanel = new JPanel(new FlowLayout());
mainPanel.add(subPanel1);
mainPanel.add(subPanel2);
mainPanel.add(subPanel3);
...
The preferred height is off, but there are ways to fix this, see WrapLayout.
As for the second requirement:
Also, to add an extra factor, everytime it reaches the edge I need to
add a new/different panel (A timeline) - so is there a way of finding
out when it is going to wrap onto a new line?
A layout manager should layout components that have already been added to a container, not add new components based on the results of the layout. Adding invisible placeholder components for the timeline after each subpanel that are made visible by the layout manager on demand might work.
You definitely need a custom layout manager to do this. To get started I would recommend to take the source of FlowLayout. In the layoutContainer implementation there is a loop that iterates over all components. After a line wrap, check if the next component is a timeline placeholder component, make it visible and wrap again.
I have a JFrame window, and I'd like to add a scrollable JTable towards the middle of it. I have a method, called collectionTableScrollPane() that generates the JScrollPane (and I know this is guaranteed to work).
I then proceed to add it to my mainPanel panel. However, I'd like there to be some forced 30px padding on the left and right of the JScrollPane. Logically, I would create a holding JPanel with a centred FlowLayout, and add Box.createHorizontalStrut(30) either side of the JScrollPane.
JPanel tableHolderPanel = new JPanel(new FlowLayout());
mainPanel.add(tableHolderPanel);
tableHolderPanel.add(Box.createHorizontalStrut(30));
tableHolderPanel.add(collectionTableScrollPane());
tableHolderPanel.add(Box.createHorizontalStrut(30));
However, I'm getting a strange result, where the JScrollPane in the middle of the window (denoted by the arrows) sort of becomes ineffectual.
Does anyone know what the problem is?
Note that the JTable contains four rows, of which only two are visible.
I had some issues in the past when i used a JScrollPane inside a panel with a FlowLayout. The behaviour could be tricky, when the content grow, the horizontal scrollbar may appear or the FlowLayout should add a new line.
In your case, i will replace the FlowLayout by a BorderLayout :
JPanel tableHolderPanel = new JPanel(new BorderLayout());
mainPanel.add(tableHolderPanel);
tableHolderPanel.add(Box.createHorizontalStrut(30), BorderLayout.WEST);
tableHolderPanel.add(collectionTableScrollPane(), BorderLayout.CENTER);
tableHolderPanel.add(Box.createHorizontalStrut(30), BorderLayout.EAST);
As far as I'm aware, Box is suppose to be used with the BoxLayout, this may be causing you some issues. Instead, why not use a EmptyBorder on the tableHolderPane
BoxLayout accepting size that came from JComponents, the same issue with default FlowLayout pre_implemented for JPanel
you have to returns PreferredSize by overrode JPanel nested JScrollPane,
use another LayoutManager, e.g. GridBagLayout or todays MigLayout
use NestedLayout, by using BorderLayout where you put two JLabels (e.i. that returns PreferredSize) to the EAST and WEST area
everything depends if you really to want to create the empty area and if shoud be resiziable or not
My current problem is that I have a JFrame with a 2x2 GridLayout. And inside one of the squares, I have a JPanel that is to display a grid. I am having a field day with the java swing library... take a look
Image
Java is automatically expanding each JLabel to fit the screen. I want it to just be those blue squares (water) and the black border and not that gray space. Is there a way I can just set the size of that JPanel permanently so that I don't have to go through changing the size of the JFrame a million times before I get the exact dimension so that the gray space disappears?
I also would like to set the size of those buttons so they are not so huge (BorderLayout is being used for the buttons and TextField)
GridBagLayout is what you really want to use. The GridLayout will force the same size for each component in the layout no matter what size constraints you put on them. GridBagLayout is a lot more powerful and a lot more complicated. Study up on the API page for it. Using GridBagLayout, the components won't fill the whole grid space if you don't want them to and can even stay the size that you ask it to be. To keep a component's size from changing, I would set all three available size constraints:
water.setPreferredSize(new Dimension(20, 20));
water.setMinimumSize(new Dimension(20, 20));
water.setMaximumSize(new Dimension(20, 20));
For your buttons, I would definitely use an inner panel as Bryan mentions. You could use either a GridLayout like he suggests or a FlowLayout if you don't want all the buttons to be the same size. Add all your buttons to that inner panel instead of the main one.
If you want the two checkerboards to stay the same size, then you'll need to have them each contained in their own JPanel. Set each of those parent JPanel's to have a layout type of GridBagLayout. Set the preferedSize for each checkerboard component and then add them to their respective containers. GridBagLayout should by default lay each board out in the center of the parent JPanel. So as the window is resized, the JPanel parent area will get larger or smaller, but the checkerboard components inside will remain the same size.
Alternatively, you could have your blue squares scale to the right size as the window is resized by having each checkboard square be a JPanel with a BorderLayout layout manager and adding the JLabel (with a blue background color) to its BorderLayout.CENTER location.
As for your buttons, try something like this:
JPanel theButtonPanel = new JPanel(new BorderLayout());
JButton button1 = new JButton("Fire");
JButton button2 = new JButton("Pass");
JButton button3 = new JButton("Forfiet");
JPanel innerButtonContainer = new JPanel(new Grid(1, 3, 8, 8));
innerButtonContainer.add(button1);
innerButtonContainer.add(button2);
innerButtonContainer.add(button3);
theButtonPanel.add(innterButtonContainer);
Lastly, consider using a design tool for your Swing user interface. Netbeans has an excellent UI designer built into it. Download Netbeans here.
If you can setResizeable( false ) on the top level frame you can then set your layout manager to null and hard code each location and size via setBounds. This is how I would do it (contingent on resizing of course).
I have had success solving problems like these using TableLayout which is a third party layout manager. You will need to download it and read the tutorial but the key would be to set the justification to CENTER when adding the JButtons to their positions in the layout.