Table columns aren't appearing - java

Simple as the title says. They just won't appear. I don't know why. BTW, The table is added on a panel that has setLayout(null); So, I don't know if that affects it. I just really don't know where the problem is coming from. I'm completely clueless.
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Change DisplayTab.add(table); to DisplayTab.add(scrollPane); and make use of appropriate layouts
Avoid using null layouts, pixel perfect layouts are an illusion within modern ui design. There are too many factors which affect the individual size of components, none of which you can control. Swing was designed to work with layout managers at the core, discarding these will lead to no end of issues and problems that you will spend more and more time trying to rectify

Related

How do I make one component visible in more than one pane in a JTabbedPane?

I was wondering if there was a way to make one component (in this case a JPanel) visible in more than one of the tabs.
I have a simple JFrame which is completely filled with a JTabbedPane. Each tab has a slightly different function, which is why they're in different tabs. However, they each output the same type of information. I was wondering if there was a way to make it so the same output panel could be seen in all the tabs, without having to create one panel for each tab.
I realize that it is impossible to add one component multiple times (and have it display independently each time), which is why I'm not optimistic about this being possible, however if it is, it would make my code much cleaner. In the case that this is not possible, I am completely open to alternate suggestions that achieve a similar result. I am in the very beginning of my project, so it won't be too difficult to change things.
This image gives a rough idea of what I'm trying to make it look like:
I have searched around for anyone dealing with this issue, however I have had little luck finding anything relevant. If I missed something, I apologize for wasting your time.

Java JLabel changes Font Automagically

I have a number of various components in a very large JavaEE application. As such, debugging is a pain, and sadly I cannot provide an SSCCE that accurately depicts the problem I'm having.
In a nutshell, somehow my fonts change by themselves for things like JLabels and JTabbedPanes. Without ever touching them, they're being repainted as bold, italicized, dramatically changed in size, or any combination thereof.
Simple question: why?
If I step through the Eclipse debugger, no changes are made, ever. So time is somehow a factor.
I'm still a Java grasshopper (working by myself), and haven't built this program in such a way that the EDT is a sacred object. I'm worried that because I'm potentially not making all repaint() calls on the EDT that the JTabbedPane, JLabel and other font properties are being reset and repainted.
EDIT:
Forgot to say that I'm constrained to Java 1.5.
I think I've narrowed it down to an issue with using HTML in JLabels and JTabbedPane tab titles...but past that I've got no idea. With regards to the JTabbedPane, it's going into the drawing methods with the right Font/FontMetrics objects, but for whatever reason it will very rarely (sometimes more often; still haven't figured out the timing trigger) switch up what font, style, and even size at which it's painting the text.

Swing: problems with component's background

I've got a problem, that swing components in different parts of program have sometimes wrong background. For example this or this.
As I mentioned, the bug is not permanent and it can appear in one place one time and never after. But still there are some places, where I can randomly reproduce it. Unfortunately, I don't see any solutions.
Has anyone some ideas how can I fix it?
If you set your components to non-opaque (I think the call is setOpaque(false)), that will let the background colour of the component that it is on top of show through.
in addition to what Paul said, there's the question if you use self made components.
Such components should take care of their complete occupied region (or at least the invalidated regions) in the paint callback. An error seen quite often that leads to strange artifacts when moving or resizing is that only "important" parts are repainted, for example a string to be shown, without drawing the background.
In this case, anything previously blitted ther will show through.

NetBeans should be named "Mexican Jumping Beans"

I have been trying to set up a Java form in NetBeans with 15 - 20 visual components (buttons, textfields, etc.) and I have been using the Free Design layout paradigm on the MAC.
According to what I've read, the Free Design layout gives me various alignment guides, but does not try to force my alignments to specific row and column delimiters. However, I'm finding that when I do this, the width of my form may arbitrarily change, or some of the components I've already placed will move around radically when I make even small adjustments to other component positions.
Is there some way to anchor all these components, once placed, or is there a better layout paradigm that gives me the freedom to place components where I wish to?
IMHO, Matisse works best when you know what you want before you start. It doesn't seem to do so well with iterative changes.
Here are a few rules I follow when using Matisse in freeform mode. They don't make it wonderful, just less painful:
Build top-to-bottom and left-to-right. Most jumping happens when you go back an try to insert something.
Build it in one pass.
When you make progress, save it. There are conditions where Matisse will drop its undo list. Don't count on Ctrl-Z to bail you out. I use a local mercurial repo to track my changes.
Keep it small. The more elements, the more likely it is to blow up. Build it out of smaller components. For example, if you have a date field with a button to open a calendar
make that a component.
Add the component to the palette,
use that in the larger component.
Maybe it's time to look into other LayoutManagers, like GridBag or something else that will give you what you want. The built-in choice by NetBeans sounds like a poor one for your needs.
If you choose a null LayoutManager you'll get absolute positioning.
But along with it comes absolute responsibility: No help in repositioning any elements.
I've found Using GroupLayout directly works really well. It can be confusing at first because horizontal and vertical layout are done separately, but once you get used to it it's not that difficult. You can definitely get things to align, and stick together when resizing. It's far better then using nested panels, GridBags, and that kind of thing.
MigLayout might work too, but GroupLayout is included in the JDK.
You may want to look at the absolute layout. It allows you to put the component exactly where you want it, without all the jumping around.
GridBag Layout is my favorite, and specially in Matisse (Netbeans GUI). You have like a wizard to graphically manage all the properties.
Will take you few examples to get things perfect as you want, but when you do, you will never look back.
Take a look at Sun Tutorials GridBag Layout
I strongly, strongly recommend MigLayout (And getting away from GUI layout tools). Any time you think you are saving by using a GUI tool quickly evaporates the second you run into layout manager behavior. Real UI's are coded, not built with drag and drop.
I found that it took me about 3 hours of fiddling to get used to MigLayout - after that break in period, I found it to be incredibly intuitive and powerful.

Java GUI LayoutManagers

I'm busy with an asignment where i have to make a graphical interface for a simple program. But i'm strugling with the layout.
This is the idea:
What is the easiest way to accomplish such a layout?
And what method do you use to make layouts in java. Just code it, or use an IDE like netbeans?
And what method do you use to make layouts in java. Just code it, or use an IDE like netbeans?
NetBeans for GUI developers is like a calculator for grade schoolers: you really shouldn't use it until you know how to do things without it, but then it will save you a lot of time.
(I'd love to answer your primary question, but the firewall I'm behind is blocking the picture.)
Well considering how simple the layout is I would suggest you use a BorderLayout with NORTH set to the top section in a container and the JTable in the CENTER of the BorderLayout. For the Top it appears to be a simple BorderLayout again with NORTH as the Instruction: south as the black box (possibly in a container with a FlowLayout). The center of the top pane appears to be 2 Containers of GridLayouts with 2 rows and 2 columns, so put thos in another container with a GirdLayout.
So in pseudo:
Container(BorderLayout)
{
#NORTH
Container(BorderLayout)
{
#NORTH
Label(Instruction);
#CENTER
Container(GridLayout(2,1))
{
Container(GirdLayout(2,2))
{
Label() TextField()
Label() TextField()
}
Container(GirdLayout(2,2))
{
Label() TextField()
Label() TextField()
}
}
#SOUTH
Container(FlowLayout())
{
JButton() //shaded thing?
}
}
#CENTER
{
JTable
}
}
I build everything by hand. Like Christian, I've had bad experiences with GUI builders; they always either refused to configure a couple of components quite right, or they generated huge amounts of unnecessary code which made later maintenance impractical, or both.
I used to do build a lot of UIs using GridBagLayout, but for years, I've never seen an office-environment UI that couldn't be built with nested BorderLayouts, GridLayouts, and the occasional BoxLayout or FlowLayout. About 98% of the stuff I've seen is doable with nested BorderLayouts.
In your case, the layout organization will be as bmeck says. Speaking from memory, using CENTER for the JTable (remember to put it in a JScrollPane!) and NORTH for everything else ensures that if you resize your JFrame, the JTable will get all of the extra space, and that should be exactly what you want. For the top labels and fields, the nested GridLayouts should ensure that each "column" of labels and fields will take up equal horizontal space. (They'll get only enough vertical space to be completely visible, and no more, since the JTable is taking up everything else.)
Everything else is just a matter of adding borders and setting the GridLayout padding reasonably.
For myself gui-builders for swing or swt never worked that well that's why i code layouts myself using layout managers.
Your question doesn't mention which gui-system you are using but i assume you want to use swing. If that's the case I would recommend to use GridBagLayout for your layout. It is not that easy to use in the beginning but as soon as you know how it works you can do most layouts in the way you want it to be and i think it is also the layoutmanager of choice for the layout you want to do.
I've used GUI layout generating tools for super rapid development (maybe get the first 2 or 3 iterations of an interface out of the way). I've ultimately found that using a simple fixed layout (no layout manager) with these tools is the best approach. Once we are starting to hone in on a design, we switch to manual layout.
Whenever I've tried to use GUI generators to create code for layout managers, I've almost always been bitten eventually where the layout would just stop working and I spent more time debugging the impossible to read auto-generated code than if I'd done the layout by hand anyway. For what it's worth, when we are doing the early phase of layouts, we use the Jigloo plugin for Eclipse. It's very inexpensive, and does a good job.
I'm a big fan of MiGLayout. I've found that it is incredibly easy to use for simple layouts, and is capable of doing extremely complicated layouts. All without the need to resort to nested panels, etc... JGoodies Forms is also good, but harder to use.
I wrote an article a while back on layout managers:
http://developer.java.sun.com/developer/onlineTraining/GUI/AWTLayoutMgr
It describes how nesting (as bmeck above demonstrates) can be used very effectively for many UI designs.
Try table layout. Works great.
https://tablelayout.dev.java.net/
Use GroupLayout
:)
All the alignments are pretty easy to do
I used to love Motif's XmForm for this sort of thing. In Java, I usually put Boxes inside of boxes. So I have a vertical box. First row of the box contains a JLabel for the Instruction. Second row contains something for the label/result stuff, possibly some sort of grid. Third row contains whatever that blacked out thing, Fourth row contains the JTable. Then I'd spend some time to try to figure out how to do the lable/result stuff. Then I'd probably end up saying "dammit", and doing it as a GridBagLayout.

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