Seeking advice on layout options - java

I'm currently doing an assignment that involves me creating an elevator simulation. This is currently where I'm at:
The way I've got it working is that when the combo box on the right is changed, the floor lines automatically redraw themselves according to the panel sizes. The tricky part now is I just want to print the floor numbers in the left 'floors' panel, just on top of the floor line. However, I have no idea how to go about it. I toyed with the idea of setting a null layout and positioning the jlabels according to the floor heights (which I have saved in an array). But everywhere I've looked, people have said this is a bad idea.
So could someone suggest a way to accomplish this with a layout manager? Thanks.

Start by breaking down you UI into manageable chunks, this will allow you to focus on the individual requirements of each section without getting overwhelmed...
...To start with...
This would suggest the use of a BorderLayout, placing the red section in the BorderLayout.NORTH position and the green in the the BorderLayout.CENTER position.
...Next...
The header is broken into (at least) two sections, this would suggest a GridLayout...
...Next...
The body suggest three equal columns, this could be achieved with a GridLayout or even a GridBagLayout, if you need the widths to be different for each column...
... Next...
This is probably the most complex. To start with the "blue" section would probably benefit from either a GridLayout, if the Number of floors label and JComboBox resided on their own JPanel (may be using a GridBagLayout) or aGridBagLayout` if you wanted more control
The red section is probably a using a GridLayout
All three sections would probably be glued together with a GridBagLayout...
For example...

Related

Swing, achieving components wrapping round onto next line when space constrained with BoxLayout

I had hoped to create a sublcass of JPanel that would retain a fixed height and width, within which i could add a series of components that would appear sequentially according to the X or Y axis, wrapping round onto the next line below where space was not available on the current line.
Unfortunatley the BoxLayout seems like it is intended to simply lay out components along the X or Y axis in a line. This seems counterintuitive however, since the documentation describes it as like the FlowLayout with additional functionality. Thus surely i assume there must be a way to achive what i am hoping to?
since the documentation describes it as like the FlowLayout with additional functionality.
It doesn't say anything about wrapping. So why would you expect this additional functionality to be wrapping?. Reread the tutorial for the supported functionality.
In any case you do want to us a FlowLayout because it does support wrapping. However the preferred size of a panel using a FlowLayout always assumes a single row. So to get around this limitation you can use the Wrap Layout on your panel.

Positioning a label in Java Swing

I have gone through lots of tutorials which teach about layouts in Java Swing, but they don't seem to suffice my need. I am creating a solar system GUI using Java Swing, and i want to place the planets in the GUI according to the values i fetch from my micro controller, which are usually float point values. I cannot use the Grid Bag Layout, as to position a label i have to specify grid x and grid y, which cannot be the case since I receive float point values from the micro controller. The best resource i found is to use absolute layout where i can specify the position of the planet by giving mere X and Y Co-ordinates, which will be fetched from the micro controller. The problem I am facing now is that the absolute layout does not have auto re-size feature.
What would be the best possible option to adopt the auto re-size feature in absolute layout?
Swing tutorials were not generally meant for situations like this -- they were meant for people who want to write more normal GUI applications, using buttons, drop-down boxes, check boxes, radio buttons, menus, and have layout that follows currently accepted practices in terms of positioning those on the screens. If any of that applies to the part of your program that is not displaying planets, I encourage you to use what they have to say about it.
But you want to place things according to calculations of your own. I recommend doing that in a panel, calculating the size and position of your objects according to the size of the panel at the point of drawing. When the panel resizes, you will need to trap the event that says it is resizing and redraw. You will need to deal with your own minimums and maximums, etc.
I don't recommend the custom layout manager suggested elsewhere for a couple of reasons. Firstly, it won't save you any work at all -- you are still going to have to write the code that determines positions of things, if you just then draw your own graphic instead of attempting to position a UI element, I think it will actually be less work. And that's the second reason -- layout managers' purpose is to position UI elements within the panel, and the pieces of your solar system don't really have any need to be UI elements, just graphics on the screen.
Good luck.

Java Swing - Keeping reasonable dimensions on different screens

I have just completed an application for my final year project and I need to create the interface for it now. The application will not include many different screens, just one introduction screen with a simple tutorial and the main screen with 5 JPanel and a JMenu. I have each part of the application providing its own JPanel, and the GUI I am about to make should put all those panels together and provide the intro.
What I want to ask is how I can properly set the sizes of different
components so that they are displayed the same on different screen sizes.(not getting really close to each other on small screens / big blank spaces on larger screens)
Should I manually set their preferred sized based on some percentage of the screen dimensions ?(e.g. 20% * width,40% * height) Or there is some other way to do it ?
Also, having one week ahead to complete this part, would it be any benefit to try and learn some library like MigLayout? I read a lot that is easier to use than standard Swing.
p.s
The JPanels include trees,textAreas,toolBar, buttons,checkboxes,comboboxes and textfields. Each one of those panels are quite simple to make.
The answer to this type of question is pretty application dependent, simply because what is 'reasonable' depends on the application and user expectations, but...
If you want the content of the frame to dictate the size of each frame, you can just call frame.pack() and an appropriate size will be guessed at based on the size requirements of the frame's children.
However, if it makes more sense to let the screen size dictate the frame dimensions, you can use Toolkit.getScreenSize() to get the screen size and do your positioning based on what you find.

How can I achieve WYSIWYG in NetBeans GUI Builder?

I've spent many fruitless hours trying to create what I consider to be a very simple GUI. One thing that makes it simple is that I don't even expect it to be resizeable. I want it to display just the way I've laid it out. Simple as that.
There's a JFrame containing two Jpanels of equal width, one above the other. I've got the JPanels behaving themselves finally, and I can slide them around without their enclosed components mysteriously shifting.
But I can't for the life of me get the JFrame to nicely enclose the JPanels. I'm attaching a screen shot showing the layout and the inspector, and another showing how it previews
(Notice that it's chopping off the bottom edge.)
Is there any way to work in a "WYSIWYG mode" in the GUI builder? I don't care about (in fact, I dread) resizeability, at all at this point. I would have thought Absolute Layout would be the right choice for this, but there's still something wrong. (I need an elementary solution, folks -- please don't suggest GridBagLayout!! ;)
EDIT: By restoring some defaults, mainly for MaximumSize, to the JFrame, I got rid of the clipping problem. The right edge was still off by one pixel, and I managed to find which of five (five!) width properties was controlling that. (bounds, max size, min size, preferred size, and width - changing min size fixed that.)
I've already found that you can't completely avoid tweaking properties (e.g. to override "snapping" and achieve pixel-precise positioning). I clearly made trouble for myself at some point by playing with some properties I shouldn't have. The question remains: for non-resizable, WYSIWYG GUI design, is Absolute Layout a reliable choice; and, what properties should I avoid editing?
Is the JFrame showing any better when you actually run than preview? I think this is an OS X specific NB behavior. I did not see this in Win32. For now, you may try adding a JLabel ( spaces as the text content) at the bottom to make sure that space is drawn when the actual JFrame runs.

How to wrap a Component to several lines

I have a large component (say width=4000px, height=200px) and would like to be able to see it entirely even on a small screen.
I don't see any easy way to do a wrapping component, my idea is the following :
given a factor (for example 4), the component would be of size 1000x800, by wrapping the child to 4 lines. The size requests would be translated in reverse to reshape the child, and so on. On painting, the component would call the paint(Graphics) of the child 4 times with a correct Graphics argument that would map the wrapped space to the child's space.
However, I can't see how to handle all the events : should I set eventlisteners for every children-generated event (PropertyChange) and for every parent-generated event (Mouse, Key, Resize, ....) ? This seems quite a lot of mapping, and I'd be happy to ear of an easier way of doing that...
I haven't looked too much at the JViewport implementation, but maybe this could help me don't you think?
thanks for your suggestions!
Frederic.
Edited to answer some of the comments that suggest to redesign the component :
Allow me to disagree here : making a component is one job, showing it is another. If I want to show it with scroll bars, I use a Scroll-Pane, whereas if I want to show it split in 4 lines, I want to use a similar solution.
I am the designer of the component in question (and had sharp words with myself, as suggested, but it lead me nowhere :-) ). I actually added "line-wrapping code" in it but it appears (really quickly!) that adding point space conversion, painting management in the codes of the component itself makes it really really messy, which is the reason why I imagine that a specialized component is a really a better solution.
Furthermore, making a custom component lets me reuse it far more easily as a "wrapper" for any other component.
Imagine if you had to recreate a JScollPane-like functionality every-time you use a JScollPane, dealing with scroll position, buffered painting and everything inside your own components : hopefully you don't have to!
You're approaching this the wrong way. It's the contents of the component, not the component itself you should be thinking about. If you want it to be 1000x800, make it that size. If the component has content - e.g. text or other components - calculate their positions appropriately. (You probably won't be able to use the standard layouts, and may end up writing your own). You'll probablky need to recalculate the layout if the component's width changes.
Don't call paint 4 times. If you've calculated the layout of the component, it's children or text, correctly then paint should just work.
In response to the comment: wrapping a histogram, in the sense of inserting arbitrary line breaks, is not likely to be useful. With graphical components the 'breaker' won't know exactly where to insert the breaks; you will also lose any information attached to the Y axis. Much better solutions would be to simply shrink the histogram in the horizontal direction until it fits the screen width, or to draw four histograms one under the other, duplicating the Y axis information for each. Alternatively allow horizontal scrolling over the whole histogram; or change the axes so the histogram is drawn horizontally. If none of the above work, perhaps because you have many hundreds of histogram bars, maybe a more interactive approach where you amalgamate some of your histogram bars together to give an overview, and allow the user to 'drill down' into the plot to get at the more detailed information.
If the issue is that you can't modify the original component, and it draws a fixed size image, then your best bet may be to call 'paint(Graphics)' on it four times with appropriate transforms and clipRects on the Graphics to draw the four parts 'stacked'. But frankly you may be as well off throwing away the original component. Histograms are not that hard to draw, and there are plenty of free plotting packages to help you. And be very rude to the designer of the original component if you meet them.
You don't mention scrolling. Put it on it's own pane and then put that pane into a scrolling panel.

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