Java Swing, making a gridlayout fill parent? - java

I just recently started using Swing to create GUIs for programs, and it's been pretty fun to mess around with so far. However, I'm having an issue with a JPanel with the layout set to gridLayout. Right now it looks like this:
The grid on the right is a JPanel set to a GridLayout, with each cell being a bordered JLabel. The options on the left are also inside a JPanel, and the left JPanel and right JPanel are nested in a GridBagLayout set on a JFrame.
Essentially, my problem is that I want to "scale" the grid on the right so that each cell is a certain height and width. The grid itself will have a variable number of rows and columns, which are set when the program first starts up. Eventually, I plan to have the right JPanel in a JScrollPane (if that's how that works...), so I'm not really concerned about whether or not all of the grid shows up onScreen.
I tried setting the fill value for the gridLayout to "BOTH" and it gave me the following result:
This is closer to my intention, but I wanted the actual ImageIcon in the JLabels to fill the entire JLabel. Additionally, I would want the JLabels to be the same height and width. However, I don't know exactly how to do that. I've been messing around with it for a while now, and I'm not sure if I'm just too much of a noob with Swing, or if I'm missing something in the documentation.
In the end, I'd like the grid cells to be a fixed height and width, no matter the number of cells, and no matter whether it goes offscreen or doesn't fill it.
(Also, I just thought, maybe it's not the best idea to code this and then shove it in a JScrollPane later and expect it to perform the same.... I guess I'll just see what happens.)

but I wanted the actual ImageIcon in the JLabels to fill the entire JLabel.
Check out Darryl's Stretch Icon which will allow the icon to resize to file the space available for the JLabel.

Related

Java button within graphics panel

I'm relatively new to developing GUI's within java so this may well be a stupid question or quite simply not possible to achieve but here we go.
I've created 1 single JPanel with no border layout set up or anything like that and I intended to paint a GUI on top of it using the graphics class. The JPanel is just plain black and then I've drawn a huge box over it leaving the black just as a border, and painted the whole GUI within this white box.
I want to add buttons within that white box GUI as well but I've no idea how. In fact they don't even have to be traditional buttons JButtons, if I could just draw a shape and have that act as a button then add an event handler to just that shape that would work also but I don't know how I'd do that either.
I have so much code for my whole program (it's a school coursework project) that I'm not sure which parts would even be worth sharing to assist with this question since there's so many GUI aspects I've already drawn so I've tried to just explain my issue in words.
Honestly I have no clue what I'm doing so any help would be appreciated.
EDIT: Here's a screenshot of my current GUI with a 'sketch' of how and where I'd like to be able to add buttons.
GUI Image
As with any suitably complex UI, you need to start by breaking it down into manageable chunks, focusing on areas of mutual interaction and functionality.
For example...
Says to me that you have two primary UI elements, the left and the right.
This could easily be established with a GridLayout, but, if the two sides are not equal in width, a GridBagLayout might be more appropriate
The right side to me says simply, JTable. You could place this within a container using a BorderLayout, allowing the table to occupy the CENTER position.
The key information would then a component laid out with either a GridLayout (top and bottom) or a GridBagLayout if the requirements are more complex. This component would then be added to the SOUTH position of the BorderLayout.
Again, this is pretty simple. The primary layout would probably be a BoderLayout, with the title in the NORTH position, the graph in the CENTER and the buttons wrapped in a component in the SOUTH.
You could use either a FlowLayout or GridBagLayout to layout the buttons depending on your how you want them to appear
Recommendations
Have a look at:
Laying Out Components Within a Container
How to Use Tables
And for the "border", I'd recommend you have a look at LineBorder. Take a look at How to use Borders more details

Can't resize JLabels in BoxLayout

I'm trying to set up a few JLabels to use as buttons inside a BoxLayout, stacked on top of each other. The layout is fine, but I'm finding that I can't resize the labels to the dimensions I want. I'm using the following code to size them:
JLabel fileAddBtn = new JLabel("Add File", SwingConstants.CENTER);
fileAddBtn.setBorder(BorderFactory.createLineBorder(Color.black));
fileAddBtn.setMaximumSize(new Dimension(Integer.MAX_VALUE, fileAddBtn.getMinimumSize().height));
and
JLabel fileRemBtn = new JLabel("Remove File", SwingConstants.CENTER);
fileRemBtn.setBorder(BorderFactory.createLineBorder(Color.black));
fileRemBtn.setMaximumSize(new Dimension(Integer.MAX_VALUE, fileRemBtn.getMinimumSize().height));
As of now I have two labels, with one being longer than the other. They are both taking the width of the longer label, which is good, but the labels are hugging the edges of the text right to the nearest pixel. Is there any way to make the labels a little bigger so that there is a bit of a border around the labels? I've tried using setSize() but it doesn't take. I've also added straight values into the above code, but it doesn't change them either. I tried adding an EmptyBorder() around them, which worked for sizing, but it hid my line border which surrounds them. Any thoughts?
Is there any way to make the labels a little bigger so that there is a bit of a border around the labels?
Sure. Add an EmptyBorder.
But since the code is already adding a border to the labels, to retain that line border, make a CompoundBorder consisting of the empty border and the line border, and set the compound border to the label.
See also Should I avoid the use of set(Preferred|Maximum|Minimum)Size methods in Java Swing? (Yes.)

Keeping a component in a fixed position within a BoxLayout

I have a JPanel that uses a horizontal Box layout and contains a JLabel that I would like to keep in the exact same position as other components within the JPanel are setVisible(false). Currently, the JLabel moves to the left as other components become invisible.
What's the easiest way to go about this?
EDIT: Pics added
So this is what the JPanel look like with all components visible
When I set the three JTextFields on the right to invisible, the JLabel set to text X moves to the left like this:
But I would like it to stay where it was like this:
EDIT2: I'm actually using Netbeans GUI editor's Free Design for this particular JLabel. I'm sorry for the mistake - I've been using a lot of BoxLayouts recently and I got confused!
Currently, the JLabel moves to the left as other components become invisible.
Yes, layout managers are designed to only work with visible components. I'm not sure if any of the default layout manager will work, but I would look into using the GridBagLayout, since this layout is based on a grid structure so as long as you have components in that grid on another row the label should not shift.
Otherwise, you could dislay the "other components" in a panel using a CardLayout. Then instead of making the components invisible, you swap the panel with an empty panel.
Read the section from the Swing tutorial on How to Use CardLayout for more information and working examples.
Edit:
Based on your picture the easiest solution is to use "glue":
panel.add(Box.createHorizontalGlue);
panel.add(xLabel);
Now the label will always be displayed at the far right of the panel. Read the tutorial on How to Use BoxLayout for more information about "glue".

Why are all my labels spaced by like 4 tabs while being boderLayout WEST?

I have a JPrame and it it set to borderLayout. Then i created another JPnael which uses BoxLayout. Now i have added labels(which contain text) and textFields to the JPanel. I have also setLayout of JPanel to WEST. Now i dont know why, but I have two problems with what is being displayed.
1) The labels are all indented 4-5 tab spaces, this is so random I dont even know why it is tabbed. All the labels in this panel are like this. Please note that this only happens if I add more stuff to the JPanel. If I only have 1 label in the JPanel it is correctly alligned to the west corner of the screen. Does anyone know why they get indented when i add more elements to the JPanel?
2)The Textfields size are huge, as in they take up many lines. I have set the size of the text fields only to 20. Yet they take up like 5 lines. Why is it not just a single line?
Im sorry guys, I have been trying to fix this for the past 2 hours and dont know what is causing this issue. I would post code, but this is an assignment and I dont feel comfortable posting it on to the internet. I hope you understand.
Just to make things clear, I have a JPanel for example called "aPanel" which is set to BorderLayout then I have another JPanel called 'subPanel' which uses boxlayout and set the layout of that to be west. After this I add stuff to this 'subPanel' expecting the elements to stack over eacher other towards the left border of the JFrame.
1) Read the section from the Swing tutorial on Fixing Alignment Problems. When you add different components to the panel they may have different "X alignment" so you get a different layout than you expect.
2) The box layout will expand to fill the available space. So you need to override the getMaximumSize() method of you text fields to return the preferred height of the text field and the maxiumum width of the text field.
Edit:
Just read the last part where you mention a FlowLayout. If this is what you are using then read the FlowLayout API. It has a parameter that controls left/center/right alignment of components added to the panel.

Draw a Jpanel's border without resizing content (Java)

I have a column of JPanel instances that has content in it, that when it is clicked, the selected Panel is set to have a border (in order to distinguish it), and only 1 at a time has the border.
The problem is that when it sets the border, it sets the outer section of the panel to the border, and shrinks the content inside. Although it seems minor it is not very professional, and I would much rather have it add more like an overlay, where the content will not shrink.
I am thinking maybe there is some method of graphics that will let me do this? I haven't been able to find any way of doing this.
Start by setting all the components to have a EmptyBorder set to a single pixel inset.
When you select a panel, simply set the newly selected panel's border as you are (presumably using a LineBorder) and the set the previously selected panel's border to the single pixel EmptyBorder.
If you're clever, you could get away with a single instance of EmptyBorder ;)

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