I have a JTextField in my JFrame and I set the text in the JTextField.
When the text is long, JTextField gets the text's length and then jTextField's new width is equal to the text. It changes my window's shape and other components' places. How can I make JTextFields have static width so they won't be resized based on the length of the text that pass in?
The simplest thing you can do is set the column width, usually during initialization of the JTextField, e.g.:
new JTextField("Hello World!", 5);
new JTextField(10);
But the container will have a layout manager -- if you didn't specify it explicitly, it likely has a default. JFrame starts with BorderLayout in the content pane, although if you've added any other panels between the JFrame and the JTextField, we'd need to know that to have a better sense of the layout manager.
Some layout managers will constrain the width of the field as well, which is another way you might address your problem.
Related
I have a set of JPanel's within a JFrame. One of the panels contains a JTextArea. At the moment I create this like so:
JTextArea = new JTextArea(5, 40);
And this gives me a text area which is 5 rows by (roughly) 40 columns.
Vertically this works as I'd like it to, the area fills the entire height of the parent container - probably because the parent is the only element positioned in that row.
Horizontally the parent width is determined by elements underneath and it is (usually) wider than the JTextArea is. So I end up with a text area with large margins on either side. What is worse, when I resize the frame smaller to the point where the text area is exactly the width of the parent container, it suddenly 'flicks' and changes into a text area that is 1 row high and is then the width of the parent.
Excuse the crude drawing below which hopefully illustrates the issue.
In short: How to I create a JTextArea that always fills the maximum space available to it? (and if possible with a minimum width after which a scrollbar appears if the user sizes the frame even smaller)
In the parent container of the JTextArea (denoted as Panel 1 in your drawing), call the function:
panel1.setLayout(new BorderLayout());
For reference, see this documentation page:
https://docs.oracle.com/javase/7/docs/api/java/awt/BorderLayout.html
As you only have a single child in panel1, the BorderLayout layout manager of panel1 will by default stretch the text area to use all available space in the parent container.
You may want to take away the constructor parameters specifying the size of your TextArea. The BorderLayout should take care of sizes for you :)
You can request that Swing respects a certain minimum size for the text area by calling:
textArea.setMinimumSize(new Dimension(minimum_width, minimum_height));
You have to use layout manager, for start see oficial Oracle docu about layout managers. For your situation, BorderLayout or GridBagLayout should work fine.
Start with:
panel1.setLayout(new BorderLayout());
or
panel1.setLayout(new GridBagLayout());
With GridBagLayout you can more preciselly do layouting (with BorderLayout you have five areas - no more, no less). With GridBagLayout you can do more complicated layouts.
can I do change in the size of JTextField using GridLayout (like width and height of field) in Java
I tried this but it doesn't work:
txt=new JTextField(20);
GridLayout will resize all components to be the same size.
One way 'around' that is to put the (e.g.) text field in a JPanel with the default flow layout, then put the panel in the grid layout. The panel will be stretched to fill, but the text field inside it will remain at its preferred size.
I need to make a fixed sized for a GridLayout with 100 buttons located in the center portion of a BorderLayout. On the east portion of the border layout is another Gridlayout that keeps shrinking the center component whenever the text is longer then the size of the current JTextAreas located in the east. The JFrame is not resizable also.
Is there a way to get a fixed size for the center component while allowing the JTextArea to still expand?
"I need to make a fixed sized for a GridLayout with 100 buttons located in the center portion of a BorderLayout".
Sorry, but that's not going to work. BorderLayout doesn't work like that. You can nest JPanel containers with different Layout managers to get your desired effect.
"Gridlayout that keeps shrinking the center component whenever the text is longer then the size of the current JTextAreas located in the east."
You should wrap your text area in a JScrollPane, and setLineWrap(true) and setWrapStyleWord(true) on you text area. The last two will set it, so that the line typed wraps when it is reaching the right edge of the text area. Also If you are setting the size to the text area, don't. Instead, use the following constructor to set its size
JTextArea jta = new JTextArea(20, 50); <--- rows, and character columns
jta.setLineWrap(true);
jta.setWrapStyleWord(true);
JScrollPane scroll = new JScrollPane(jta);
container.add(scroll); <--- make sure you don add jta anywhere else
Without more context to your querstion, these are really the only valid suggestions I can make.
I created a JFrame initialized with a BorderLayout and a JScrollPane as its CENTER element.
The scroll pane is set with VERTICAL_SCROLLBAR_ALWAYS and HORIZONTAL_SCROLLBAR_NEVER policies. The intent of my frame is to have a controlled width, while the height should grow/shrink as data is added/removed.
Inside my scroll pane, I added a simple JPanel (lets call it the content panel) which is initialized with a FlowLayout (and LEADING policy).
In order to test this, I simply populate my content panel with 20 JLabel("Item " + n) components where n is the loop counter.
I would expect to see my labels shown on a single row if the frame is large enough and the labels wrap to other lines when I shrink the width. But instead, there is only a single line displayed with no wrapping... ever.
Does anyone know why the flow layout does not wrap when a scroll pane is involved?
If I remove the scroll pane all together and put the content panel directly in the frame, the desired wrapping effect occurs, but if the frame height is shrunk smaller than the content panel height it just disappears.
The idea is that I want my labels to be wrapped when necessary but also always be visible if it means having to scroll up/down.
Any suggestions on how to fix this?
Thanks.
Wrap Layout gives an explanation and a solution.
If you work with the designer, you have to set the prefferedSize property to null (delete what is set) then set the preferred size by clicking the triple dots [...] button next to the prefferedsize property name and put your preferred value.
I encountered the same problem and it works for me.
Is it possible to add a JLabel on top of another JLabel? Thanks.
The short answer is yes, as a JLabel is a Container, so it can accept a Component (a JLabel is a subclass of Component) to add into the JLabel by using the add method:
JLabel outsideLabel = new JLabel("Hello");
JLabel insideLabel = new JLabel("World");
outsideLabel.add(insideLabel);
In the above code, the insideLabel is added to the outsideLabel.
However, visually, a label with the text "Hello" shows up, so one cannot really see the label that is contained within the label.
So, the question comes down what one really wants to accomplish by adding a label on top of another label.
Edit:
From the comments:
well, what i wanted to do was first,
read a certain fraction from a file,
then display that fraction in a
jlabel. what i thought of was to
divide the fraction into 3 parts, then
use a label for each of the three.
then second, i want to be able to drag
the fraction, so i thought i could use
another jlabel, and place the 3'mini
jlabels' over the big jlabel. i don't
know if this will work though..:|
It sounds like one should look into how to use layout managers in Java.
A good place to start would be Using Layout Managers and A Visual Guide to Layout Managers, both from The Java Tutorials.
It sounds like a GridLayout could be one option to accomplish the task.
JPanel p = new JPanel(new GridLayout(0, 1));
p.add(new JLabel("One"));
p.add(new JLabel("Two"));
p.add(new JLabel("Three"));
In the above example, the JPanel is made to use a GridLayout as the layout manager, and is told to make a row of JLabels.
The answer to your original question is yes for the reasons given that any Component can be added to a Container.
The reason you don't see the second label is because by default a JLabel uses a null layout manager and the size of the second label is (0, 0) so there is nothing to paint. So all you need to do is set the bounds of the second label and away you go.
You can't use a layout manager if you want to drag components around because as soon as you resize the frame etc, the layout manager will be invoked and the components will be repositioned based on the layout manager of the component.
it's a matter of layout.
you can do that using null layout (with hard coded locations) or with a custom layout.
you can use a JLayeredPane and set it's border to No Border.
you can add put them above each others by using the horizontal or vertical gap (hgap,vgap) the attributes of the layout
JPanel p = new JPanel(new GridLayout(2, 1,-40,0));
//the 40 is the hgap , make it the same with the label height .