I'm working on a Swing application that uses the default Swing methods for handling focus. Focus isn't working as I'd expect.
In one case, I have a JTextField that I call .requestFocusInWindow() When the window is displayed a JLabel has focus instead
The Java 6 docs for JLabel say "As a result, it cannot get the keyboard focus." http://docs.oracle.com/javase/6/docs/api/javax/swing/JLabel.html
However, I have a sample application that shows a JLabel receiving focus and KeyboardFocusManager.getFocusOwner() returns that component. (http://github.com/akinsgre/swingStarter)
The code the the class is https://raw.github.com/akinsgre/swingStarter/master/src/main/java/test/HelloWorldSwing.java
Can anyone help me understand or explain what I'm missing?
I think you need to associate the label with the text field. So try using the setLabelFor method and see if that helps.
Related
Simple question. I've been trying to block/disable my textfield in my JFrame, but unfortunately it just doesn't work!
Suppose the name of my disable textfield is "fnTxt", so in the code I wrote fnTxt.setEnabled(false);. And when I run it, nothing happen! The textfield is still able to be click/fill.
Am I doing it wrong or it's something else?
setEnabled works fine for what it is meant for.
But I assume you want to make it invisible, for that you simple have to use fnTxt.setVisible(false);
I'm working on one of my first java applets and I want to start of fairly simple (though I have a good understanding of how code works I dont know much in terms of what methods I all have at my disposal when using java)
I have created a Jframe window that has a JTextarea in it. I would like to execute certain lines of code when certain things are typed into this box. In essence, its a simple text input system. How would I go about doing this or is there a better component to use for this?
in addition to getText(), for JTextField some prefer the getDocument() method. In Java, Listeners are used to capture events, such as "what was typed to the text area". This tutorial will get you started, if you have trouble implementing you can come back with a more specfic question and some code :)
I am designing a Jframe using netbeans. I do have few questions.
Can we create a label for a field in a desired location(For eg.,we have a field named height, I need to display a label below it indicating height is in cm) conditionally?
Can we disable a field based on a condition?(by disable I mean it shouldn't be displayed in my frame)
Can someone suggest me whether we can achieve them through some examples.
Tried this, after some helpful suggestions
private void englishRadioButtonActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
JLabel userlabel;
if (englishRadioButton.isSelected())
{
userlabel = new JLabel("Inches");
userlabel.setBounds(311, 59, 64, 36);
//userlabel.setLocation(307,55);
//userlabel.setSize(70,40);
userlabel.setForeground(Color.green);
userlabel.setText("Inches");
userlabel.setVisible(true);
System.out.println(englishRadioButton.getBounds());
inchesTextField.setVisible(true);
}
}
The textfield is visible only when I click the English radio button,at the same time I need to get a label but it's not displayed with the above code. Can I know where I am going wrong?
Please see the attached screenshots
When English button is clicked, I need a label beneath the second textfield as inches, I am disabling the text field when Metric is displayed. I am able to achieve the later one but not the former one
Thanks!!
Yes, relative placement of components is easily achieved with use of layout managers.
Yes, all components have a setEnabled(...) and a setVisible(...) method either of which can be called at any time during a program's run. The former helps you activate/inactivate components and the latter helps make them visible/invisible. If you want to swap complete "views", use a CardLayout.
Regarding:
Can someone suggest me whether we can achieve them through some examples.
Please, you first as I strongly believe that the onus of effort here should be yours, the questioner's, since you're the one asking the questions, and the one with the most to learn by coding as much as possible. Let's see your attempts and we can help you with them. Otherwise the best examples are to be found at the Swing Tutorials.
For links, please look here: Swing Tag Info.
Edit
You ask:
I tried the above posted code,conditionally disabling the text field works well but getting a label doesn't work. Can you please suggest on that?
I don't see you adding your JLabel to any component. If you are going to create a component on an event, you must add it to a component whose ancestor hierarchy eventually reaches a visible top-level component such as a JFrame. Then after adding a component to a container (say a JFrame), you must call revalidate() on the container to have its layout managers re-layout its components, and then repaint() to repaint any "dirty" pixels.
I again will re-iterate that you're far better off not using null layout and absolute positioning, but rather using layout managers and relative positioning. If you want a label with and without visible text, it's often best to add an empty JLabel to the GUI on GUI creation, and just set its text when needed, as long as the label is located somewhere that allows its text to shrink and expand.
Also, as to your current problem, you might wish to show a picture of what you're trying to achieve, and what you're getting. Or if you can't post a picture here yet, post a link to an image or images you've created, and then we'll post it for you.
I am writting a simple server chat client using gui to make the chat box and so on. I am simply wondering if I should use jtextarea instead of jtextfield if someone wants to write a long message since jtextfield does not allow word wrap.
Does it matter if I use jtextarea of jtextfield or is there a specific reason not to use jtextarea as my input box?
My guess:
You'll probably need both a JTextField and a JTextArea (or other multi-line text component).
The JTextField would be for the user to type in their chat messages to be sent. It would be editable.
and the JTextArea would show the incoming chats as well as the chats the user has sent. It would not be editable.
Consider placing the JTextArea in a JScrollPane
Consider placing both in a BorderLayout-using container with the JScrollPane that holds the JTextArea placed in the CENTER position and the JTextField in the SOUTH position.
A JTextField is a little easier to work with. You can add an ActionListener to it so that when the user hits enter the Action can be invoked an the message will be sent. Of course you can still have a "Send" JButton. the user can click on as well.
With a JTextArea, the Enter key will add a new line, so it you want the user to be able to sent the text when Enter is used you will need to customize the processing, maybe by using Key Bindings. I would prefer the text area because I like to see as much of the text as possible, like I am doing now as I repond to this question.
From oracle docs and personal experience, the JTextField makes life a lot easier as the ActionEventListener is set by default so the actions(characters or text) set in the field are copied to the JTextArea which is like a log of activity carried out in the field.
So the ball is in your court. You can use it JTextField together with JTextArea or JTextArea alone and write the listener class to suit you purpose and certainerly added a listenable event e.g a button.
Besides, always specify the size of the field to avoid layout issues that may compromise the Ui of your application as there is always a dynamic resizing if the size is not specified out rightly.
I have a very simple Swing GUI with just a JTetxtArea. I am trying to programmatically select a part of text using:
textArea.select(startSelection,endSelection);
This work. However as soon as I add some other components to the GUI I do not see selection anymore
frame.getContentPane().add(button);
frame.getContentPane().add(textArea);
textArea.select(startSelection,endSelection);
I suspect that during layouting the gui, some event causes the text to be deselected. Am I right? And could anybody suggest a solution?
My goal is to have a program which displays a text, and allows the user to input start and end selection position, and a selection appears between these two position. Thank you.
Text selection only shows when the text component has focus.
Text components also support "highlighting" by using the getHighlighter().addHighlight() method. In this case the highlighting remains whether the component has focus or not.
If you need more help post your SSCCE that demonstrates the problem.
If what you really want is just a selection, not highlight (which behaves differently), you can use JTextComponent.getCaret().setSelectionVisible(true).