I'm using
int TxtAge = Integer.parseInt(tfAge.getText().trim());
to get value from my textfield and search it in database.
Then, I'm using Integer age = Integer.parseInt(stringTokenizer.nextElement().toString()); to go to next attributes in my database.
I have no problem using those codes for textfield but when I'm using the JComboBox the result won't display. How to use the StringTokenizer.nextElement() for JComboBox? Is is the same with TextField?
String sex=(String) stringTokenizer.nextElement();
I tried this code but still failed :(
You seem to have left out the relevant portions of your code, i.e. how you are handling setting/getting items in the JComboBox. Whether you read these values from a database, a file or have them hardcoded is irrelevant to the question.
Since you do ask whether it is the same as with a JTextField, I can at least answer this; it is not the same. The question indicates that you're quite new to Swing. You would probably benefit from working through a basic Swing tutorial, just to get a grip on how to work with these basic GUI elements. For JComboBox, check out Oracles own How to Use Combo Boxes.
Anyways, when working with JComboBox, you will need to first populate it with the values that users can choose from and set the currently selected value. Retrieving the currently selected value is just a simple method call.
Further, you have the possibility of making a combobox editable. This means that the user can edit the text in the combo box to something that was not pre-populated. By default, this option is turned off.
I'll provide some examples.
Initialize:
JComboBox sexComboBox = new JComboBox();
sexComboBox.addItem("Not selected");
sexComboBox.addItem("Male");
sexComboBox.addItem("Female");
sexComboBox.addItem("Do not want to disclose");
By default, the first item you added is selected. To select another one, you need to add one of the following lines:
sexComboBox.setSelectedIndex(1); // zero-based index, "Male" is selected item
sexComboBox.setSelectedItem("Female"); // sets the selected item to "Female"
To enable user to edit the contents to something that was not pre-defined, just add the line:
sexComboBox.setEditable(true);
To retrieve the currently selected value:
String selectedItem = (String) sexComboBox.getSelectedItem();
Related
I have a combobox that I would like to act as a search field. When I enter some value I want to call a backend service that would based on the entered value return a list of possible values. I would like to set these values as the combobox items dynamically. So far I have this code:
ComboBox<String> comboBox = new ComboBox<>("Name");
comboBox.setAllowCustomValue(true);
comboBox.setAutofocus(true);
comboBox.addCustomValueSetListener(e -> comboBox.setItems(backendService.getData(e.getValue())));
This works, but it is not ideal, as I (the user) has to type the value, hit enter and focus the combobox again. At this point the matched values from backend are set as items in the combobox. Is there a way to fetch items from the backend dynamically as the user writes in the input with some time delay (e.g. ValueChangeMode.LAZY for TextField) and set them as combobox items while writing user input?
After reading through this link I found a solution using lazy data loading. I had to adjust my backend service to accept a PageRequest object, so the following line of code did exactly what I wanted:
comboBox.setItems(query ->
backendService.getData(PageRequest.of(query.getPage(), query.getPageSize())));
I am using multiple JComboBox in a single JPanel. I was wondering what is the go to initial JComboBox selection text?
For example I can put "None" but that will seem as if some value is already selected in the JComboBox. I am using labels for which type of data they are so writing their type is unnecessary.
I can either put "" but something like "----" seems better. Is there a standard text when you want the user to select some value from JComboBox?
If you want to set an initial value to JComboBox that should be non-selectable (as soon as user selects another option, it will not be possible to select the initial one again), than it has been already answered here.
One way is to use a custom renderer. The renderer will simply display a default prompt when no item of the combo box has been selected.
Check out Combo Box Prompt for an example of this approach.
I have a JFrame form with labels, text fields, a combo box and a button group that has 2 radio buttons. In another form I have a JTable filled with data about students (student id, name...), and when I select a row from a table, the form opens and its field need to be filled with same values (eg. if Peter Peterson was selected from the table, then his name should be shown in text filed Name on the form, so I did txtfieldName.setText(student.getName), my question is how do I do this for radio button? Do I need to have yes/no column in the table, so when I select a table row where the value is, say, ''yes'' in order to have yes radio button selected on the form?
if (result.getString(5).equals("Male")) {
jRadioButton1.setSelected(true);
} else {
jRadioButton2.setSelected(true);
}
This depends. Is the value that is being applied to the radio button part of the underlying table data (ie from your student object)? If it is, then, no, you don't HAVE to have yes/no column, although it might be of use if you are trying to make decisions on it. Instead, you would simply extract it from the student object.
I would display the yes/no value as a column If it was relevant to the decsion making process.
If the value you want to use to set the radio button is NOT part of the student oect then you need to make some decisions.
Personally, I would create a wrapper object that represented the state of the row, this would include the student object and any other relevant details you might want. This makes the data self contained and makes accessing that information easier.
If that wasnt desirable, then, yes, you would need to probably display the value as a column and maintain it as separate value within the table model.
This will also come down to how you've Implemented the table model
Updated with feedback from the OP
Okay, so, with your student object hand. You can get the boolean property from the student (that is begin represented on the screen by you radio buttons) and make a choice...
trueRadioButton.setSelected(booleanValue);
trueRadioButton.setSelected(!booleanValue);
You could make it even more simpler by using a JCheckBox instead...
checkBox.setSelected(booleanValue);
You select the radio buttons through the ButtonGroup:
group.getSelected(button.getModel(), true);
You don't have to know which radio button is selected a priori, so you don't have to have that information in the table if you don't want to. You can instantiate both radio buttons with the 'selected' parameter set to false:
JRadioButton button = new JRadioButton("My button label", false);
JRadioButton otherButton = new JRadioButton("My other button label", false);
ButtonGroup group = new ButtonGroup();
group.add(button);
group.add(otherButton);
I'm new to GWT. I have a simple SuggestBox which is populated using a MultiWordSuggestOracle. Users input their data to this SuggestBox, and if they find any match with the existing Suggestions its well and good. I'm able to retrieve this value in the SelectionHandler code as below.
display.getSuggestBox().addSelectionHandler(new SelectionHandler<Suggestion>() {
public void onSelection(SelectionEvent<Suggestion> event) {
String selectedProperty = ((SuggestBox)event.getSource()).getValue();
// do something with the property value
}
});
But users are allowed to enter values which are not already in the Suggestion oracle, in which case I should read this value and do something with this,may be saving to db as a new data.(The thing which I'm looking for is something like a browsers navigation widget where we show suggestions, users can pick up any suggestion or he can type in his new entry and carry on.) What I needed is a way to retrieve this new text user has entered? Data will be read on a button click. What I tried out is this.
display.getSaveBtn().addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
String selectedProperty = display.getSuggestBox().getValue();
//String selectedProperty2 = display.getSuggestBox().getText();
// Blank in both cases :(
// tried display.getSuggestBox().getTextBox().getValue(),but blank again
}
});
I tried to employ onChange() event handlers (as shown below)
display.getSuggestBox().addValueChangeHandler(new ValueChangeHandler<String>() {
public void onValueChange(ValueChangeEvent<String> event) {
String selectedProperty = ((SuggestBox)event.getSource()).getValue();
Window.alert("on change -- "+selectedProperty);
}
});
This is working fine except one scenario. Suppose there are two suggestions in the oracle,say 'createTicketWsdl' and 'createTicketTimeout'. When the user types in 'cr', he is opted with these two options, and if he selects 'createTicketWsdl' by pressing keyboard ENTER, then my alert is printing 'createTicketWsdl' which is correct. But if he selects 'createTicketWsdl' using mouse, then my alert is printing 'cr' (I tried to post the screenshot to give a better understanding, but being a new user I'm not allowed).(which I wanted to get as 'createTicketWsdl'since thats what he has selected). Soon after printing my alert, the value in the SuggestBox changes to 'createTicketWsdl'.
Is there a way to retrieve the value of the suggest box? I saw a similiar thread GWT SuggestBox + ListBox Widget, where some source code for a custom widget is available. But I didn't take the pain of trying out that, since what I want is simply get the current value from the SuggestBox and I hope there should be some easy way.
Thanks for all your help!
Your question is not very clear. You need to clarify your language a lil' bit. For example - is the following a question or an assertion? I mean, it sounds like an assertion but it has a question mark.
What I needed is a way to retrieve this new text user has entered?
Also, I do not understand what you mean by "he is opted by". Did you mean to say, "he is presented with the options ..." ?
Therefore, I am guessing your situation.
You have a listbox of existing items.
You have a textbox which allows freeform text entry
Any items whose prefix values matches the current textbox entry, the listbox items would be filtered to be limited to the matching items.
Even if the current textbox entry presents matching prefixes to filtering the listbox, the user can still perform freeform text entry. So, there are two possible cases here
4.1 the user clicks on the list box to select one of the filtered items
4.2 the user press enter key, which triggers selection of the current value of the textbox.
However, you find your widget participating in a race condition, so that when you click on the widget, the ValueChangeHandler gets triggered rather than the SelectionHandler. I do not know the structure of your widget so that is my best guess.
The problem is that you are allowing two separate modes of obtaining an outcome and you probably did not have well-defined state machine to handle choosing the appropriate mode. One mode is by the textbox and the other is by selection on the listbox - and you do not have a well-defined way of which would mode would be effective at any moment.
If my guess is accurate, this is what you need to do:
You must restrict your outcome to coming from only the textbox.
Your listbox selection must not trigger any outcome. Any change in listbox selection must propagate back to the textbox - to allow the user the chance of making further freeform entry based on that value.
only the keyboard enter on the textbox will trigger the final outcome.
I'm trying to use a JDialog box that has a search text field that as text is entered, it shortens a list to those that match. On this list I would like to display each line with a checkbox that can be selected. I might also want the ability for it to function like a select all list where Ctrl + Click on the line would select the item and check its box. How do I get this done?
Jlist is exactly what you're looking for. You can use a list of checkboxes and ctrl-click them.
I would use a JTable with two columns. The first column can be your check box and the second column could be the text.
Read the section from the Swing tutorial on "How to Use Tables" in particular the part on Sorting and Filtering for an example.