Develop Reference

How can add an "All Items" field to a jcombobox

I am trying to make a Swing GUI in Netbeans. I create a jcombobox and I bind it (using a query component, a list component and a renderer) to an entity called 'Item', so that the combobox shows the names of the items that currently exist in the table "Item" and so far it works fine. However, I need to add an "All Items" field to the combobox. Does anybody have any hints on where I should start?

Try
List<String> listItems = classDAO.findElement();
DefaultComboBoxModel<String> comboModel = new DefaultComboBoxModel();
for(String string : listItems)
{
comboModel.addElement(string);
}
comboModel.addElement("All items");
JComboBox<String> comboBox = new JComboBox<>(comboModel);

You can manually add an item to the combo box after the items from the table have been added to the combo box:
comboBox.addItemAt("All Items", 0);
will insert a new item at the top of the combo box.

Java: Get List<> Items from one class into JComboBox of another class

Here's the thing:
I created a 'cocktailbar' software, and I have the following classes:
Cocktail,
CocktailBar,
CreateNewCPanel,
HelloPanel,
SearchCPanel,
ShowAllCPanel,
CocktailMixerGUI,
Ingredients.
Now: When adding a new Cocktail in the CreateNewCPanel, I add the cocktail to a List in the CocktailBar class.
Box buttonBox = Box.createHorizontalBox();
JButton speicherButton = new JButton("Speichern");
speicherButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
neuerC.setCName(cName.getText());
neuerC.fuegeZubereitungHinzu(zubereitungTextArea.getText());
CocktailBar.addCocktail(neuerC);
Now I need to see all created cocktails in a 'dropdown' menu in the ShowAllCPanel. I've got the following:
//Adding the DropDown Menu, first a Box, then a ComboBox inside.
Box cDropDownBox = Box.createHorizontalBox();
cDropDownBox.add(Box.createHorizontalGlue());
JComboBox cChoose = new JComboBox();
groesseEinsetzen(cChoose, 500, 20);
cChoose.setAlignmentX(SwingConstants.LEFT);
cDropDownBox.add(cChoose);
But now I am wondering how do I get my List from the CocktailBar class into the ShowAllCPanel?
edit: forgot to mention: i have a getter in the CocktailBar class, and i already tried:
cChoose.addItem(CocktailBar.getCocktails());
within the comboBox in the ShowAllCPanel, but it doesnt show up anything in the dropdown.
thanks to #Do Re, i inserted this:
//Adding the DropDown Menu, first a Box, then a ComboBox inside.
Box cDropDownBox = Box.createHorizontalBox();
cDropDownBox.add(Box.createHorizontalGlue());
JComboBox cChoose = new JComboBox();
if (CocktailBar.getCocktails() != null){
for (Cocktail c : CocktailBar.getCocktails())
cChoose.addItem(c);
}
but still - when running, the dropdown list stays empty.

As you mentioned in the comments, you created a getter for the cocktails.
Try something like this
for (Coctail c : CocktailBar.getCocktails())
cChoose.addItem(c);
This iterates over the list of cocktails and adds each item seperately rather than adding a list of Cocktails at once.
Edit
try
cDropDownBox.revalidate();
cDropDownBox.repaint();
or
cChoose.revalidate();
cChoose.repaint();

I have an ArrayList<JCheckBox> that i want to convert to an ArrayList<String>

I have an ArrayList<JCheckBox> that i want to convert to an ArrayList<String>
First I do like this. I get all my titles from a file and put them into a new ArrayList. Afterwords I make a new JCheckBox Array that contains all the Strings from the StringArray.
ArrayList<String> titler = new ArrayList<String>();
titler.addAll(FileToArray.getName());
ArrayList<JCheckBox> filmListe = new ArrayList<JCheckBox>();
for(String titel:titler){
filmListe.add(new JCheckBox(titel));
}
for(JCheckBox checkbox:filmListe){
CenterCenter.add(checkbox);
}
This is what I am trying to do: First I make a new ArrayList (still in the JCheckBox format), that contains alle the selected Checkboxes. Afterwords I want to add the to a new ArrayList in a String format.
The main problem is italicized (with **):
ArrayList<JCheckBox> selectedBoxes = new ArrayList<JCheckBox>();
for(JCheckBox checkbox: filmListe){
if (checkbox.isSelected()){
selectedBoxes.add(checkbox);
}
ArrayList<String> titlesArr = new ArrayList<String>();
for(JCheckBox titel:selectedBoxes){
*titlesArr.add(titel);*
}
A lot of code and text for a little problem! But I really appreciate your help! :)

You can't add a JCheckBox to a List<String>, the types JCheckBox and String are incompatibles.
I guess you want to add the text of the check box into your list, so you have to retrieve it manually, using:
titlesArr.add(titel.getText());

Assuming the checkbox's label is exactly the same as what you originally had in your list of titles, just use the checkbox's getText method (which gets the String label). You don't need to make a separate list of checkboxes that are checked - just put an if-block inside your first loop like this:
ArrayList<String> titlesArr = new ArrayList<String>(filmListe.size());
for (JCheckBox checkbox : filmListe) {
if (checkbox.isSelected()) {
titlesArr.add(checkbox.getText());
}
}

Try this:
ArrayList<String> titlesArr = new ArrayList<String>();
for(JCheckBox checkbox: filmListe)
if (checkbox.isSelected())
titlesArr.add(checkbox.getText());
Now titlesArr contains what you wanted.

java swing combobox

I have a combo box and a string array that holds all the values of the combo box in it. I erase the items from the combo box and then want to add in the values from the string array. It doesn't seem to let me just add in a string array. And I tried to itterate through the string adding items one by one but won't let me do that (or atleast the way I wrote it, it won't work).
May seem like a stupid question but I am new to working with swing in java.
Here's the code where I want to "reload" the items from the combo box:
String str = JOptionPane.showInputDialog(null, "Enter Name: ", "", 1);
if(str != null){
JOptionPane.showMessageDialog(null, "New name added: " + str, "", 1);
nameCreator.addName(strNames, str);
strNames = NameLoader.getNames();
nameList.removeAllItems();
nameList.addItem(strNames);
}
EDIT: Made small typo and didn't realize what was wrong. Working now. Thanks for everyones help.

Did you used the method addItem(Object anObject)?
You should iterate your array an use that method:
String[] data = {a;b;c;d;e}
for(int i=0; i < data.length; i++){
comboBox.addItem(data[i]);
}
Luca

I'd suggest you to implement your own ComboBoxModel:
public class YourComboBoxModel implements ComboBoxModel{
#Override
public Object getSelectedItem() {
//return selected item Object;
}
#Override
public void setSelectedItem(Object anItem) {
//set selected item
}
#Override
public Object getElementAt(int index) {
//return the element based on the index
}
#Override
public int getSize() {
//return the size of your combo box list
}
}
And build your JComboBox passing that model as parameter:
ComboBoxModel yourModel = new YourComboBoxModel();
JComboBox yourComboBox = new JComboBox(yourModel);
Using a custom ComboBoxModel is the most flexible solution. It allows you to change the datastructure holding your datas, and the way you access it, modifying only the model you implemented instead of other unrelated part of code.

Whenever you need to work with editable models for these kinds of GUI elements it is always good to use a model. For the JComboBox you have an easy-to-use DefaultComboBoxModel.
It works easily:
DefaultComboBoxModel model = new DefaultComboBoxModel(new String[]{"Item1","Item2","Item3"});
JComboBox comboBox = new JComboBox(model);
in this way you have the model attached to the combobox, and it will display items from the array. Whenever you need to change them just do:
model.removeAllElements(); // if you need to empty it
model.addElement("New Item1");
model.addElement("New Item2");
model.addElement("New Item3");
model.fireContentsChanged();
and you'll have new items updated inside the GUI.
A bonus note: if you need to manage custom objects instead that strings you can easily add them to the JComboBox (in the sameway showed before), you just need to provide a custom public String toString() method that will manage the string representation.
In your example I don't get why you readd all the items everytime, you could just call addItem with the new String without removing everything and adding them back.

the best way to add some thing in your combo box in order that you can change it easily is to describe an array list first,if you would like to be dynamic you can user a text field then in a text field you can run an array list .
textField = new JTextField();
textField.setBounds(131, 52, 86, 20);
contentPane.add(textField);
textField.setColumns(10);
then you have to create an array list
ArrayList al=new ArrayList();
then you have to equal your text field text to a string
String str=textfield.getText();
then add it to your array
al.add(str);
then add al item to your combo box.
JComboBox comboBox = new JComboBox();
comboBox.setBounds(112, 115, 145, 20);
contentPane.add(comboBox);
comboBox.addItem(al);

Insert list of values to JTextField with Java2sAutoTextField

I want th auto generate values for the empId (or empName) when inserting values to the jtextfield
I went through the Java2sAutoTextField class but I can't add it in to a jframe.
Here's a part of code I extracted from here:
List possible = new ArrayList();
possible.add("Austria");
possible.add("Italy");
possible.add("Croatia");
possible.add("Hungary");
Java2sAutoTextField autoCompleter = new Java2sAutoTextField(possible);
i dont know how to put the above coding into the jtextfield
Also I tried out JSuggestField, but I can't add it from netbeans palette.
Any assistance is appreciated.

Done! i just had to implement the jtextfield as
List possible = new ArrayList();
possible.add("");
possible.add("Austria");
possible.add("Italy");
possible.add("Croatia");
possible.add("Hungary");
jTextField2 = new Java2sAutoTextField(possible);