CODEWITHSUNDEEP
javaarraylistcomboboxslider
Pippo
Pippo

Reputation: 23

Storing Current Items From Comboboxes in an ArrayList

I have a simple program that makes shapes of different sizes and colours.

The shapes and colours are selected from ComboBoxes, while the size is controlled by a slider. I want to store the -currently selected- shape, size and the colour in an ArrayList of a new class that I defined by pressing a button and then print the info pressing another.

private ArrayList<ShapeItem> ShapeItem;


    slider = new JSlider (JSlider.HORIZONTAL,minValue,maxValue,initValue);
    add(slider);
    slider.addChangeListener(this);


    // Instantiate a new ComboBox with options for Shape
    shapeChoice = new JComboBox();
    shapeChoice.addItem("Point");
    shapeChoice.addItem("Square");
    shapeChoice.addItem("Circle");
    shapeChoice.addItem("Doughnut");
    shapeChoice.addItem("Pentagon");
    shapeChoice.addItem("Hexagon");
    add(shapeChoice); // Add the JComboBox to the JPanel
    shapeChoice.addActionListener(this);  //Register the JComboBox selection with Java

    // Instantiate a new ComboBox with options for Colour
    colorChoice = new JComboBox();
    colorChoice.addItem("Black");
    colorChoice.addItem("Red");
    colorChoice.addItem("Green");

Then:

readItems = new JButton("Read values");
    add(readItems);
    readItems.addActionListener(this);

    printItems = new JButton("List all values");
    add(printItems);
    printItems.addActionListener(this);

ShapeItem = new ArrayList<ShapeItem>();

My best bet at achieving that was introducting

if (e.getSource() == readItems)
    {
       String item0 = shapeChoice.getSelectedItem();
       String item1 = colorChoice.getSelectedItem(); 


    }

    // if the "List all values" button is pressed    
    else if (e.getSource() == printItems)
    {
        // loop through the ArrayList of items prnting each one out in turn to the JTextArea
        for (int j=0; j<i; j++)
        {
           textOutput.append(itemList.get(j).shapeChoose + "\n");
           textOutput.append(itemList.get(j).colourChoose + "\n");
           textOutput.append("\n");
        }
    }

But at the

String item0 = shapeChoice.getSelectedItem();

I get an "incompatible types error"

The new class I made is this:

public class ShapeItem

{

public String shapeChoose;
public String colorChoose;
public int thesize;

}

Am I trying the right way or there is another method to achieve that?

Upvotes: 2

Views: 1347

Answers (1)

Mansueli
Mansueli

Reputation: 7004

There is no shortcut, you'll have to iterate through the items in the JComboBox and add each of them to the array.

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JComboBox;

public class Main {
        JComboBox<String> shapeChoice = new JComboBox<>();
        shapeChoice.addItem("Point");
        shapeChoice.addItem("Square");
        shapeChoice.addItem("Circle");
        shapeChoice.addItem("Doughnut");
        shapeChoice.addItem("Pentagon");
        shapeChoice.addItem("Hexagon");
        System.out.println(combo2Array(shapeChoice).toString());
    }
    public static List<String> combo2Array(JComboBox<String> combo){

        List<String> list = new ArrayList<>();
        for(int i=0;i<combo.getItemCount();i++){
            list.add(combo.getItemAt(i));
        }
        return list;
    }
}

Output:

[Point, Square, Circle, Doughnut, Pentagon, Hexagon]

You can also change it to generics, if you want (it doesn't have to be Strings). But the idea will be the same.

I made what I believe is the design you are looking for and posted it on gist. But it will be an awful design choice, as you are creating a list with a size much larger than what you actually need. Using 3 Lists (one for each component) will be a better design choice and that's why I will not update my answer here with the gist code.

EDIT2:

To add just what is currently selected:

public void addSelected2List(){
    ShapeItem shape = new ShapeItem();
    shape.setShapeChoose((String)shapeChoice.getSelectedItem());
    shape.setColourChoose((String)colourChoice.getSelectedItem());
    shape.setSize((int)sizeChoice.getSelectedItem());
    list.add(shape);
}

Upvotes: 2

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