How to make a Wheel picker

Question

I am trying to make a wheel picker like this I have tried downloading this project but the only files included in the .zip download are wheel-demo.apk and notes.txt. Notes.txt does not have any instructions on how to use this file with android studio. I found a post that suggested using ListViews to create the same effect. Rather than making my own I spent another day searching the internet and I found source code here but when I imported the files into my project the IDE showed dozens of errors. Through trial and error I managed to fix all but 3 errors. Pretty sure I have put the relevant code below
MainActivity.java:

OnWheelScrollListener scrolledListener = new OnWheelScrollListener()
{
    public void onScrollingStarted(WheelView wheel)
    {
        wheelScrolled = true;// "Cannot resolve symbol wheelScrolled
    }

    public void onScrollingFinished(WheelView wheel)
    {
        wheelScrolled = false;// "Cannot resolve symbol wheelScrolled
        updateStatus();
    }
};

// Wheel changed listener
private final OnWheelChangedListener changedListener = new OnWheelChangedListener()
{
    public void onChanged(WheelView wheel, int oldValue, int newValue)
    {
        if (!wheelScrolled)// "Cannot resolve symbol wheelScrolled
        {
            updateStatus();
        }
    }
};
private void initWheel1(int id)
{
    WheelView wheel = (WheelView) findViewById(id);
    wheel.setAdapter(new ArrayWheelAdapter<String>(wheelMenu1)); //cannot resolve method 'setAdapter(com.projectname.ArrayWheelAdapter<Java.lang.String>)
    wheel.setVisibleItems(2);
    wheel.setCurrentItem(0);
    wheel.addChangingListener(changedListener);
    wheel.addScrollingListener(scrolledListener);
}

OnWheelScrollListener.java:

public interface OnWheelScrollListener {
/**
 * Callback method to be invoked when scrolling started.
 * @param wheel the wheel view whose state has changed.
 */
void onScrollingStarted(WheelView wheel);

/**
 * Callback method to be invoked when scrolling ended.
 * @param wheel the wheel view whose state has changed.
 */
void onScrollingFinished(WheelView wheel);}

OnWheelChangedListener.java:

    public interface OnWheelChangedListener {
    /**
     * Callback method to be invoked when current item changed
     * @param wheel the wheel view whose state has changed
     * @param oldValue the old value of current item
     * @param newValue the new value of current item
     */
    void onChanged(WheelView wheel, int oldValue, int newValue);
}

ArrayWheelAdapter.java

    public class ArrayWheelAdapter<T> extends AbstractWheelTextAdapter {

    // items
    private T items[];

    /**
     * Constructor
     * @param context the current context
     * @param items the items
     */
    public ArrayWheelAdapter(Context context, T items[]) {
        super(context);

        //setEmptyItemResource(TEXT_VIEW_ITEM_RESOURCE);
        this.items = items;
    }

    @Override
    public CharSequence getItemText(int index) {
        if (index >= 0 && index < items.length) {
            T item = items[index];
            if (item instanceof CharSequence) {
                return (CharSequence) item;
            }
            return item.toString();
        }
        return null;
    }

    @Override
    public int getItemsCount() {
        return items.length;
    }
}

All 3 of the .java files have been added to the import list in MainActivity thinking it might solve the issue, it didn't. Thank you for the advice so far.

Answer 1

You can just use the default NumberPicker included in Android since API 11. You can display any Strings you want by using NumberPicker#setDisplayedValues.

XML:

<NumberPicker
        android:id="@+id/number_picker"
        android:layout_width="match_parent"
        android:layout_height="180dp" />

Java:

    String[] data = new String[]{"Berlin", "Moscow", "Tokyo", "Paris"};
    picker.setMinValue(0);
    picker.setMaxValue(data.length-1);
    picker.setDisplayedValues(data);

Screenshot:

Answer 2

Try this

public class MainActivity extends Activity
    {
        // TODO: Externalize string-array
        String wheelMenu1[] = new String[]{"name 1", "name 2", "name 3", "name 4", "name 5", "name 6","name 7","name 8","name 9"};
        String wheelMenu2[] = new String[]{"age 1", "age 2", "age 3"};
        String wheelMenu3[] = new String[]{"10", "20","30","40","50","60"};

        // Wheel scrolled flag
        private boolean wheelScrolled = false;

        private TextView text;
        private EditText text1;
        private EditText text2;
        private EditText text3;

        @Override
        public void onCreate(Bundle savedInstanceState)
            {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.main);

                initWheel1(R.id.p1);
                initWheel2(R.id.p2);
                initWheel3(R.id.p3);

                text1 = (EditText) this.findViewById(R.id.r1);
                text2 = (EditText) this.findViewById(R.id.r2);
                text3 = (EditText) this.findViewById(R.id.r3);
                text = (TextView) this.findViewById(R.id.result);
            }

        // Wheel scrolled listener
        OnWheelScrollListener scrolledListener = new OnWheelScrollListener()
            {
                public void onScrollStarts(WheelView wheel)
                    {
                        wheelScrolled = true;
                    }

                public void onScrollEnds(WheelView wheel)
                    {
                        wheelScrolled = false;
                        updateStatus();
                    }
            };

        // Wheel changed listener
        private final OnWheelChangedListener changedListener = new OnWheelChangedListener()
            {
                public void onChanged(WheelView wheel, int oldValue, int newValue)
                    {
                        if (!wheelScrolled)
                            {
                                updateStatus();
                            }
                    }
            };

        /**
         * Updates entered PIN status
         */
        private void updateStatus()
            {
                text1.setText(wheelMenu1[getWheel(R.id.p1).getCurrentItem()]);
                text2.setText(wheelMenu2[getWheel(R.id.p2).getCurrentItem()]);
                text3.setText(wheelMenu3[getWheel(R.id.p3).getCurrentItem()]);

                text.setText(wheelMenu1[getWheel(R.id.p1).getCurrentItem()] + " - " + wheelMenu2[getWheel(R.id.p2).getCurrentItem()] + " - " + wheelMenu3[getWheel(R.id.p3).getCurrentItem()]);
            }

        /**
         * Initializes wheel
         * 
         * @param id
         *          the wheel widget Id
         */

        private void initWheel1(int id)
            {
                WheelView wheel = (WheelView) findViewById(id);
                wheel.setAdapter(new ArrayWheelAdapter<String>(wheelMenu1));
                wheel.setVisibleItems(2);
                wheel.setCurrentItem(0);
                wheel.addChangingListener(changedListener);
                wheel.addScrollingListener(scrolledListener);
            }

        private void initWheel2(int id)
            {
                WheelView wheel = (WheelView) findViewById(id);
                wheel.setAdapter(new ArrayWheelAdapter<String>(wheelMenu2));
                wheel.setVisibleItems(2);
                wheel.setCurrentItem(0);
                wheel.addChangingListener(changedListener);
                wheel.addScrollingListener(scrolledListener);
            }

        private void initWheel3(int id)
            {
                WheelView wheel = (WheelView) findViewById(id);

                wheel.setAdapter(new ArrayWheelAdapter<String>(wheelMenu3));
                wheel.setVisibleItems(2);
                wheel.setCurrentItem(0);
                wheel.addChangingListener(changedListener);
                wheel.addScrollingListener(scrolledListener);
            }

        /**
         * Returns wheel by Id
         * 
         * @param id
         *          the wheel Id
         * @return the wheel with passed Id
         */
        private WheelView getWheel(int id)
            {
                return (WheelView) findViewById(id);
            }

        /**
         * Tests wheel value
         * 
         * @param id
         *          the wheel Id
         * @param value
         *          the value to test
         * @return true if wheel value is equal to passed value
         */
        private int getWheelValue(int id)
            {
                return getWheel(id).getCurrentItem();
            }
    }

main.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:background="@drawable/layout_bg">


    <LinearLayout
        android:layout_marginTop="24dp"
        android:layout_gravity="center_horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

        <com.example.wheel.WheelView
            android:id="@+id/p1"
            android:layout_height="wrap_content"
            android:layout_width="wrap_content" />
        <com.example.wheel.WheelView
            android:id="@+id/p2"
            android:layout_height="wrap_content"
            android:layout_width="wrap_content" />
        <com.example.wheel.WheelView
            android:id="@+id/p3"
            android:layout_height="wrap_content"
            android:layout_width="wrap_content" />
    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_gravity="center_horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="24dp">
        <EditText
            android:id="@+id/r1"
            android:layout_width="100dip"
            android:layout_height="wrap_content"
            android:layout_marginTop="24dp"
            android:layout_gravity="center_horizontal"
            android:textSize="18sp"
            android:textColor="#000">
        </EditText>
        <EditText
            android:id="@+id/r2"
            android:layout_width="80dip"
            android:layout_height="wrap_content"
            android:layout_marginTop="24dp"
            android:layout_gravity="center_horizontal"
            android:textSize="18sp"
            android:textColor="#000">
        </EditText>
        <EditText
            android:id="@+id/r3"
            android:layout_width="80dip"
            android:layout_height="wrap_content"
            android:layout_marginTop="24dp"
            android:layout_gravity="center_horizontal"
            android:textSize="18sp"
            android:textColor="#000">
        </EditText>
    </LinearLayout>

    <TextView
        android:id="@+id/result"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="24dp"
        android:layout_gravity="center_horizontal"
        android:textSize="18sp"
        android:textColor="#FFF"
        android:text="Your choice">
    </TextView>
</LinearLayout>

Also Try this demo