WheelView

WheelView is an Android library that allows drawables to be placed on a rotatable wheel. It behaves like a Circular ListView where items rotate rather than scroll vertically. It isn't limited by the number of items that can fit on the wheel since it will cycle through each adapter position when the wheel is rotated. It can be rotated at any angle and from any position.

The WheelView can be used as a way to select one item from a list. The SelectionAngle determines what position on the wheel is selected. You can also receive a callback for when an item is clicked, and whether it is selected. Have a look at the sample for a working example!

Note - Frame rate is much better than these poorly converted gifs!

Setup

Include this in build.gradle project dependencies:

dependencies {
    compile 'com.github.lukedeighton:wheelview:0.3.1'
}

Usage

Add a custom view in xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.lukedeighton.wheelview.WheelView
        android:id="@+id/wheelview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:wheelColor="@color/grey_400"
        app:rotatableWheelDrawable="false"
        app:selectionAngle="90.0"
        app:wheelPosition="bottom"
        app:wheelOffsetY="60dp"
        app:repeatItems="true"
        app:wheelRadius="276dp"
        app:wheelItemCount="14"
        app:wheelPadding="13dp"
        app:wheelItemRadius="43dp"/>
</RelativeLayout>

Set a WheelAdapter similar to how you would set an adapter with a ListView

wheelView.setAdapter(new WheelAdapter() {
    @Override
    public Drawable getDrawable(int position) {
        //return drawable here - the position can be seen in the gifs above
    }

    @Override
    public int getCount() {
        //return the count
    }
});

Please note that the WheelAdapter doesn't behave exactly like a ListAdapter since Drawables don't need to be recycled in comparison to Views where inflation is expensive. If you need to refresh the Adapter / Items then call setAdapter again.

Listeners

A listener for when the closest item to the SelectionAngle changes.

wheelView.setOnWheelItemSelectedListener(new WheelView.OnWheelItemSelectListener() {
    @Override
    public void onWheelItemSelected(WheelView parent,  Drawable itemDrawable, int position) {
        //the adapter position that is closest to the selection angle and it's drawable
    }
});

A listener for when an item is clicked.

wheelView.setOnWheelItemClickListener(new WheelView.OnWheelItemClickListener() {
    @Override
    public void onWheelItemClick(WheelView parent, int position, boolean isSelected) {
        //the position in the adapter and whether it is closest to the selection angle
    }
});

A listener for when the wheel's angle is changed.

wheelView.setOnWheelAngleChangeListener(new WheelView.OnWheelAngleChangeListener() {
    @Override
    public void onWheelAngleChange(float angle) {
        //the new angle of the wheel
    }
});

Attributes

The WheelView is highly customisable with many attributes that can be set via xml or programmatically (recommend using xml as programmatically set attributes is half implemented at the moment). Here are the custom attributes that can be declared in xml:

wheelDrawable
wheelColor
emptyItemDrawable
emptyItemColor
selectionDrawable
selectionColor
selectionPadding
selectionAngle
repeatItems
wheelRadius
wheelItemRadius
rotatableWheelDrawable
wheelOffsetX
wheelOffsetY
wheelItemCount
wheelItemAngle
wheelToItemDistance
wheelPosition
wheelPadding
wheelItemTransformer
selectionTransformer

WheelItemTransformer

Determines the draw bounds of the WheelItem in relation to the selection angle.

SimpleItemTransformer - All items are the same size
ScalingItemTransformer - Items grow in size near to the selection angle

Future Goals

Convert this project to use LayoutManager to replace Drawables with Views

License

Apache License Version 2.0 http://apache.org/licenses/LICENSE-2.0.txt

SeanChristopherConway/WheelView