A lightweight dropdown popup spinner with an arrow and animations

PowerSpinner

A lightweight dropdown popup spinner with an arrow and animations.

Including in your project

Gradle

Add below codes to your root build.gradle file (not your module build.gradle file).

allprojects {
    repositories {
        jcenter()
    }
}

And add a dependency code to your module's build.gradle file.

dependencies {
    implementation "com.github.skydoves:powerspinner:1.0.1"
}

Usage

Add following XML namespace inside your XML layout file.

xmlns:app="http://schemas.android.com/apk/res-auto"

PowerSpinnerView

Here is a basic example of implementing PowerSpinnerView.

Basically the PowerSpinnerView extends TextView, so we can use it like a TextView.

You can set the unselected text using hint and textColorHint attributes.

<com.skydoves.powerspinner.PowerSpinnerView
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:background="@color/md_blue_200"
  android:gravity="center"
  android:hint="Question 1"
  android:padding="10dp"
  android:textColor="@color/white_93"
  android:textColorHint="@color/white_70"
  android:textSize="14.5sp"
  app:spinner_arrow_gravity="end"
  app:spinner_arrow_padding="8dp"
  app:spinner_divider_color="@color/white_70"
  app:spinner_divider_show="true"
  app:spinner_divider_size="0.4dp"
  app:spinner_item_array="@array/questions"
  app:spinner_popup_animation="dropdown"
  app:spinner_popup_background="@color/background800"
  app:spinner_popup_elevation="14dp" />

Create using builder class

We can create an instance of PowerSpinnerView using the builder class.

val mySpinnerView = createPowerSpinnerView(this) {
  setSpinnerPopupWidth(300)
  setSpinnerPopupHeight(350)
  setArrowPadding(6)
  setArrowAnimate(true)
  setArrowAnimationDuration(200L)
  setArrowGravity(SpinnerGravity.START)
  setArrowTint(ContextCompat.getColor(this@MainActivity, R.color.md_blue_200))
  setSpinnerPopupAnimation(SpinnerAnimation.BOUNCE)
  setShowDivider(true)
  setDividerColor(Color.WHITE)
  setDividerSize(2)
  setLifecycleOwner(this@MainActivity)
}

Show and dismiss

Basically, when the PowerSpinnerView is clicked, the spinner popup will be showed and

when an item is selected, the spinner popup will be dismissed.

But you can show and dismiss manually using methods.

powerSpinnerView.show() // show the spinner popup
powerSpinnerView.dismiss() // dismiss the spinner popup

// If the popup is not showing, shows the spinner popup menu.
// If the popup is already showing, dismiss the spinner popup menu.
powerSpinnerView.showOrDismiss()

And you can set the show and dismiss actions using some listener and attributes.

// the spinner popup will not be shown when clicked.
powerSpinnerView.setOnClickListener { }

// the spinner popup will not be dismissed when item selected.
powerSpinnerView.dismissWhenNotifiedItemSelected = false

OnSpinnerItemSelectedListener

Interface definition for a callback to be invoked when selected item on the spinner popup.

setOnSpinnerItemSelectedListener<String> { index, text ->
   toast("$text selected!")
}

Here is the java way.

powerSpinnerView.setOnSpinnerItemSelectedListener(new OnSpinnerItemSelectedListener<String>() {
  @Override public void onItemSelected(int position, String item) {
    toast(item + " selected!")
  }
});

selectItemByIndex

We can select an item manually or initially using the below method.

spinnerView.selectItemByIndex(4)

SpinnerAnimation

We can customize the showing and dimsmiss animation.

SpinnerAnimation.DROPDOWN
SpinnerAnimation.FADE
SpinnerAnimation.BOUNCE

Dropdown	Fade	Bounce

Customized adapter

We can use our customized adapter and binds to the PowerSpinnerView.

The PowerSpinnerView provides the spinner popup's recyclerview via getSpinnerRecyclerView method.

Here is a sample of the customized adapter.

val adapter = IconSpinnerAdapter(spinnerView)
spinnerView.setSpinnerAdapter(adapter)
spinnerView.getSpinnerRecyclerView().layoutManager = GridLayoutManager(context, 2)

IconSpinnerAdapter

Basically, this library provides a customized adapter.

We should create an instance of the IconSpinnerAdapter and call setItems using a list of IconSpinnerItem.

spinnerView.apply {
  setSpinnerAdapter(IconSpinnerAdapter(this))
  setItems(
    arrayListOf(
        IconSpinnerItem(contextDrawable(R.drawable.unitedstates), "Item1")))
  getSpinnerRecyclerView().layoutManager = GridLayoutManager(context, 2)
  selectItemByIndex(0) // select an item initially.
  lifecycleOwner = this@MainActivity
}

Here is the java way.

List<IconSpinnerItem> iconSpinnerItems = new ArrayList<>();
iconSpinnerItems.add(new IconSpinnerItem(contextDrawable(R.drawable.unitedstates), "item1"));

IconSpinnerAdapter iconSpinnerAdapter = new IconSpinnerAdapter(spinnerView);
spinnerView.setSpinnerAdapter(iconSpinnerAdapter);
spinnerView.setItems(iconSpinnerItems);
spinnerView.selectItemByIndex(0);
spinnerView.setLifecycleOwner(this);

Customized adapter

Here is a way to customize your adapter for binding the PowerSpinnerView.

Firstly, create a new adapter and viewHolder extending RecyclerView.Adapter and PowerSpinnerInterface<T>.

You shoud override spinnerView, onSpinnerItemSelectedListener fields and setItems, notifyItemSelected methods.

class MySpinnerAdapter(
  powerSpinnerView: PowerSpinnerView
) : RecyclerView.Adapter<MySpinnerAdapter.MySpinnerViewHolder>(),
  PowerSpinnerInterface<MySpinnerItem> {

  override val spinnerView: PowerSpinnerView = powerSpinnerView
  override var onSpinnerItemSelectedListener: OnSpinnerItemSelectedListener<MySpinnerItem>? = null

On the customized adapter, you must call spinnerView.notifyItemSelected method when your item is clicked or the spinner item should be changed.

override fun onBindViewHolder(holder: MySpinnerViewHolder, position: Int) {
  holder.itemView.setOnClickListener {
    notifyItemSelected(position)
  }
}

// we must call the spinnerView.notifyItemSelected method to let PowerSpinnerView know about changed information.
override fun notifyItemSelected(index: Int) {
  this.spinnerView.notifyItemSelected(index, this.spinnerItems[index].text)
  this.onSpinnerItemSelectedListener?.onItemSelected(index, this.spinnerItems[index])
}

And we can listen to the selected item's information.

spinnerView.setOnSpinnerItemSelectedListener<MySpinnerItem> { index, item ->  toast(item.text) }

Avoid Memory leak

Dialog, PopupWindow and etc.. have memory leak issue if not dismissed before activity or fragment are destroyed.

But Lifecycles are now integrated with the Support Library since Architecture Components 1.0 Stable released.

So we can solve the memory leak issue so easily.

Just use setLifecycleOwner method. Then dismiss method will be called automatically before activity or fragment would be destroyed.

.setLifecycleOwner(lifecycleOwner)

PowerSpinnerView Attributes

GitHub