cascade builds nested popup menus with smooth height animations. It is designed to be a drop-in replacement for PopupMenu so using it in your project is beautifully only a word away:

implementation "me.saket.cascade:cascade:1.0.0"

- val menu = PopupMenu(context, anchor)
+ val menu = CascadePopupMenu(context, anchor)
  menu.inflate(R.menu.nicolas_cage_movies)
  menu.show()

Try out the sample app on your phone to see cascade in action.

Customization

cascade is great for apps that prefer applying dynamic themes at runtime, which PopupMenu makes it extremely hard to do so. By providing a CascadePopupMenu.Styler object, you can adjust colors, spacings and text styles from Kotlin. See the sample app for an example.

By default, CascadePopupMenu will pick up values from your theme in the same way as PopupMenu would.

<style name="AppTheme">
  <item name="popupMenuStyle">@style/PopupMenuStyle</item>
  <item name="colorControlNormal">@color/menu_icon_color</item>
  <item name="android:textColorPrimary">@color/menu_item_color</item>
  <item name="android:textColorSecondary">@color/menu_title_color</item>
</style>

<style name="PopupMenuStyle" parent="@style/Widget.AppCompat.PopupMenu">
  <item name="android:popupBackground">...</item>
  <item name="android:popupElevation">...</item>
</style>

Navigation

For sub-menus, cascade will automatically navigate to the parent menu when the title is pressed. For manual navigation, CascadePopupMenu#navigateBack() can be used.

popup.menu.addSubMenu("Remove").also {
  it.setHeaderTitle("Are you sure?")
  it.add("Burn them all")
  it.add("Take me back").setOnMenuItemClickListener {
    popupMenu.navigateBack()
    true
  }
}

Custom layouts

cascade was originally inspired by Google Drive's menu that uses a variety of complex controls. Apps that wanna do something similar, a batteries-included CascadePopupWindow is also provided for use with custom layouts.

val popup = CascadePopupWindow(context)
val menuView = CustomMenuView(context)
popup.contentView.goForward(menuView)

val subMenuView = CustomSubMenuView(context)
menuView.setOnClickListener { 
  popup.contentView.goForward(subMenuView)
}
subMenuView.setOnClickListener {
  popup.contentView.goBack(menuView)
}

popup.showAsDropdown(anchor, ...)

Copyright 2020 Saket Narayan.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.