InboxRecyclerView is a library for building expandable descendant navigation, inspired by Google Inbox and Reply. If you're interested in learning how it was created, here's a detailed blog post.

implementation 'me.saket:inboxrecyclerview:1.0.0-beta2'

FYI, InboxRecyclerView has a dependency on androidx. If you haven't migrated from the support library already, this would be a good opportunity.

Usage

InboxRecyclerView can be dropped in existing projects without requiring any effort. You can take a look at the sample app for best practices or download its APK for trying it out on your phone.

Layout

<me.saket.expand.InboxRecyclerView
  android:layout_width="match_parent"
  android:layout_height="match_parent" />

<!--
  It's recommended that the content page has a higher z-index
  than the list. This can be achieved by either giving it a
  higher view position or a higher elevation.
-->
<me.saket.expand.page.ExpandablePageLayout
  android:layout_width="match_parent"
  android:layout_height="match_parent" />

Expanding content

recyclerView.setExpandablePage(contentPage)

recyclerViewAdapter.itemClickListener = { clickedItem ->
  expandableFragment.loadContent(clickedItem)
  recyclerView.expandItem(clickedItem.adapterId)
}

How do I…

• customize item expand animations?
• control the pull-to-collapse gesture?
• change the background tint?
• listen to state changes?

Pull collapsible activities

To maintain consistency across the whole app, this library also includes a PullCollapsibleActivity that brings the same animations and gesture to activities with little effort.

Step 1. Extend PullCollapsibleActivity.

Step 2. Add these attributes to the activity’s theme:

<item name=“android:windowIsTranslucent”>true</item>
<item name=“android:colorBackgroundCacheHint”>@null</item>

License

Copyright 2018 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.