RecyclerView-FastScroll

A simple FastScroller for Android's RecyclerView.

Supports vertical RecyclerViews using either LinearLayoutManager or GridLayoutManager (including multiple spans).

The style is loosely based on the ListView FastScroller from whatever the last version of Lollipop was. This library borrows heavily from Google's Launcher3 FastScroller

Gradle

compile 'com.simplecityapps:recyclerview-fastscroll:1.0.18'

Usage

You must use FastScrollRecyclerView as your base RecyclerView. See the sample project if you're having trouble.

Via xml:

 <com.simplecityapps.recyclerview_fastscroll.views.FastScrollRecyclerView
         android:id="@+id/recycler"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         app:fastScrollPopupBgColor="@color/colorAccent"
         app:fastScrollPopupTextColor="@android:color/primary_text_dark"
         app:fastScrollThumbColor="@color/colorAccent" />

To display the FastScrollPopup, your adapter must implement FastScrollRecyclerView.SectionedAdapter and override getSectionName().

If you need to know when fast-scrolling starts or stops, you can attach an OnFastScrollStateChangedListener to the FastScrollRecyclerView.

Varying Row Heights

By default, FastScrollRecyclerView assumes that all items in the adapter have the same height. If your adapter has item views with different heights, then you should make your adapter implement the MeasurableAdapter interface and override getViewTypeHeight() – otherwise the scroll thumb may not appear in the correct position and scrolling may be inconsistent.

getViewTypeHeight() returns the height of a single view of a given type in pixels. The height of each view must be fixed and constant between all instances of a view type. Because the implementor is responsible for computing this value before views are laid out, this is not suitable for view types where the height of a view is determined by a variable number of lines of text that the item consumes.

Currently, MeasurableAdapter only works with LinearLayoutManager. Using MeasurableAdapter with a GridLayoutManager that has more than one span will cause the scrollbar thumb to reach the bottom of the list before the halfway point on the scrollbar's background.

Customisation

You can enable/disable autohide using the fastScrollAutoHide & fastScrollAutoHideDelay attributes in xml:

 <com.simplecityapps.recyclerview_fastscroll.views.FastScrollRecyclerView
         app:fastScrollAutoHide="true"
         app:fastScrollAutoHideDelay="1500"
         ...

Or programmatically via setAutoHideDelay(int hideDelay) and setAutoHideEnabled(boolean autoHideEnabled)

The popup background, popup text, popupbackground size, popup text size, track background, thumb color and popup position can all be styled via xml:

  <com.simplecityapps.recyclerview_fastscroll.views.FastScrollRecyclerView
              app:fastScrollPopupBgColor="@color/colorAccent"
              app:fastScrollPopupTextColor="@android:color/primary_text_dark"
              app:fastScrollPopupTextSize="56sp"
              app:fastScrollPopupBackgroundSize="88dp"
              app:fastScrollThumbColor="@color/colorAccent"
              app:fastScrollTrackColor="#1f000000" 
              app:fastScrollPopupPosition="adjacent"/>
              ...

Or programmatically via setThumbColor(@ColorInt int color), setTrackColor(@ColorInt int color), setPopupBgColor(@ColorInt int color), setPopupTextColor(@ColorInt int color), setPopupTextSize(int size) & setPopupPosition(@FastScroller.FastScrollerPopupPosition int position)

You can enable/disable fast-scrolling via:

  <com.simplecityapps.recyclerview_fastscroll.views.FastScrollRecyclerView
              app:fastScrollThumbEnabled="false"
              ...

Or programmatically via setFastScrollThumbEnabled(boolean enabled)

Updates

1.0.18

• Added method showScrollbar() to FastScrollRecyclerView
• Added method setThumbInactiveColor(ColorInt) to FastScroller
• Renamed setThumbInactiveColor(boolean) to enableThumbInactiveColor(boolean).
• Renamed setStateChangeListener to setOnFastScrollStateChangedListener
• Renamed setThumbEnabled to setFastScrollEnabled
• Set enableThumbInactiveColor to true by default
• Pass ViewHolder into MeasurableAdapter to ease item height calculations
• Dependency updates

1.0.17

• MeasurableAdapter tweaks
• Improved sample, better demonstration of MeasurableAdapter
• Add option to enable/disable fastscroll (via fastScrollThumbEnabled property)
• Dependency updates

1.0.16

• Added support for varying row heights via MeasurableAdapter

1.0.15

• Fixed an issue preventing the view from rendering in the Android Studio 'design' panel.
• Updated dependencies

1.0.14

• Make it possible to set popup position programmatically

1.0.13

• Added option to position the FastScroll-Popup in the center of the RecyclerView (rather than tracking adjacent to the FastScroll thumb)

1.0.12

• Fixed a Proguard Obfuscation issue preventing animations from running
• Fixed an issue where popup background color ignored alpha channel
• Added support for item decorations

1.0.11

• Added FastScrollStateChanged listener. Notifies when scrolling starts & stops.

1.0.10

• Added methods/attributes to set popup background & text size
• Added method to set popup typeface
• Fixed issue where item decorations were drawn over the top of the popup (#18)
• Updated dependencies

v1.0.9

• Updated gradle & dependencies
• Fixed crash when no adapter was set on the RecyclerView
• Fixed crash when RecyclerView children are null (itemCount is non zero, but getChildAt(0) returns null).

v1.0.6

• The FastScrollPopup no longer requires your adapter to implement SectionIndexer, but rather FastScrollRecyclerView.SectionedAdapter, which is much easier to use.

Licenses

RecyclerView-FastScroll

 Copyright (C) 2016 Tim Malseed

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.

Launcher 3:

 Copyright (C) 2010 The Android Open Source Project

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.