SkeletonLayout

Make your app feel faster

Users are time-sensitive and may skip an app due to long loading times and missing visual feedback. Instagram, Facebook, Google and other services tackled this problem with the so-called Skeleton View. This view is being displayed during the process of fetching or requesting data asynchronously which leads to a perceivedly more responsive app.

This library implements the Skeleton View pattern and provides an easy way for other developers to enable it in their apps.

Demo

Preview

The SkeletonLayout mimics the design of established implementations per default, but you are free to get creative. Create your own skeleton view with custom shapes, colors and shimmers.

Features

Make your app feel faster: Immediate visual feedback long before your data has been fetched or requested
Support any View: Apply to any type of View or ViewGroup
RecyclerView on speed: Convenience adapter for RecyclerView as it is the main use case
ViewPager2 support: Convenience adapter for ViewPager2 as it uses a RecyclerView under the hood
Customization: Adjust shimmer, color and shape of the skeleton to set you apart from other apps
Minimum effort: A fistful lines of code to use the SkeletonLayout
Minimum footprint: org.jetbrains.kotlin:kotlin-stdlib-jdk7, androidx.recyclerview:recyclerview and androidx.viewpager2.widget.ViewPager2 are the only dependencies

Getting Started

Gradle

buildscript {
    repositories {
        mavenCentral()
    }
}

dependencies {
    implementation 'com.faltenreich:skeletonlayout:<version>'
}

XML

<com.faltenreich.skeletonlayout.SkeletonLayout
    android:id="@+id/skeletonLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    
    <!-- Views to mask -->
    
</com.faltenreich.skeletonlayout.SkeletonLayout>

Kotlin

class MainActivity : AppCompatActivity() {

    private lateinit var skeleton: Skeleton

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Either use an existing Skeletonlayout
        skeleton = findViewById(R.id.skeletonLayout)

        // or create a new SkeletonLayout from a given View
        skeleton = view.createSkeleton()

        // or apply a new SkeletonLayout to a RecyclerView
        skeleton = recyclerView.applySkeleton(R.layout.list_item_recyclerview)

        // or apply a new SkeletonLayout to a ViewPager2
        skeleton = viewPager2.applySkeleton(R.layout.list_item_viewpager2)

        skeleton.showSkeleton()
    }

    // Example callback that hides skeleton
    private fun onDataLoaded() {
        skeleton.showOriginal()
    }
}

Java

public class MainActivity extends AppCompatActivity {
    
    private Skeleton skeleton;
    
    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        // Either use an existing Skeletonlayout
        skeleton = findViewById(R.id.skeletonLayout);
        
        // or create a new SkeletonLayout from a given View
        skeleton = SkeletonLayoutUtils.createSkeleton(view);
        
        // or apply a new SkeletonLayout to a RecyclerView
        skeleton = SkeletonLayoutUtils.applySkeleton(recyclerView, R.layout.list_item_recyclerview);

        // or apply a new SkeletonLayout to a ViewPager2
        skeleton = SkeletonLayoutUtils.applySkeleton(viewPager2, R.layout.list_item_viewpager2);

        skeleton.showSkeleton();
    }
    
    // Example callback that hides skeleton
    private void onDataLoaded() {
        skeleton.showOriginal();
    }
}

Configuration

Property	Type	Description
maskColor	color	Color of the mask that fills the original view bounds (defaults to #E0E0E0)
maskCornerRadius	dimension	The x- and y-radius of the oval used to round the mask corners (defaults to 25)
showShimmer	boolean	Animate shimmer if set to true (defaults to true)
shimmerColor	color	Color of the animated shimmer (defaults to #d5d5d5)
shimmerDurationInMillis	integer	Duration in milliseconds for one shimmer animation interval (defaults to 2000)
shimmerDirection	enum	Direction of animated shimmer (defaults to LEFT_TO_RIGHT)
shimmerAngle	integer	Angle in degrees for animated shimmer (defaults to 0)
itemCount	integer	Item count for Skeleton adapter (RecyclerView and ViewPager2 only, defaults to 3)

FAQ

When and how is the skeleton created? The skeleton gets created after the original view's onLayout(), since we rely on it to be fully rendered in order to mask its bounds.

How does the masking work? The mask is drawn onto a single Bitmap by iterating once through the given Views and their bounds.

May properties of the SkeletonLayout be changed at runtime? Yes. Any change to the skeleton leads to a redraw, since the whole content of the SkeletonLayout gets drawn onto a single bitmap.

Will the shimmer eat my users' battery? The shimmer is a shader (LinearGradient) whose local matrix is updated according to the framerate of the target device, so no redrawing is required and processing time is kept to an absolute minimum. Additionally the shimmer gets inactive onWindowFocusChanged() and onDetachedFromWindow().

Third-party licenses

This software uses following technologies with great appreciation:

License

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.

lnfg/SkeletonLayout