README.md

DoubleTapPlayerView

A simple library to include double tap behavior to ExoPlayer's PlayerView. Created to handle fast forward/rewind behavior like YouTube.

Sample app

If you would like to test the YouTube overlay, then you can either download the demo app, which can be found under Assets of the release or build it yourself from code. It provides all main modifications available.

The sample videos own by Blender Foundation and a full list can be found here.

Download

The Gradle dependency is available via jitpack.io. To be able to load this library, you have to add the repository to your project's gradle file:

allprojects {
  repositories {
    ...
    maven { url 'https://jitpack.io' }
  }
}

Then, in your app's directory, you can include it the same way like other libraries:

android {
  ...
  // If you face problems during building you should try including the below lines if you
  // haven't already
  
  // compileOptions {
  //   sourceCompatibility JavaVersion.VERSION_1_8
  //   targetCompatibility JavaVersion.VERSION_1_8
  // }
}

dependencies {
  implementation 'com.github.vkay94:DoubleTapPlayerView:1.0.4'
}

The minimum API level supported by this library is API 16 as ExoPlayer does, but I can't verify versions below API level 21 (Lollipop) myself. So feedback is welcomed.

Getting started

In order to start using the YouTube overlay, the easiest way is to include it directly into your XML layout, e.g. on top of DoubleTapPlayerView or inside ExoPlayer's controller:

<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
    
    <com.github.vkay94.dtpv.DoubleTapPlayerView
        android:id="@+id/playerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        
        app:dtpv_controller="@+id/youtube_overlay" />

    <com.github.vkay94.dtpv.youtube.YouTubeOverlay
        android:id="@+id/youtube_overlay"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="invisible"
        
        app:yt_playerView="@+id/playerView" />
</FrameLayout>

Then, inside your Activity or Fragment, you can specify which preparations should be done before and after the animation, but at least, you have got to toggle the visibility of the overlay and reference the (Simple)ExoPlayer to it:

youtube_overlay
    .performListener(object : YouTubeOverlay.PerformListener {
        override fun onAnimationStart() {
            // Do UI changes when circle scaling animation starts (e.g. hide controller views)
            youtube_overlay.visibility = View.VISIBLE
        }

        override fun onAnimationEnd() {
            // Do UI changes when circle scaling animation starts (e.g. show controller views)
            youtube_overlay.visibility = View.GONE
        }
    })
    // Uncomment this line if you haven't set yt_playerView in XML
    // .playerView(playerView)

// Uncomment this line if you haven't set dtpv_controller in XML 
// playerView.controller(youtube_overlay)

// Call this method whenever the player is released and recreated
youtube_overlay.player(simpleExoPlayer)

This way, you have more control about the appearance, for example you could apply a fading animation to it. For a full initialization you can refer to the demo application's MainActivity and layout files.

---

API documentation

The following sections provide detailed documentation for the components of the library.

DoubleTapPlayerView

DoubleTapPlayerView is the core of this library. It recognizes specific gestures which provides more control for the double tapping gesture. An overview about the added methods can be found in the PlayerDoubleTapListener interface.

You can adjust how long the double tap mode remains after the last action, the default value is 650 milliseconds.

YouTubeOverlay

YouTubeOverlay is the reason for this library. It provides nearly the same experience like the fast forward/rewind feature which is used by YouTube's Android app. It is highly modifiable.

XML attributes

If you add the view to your XML layout you can set some custom attributes to customize the view's look and behavior. Every attributes value can also be get and set programmatically.

Attribute name	Description	Type
yt_seekSeconds	Fast forward/rewind seconds skip per tap. The text xx seconds will be changed where xx is value.	int
yt_animationDuration	Speed of the circle scaling / time in millis to expand completely. When this time has passed, YouTubeOverlay's PerformListener.onAnimationEnd() will be called.	int
yt_arcSize	Arc of the background circle. The higher the value the more roundish the shape becomes. This attribute should be set dynamically depending on screen size and orientation.	dimen
yt_tapCircleColor	Color of the scaling circle after tap.	color
yt_backgroundCircleColor	Color of the background shape.	color
yt_iconAnimationDuration	Time in millis to run through an full fade cycle.	int
yt_icon	One of the three forward icons. Will be multiplied by three and mirrored for rewind.	drawable
yt_textAppearance	Text appearance for the xx seconds text.	style

I'd recommend the sample app to try out the different values for them.

YouTubeOverlay.PerformListener

This interface listens to the lifecycle of the overlay.

// Obligatory: Called when the overlay is not visible and the first valid double tap event occurred.
// Visibility of the overlay should be set to VISIBLE within this interface method.
fun onAnimationStart()

// Obligatory: Called when the circle animation is finished.
// Visibility of the overlay should be set to GONE or INVISIBLE within this interface method.
fun onAnimationEnd()

// Optional: Determines whether the player should forward (true), rewind (false) or ignore (null) taps.
fun shouldForward(player: Player, playerView: DoubleTapPlayerView, posX: Float): Boolean?

SeekListener

This interface reacts to the events during rewinding/forwarding.

// Called when the start of the video is reached
fun onVideoStartReached()

// Called when the end of the video is reached
fun onVideoEndReached()