Material Design play/pause Drawable with animation, compatible with Android 4.0+.
- Correct play icon that is the same as the one in Material Design Icons, not horizontally stretched (1, 2).
- Robust state handling that always animates to the correct final state without visual glitch.
- Can be used flexibly as
Drawable,ImageVieworImageButton. Drawablecomes with the intrinsic size of 24dp.- Compatible down to Android 4.0.
Gradle:
implementation 'me.zhanghai.android.materialplaypausedrawable:library:1.0.0'Simply use MaterialPlayPauseView (subclass of ImageView) or MaterialPlayPauseButton (subclass of ImageButton), e.g.
<me.zhanghai.android.materialplaypausedrawable.MaterialPlayPauseButton
android:id="@+id/play_pause"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:tint="?colorAccent" />The Drawable is by default black, so you might want to tint it with android:tint. The default size will be determined by the Drawable which will be 24dp.
Some interesting methods include setAnimationDuration(), getState(), setState() and jumpToState(), which you can use to control the play/pause state of the Drawable.
Implementation detail: The Drawable actually internally holds up to three states, namely the previous, current and next state. Animation happens between the previous and current state, and the next state is used to save the upcoming state while animation is running. If setState() is called while animation is running, it will simply replace the next state so that when current animation ends it can seamlessly transition to the final state without a glitch, while discarding any intermediate states. (And just to make things clear, getState() always returns the most recent state set by setState().)
(This library is using State.PLAY and State.PAUSE to denote the two icons instead of using a boolean, because the latter can actually be confusing when isPlaying == true actually means showing a pause icon.)
You can also use the MaterialPlayPauseDrawable directly. It has an intrinsic size of 24dp and default color of black. It also exposed the same methods namely setAnimationDuration(), getPlayPauseState() (renamed to avoid clashing with Drawable.getState()), setState() and jumpToState().
One caveat is that on Android 7.0+, the framework uses View.onVisibilityAggregated() instead of View.onVisibilityChanged(), and it is broken in that it won't set our Drawable to invisible when the containing view is set to invisible before attached to the view hierarchy (e.g. when inside onBindViewHolder()). This can lead to erroneous animation when the view is later set to visible because our Drawable won't be able to skip its animation when it was invisible.
To work around this issue, I created VisibilityAggregatedImageView and VisibilityAggregatedImageButton, and you might want to use or derive from them when using the Drawable directly. (If you are using MaterialPlayPauseView or MaterialPlayPauseButton, this is automatically handled for you.)
Copyright 2018 Zhang Hai
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
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http://www.apache.org/licenses/LICENSE-2.0
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