Added Swipe on Lyrics to change songs

app/src/main/java/code/name/monkey/retromusic/fragments/player/PlayerAlbumCoverFragment.kt

@@ -136,13 +136,26 @@ class PlayerAlbumCoverFragment : AbsMusicServiceFragment(R.layout.fragment_playe
         progressViewUpdateHelper = MusicProgressViewUpdateHelper(this, 500, 1000)
         maybeInitLyrics()
         lrcView.apply {
-            setDraggable(true, object : CoverLrcView.OnPlayClickListener {
-                override fun onPlayClick(time: Long): Boolean {
+            setDraggable(true) { time ->
                 MusicPlayerRemote.seekTo(time.toInt())
                 MusicPlayerRemote.resumePlaying()
-                    return true
+                true
+            }
+            setOnFlingXListener { velocityX ->
+                when {
+                    velocityX < 0 -> {
+                        MusicPlayerRemote.playNextSong()
+                        true
+                    }
+                    velocityX > 0 -> {
+                        MusicPlayerRemote.playPreviousSong()
+                        true
+                    }
+                    else -> {
+                        false
+                    }
+                }
             }
-            })
         }
     }
 

app/src/main/java/code/name/monkey/retromusic/lyrics/CoverLrcView.kt

@@ -35,6 +35,7 @@ import android.view.animation.LinearInterpolator
 import android.widget.Scroller
 import androidx.core.content.ContextCompat
 import code.name.monkey.retromusic.R
+import code.name.monkey.retromusic.helper.MusicPlayerRemote
 import java.io.File
 import java.util.*
 import kotlin.math.abs
@@ -67,6 +68,7 @@ class CoverLrcView @JvmOverloads constructor(
     private var mDefaultLabel: String? = null
     private var mLrcPadding = 0f
     private var mOnPlayClickListener: OnPlayClickListener? = null
+    private var mOnFlingXListener: OnFlingXListener? = null
     private var mAnimator: ValueAnimator? = null
     private var mGestureDetector: GestureDetector? = null
     private var mScroller: Scroller? = null
@@ -131,6 +133,9 @@ class CoverLrcView @JvmOverloads constructor(
                 velocityX: Float,
                 velocityY: Float
             ): Boolean {
+                if (mOnFlingXListener != null && abs(velocityX) > abs(velocityY)) {
+                    return mOnFlingXListener!!.onFlingX(velocityX)
+                }
                 if (hasLrc()) {
                     mScroller!!.fling(
                         0,
@@ -313,6 +318,10 @@ class CoverLrcView @JvmOverloads constructor(
         mOnPlayClickListener = onPlayClickListener
     }
 
+    fun setOnFlingXListener(onFlingXListener: OnFlingXListener) {
+        mOnFlingXListener = onFlingXListener
+    }
+
     /** 设置歌词为空时屏幕中央显示的文字，如“暂无歌词”  */
     fun setLabel(label: String?) {
         runOnUi {
@@ -661,6 +670,7 @@ class CoverLrcView @JvmOverloads constructor(
 
     /** 获取歌词距离视图顶部的距离 采用懒加载方式  */
     private fun getOffset(line: Int): Float {
+        if (mLrcEntryList.isEmpty()) return 0F
         if (mLrcEntryList[line].offset == Float.MIN_VALUE) {
             var offset = (height / 2).toFloat()
             for (i in 1..line) {
@@ -686,7 +696,7 @@ class CoverLrcView @JvmOverloads constructor(
     }
 
     /** 播放按钮点击监听器，点击后应该跳转到指定播放位置  */
-    interface OnPlayClickListener {
+    fun interface OnPlayClickListener {
         /**
          * 播放按钮被点击，应该跳转到指定播放位置
          *
@@ -695,6 +705,10 @@ class CoverLrcView @JvmOverloads constructor(
         fun onPlayClick(time: Long): Boolean
     }
 
+    fun interface OnFlingXListener {
+        fun onFlingX(velocityX: Float): Boolean
+    }
+
     companion object {
         private const val ADJUST_DURATION: Long = 100
         private const val TIMELINE_KEEP_TIME = 4 * DateUtils.SECOND_IN_MILLIS