[Internal] Use AnimatorSet#playTogether without workarounds on API 23+

Author: pubiqq

lib/java/com/google/android/material/animation/AnimatorSetCompat.java

@@ -18,9 +18,14 @@
 import android.animation.Animator;
 import android.animation.AnimatorSet;
 import android.animation.ValueAnimator;
+import android.os.Build;
 import androidx.annotation.NonNull;
+import androidx.annotation.RequiresApi;
 import androidx.annotation.RestrictTo;
 import androidx.annotation.RestrictTo.Scope;
+
+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 
 /**
@@ -33,17 +38,35 @@ public class AnimatorSetCompat {
 
   /** Sets up this AnimatorSet to play all of the supplied animations at the same time. */
   public static void playTogether(@NonNull AnimatorSet animatorSet, @NonNull List<Animator> items) {
-    // Fix for pre-M bug where animators with start delay are not played correctly in an
-    // AnimatorSet.
-    long totalDuration = 0;
-    for (int i = 0, count = items.size(); i < count; i++) {
-      Animator animator = items.get(i);
-      totalDuration = Math.max(totalDuration, animator.getStartDelay() + animator.getDuration());
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+      Api23Impl.playTogether(animatorSet, items);
+    } else {
+      Api21Impl.playTogether(animatorSet, items);
     }
-    Animator fix = ValueAnimator.ofInt(0, 0);
-    fix.setDuration(totalDuration);
-    items.add(0, fix);
+  }
 
-    animatorSet.playTogether(items);
+  @RequiresApi(Build.VERSION_CODES.M)
+  static class Api23Impl {
+    static void playTogether(@NonNull AnimatorSet animatorSet, @NonNull Collection<Animator> items) {
+      animatorSet.playTogether(items);
+    }
+  }
+
+  static class Api21Impl {
+    static void playTogether(@NonNull AnimatorSet animatorSet, @NonNull Collection<Animator> items) {
+      // Fix for pre-M bug where animators with start delay are not played correctly in an
+      // AnimatorSet.
+      long totalDuration = 0;
+      for (Animator animator : items) {
+        totalDuration = Math.max(totalDuration, animator.getStartDelay() + animator.getDuration());
+      }
+      Animator fix = ValueAnimator.ofInt(0, 0);
+      fix.setDuration(totalDuration);
+
+      List<Animator> animators = new ArrayList<>(items.size() + 1);
+      animators.add(fix);
+      animators.addAll(items);
+      animatorSet.playTogether(animators);
+    }
   }
 }