Return true from CuesResolver.addCues if the output changed

This belongs in the resolver, because it depends on the resolution
algorithm (and therefore the logic can't live in `TextRenderer`).

This also fixes a bug in `TextRenderer` where we were doing arithmetic
with `cues.durationUs` without checking if it was `TIME_UNSET` first.

#minor-release

PiperOrigin-RevId: 571332750
(cherry picked from commit 272428734b)

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/text/CuesResolver.java

@@ -30,8 +30,11 @@ import com.google.common.collect.ImmutableList;
  */
 /* package */ interface CuesResolver {
 
-  /** Adds cues to this instance. */
+  /**
-  void addCues(CuesWithTiming cues);
+   * Adds {@code cues} to this instance, returning whether this changes the cues displayed at {@code
+   * currentPositionUs}.
+   */
+  boolean addCues(CuesWithTiming cues, long currentPositionUs);
 
   /**
    * Returns the {@linkplain Cue cues} that should be shown at time {@code timeUs}.

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/text/MergingCuesResolver.java

@@ -60,16 +60,19 @@ import java.util.List;
   }
 
   @Override
-  public void addCues(CuesWithTiming cues) {
+  public boolean addCues(CuesWithTiming cues, long currentPositionUs) {
     checkArgument(cues.startTimeUs != C.TIME_UNSET);
     checkArgument(cues.durationUs != C.TIME_UNSET);
+    boolean cuesAreShownAtCurrentTime =
+        cues.startTimeUs <= currentPositionUs && currentPositionUs < cues.endTimeUs;
     for (int i = cuesWithTimingList.size() - 1; i >= 0; i--) {
       if (cues.startTimeUs >= cuesWithTimingList.get(i).startTimeUs) {
         cuesWithTimingList.add(i + 1, cues);
-        return;
+        return cuesAreShownAtCurrentTime;
       }
     }
     cuesWithTimingList.add(0, cues);
+    return cuesAreShownAtCurrentTime;
   }
 
   @Override

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/text/ReplacingCuesResolver.java

@@ -15,6 +15,8 @@
  */
 package androidx.media3.exoplayer.text;
 
+import static androidx.media3.common.util.Assertions.checkArgument;
+
 import androidx.media3.common.C;
 import androidx.media3.common.text.Cue;
 import androidx.media3.extractor.text.CuesWithTiming;
@@ -43,14 +45,23 @@ import java.util.ArrayList;
   }
 
   @Override
-  public void addCues(CuesWithTiming cues) {
+  public boolean addCues(CuesWithTiming cues, long currentPositionUs) {
+    checkArgument(cues.startTimeUs != C.TIME_UNSET);
+    boolean cuesAreShownAtCurrentTime =
+        cues.startTimeUs <= currentPositionUs
+            && (cues.endTimeUs == C.TIME_UNSET || currentPositionUs < cues.endTimeUs);
     for (int i = cuesWithTimingList.size() - 1; i >= 0; i--) {
       if (cues.startTimeUs >= cuesWithTimingList.get(i).startTimeUs) {
         cuesWithTimingList.add(i + 1, cues);
-        return;
+        return cuesAreShownAtCurrentTime;
+      } else if (cuesWithTimingList.get(i).startTimeUs <= currentPositionUs) {
+        // There's a cue that starts after the new cues, but before the current time, meaning
+        // the new cues will not be displayed at the current time.
+        cuesAreShownAtCurrentTime = false;
       }
     }
     cuesWithTimingList.add(0, cues);
+    return cuesAreShownAtCurrentTime;
   }
 
   @Override

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/text/TextRenderer.java

@@ -312,12 +312,7 @@ public final class TextRenderer extends BaseRenderer implements Callback {
                 cueData.limit());
         cueDecoderInputBuffer.clear();
 
-        cuesResolver.addCues(cuesWithTiming);
+        return cuesResolver.addCues(cuesWithTiming, positionUs);
-
-        // Return whether the CuesWithTiming we added to CuesMerger changes the subtitles that
-        // should be on-screen *now*.
-        return cuesWithTiming.startTimeUs <= positionUs
-            && positionUs < cuesWithTiming.startTimeUs + cuesWithTiming.durationUs;
       case C.RESULT_FORMAT_READ:
       case C.RESULT_NOTHING_READ:
       default:

libraries/exoplayer/src/test/java/androidx/media3/exoplayer/text/MergingCuesResolverTest.java

@@ -62,8 +62,8 @@ public final class MergingCuesResolverTest {
         new CuesWithTiming(SECOND_CUES, /* startTimeUs= */ 6_000_000, /* durationUs= */ 1_000_000);
 
     // Reverse the addCues call to check everything still works (it should).
-    mergingCuesResolver.addCues(secondCuesWithTiming);
+    mergingCuesResolver.addCues(secondCuesWithTiming, /* currentPositionUs= */ 0);
-    mergingCuesResolver.addCues(firstCuesWithTiming);
+    mergingCuesResolver.addCues(firstCuesWithTiming, /* currentPositionUs= */ 0);
 
     assertCuesStartAt(mergingCuesResolver, 3_000_000);
 
@@ -82,8 +82,8 @@ public final class MergingCuesResolverTest {
     CuesWithTiming secondCuesWithTiming =
         new CuesWithTiming(SECOND_CUES, /* startTimeUs= */ 2_000_000, /* durationUs= */ 4_000_000);
 
-    mergingCuesResolver.addCues(firstCuesWithTiming);
+    mergingCuesResolver.addCues(firstCuesWithTiming, /* currentPositionUs= */ 0);
-    mergingCuesResolver.addCues(secondCuesWithTiming);
+    mergingCuesResolver.addCues(secondCuesWithTiming, /* currentPositionUs= */ 0);
 
     assertCuesStartAt(mergingCuesResolver, 1_000_000);
     assertCueTextBetween(mergingCuesResolver, 1_000_000, 2_000_000, "first cue");
@@ -109,8 +109,8 @@ public final class MergingCuesResolverTest {
     CuesWithTiming secondCuesWithTiming =
         new CuesWithTiming(SECOND_CUES, /* startTimeUs= */ 1_000_000, /* durationUs= */ 3_000_000);
 
-    mergingCuesResolver.addCues(firstCuesWithTiming);
+    mergingCuesResolver.addCues(firstCuesWithTiming, /* currentPositionUs= */ 0);
-    mergingCuesResolver.addCues(secondCuesWithTiming);
+    mergingCuesResolver.addCues(secondCuesWithTiming, /* currentPositionUs= */ 0);
 
     assertCuesStartAt(mergingCuesResolver, 1_000_000);
     // secondCuesWithTiming has a shorter duration than firstCuesWithTiming, so should appear later
@@ -134,8 +134,8 @@ public final class MergingCuesResolverTest {
     CuesWithTiming secondCuesWithTiming =
         new CuesWithTiming(SECOND_CUES, /* startTimeUs= */ 2_000_000, /* durationUs= */ 3_000_000);
 
-    mergingCuesResolver.addCues(firstCuesWithTiming);
+    mergingCuesResolver.addCues(firstCuesWithTiming, /* currentPositionUs= */ 0);
-    mergingCuesResolver.addCues(secondCuesWithTiming);
+    mergingCuesResolver.addCues(secondCuesWithTiming, /* currentPositionUs= */ 0);
 
     assertCuesStartAt(mergingCuesResolver, 1_000_000);
     // secondCuesWithTiming has a shorter duration than firstCuesWithTiming, so should appear later
@@ -158,7 +158,59 @@ public final class MergingCuesResolverTest {
         new CuesWithTiming(
             FIRST_CUES, /* startTimeUs= */ 3_000_000, /* durationUs= */ C.TIME_UNSET);
 
-    assertThrows(IllegalArgumentException.class, () -> mergingCuesResolver.addCues(cuesWithTiming));
+    assertThrows(
+        IllegalArgumentException.class,
+        () -> mergingCuesResolver.addCues(cuesWithTiming, /* currentPositionUs= */ 0));
+  }
+
+  @Test
+  public void addCues_cuesStartAfterCurrentPosition() {
+    MergingCuesResolver mergingCuesResolver = new MergingCuesResolver();
+    CuesWithTiming cuesWithTiming =
+        new CuesWithTiming(FIRST_CUES, /* startTimeUs= */ 3_000_000, /* durationUs= */ 2_000_000);
+
+    assertThat(mergingCuesResolver.addCues(cuesWithTiming, /* currentPositionUs= */ 1_000_000))
+        .isFalse();
+  }
+
+  @Test
+  public void addCues_cuesStartAtCurrentPosition() {
+    MergingCuesResolver mergingCuesResolver = new MergingCuesResolver();
+    CuesWithTiming cuesWithTiming =
+        new CuesWithTiming(FIRST_CUES, /* startTimeUs= */ 3_000_000, /* durationUs= */ 2_000_000);
+
+    assertThat(mergingCuesResolver.addCues(cuesWithTiming, /* currentPositionUs= */ 3_000_000))
+        .isTrue();
+  }
+
+  @Test
+  public void addCues_cuesDisplayedAtCurrentPosition() {
+    MergingCuesResolver mergingCuesResolver = new MergingCuesResolver();
+    CuesWithTiming cuesWithTiming =
+        new CuesWithTiming(FIRST_CUES, /* startTimeUs= */ 3_000_000, /* durationUs= */ 2_000_000);
+
+    assertThat(mergingCuesResolver.addCues(cuesWithTiming, /* currentPositionUs= */ 4_000_000))
+        .isTrue();
+  }
+
+  @Test
+  public void addCues_cuesEndBeforeCurrentPosition() {
+    MergingCuesResolver mergingCuesResolver = new MergingCuesResolver();
+    CuesWithTiming cuesWithTiming =
+        new CuesWithTiming(FIRST_CUES, /* startTimeUs= */ 3_000_000, /* durationUs= */ 2_000_000);
+
+    assertThat(mergingCuesResolver.addCues(cuesWithTiming, /* currentPositionUs= */ 6_000_000))
+        .isFalse();
+  }
+
+  @Test
+  public void addCues_cuesEndAtCurrentPosition() {
+    MergingCuesResolver mergingCuesResolver = new MergingCuesResolver();
+    CuesWithTiming cuesWithTiming =
+        new CuesWithTiming(FIRST_CUES, /* startTimeUs= */ 3_000_000, /* durationUs= */ 2_000_000);
+
+    assertThat(mergingCuesResolver.addCues(cuesWithTiming, /* currentPositionUs= */ 5_000_000))
+        .isFalse();
   }
 
   @Test
@@ -171,9 +223,9 @@ public final class MergingCuesResolverTest {
     CuesWithTiming thirdCuesWithTiming =
         new CuesWithTiming(THIRD_CUES, /* startTimeUs= */ 8_000_000, /* durationUs= */ 4_000_000);
 
-    mergingCuesResolver.addCues(firstCuesWithTiming);
+    mergingCuesResolver.addCues(firstCuesWithTiming, /* currentPositionUs= */ 0);
-    mergingCuesResolver.addCues(secondCuesWithTiming);
+    mergingCuesResolver.addCues(secondCuesWithTiming, /* currentPositionUs= */ 0);
-    mergingCuesResolver.addCues(thirdCuesWithTiming);
+    mergingCuesResolver.addCues(thirdCuesWithTiming, /* currentPositionUs= */ 0);
 
     // Remove only firstCuesWithTiming (secondCuesWithTiming should be kept because it ends after
     // this time).
@@ -195,9 +247,9 @@ public final class MergingCuesResolverTest {
     CuesWithTiming thirdCuesWithTiming =
         new CuesWithTiming(THIRD_CUES, /* startTimeUs= */ 8_000_000, /* durationUs= */ 4_000_000);
 
-    mergingCuesResolver.addCues(firstCuesWithTiming);
+    mergingCuesResolver.addCues(firstCuesWithTiming, /* currentPositionUs= */ 0);
-    mergingCuesResolver.addCues(secondCuesWithTiming);
+    mergingCuesResolver.addCues(secondCuesWithTiming, /* currentPositionUs= */ 0);
-    mergingCuesResolver.addCues(thirdCuesWithTiming);
+    mergingCuesResolver.addCues(thirdCuesWithTiming, /* currentPositionUs= */ 0);
 
     mergingCuesResolver.clear();
 

libraries/exoplayer/src/test/java/androidx/media3/exoplayer/text/ReplacingCuesResolverTest.java

@@ -64,8 +64,8 @@ public final class ReplacingCuesResolverTest {
             SECOND_CUES, /* startTimeUs= */ 6_000_000, /* durationUs= */ C.TIME_UNSET);
 
     // Reverse the addCues call to check everything still works (it should).
-    replacingCuesResolver.addCues(secondCuesWithTiming);
+    replacingCuesResolver.addCues(secondCuesWithTiming, /* currentPositionUs= */ 0);
-    replacingCuesResolver.addCues(cuesWithTiming);
+    replacingCuesResolver.addCues(cuesWithTiming, /* currentPositionUs= */ 0);
 
     assertCuesStartAt(replacingCuesResolver, 3_000_000);
     assertCueTextBetween(replacingCuesResolver, 3_000_000, 6_000_000, "first cue");
@@ -81,8 +81,8 @@ public final class ReplacingCuesResolverTest {
     CuesWithTiming secondCuesWithTiming =
         new CuesWithTiming(SECOND_CUES, /* startTimeUs= */ 6_000_000, /* durationUs= */ 1_000_000);
 
-    replacingCuesResolver.addCues(firstCuesWithTiming);
+    replacingCuesResolver.addCues(firstCuesWithTiming, /* currentPositionUs= */ 0);
-    replacingCuesResolver.addCues(secondCuesWithTiming);
+    replacingCuesResolver.addCues(secondCuesWithTiming, /* currentPositionUs= */ 0);
 
     assertCuesStartAt(replacingCuesResolver, 3_000_000);
 
@@ -101,8 +101,8 @@ public final class ReplacingCuesResolverTest {
     CuesWithTiming secondCuesWithTiming =
         new CuesWithTiming(SECOND_CUES, /* startTimeUs= */ 2_000_000, /* durationUs= */ 4_000_000);
 
-    replacingCuesResolver.addCues(firstCuesWithTiming);
+    replacingCuesResolver.addCues(firstCuesWithTiming, /* currentPositionUs= */ 0);
-    replacingCuesResolver.addCues(secondCuesWithTiming);
+    replacingCuesResolver.addCues(secondCuesWithTiming, /* currentPositionUs= */ 0);
 
     assertCuesStartAt(replacingCuesResolver, 1_000_000);
     assertCueTextBetween(replacingCuesResolver, 1_000_000, 2_000_000, "first cue");
@@ -119,8 +119,8 @@ public final class ReplacingCuesResolverTest {
     CuesWithTiming secondCuesWithTiming =
         new CuesWithTiming(SECOND_CUES, /* startTimeUs= */ 1_000_000, /* durationUs= */ 3_000_000);
 
-    replacingCuesResolver.addCues(firstCuesWithTiming);
+    replacingCuesResolver.addCues(firstCuesWithTiming, /* currentPositionUs= */ 0);
-    replacingCuesResolver.addCues(secondCuesWithTiming);
+    replacingCuesResolver.addCues(secondCuesWithTiming, /* currentPositionUs= */ 0);
 
     assertCuesStartAt(replacingCuesResolver, 1_000_000);
     assertCueTextBetween(
@@ -128,6 +128,75 @@ public final class ReplacingCuesResolverTest {
     assertCuesEndAt(replacingCuesResolver, 4_000_000);
   }
 
+  @Test
+  public void addCues_cuesStartAfterCurrentPosition() {
+    ReplacingCuesResolver replacingCuesResolver = new ReplacingCuesResolver();
+    CuesWithTiming cuesWithTiming =
+        new CuesWithTiming(FIRST_CUES, /* startTimeUs= */ 3_000_000, /* durationUs= */ 2_000_000);
+
+    assertThat(replacingCuesResolver.addCues(cuesWithTiming, /* currentPositionUs= */ 1_000_000))
+        .isFalse();
+  }
+
+  @Test
+  public void addCues_cuesStartAtCurrentPosition() {
+    ReplacingCuesResolver replacingCuesResolver = new ReplacingCuesResolver();
+    CuesWithTiming cuesWithTiming =
+        new CuesWithTiming(FIRST_CUES, /* startTimeUs= */ 3_000_000, /* durationUs= */ 2_000_000);
+
+    assertThat(replacingCuesResolver.addCues(cuesWithTiming, /* currentPositionUs= */ 3_000_000))
+        .isTrue();
+  }
+
+  @Test
+  public void addCues_cuesDisplayedAtCurrentPosition() {
+    ReplacingCuesResolver replacingCuesResolver = new ReplacingCuesResolver();
+    CuesWithTiming cuesWithTiming =
+        new CuesWithTiming(FIRST_CUES, /* startTimeUs= */ 3_000_000, /* durationUs= */ 2_000_000);
+
+    assertThat(replacingCuesResolver.addCues(cuesWithTiming, /* currentPositionUs= */ 4_000_000))
+        .isTrue();
+  }
+
+  @Test
+  public void addCues_cuesDisplayedAtCurrentPosition_butAlreadyReplacedByLaterCues() {
+    ReplacingCuesResolver replacingCuesResolver = new ReplacingCuesResolver();
+    CuesWithTiming firstCuesWithTiming =
+        new CuesWithTiming(FIRST_CUES, /* startTimeUs= */ 3_000_000, /* durationUs= */ 3_000_000);
+    CuesWithTiming secondCuesWithTiming =
+        new CuesWithTiming(SECOND_CUES, /* startTimeUs= */ 4_000_000, /* durationUs= */ 3_000_000);
+    CuesWithTiming thirdCuesWithTiming =
+        new CuesWithTiming(THIRD_CUES, /* startTimeUs= */ 5_000_000, /* durationUs= */ 3_000_000);
+    replacingCuesResolver.addCues(thirdCuesWithTiming, /* currentPositionUs= */ 0);
+
+    assertThat(
+            replacingCuesResolver.addCues(firstCuesWithTiming, /* currentPositionUs= */ 5_000_000))
+        .isFalse();
+    assertThat(
+            replacingCuesResolver.addCues(secondCuesWithTiming, /* currentPositionUs= */ 5_500_000))
+        .isFalse();
+  }
+
+  @Test
+  public void addCues_cuesEndBeforeCurrentPosition() {
+    ReplacingCuesResolver replacingCuesResolver = new ReplacingCuesResolver();
+    CuesWithTiming cuesWithTiming =
+        new CuesWithTiming(FIRST_CUES, /* startTimeUs= */ 3_000_000, /* durationUs= */ 2_000_000);
+
+    assertThat(replacingCuesResolver.addCues(cuesWithTiming, /* currentPositionUs= */ 6_000_000))
+        .isFalse();
+  }
+
+  @Test
+  public void addCues_cuesEndAtCurrentPosition() {
+    ReplacingCuesResolver replacingCuesResolver = new ReplacingCuesResolver();
+    CuesWithTiming cuesWithTiming =
+        new CuesWithTiming(FIRST_CUES, /* startTimeUs= */ 3_000_000, /* durationUs= */ 2_000_000);
+
+    assertThat(replacingCuesResolver.addCues(cuesWithTiming, /* currentPositionUs= */ 5_000_000))
+        .isFalse();
+  }
+
   @Test
   public void discardCuesBeforeTimeUs() {
     ReplacingCuesResolver replacingCuesResolver = new ReplacingCuesResolver();
@@ -136,8 +205,8 @@ public final class ReplacingCuesResolverTest {
     CuesWithTiming secondCuesWithTiming =
         new CuesWithTiming(SECOND_CUES, /* startTimeUs= */ 6_000_000, /* durationUs= */ 1_000_000);
 
-    replacingCuesResolver.addCues(firstCuesWithTiming);
+    replacingCuesResolver.addCues(firstCuesWithTiming, /* currentPositionUs= */ 0);
-    replacingCuesResolver.addCues(secondCuesWithTiming);
+    replacingCuesResolver.addCues(secondCuesWithTiming, /* currentPositionUs= */ 0);
 
     // Remove firstCuesWithTiming
     replacingCuesResolver.discardCuesBeforeTimeUs(5_500_000);
@@ -158,9 +227,9 @@ public final class ReplacingCuesResolverTest {
     CuesWithTiming thirdCuesWithTiming =
         new CuesWithTiming(THIRD_CUES, /* startTimeUs= */ 8_000_000, /* durationUs= */ 4_000_000);
 
-    replacingCuesResolver.addCues(firstCuesWithTiming);
+    replacingCuesResolver.addCues(firstCuesWithTiming, /* currentPositionUs= */ 0);
-    replacingCuesResolver.addCues(secondCuesWithTiming);
+    replacingCuesResolver.addCues(secondCuesWithTiming, /* currentPositionUs= */ 0);
-    replacingCuesResolver.addCues(thirdCuesWithTiming);
+    replacingCuesResolver.addCues(thirdCuesWithTiming, /* currentPositionUs= */ 0);
 
     replacingCuesResolver.clear();