Remove TTML package from null-checking blacklist

PiperOrigin-RevId: 290629644

library/core/src/main/java/com/google/android/exoplayer2/text/ttml/TtmlNode.java

@@ -31,6 +31,7 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.TreeMap;
 import java.util.TreeSet;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
 /**
  * A package internal representation of TTML node.
@@ -93,7 +94,7 @@ import java.util.TreeSet;
   private final HashMap<String, Integer> nodeStartsByRegion;
   private final HashMap<String, Integer> nodeEndsByRegion;
 
-  private List<TtmlNode> children;
+  @MonotonicNonNull private List<TtmlNode> children;
 
   public static TtmlNode buildTextNode(String text) {
     return new TtmlNode(
@@ -196,6 +197,7 @@ import java.util.TreeSet;
     }
   }
 
+  @Nullable
   public String[] getStyleIds() {
     return styleIds;
   }
@@ -217,7 +219,7 @@ import java.util.TreeSet;
 
     // Create image based cues.
     for (Pair<String, String> regionImagePair : regionImageOutputs) {
-      String encodedBitmapData = imageMap.get(regionImagePair.second);
+      @Nullable String encodedBitmapData = imageMap.get(regionImagePair.second);
       if (encodedBitmapData == null) {
         // Image reference points to an invalid image. Do nothing.
         continue;
@@ -225,7 +227,7 @@ import java.util.TreeSet;
 
       byte[] bitmapData = Base64.decode(encodedBitmapData, Base64.DEFAULT);
       Bitmap bitmap = BitmapFactory.decodeByteArray(bitmapData, /* offset= */ 0, bitmapData.length);
-      TtmlRegion region = regionMap.get(regionImagePair.first);
+      TtmlRegion region = Assertions.checkNotNull(regionMap.get(regionImagePair.first));
 
       cues.add(
           new Cue.Builder()
@@ -241,7 +243,7 @@ import java.util.TreeSet;
 
     // Create text based cues.
     for (Entry<String, SpannableStringBuilder> entry : regionTextOutputs.entrySet()) {
-      TtmlRegion region = regionMap.get(entry.getKey());
+      TtmlRegion region = Assertions.checkNotNull(regionMap.get(entry.getKey()));
       cues.add(
           new Cue(
               cleanUpText(entry.getValue()),
@@ -286,7 +288,7 @@ import java.util.TreeSet;
     String resolvedRegionId = ANONYMOUS_REGION_ID.equals(regionId) ? inheritedRegion : regionId;
 
     if (isTextNode && descendsPNode) {
-      getRegionOutput(resolvedRegionId, regionOutputs).append(text);
+      getRegionOutput(resolvedRegionId, regionOutputs).append(Assertions.checkNotNull(text));
     } else if (TAG_BR.equals(tag) && descendsPNode) {
       getRegionOutput(resolvedRegionId, regionOutputs).append('\n');
     } else if (isActive(timeUs)) {
@@ -330,7 +332,7 @@ import java.util.TreeSet;
       int start = nodeStartsByRegion.containsKey(regionId) ? nodeStartsByRegion.get(regionId) : 0;
       int end = entry.getValue();
       if (start != end) {
-        SpannableStringBuilder regionOutput = regionOutputs.get(regionId);
+        SpannableStringBuilder regionOutput = Assertions.checkNotNull(regionOutputs.get(regionId));
         applyStyleToOutput(globalStyles, regionOutput, start, end);
       }
     }
@@ -344,7 +346,7 @@ import java.util.TreeSet;
       SpannableStringBuilder regionOutput,
       int start,
       int end) {
-    TtmlStyle resolvedStyle = TtmlRenderUtil.resolveStyle(style, styleIds, globalStyles);
+    @Nullable TtmlStyle resolvedStyle = TtmlRenderUtil.resolveStyle(style, styleIds, globalStyles);
     if (resolvedStyle != null) {
       TtmlRenderUtil.applyStylesToSpan(regionOutput, start, end, resolvedStyle);
     }

library/core/src/main/java/com/google/android/exoplayer2/text/ttml/TtmlRenderUtil.java

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer2.text.ttml;
 
+import android.text.Layout.Alignment;
 import android.text.SpannableStringBuilder;
 import android.text.Spanned;
 import android.text.style.AbsoluteSizeSpan;
@@ -26,6 +27,7 @@ import android.text.style.StrikethroughSpan;
 import android.text.style.StyleSpan;
 import android.text.style.TypefaceSpan;
 import android.text.style.UnderlineSpan;
+import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.text.SpanUtil;
 import java.util.Map;
 
@@ -34,30 +36,35 @@ import java.util.Map;
  */
 /* package */ final class TtmlRenderUtil {
 
-  public static TtmlStyle resolveStyle(TtmlStyle style, String[] styleIds,
-      Map<String, TtmlStyle> globalStyles) {
-    if (style == null && styleIds == null) {
-      // No styles at all.
-      return null;
-    } else if (style == null && styleIds.length == 1) {
-      // Only one single referential style present.
-      return globalStyles.get(styleIds[0]);
-    } else if (style == null && styleIds.length > 1) {
-      // Only multiple referential styles present.
-      TtmlStyle chainedStyle = new TtmlStyle();
-      for (String id : styleIds) {
-        chainedStyle.chain(globalStyles.get(id));
+  @Nullable
+  public static TtmlStyle resolveStyle(
+      @Nullable TtmlStyle style, @Nullable String[] styleIds, Map<String, TtmlStyle> globalStyles) {
+    if (style == null) {
+      if (styleIds == null) {
+        // No styles at all.
+        return null;
+      } else if (styleIds.length == 1) {
+        // Only one single referential style present.
+        return globalStyles.get(styleIds[0]);
+      } else if (styleIds.length > 1) {
+        // Only multiple referential styles present.
+        TtmlStyle chainedStyle = new TtmlStyle();
+        for (String id : styleIds) {
+          chainedStyle.chain(globalStyles.get(id));
+        }
+        return chainedStyle;
       }
-      return chainedStyle;
-    } else if (style != null && styleIds != null && styleIds.length == 1) {
-      // Merge a single referential style into inline style.
-      return style.chain(globalStyles.get(styleIds[0]));
-    } else if (style != null && styleIds != null && styleIds.length > 1) {
-      // Merge multiple referential styles into inline style.
-      for (String id : styleIds) {
-        style.chain(globalStyles.get(id));
+    } else /* style != null */ {
+      if (styleIds != null && styleIds.length == 1) {
+        // Merge a single referential style into inline style.
+        return style.chain(globalStyles.get(styleIds[0]));
+      } else if (styleIds != null && styleIds.length > 1) {
+        // Merge multiple referential styles into inline style.
+        for (String id : styleIds) {
+          style.chain(globalStyles.get(id));
+        }
+        return style;
       }
-      return style;
     }
     // Only inline styles available.
     return style;
@@ -100,10 +107,11 @@ import java.util.Map;
           end,
           Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
     }
-    if (style.getTextAlign() != null) {
+    @Nullable Alignment textAlign = style.getTextAlign();
+    if (textAlign != null) {
       SpanUtil.addOrReplaceSpan(
           builder,
-          new AlignmentSpan.Standard(style.getTextAlign()),
+          new AlignmentSpan.Standard(textAlign),
           start,
           end,
           Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);

library/core/src/main/java/com/google/android/exoplayer2/text/ttml/TtmlStyle.java

@@ -18,9 +18,11 @@ package com.google.android.exoplayer2.text.ttml;
 import android.graphics.Typeface;
 import android.text.Layout;
 import androidx.annotation.IntDef;
+import androidx.annotation.Nullable;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
 /**
  * Style object of a <code>TtmlNode</code>
@@ -58,7 +60,7 @@ import java.lang.annotation.RetentionPolicy;
   private static final int OFF = 0;
   private static final int ON = 1;
 
-  private String fontFamily;
+  private @MonotonicNonNull String fontFamily;
   private int fontColor;
   private boolean hasFontColor;
   private int backgroundColor;
@@ -69,8 +71,8 @@ import java.lang.annotation.RetentionPolicy;
   @OptionalBoolean private int italic;
   @FontSizeUnit private int fontSizeUnit;
   private float fontSize;
-  private String id;
-  private Layout.Alignment textAlign;
+  private @MonotonicNonNull String id;
+  private Layout.@MonotonicNonNull Alignment textAlign;
 
   public TtmlStyle() {
     linethrough = UNSPECIFIED;
@@ -122,6 +124,7 @@ import java.lang.annotation.RetentionPolicy;
     return this;
   }
 
+  @Nullable
   public String getFontFamily() {
     return fontFamily;
   }
@@ -171,7 +174,7 @@ import java.lang.annotation.RetentionPolicy;
    *
    * @param ancestor the referential style to inherit from
    */
-  public TtmlStyle chain(TtmlStyle ancestor) {
+  public TtmlStyle chain(@Nullable TtmlStyle ancestor) {
     return inherit(ancestor, true);
   }
 
@@ -182,11 +185,11 @@ import java.lang.annotation.RetentionPolicy;
    *
    * @param ancestor the ancestor style to inherit from
    */
-  public TtmlStyle inherit(TtmlStyle ancestor) {
+  public TtmlStyle inherit(@Nullable TtmlStyle ancestor) {
     return inherit(ancestor, false);
   }
 
-  private TtmlStyle inherit(TtmlStyle ancestor, boolean chaining) {
+  private TtmlStyle inherit(@Nullable TtmlStyle ancestor, boolean chaining) {
     if (ancestor != null) {
       if (!hasFontColor && ancestor.hasFontColor) {
         setFontColor(ancestor.fontColor);
@@ -197,7 +200,7 @@ import java.lang.annotation.RetentionPolicy;
       if (italic == UNSPECIFIED) {
         italic = ancestor.italic;
       }
-      if (fontFamily == null) {
+      if (fontFamily == null && ancestor.fontFamily != null) {
         fontFamily = ancestor.fontFamily;
       }
       if (linethrough == UNSPECIFIED) {
@@ -206,7 +209,7 @@ import java.lang.annotation.RetentionPolicy;
       if (underline == UNSPECIFIED) {
         underline = ancestor.underline;
       }
-      if (textAlign == null) {
+      if (textAlign == null && ancestor.textAlign != null) {
         textAlign = ancestor.textAlign;
       }
       if (fontSizeUnit == UNSPECIFIED) {
@@ -226,10 +229,12 @@ import java.lang.annotation.RetentionPolicy;
     return this;
   }
 
+  @Nullable
   public String getId() {
     return id;
   }
 
+  @Nullable
   public Layout.Alignment getTextAlign() {
     return textAlign;
   }