Fix a bug with TTML using font size as % of cellResolution.

After [] we support default font size for TTML, relative to the cellResolution of the document. However, this introduced a bug that makes TTML font-size in such case always follow the cellResolution font size, even when SubtitleView.setApplyEmbeddedStyles(false) and SubtitleView.setApplyEmbeddedFontSizes(false) were used.

This CL updates the fix so that the default font-size using cellResolution works in the same way as other embedded styles, and can be turned off using setters from SubtitleView.

GitHub: #4491

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=204467033

RELEASENOTES.md

@@ -11,6 +11,12 @@
     map.
   * Add support for mu-law and A-law PCM with the ffmpeg extension
     ([#4360](https://github.com/google/ExoPlayer/issues/4360)).
+* Captions:
+  * TTML: Fix an issue with TTML using font size as % of cell resolution that
+    makes `SubtitleView.setApplyEmbeddedFontSizes()` not work correctly.
+    ([#4491](https://github.com/google/ExoPlayer/issues/4491)).
+  * CEA-608: Improve handling of embedded styles
+    ([#4321](https://github.com/google/ExoPlayer/issues/4321)).
 * Allow apps to pass a `CacheKeyFactory` for setting custom cache keys when
   creating a `CacheDataSource`.
 * Turned on Java 8 compiler support for the ExoPlayer library. Apps that depend
@@ -45,8 +51,6 @@
   * Allow DrmInitData to carry a license server URL
     ([#3393](https://github.com/google/ExoPlayer/issues/3393)).
 * Add callback to `VideoListener` to notify of surface size changes.
-* CEA-608: Improve handling of embedded styles
-  ([#4321](https://github.com/google/ExoPlayer/issues/4321)).
 * Fix bug when reporting buffered position for multi-period windows and add
   two additional convenience methods `Player.getTotalBufferedDuration` and
   `Player.getContentBufferedDuration`

library/ui/src/main/java/com/google/android/exoplayer2/ui/SubtitlePainter.java

@@ -84,7 +84,8 @@ import com.google.android.exoplayer2.util.Util;
   private int edgeColor;
   @CaptionStyleCompat.EdgeType
   private int edgeType;
-  private float textSizePx;
+  private float defaultTextSizePx;
+  private float cueTextSizePx;
   private float bottomPaddingFraction;
   private int parentLeft;
   private int parentTop;
@@ -124,8 +125,8 @@ import com.google.android.exoplayer2.util.Util;
 
   /**
    * Draws the provided {@link Cue} into a canvas with the specified styling.
-   * <p>
+   *
-   * A call to this method is able to use cached results of calculations made during the previous
+   * <p>A call to this method is able to use cached results of calculations made during the previous
    * call, and so an instance of this class is able to optimize repeated calls to this method in
    * which the same parameters are passed.
    *
@@ -134,7 +135,8 @@ import com.google.android.exoplayer2.util.Util;
    * @param applyEmbeddedFontSizes If {@code applyEmbeddedStyles} is true, defines whether font
    *     sizes embedded within the cue should be applied. Otherwise, it is ignored.
    * @param style The style to use when drawing the cue text.
-   * @param textSizePx The text size to use when drawing the cue text, in pixels.
+   * @param defaultTextSizePx The default text size to use when drawing the text, in pixels.
+   * @param cueTextSizePx The embedded text size of this cue, in pixels.
    * @param bottomPaddingFraction The bottom padding fraction to apply when {@link Cue#line} is
    *     {@link Cue#DIMEN_UNSET}, as a fraction of the viewport height
    * @param canvas The canvas into which to draw.
@@ -143,9 +145,19 @@ import com.google.android.exoplayer2.util.Util;
    * @param cueBoxRight The right position of the enclosing cue box.
    * @param cueBoxBottom The bottom position of the enclosing cue box.
    */
-  public void draw(Cue cue, boolean applyEmbeddedStyles, boolean applyEmbeddedFontSizes,
+  public void draw(
-      CaptionStyleCompat style, float textSizePx, float bottomPaddingFraction, Canvas canvas,
+      Cue cue,
-      int cueBoxLeft, int cueBoxTop, int cueBoxRight, int cueBoxBottom) {
+      boolean applyEmbeddedStyles,
+      boolean applyEmbeddedFontSizes,
+      CaptionStyleCompat style,
+      float defaultTextSizePx,
+      float cueTextSizePx,
+      float bottomPaddingFraction,
+      Canvas canvas,
+      int cueBoxLeft,
+      int cueBoxTop,
+      int cueBoxRight,
+      int cueBoxBottom) {
     boolean isTextCue = cue.bitmap == null;
     int windowColor = Color.BLACK;
     if (isTextCue) {
@@ -174,7 +186,8 @@ import com.google.android.exoplayer2.util.Util;
         && this.edgeType == style.edgeType
         && this.edgeColor == style.edgeColor
         && Util.areEqual(this.textPaint.getTypeface(), style.typeface)
-        && this.textSizePx == textSizePx
+        && this.defaultTextSizePx == defaultTextSizePx
+        && this.cueTextSizePx == cueTextSizePx
         && this.bottomPaddingFraction == bottomPaddingFraction
         && this.parentLeft == cueBoxLeft
         && this.parentTop == cueBoxTop
@@ -203,7 +216,8 @@ import com.google.android.exoplayer2.util.Util;
     this.edgeType = style.edgeType;
     this.edgeColor = style.edgeColor;
     this.textPaint.setTypeface(style.typeface);
-    this.textSizePx = textSizePx;
+    this.defaultTextSizePx = defaultTextSizePx;
+    this.cueTextSizePx = cueTextSizePx;
     this.bottomPaddingFraction = bottomPaddingFraction;
     this.parentLeft = cueBoxLeft;
     this.parentTop = cueBoxTop;
@@ -222,8 +236,8 @@ import com.google.android.exoplayer2.util.Util;
     int parentWidth = parentRight - parentLeft;
     int parentHeight = parentBottom - parentTop;
 
-    textPaint.setTextSize(textSizePx);
+    textPaint.setTextSize(defaultTextSizePx);
-    int textPaddingX = (int) (textSizePx * INNER_PADDING_RATIO + 0.5f);
+    int textPaddingX = (int) (defaultTextSizePx * INNER_PADDING_RATIO + 0.5f);
 
     int availableWidth = parentWidth - textPaddingX * 2;
     if (cueSize != Cue.DIMEN_UNSET) {
@@ -234,14 +248,12 @@ import com.google.android.exoplayer2.util.Util;
       return;
     }
 
+    CharSequence cueText = this.cueText;
     // Remove embedded styling or font size if requested.
-    CharSequence cueText;
+    if (!applyEmbeddedStyles) {
-    if (applyEmbeddedFontSizes && applyEmbeddedStyles) {
+      cueText = cueText.toString(); // Equivalent to erasing all spans.
-      cueText = this.cueText;
+    } else if (!applyEmbeddedFontSizes) {
-    } else if (!applyEmbeddedStyles) {
+      SpannableStringBuilder newCueText = new SpannableStringBuilder(cueText);
-      cueText = this.cueText.toString(); // Equivalent to erasing all spans.
-    } else {
-      SpannableStringBuilder newCueText = new SpannableStringBuilder(this.cueText);
       int cueLength = newCueText.length();
       AbsoluteSizeSpan[] absSpans = newCueText.getSpans(0, cueLength, AbsoluteSizeSpan.class);
       RelativeSizeSpan[] relSpans = newCueText.getSpans(0, cueLength, RelativeSizeSpan.class);
@@ -252,6 +264,19 @@ import com.google.android.exoplayer2.util.Util;
         newCueText.removeSpan(relSpan);
       }
       cueText = newCueText;
+    } else {
+      // Apply embedded styles & font size.
+      if (cueTextSizePx > 0) {
+        // Use a SpannableStringBuilder encompassing the whole cue text to apply the default
+        // cueTextSizePx.
+        SpannableStringBuilder newCueText = new SpannableStringBuilder(cueText);
+        newCueText.setSpan(
+            new AbsoluteSizeSpan((int) cueTextSizePx),
+            /* start= */ 0,
+            /* end= */ newCueText.length(),
+            Spanned.SPAN_PRIORITY);
+        cueText = newCueText;
+      }
     }
 
     if (Color.alpha(backgroundColor) > 0) {

library/ui/src/main/java/com/google/android/exoplayer2/ui/SubtitleView.java

@@ -271,15 +271,15 @@ public final class SubtitleView extends View implements TextOutput {
 
     for (int i = 0; i < cueCount; i++) {
       Cue cue = cues.get(i);
-      float textSizePx =
+      float cueTextSizePx = resolveCueTextSize(cue, rawViewHeight, viewHeightMinusPadding);
-          resolveTextSizeForCue(cue, rawViewHeight, viewHeightMinusPadding, defaultViewTextSizePx);
       SubtitlePainter painter = painters.get(i);
       painter.draw(
           cue,
           applyEmbeddedStyles,
           applyEmbeddedFontSizes,
           style,
-          textSizePx,
+          defaultViewTextSizePx,
+          cueTextSizePx,
           bottomPaddingFraction,
           canvas,
           left,
@@ -289,14 +289,13 @@ public final class SubtitleView extends View implements TextOutput {
     }
   }
 
-  private float resolveTextSizeForCue(
+  private float resolveCueTextSize(Cue cue, int rawViewHeight, int viewHeightMinusPadding) {
-      Cue cue, int rawViewHeight, int viewHeightMinusPadding, float defaultViewTextSizePx) {
     if (cue.textSizeType == Cue.TYPE_UNSET || cue.textSize == Cue.DIMEN_UNSET) {
-      return defaultViewTextSizePx;
+      return 0;
     }
     float defaultCueTextSizePx =
         resolveTextSize(cue.textSizeType, cue.textSize, rawViewHeight, viewHeightMinusPadding);
-    return defaultCueTextSizePx > 0 ? defaultCueTextSizePx : defaultViewTextSizePx;
+    return Math.max(defaultCueTextSizePx, 0);
   }
 
   private float resolveTextSize(