Merge "Redesign the fallback XML syntax to be able to have static and variable font." into main

8 files changed, 551 insertions, 420 deletions

diff --git a/core/java/android/text/FontConfig.java b/core/java/android/text/FontConfig.java
index 94c8eaf13ccb..783f3b7aa64b 100644
--- a/core/java/android/text/FontConfig.java
+++ b/core/java/android/text/FontConfig.java
@@ -26,7 +26,6 @@ import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.annotation.TestApi;
 import android.compat.annotation.UnsupportedAppUsage;
-import android.graphics.fonts.FontFamily.Builder.VariableFontFamilyType;
 import android.graphics.fonts.FontStyle;
 import android.graphics.fonts.FontVariationAxis;
 import android.icu.util.ULocale;
@@ -240,6 +239,23 @@ public final class FontConfig implements Parcelable {
         private final @IntRange(from = 0) int mIndex;
         private final @NonNull String mFontVariationSettings;
         private final @Nullable String mFontFamilyName;
+        private final @VarTypeAxes int mVarTypeAxes;
+
+        /** @hide */
+        @Retention(SOURCE)
+        @IntDef(prefix = { "VAR_TYPE_AXES_" }, value = {
+                VAR_TYPE_AXES_NONE,
+                VAR_TYPE_AXES_WGHT,
+                VAR_TYPE_AXES_ITAL,
+        })
+        public @interface VarTypeAxes {}
+
+        /** @hide */
+        public static final int VAR_TYPE_AXES_NONE = 0;
+        /** @hide */
+        public static final int VAR_TYPE_AXES_WGHT = 1;
+        /** @hide */
+        public static final int VAR_TYPE_AXES_ITAL = 2;
 
         /**
          * Construct a Font instance.
@@ -248,7 +264,8 @@ public final class FontConfig implements Parcelable {
          */
         public Font(@NonNull File file, @Nullable File originalFile, @NonNull String postScriptName,
                 @NonNull FontStyle style, @IntRange(from = 0) int index,
-                @NonNull String fontVariationSettings, @Nullable String fontFamilyName) {
+                @NonNull String fontVariationSettings, @Nullable String fontFamilyName,
+                @VarTypeAxes int varTypeAxes) {
             mFile = file;
             mOriginalFile = originalFile;
             mPostScriptName = postScriptName;
@@ -256,6 +273,7 @@ public final class FontConfig implements Parcelable {
             mIndex = index;
             mFontVariationSettings = fontVariationSettings;
             mFontFamilyName = fontFamilyName;
+            mVarTypeAxes = varTypeAxes;
         }
 
         @Override
@@ -273,6 +291,7 @@ public final class FontConfig implements Parcelable {
             dest.writeInt(mIndex);
             dest.writeString8(mFontVariationSettings);
             dest.writeString8(mFontFamilyName);
+            dest.writeInt(mVarTypeAxes);
         }
 
         public static final @NonNull Creator<Font> CREATOR = new Creator<Font>() {
@@ -288,9 +307,10 @@ public final class FontConfig implements Parcelable {
                 int index = source.readInt();
                 String varSettings = source.readString8();
                 String fallback = source.readString8();
+                int varTypeAxes = source.readInt();
 
                 return new Font(path, originalPath, postScriptName, new FontStyle(weight, slant),
-                        index, varSettings, fallback);
+                        index, varSettings, fallback, varTypeAxes);
             }
 
             @Override
@@ -366,6 +386,15 @@ public final class FontConfig implements Parcelable {
         }
 
         /**
+         * Returns the list of supported axes tags for variable family type resolution.
+         *
+         * @hide
+         */
+        public @VarTypeAxes int getVarTypeAxes() {
+            return mVarTypeAxes;
+        }
+
+        /**
          * Returns the list of axes associated to this font.
          * @deprecated Use getFontVariationSettings
          * @hide
@@ -408,13 +437,14 @@ public final class FontConfig implements Parcelable {
                     && Objects.equals(mOriginalFile, font.mOriginalFile)
                     && Objects.equals(mStyle, font.mStyle)
                     && Objects.equals(mFontVariationSettings, font.mFontVariationSettings)
-                    && Objects.equals(mFontFamilyName, font.mFontFamilyName);
+                    && Objects.equals(mFontFamilyName, font.mFontFamilyName)
+                    && mVarTypeAxes == font.mVarTypeAxes;
         }
 
         @Override
         public int hashCode() {
             return Objects.hash(mFile, mOriginalFile, mStyle, mIndex, mFontVariationSettings,
-                    mFontFamilyName);
+                    mFontFamilyName, mVarTypeAxes);
         }
 
         @Override
@@ -426,6 +456,7 @@ public final class FontConfig implements Parcelable {
                     + ", mIndex=" + mIndex
                     + ", mFontVariationSettings='" + mFontVariationSettings + '\''
                     + ", mFontFamilyName='" + mFontFamilyName + '\''
+                    + ", mVarTypeAxes='" + mVarTypeAxes + '\''
                     + '}';
         }
     }
@@ -549,7 +580,6 @@ public final class FontConfig implements Parcelable {
         private final @NonNull List<Font> mFonts;
         private final @NonNull LocaleList mLocaleList;
         private final @Variant int mVariant;
-        private final int mVariableFontFamilyType;
 
         /** @hide */
         @Retention(SOURCE)
@@ -589,11 +619,10 @@ public final class FontConfig implements Parcelable {
          * @hide Only system server can create this instance and passed via IPC.
          */
         public FontFamily(@NonNull List<Font> fonts, @NonNull LocaleList localeList,
-                @Variant int variant, int variableFontFamilyType) {
+                @Variant int variant) {
             mFonts = fonts;
             mLocaleList = localeList;
             mVariant = variant;
-            mVariableFontFamilyType = variableFontFamilyType;
         }
 
         /**
@@ -644,20 +673,6 @@ public final class FontConfig implements Parcelable {
             return mVariant;
         }
 
-        /**
-         * Returns the font family type.
-         *
-         * @see Builder#VARIABLE_FONT_FAMILY_TYPE_NONE
-         * @see Builder#VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ITAL
-         * @see Builder#VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ONLY
-         * @see Builder#VARIABLE_FONT_FAMILY_TYPE_TWO_FONTS_WGHT
-         * @hide
-         * @return variable font family type.
-         */
-        public @VariableFontFamilyType int getVariableFontFamilyType() {
-            return mVariableFontFamilyType;
-        }
-
         @Override
         public int describeContents() {
             return 0;
@@ -668,7 +683,6 @@ public final class FontConfig implements Parcelable {
             dest.writeTypedList(mFonts, flags);
             dest.writeString8(mLocaleList.toLanguageTags());
             dest.writeInt(mVariant);
-            dest.writeInt(mVariableFontFamilyType);
         }
 
         public static final @NonNull Creator<FontFamily> CREATOR = new Creator<FontFamily>() {
@@ -679,10 +693,8 @@ public final class FontConfig implements Parcelable {
                 source.readTypedList(fonts, Font.CREATOR);
                 String langTags = source.readString8();
                 int variant = source.readInt();
-                int varFamilyType = source.readInt();
 
-                return new FontFamily(fonts, LocaleList.forLanguageTags(langTags), variant,
-                        varFamilyType);
+                return new FontFamily(fonts, LocaleList.forLanguageTags(langTags), variant);
             }
 
             @Override
diff --git a/core/tests/coretests/src/android/graphics/FontListParserTest.java b/core/tests/coretests/src/android/graphics/FontListParserTest.java
index 4dd5889fdf5d..5f96c1789015 100644
--- a/core/tests/coretests/src/android/graphics/FontListParserTest.java
+++ b/core/tests/coretests/src/android/graphics/FontListParserTest.java
@@ -22,14 +22,18 @@ import static android.graphics.fonts.FontStyle.FONT_WEIGHT_NORMAL;
 import static android.text.FontConfig.FontFamily.VARIANT_COMPACT;
 import static android.text.FontConfig.FontFamily.VARIANT_DEFAULT;
 import static android.text.FontConfig.FontFamily.VARIANT_ELEGANT;
+import static android.graphics.fonts.FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE;
+import static android.graphics.fonts.FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ONLY;
+import static android.graphics.fonts.FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ITAL;
+import static android.graphics.fonts.FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_TWO_FONTS_WGHT;
 
 import static com.google.common.truth.Truth.assertThat;
 
 import static junit.framework.Assert.fail;
 
 import android.graphics.fonts.FontCustomizationParser;
-import android.graphics.fonts.FontFamily;
 import android.graphics.fonts.FontStyle;
+import android.graphics.fonts.SystemFonts;
 import android.os.LocaleList;
 import android.text.FontConfig;
 import android.util.Xml;
@@ -64,9 +68,9 @@ public final class FontListParserTest {
         FontConfig.NamedFamilyList expected = new FontConfig.NamedFamilyList(
                 Collections.singletonList(new FontConfig.FontFamily(
                     Arrays.asList(new FontConfig.Font(new File("test.ttf"), null, "test",
-                        new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT), 0, "", null)),
-                    LocaleList.getEmptyLocaleList(), VARIANT_DEFAULT,
-                        FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE)), "sans-serif");
+                            new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT), 0, "", null,
+                            FontConfig.Font.VAR_TYPE_AXES_NONE)),
+                    LocaleList.getEmptyLocaleList(), VARIANT_DEFAULT)), "sans-serif");
         FontConfig.NamedFamilyList family = readNamedFamily(xml);
         assertThat(family).isEqualTo(expected);
     }
@@ -82,12 +86,11 @@ public final class FontListParserTest {
                 Arrays.asList(
                         new FontConfig.Font(new File("test.ttf"), null, "test",
                                 new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT),
-                                0, "", null),
+                                0, "", null, FontConfig.Font.VAR_TYPE_AXES_NONE),
                         new FontConfig.Font(new File("test.ttf"), null, "test",
                                 new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT),
-                                0, "", "serif")),
-                LocaleList.forLanguageTags("en"), VARIANT_DEFAULT,
-                FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE);
+                                0, "", "serif", FontConfig.Font.VAR_TYPE_AXES_NONE)),
+                LocaleList.forLanguageTags("en"), VARIANT_DEFAULT);
 
         FontConfig.FontFamily family = readFamily(xml);
         assertThat(family).isEqualTo(expected);
@@ -103,9 +106,8 @@ public final class FontListParserTest {
                 Arrays.asList(
                         new FontConfig.Font(new File("test.ttf"), null, "test",
                                 new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT),
-                                0, "", null)),
-                LocaleList.forLanguageTags("en"), VARIANT_COMPACT,
-                FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE);
+                                0, "", null, FontConfig.Font.VAR_TYPE_AXES_NONE)),
+                LocaleList.forLanguageTags("en"), VARIANT_COMPACT);
 
         FontConfig.FontFamily family = readFamily(xml);
         assertThat(family).isEqualTo(expected);
@@ -121,9 +123,8 @@ public final class FontListParserTest {
                 Arrays.asList(
                         new FontConfig.Font(new File("test.ttf"), null, "test",
                                 new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT),
-                                0, "", null)),
-                LocaleList.forLanguageTags("en"), VARIANT_ELEGANT,
-                FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE);
+                                0, "", null, FontConfig.Font.VAR_TYPE_AXES_NONE)),
+                LocaleList.forLanguageTags("en"), VARIANT_ELEGANT);
 
         FontConfig.FontFamily family = readFamily(xml);
         assertThat(family).isEqualTo(expected);
@@ -140,13 +141,15 @@ public final class FontListParserTest {
         FontConfig.NamedFamilyList expected = new FontConfig.NamedFamilyList(
                 Collections.singletonList(new FontConfig.FontFamily(Arrays.asList(
                       new FontConfig.Font(new File("normal.ttf"), null, "test",
-                        new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT), 0, "", null),
+                            new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT), 0, "", null,
+                              FontConfig.Font.VAR_TYPE_AXES_NONE),
                       new FontConfig.Font(new File("weight.ttf"), null, "test",
-                        new FontStyle(100, FONT_SLANT_UPRIGHT), 0, "", null),
+                            new FontStyle(100, FONT_SLANT_UPRIGHT), 0, "", null,
+                              FontConfig.Font.VAR_TYPE_AXES_NONE),
                       new FontConfig.Font(new File("italic.ttf"), null, "test",
-                        new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_ITALIC), 0, "", null)),
-                    LocaleList.getEmptyLocaleList(), VARIANT_DEFAULT,
-                        FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE)), "sans-serif");
+                            new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_ITALIC), 0, "", null,
+                              FontConfig.Font.VAR_TYPE_AXES_NONE)),
+                    LocaleList.getEmptyLocaleList(), VARIANT_DEFAULT)), "sans-serif");
         FontConfig.NamedFamilyList family = readNamedFamily(xml);
         assertThat(family).isEqualTo(expected);
     }
@@ -168,12 +171,13 @@ public final class FontListParserTest {
                 Collections.singletonList(new FontConfig.FontFamily(Arrays.asList(
                         new FontConfig.Font(new File("test-VF.ttf"), null, "test",
                                 new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT),
-                                0, "'wdth' 100.0,'wght' 200.0", null),
+                                0, "'wdth' 100.0,'wght' 200.0", null,
+                                FontConfig.Font.VAR_TYPE_AXES_NONE),
                         new FontConfig.Font(new File("test-VF.ttf"), null, "test",
                                 new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT),
-                                0, "'wdth' 400.0,'wght' 700.0", null)),
-                        LocaleList.getEmptyLocaleList(), VARIANT_DEFAULT,
-                        FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE)),
+                                0, "'wdth' 400.0,'wght' 700.0", null,
+                                FontConfig.Font.VAR_TYPE_AXES_NONE)),
+                        LocaleList.getEmptyLocaleList(), VARIANT_DEFAULT)),
                 "sans-serif");
         FontConfig.NamedFamilyList family = readNamedFamily(xml);
         assertThat(family).isEqualTo(expected);
@@ -190,12 +194,11 @@ public final class FontListParserTest {
                 Collections.singletonList(new FontConfig.FontFamily(Arrays.asList(
                         new FontConfig.Font(new File("test.ttc"), null, "test",
                                 new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT),
-                                0, "", null),
+                                0, "", null, FontConfig.Font.VAR_TYPE_AXES_NONE),
                         new FontConfig.Font(new File("test.ttc"), null, "test",
                                 new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT),
-                                1, "", null)),
-                                LocaleList.getEmptyLocaleList(), VARIANT_DEFAULT,
-                        FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE)),
+                                1, "", null, FontConfig.Font.VAR_TYPE_AXES_NONE)),
+                                LocaleList.getEmptyLocaleList(), VARIANT_DEFAULT)),
                 "sans-serif");
         FontConfig.NamedFamilyList family = readNamedFamily(xml);
         assertThat(family).isEqualTo(expected);
@@ -211,11 +214,12 @@ public final class FontListParserTest {
         FontConfig.NamedFamilyList expected = new FontConfig.NamedFamilyList(
                 Collections.singletonList(new FontConfig.FontFamily(Arrays.asList(
                       new FontConfig.Font(new File("test.ttc"), null, "foo",
-                        new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT), 0, "", null),
+                            new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT), 0, "", null,
+                              FontConfig.Font.VAR_TYPE_AXES_NONE),
                       new FontConfig.Font(new File("test.ttc"), null, "test",
-                        new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT), 1, "", null)),
-                    LocaleList.getEmptyLocaleList(), VARIANT_DEFAULT,
-                        FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE)), "sans-serif");
+                            new FontStyle(FONT_WEIGHT_NORMAL, FONT_SLANT_UPRIGHT), 1, "", null,
+                              FontConfig.Font.VAR_TYPE_AXES_NONE)),
+                    LocaleList.getEmptyLocaleList(), VARIANT_DEFAULT)), "sans-serif");
         FontConfig.NamedFamilyList family = readNamedFamily(xml);
         assertThat(family).isEqualTo(expected);
     }
@@ -385,14 +389,81 @@ public final class FontListParserTest {
     public void varFamilyType() throws Exception {
         String xml = "<?xml version='1.0' encoding='UTF-8'?>"
                 + "<familyset>"
-                + "  <family name='sans-serif' varFamilyType='1'>"
-                + "    <font>test.ttf</font>"
+                + "  <family name='sans-serif'>"
+                + "    <font supportedAxes='wght'>test.ttf</font>"
+                + "    <font supportedAxes='ital'>test.ttf</font>"
+                + "    <font supportedAxes='wght,ital'>test.ttf</font>"
                 + "  </family>"
                 + "</familyset>";
         FontConfig config = readFamilies(xml, true /* include non-existing font files */);
         List<FontConfig.FontFamily> families = config.getFontFamilies();
         assertThat(families.size()).isEqualTo(1);  // legacy one should be ignored.
-        assertThat(families.get(0).getVariableFontFamilyType()).isEqualTo(1);
+        assertThat(families.get(0).getFontList().get(0).getVarTypeAxes())
+                .isEqualTo(FontConfig.Font.VAR_TYPE_AXES_WGHT);
+        assertThat(families.get(0).getFontList().get(1).getVarTypeAxes())
+                .isEqualTo(FontConfig.Font.VAR_TYPE_AXES_ITAL);
+        assertThat(families.get(0).getFontList().get(2).getVarTypeAxes())
+                .isEqualTo(FontConfig.Font.VAR_TYPE_AXES_WGHT | FontConfig.Font.VAR_TYPE_AXES_ITAL);
+    }
+
+    @Test
+    public void varFamilyTypeRsolve() throws Exception {
+        String xml = "<?xml version='1.0' encoding='UTF-8'?>"
+                + "<familyset>"
+                + "  <family name='sans-serif'>"
+                + "    <font style='normal' supportedAxes='wght'>test.ttf</font>"
+                + "  </family>"
+                + "  <family>"
+                + "    <font style='normal' supportedAxes='wght'>test.ttf</font>"
+                + "    <font style='italic' supportedAxes='wght'>test.ttf</font>"
+                + "  </family>"
+                + "  <family>"
+                + "    <font supportedAxes='wght,ital'>test.ttf</font>"
+                + "  </family>"
+                + "  <family>"
+                + "    <font supportedAxes='ital'>test.ttf</font>"
+                + "  </family>"
+                + "  <family>"
+                + "    <font>test.ttf</font>"
+                + "  </family>"
+                + "</familyset>";
+        FontConfig config = readFamilies(xml, true /* include non-existing font files */);
+        List<FontConfig.FontFamily> families = config.getFontFamilies();
+        assertThat(families.size()).isEqualTo(5);
+        assertThat(SystemFonts.resolveVarFamilyType(families.get(0), null))
+                .isEqualTo(VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ONLY);
+        assertThat(SystemFonts.resolveVarFamilyType(families.get(1), null))
+                .isEqualTo(VARIABLE_FONT_FAMILY_TYPE_TWO_FONTS_WGHT);
+        assertThat(SystemFonts.resolveVarFamilyType(families.get(2), null))
+                .isEqualTo(VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ITAL);
+        assertThat(SystemFonts.resolveVarFamilyType(families.get(3), null))
+                .isEqualTo(VARIABLE_FONT_FAMILY_TYPE_NONE);
+        assertThat(SystemFonts.resolveVarFamilyType(families.get(4), null))
+                .isEqualTo(VARIABLE_FONT_FAMILY_TYPE_NONE);
+    }
+
+    @Test
+    public void varFamilyTypeRsolve_ForName() throws Exception {
+        String xml = "<?xml version='1.0' encoding='UTF-8'?>"
+                + "<familyset>"
+                + "  <family name='sans-serif'>"
+                + "    <font style='normal' supportedAxes='wght'>test.ttf</font>"
+                + "  </family>"
+                + "  <family name='serif'>"
+                + "    <font style='normal' supportedAxes='wght'>test.ttf</font>"
+                + "  </family>"
+                + "  <family>"
+                + "    <font style='normal' supportedAxes='wght'>test.ttf</font>"
+                + "    <font fallbackFor='serif' supportedAxes='wght,ital'>test.ttf</font>"
+                + "  </family>"
+                + "</familyset>";
+        FontConfig config = readFamilies(xml, true /* include non-existing font files */);
+        List<FontConfig.FontFamily> families = config.getFontFamilies();
+        assertThat(families.size()).isEqualTo(2);
+        assertThat(SystemFonts.resolveVarFamilyType(families.get(1), null))
+                .isEqualTo(VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ONLY);
+        assertThat(SystemFonts.resolveVarFamilyType(families.get(1), "serif"))
+                .isEqualTo(VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ITAL);
     }
 
     private FontConfig readFamilies(String xml, boolean allowNonExisting)
diff --git a/data/fonts/font_fallback.xml b/data/fonts/font_fallback.xml
index 1bd182f96bde..15ea15a9b4c1 100644
--- a/data/fonts/font_fallback.xml
+++ b/data/fonts/font_fallback.xml
@@ -11,12 +11,84 @@
     effectively add 300 to the weight, this ensures that 900 is the bold
     paired with the 500 weight, ensuring adequate contrast.
 
-    TODO(rsheeter) update comment; ordering to match 800 to 900 is no longer required
+
+    The font_fallback.xml defines the list of font used by the system.
+
+    `familyset` node:
+      A `familyset` element must be a root node of the font_fallback.xml. No attributes are allowed
+      to `familyset` node.
+      The `familyset` node can contains `family` and `alias` nodes. Any other nodes will be ignored.
+
+    `family` node:
+      A `family` node defines a single font family definition.
+      A font family is a set of fonts for drawing text in various styles such as weight, slant.
+      There are three types of families, default family, named family and locale fallback family.
+
+      The default family is a special family node appeared the first node of the `familyset` node.
+      The default family is used as first priority fallback.
+      Only `name` attribute can be used for default family node. If the `name` attribute is
+      specified, This family will also works as named family.
+
+      The named family is a family that has name attribute. The named family defines a new fallback.
+      For example, if the name attribute is "serif", it creates serif fallback. Developers can
+      access the fallback by using Typeface#create API.
+      The named family can not have attribute other than `name` attribute. The `name` attribute
+      cannot be empty.
+
+      The locale fallback family is a font family that is used for fallback. The fallback family is
+      used when the named family or default family cannot be used. The locale fallback family can
+      have `lang` attribute and `variant` attribute. The `lang` attribute is an optional comma
+      separated BCP-47i language tag. The `variant` is an optional attribute that can be one one
+      `element`, `compact`. If a `variant` attribute is not specified, it is treated as default.
+
+    `alias` node:
+      An `alias` node defines a alias of named family with changing weight offset. An `alias` node
+      can have mandatory `name` and `to` attribute and optional `weight` attribute. This `alias`
+      defines new fallback that has the name of specified `name` attribute. The fallback list is
+      the same to the fallback that of the name specified with `to` attribute. If `weight` attribute
+      is specified, the base weight offset is shifted to the specified value. For example, if the
+      `weight` is 500, the output text is drawn with 500 of weight.
+
+    `font` node:
+      A `font` node defines a single font definition. There are two types of fonts, static font and
+      variable font.
+
+      A static font can have `weight`, `style`, `index` and `postScriptName` attributes. A `weight`
+      is a mandatory attribute that defines the weight of the font. Any number between 0 to 1000 is
+      valid. A `style` is a mandatory attribute that defines the style of the font. A 'style'
+      attribute can be `normal` or `italic`. An `index` is an optional attribute that defines the
+      index of the font collection. If this is not specified, it is treated as 0. If the font file
+      is not a font collection, this attribute is ignored. A `postScriptName` attribute is an
+      optional attribute. A PostScript name is used for identifying target of system font update.
+      If this is not specified, the system assumes the filename is same to PostScript name of the
+      font file. For example, if the font file is "Roboto-Regular.ttf", the system assume the
+      PostScript name of this font is "Roboto-Regular".
+
+      A variable font can be only defined for the variable font file. A variable font can have
+      `axis` child nodes for specifying axis values. A variable font can have all attribute of
+      static font and can have additional `supportedAxes` attribute. A `supportedAxes` attribute
+      is a comma separated supported axis tags. As of Android V, only `wght` and `ital` axes can
+      be specified.
+
+      If `supportedAxes` attribute is not specified, this `font` node works as static font of the
+      single instance of variable font specified with `axis` children.
+
+      If `supportedAxes` attribute is specified, the system dynamically create font instance for the
+      given weight and style value. If `wght` is specified in `supportedAxes` attribute the `weight`
+      attribute and `axis` child that has `wght` tag become optional and ignored because it is
+      determined by system at runtime. Similarly, if `ital` is specified in `supportedAxes`
+      attribute, the `style` attribute and `axis` child that has `ital` tag become optional and
+      ignored.
+
+    `axis` node:
+      An `axis` node defines a font variation value for a tag. An `axis` node can have two mandatory
+      attributes, `tag` and `value`. If the font is variable font and the same tag `axis` node is
+      specified in `supportedAxes` attribute, the style value works like a default instance.
 -->
-<familyset version="23">
+<familyset>
     <!-- first font is default -->
-    <family name="sans-serif" varFamilyType="2">
-        <font>Roboto-Regular.ttf
+    <family name="sans-serif">
+        <font supportedAxes="wght,ital">Roboto-Regular.ttf
           <axis tag="wdth" stylevalue="100" />
         </font>
    </family>
@@ -32,8 +104,8 @@
     <alias name="tahoma" to="sans-serif" />
     <alias name="verdana" to="sans-serif" />
 
-    <family name="sans-serif-condensed" varFamilyType="2">
-      <font>Roboto-Regular.ttf
+    <family name="sans-serif-condensed">
+      <font supportedAxes="wght,ital">Roboto-Regular.ttf
         <axis tag="wdth" stylevalue="75" />
       </font>
     </family>
@@ -72,8 +144,8 @@
         <font weight="400" style="normal" postScriptName="ComingSoon-Regular">ComingSoon.ttf</font>
     </family>
 
-    <family name="cursive" varFamilyType="1">
-      <font>DancingScript-Regular.ttf</font>
+    <family name="cursive">
+      <font supportedAxes="wght">DancingScript-Regular.ttf</font>
     </family>
 
     <family name="sans-serif-smallcaps">
@@ -90,8 +162,8 @@
     </family>
     <alias name="source-sans-pro-semi-bold" to="source-sans-pro" weight="600"/>
 
-    <family name="roboto-flex" varFamilyType="2">
-        <font>RobotoFlex-Regular.ttf
+    <family name="roboto-flex">
+        <font supportedAxes="wght">RobotoFlex-Regular.ttf
           <axis tag="wdth" stylevalue="100" />
         </font>
     </family>
@@ -109,11 +181,11 @@
         </font>
         <font weight="700" style="normal">NotoNaskhArabicUI-Bold.ttf</font>
     </family>
-    <family lang="und-Ethi" varFamilyType="1">
-        <font postScriptName="NotoSansEthiopic-Regular">
+    <family lang="und-Ethi">
+        <font postScriptName="NotoSansEthiopic-Regular" supportedAxes="wght">
             NotoSansEthiopic-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifEthiopic-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifEthiopic-Regular" supportedAxes="wght">
             NotoSerifEthiopic-VF.ttf
         </font>
     </family>
@@ -140,32 +212,32 @@
         </font>
         <font weight="700" style="normal">NotoSansThaiUI-Bold.ttf</font>
     </family>
-    <family lang="und-Armn" varFamilyType="1">
-        <font postScriptName="NotoSansArmenian-Regular">
+    <family lang="und-Armn">
+        <font postScriptName="NotoSansArmenian-Regular" supportedAxes="wght">
             NotoSansArmenian-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifArmenian-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifArmenian-Regular" supportedAxes="wght">
             NotoSerifArmenian-VF.ttf
         </font>
     </family>
-    <family lang="und-Geor,und-Geok" varFamilyType="1">
-        <font postScriptName="NotoSansGeorgian-Regular">
+    <family lang="und-Geor,und-Geok">
+        <font postScriptName="NotoSansGeorgian-Regular" supportedAxes="wght">
             NotoSansGeorgian-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifGeorgian-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifGeorgian-Regular" supportedAxes="wght">
             NotoSerifGeorgian-VF.ttf
         </font>
     </family>
-    <family lang="und-Deva" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansDevanagari-Regular">
+    <family lang="und-Deva" variant="elegant">
+        <font postScriptName="NotoSansDevanagari-Regular" supportedAxes="wght">
             NotoSansDevanagari-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifDevanagari-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifDevanagari-Regular" supportedAxes="wght">
             NotoSerifDevanagari-VF.ttf
         </font>
     </family>
-    <family lang="und-Deva" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansDevanagariUI-Regular">
+    <family lang="und-Deva" variant="compact">
+        <font postScriptName="NotoSansDevanagariUI-Regular" supportedAxes="wght">
             NotoSansDevanagariUI-VF.ttf
         </font>
     </family>
@@ -178,21 +250,9 @@
             NotoSansGujarati-Regular.ttf
         </font>
         <font weight="700" style="normal">NotoSansGujarati-Bold.ttf</font>
-        <font weight="400" style="normal" fallbackFor="serif"
-              postScriptName="NotoSerifGujarati-Regular">NotoSerifGujarati-VF.ttf
-            <axis tag="wght" stylevalue="400"/>
-        </font>
-        <font weight="500" style="normal" fallbackFor="serif"
-              postScriptName="NotoSerifGujarati-Regular">NotoSerifGujarati-VF.ttf
-            <axis tag="wght" stylevalue="500"/>
-        </font>
-        <font weight="600" style="normal" fallbackFor="serif"
-              postScriptName="NotoSerifGujarati-Regular">NotoSerifGujarati-VF.ttf
-            <axis tag="wght" stylevalue="600"/>
-        </font>
-        <font weight="700" style="normal" fallbackFor="serif"
-              postScriptName="NotoSerifGujarati-Regular">NotoSerifGujarati-VF.ttf
-            <axis tag="wght" stylevalue="700"/>
+        <font style="normal" fallbackFor="serif" postScriptName="NotoSerifGujarati-Regular"
+          supportedAxes="wght">
+          NotoSerifGujarati-VF.ttf
         </font>
     </family>
     <family lang="und-Gujr" variant="compact">
@@ -201,81 +261,81 @@
         </font>
         <font weight="700" style="normal">NotoSansGujaratiUI-Bold.ttf</font>
     </family>
-    <family lang="und-Guru" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansGurmukhi-Regular">
+    <family lang="und-Guru" variant="elegant">
+        <font postScriptName="NotoSansGurmukhi-Regular" supportedAxes="wght">
             NotoSansGurmukhi-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifGurmukhi-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifGurmukhi-Regular" supportedAxes="wght">
             NotoSerifGurmukhi-VF.ttf
         </font>
     </family>
-    <family lang="und-Guru" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansGurmukhiUI-Regular">
+    <family lang="und-Guru" variant="compact">
+        <font postScriptName="NotoSansGurmukhiUI-Regular" supportedAxes="wght">
             NotoSansGurmukhiUI-VF.ttf
         </font>
     </family>
-    <family lang="und-Taml" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansTamil-Regular">
+    <family lang="und-Taml" variant="elegant">
+        <font postScriptName="NotoSansTamil-Regular" supportedAxes="wght">
             NotoSansTamil-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifTamil-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifTamil-Regular" supportedAxes="wght">
             NotoSerifTamil-VF.ttf
         </font>
     </family>
-    <family lang="und-Taml" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansTamilUI-Regular">
+    <family lang="und-Taml" variant="compact">
+        <font postScriptName="NotoSansTamilUI-Regular" supportedAxes="wght">
             NotoSansTamilUI-VF.ttf
         </font>
     </family>
-    <family lang="und-Mlym" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansMalayalam-Regular">
+    <family lang="und-Mlym" variant="elegant">
+        <font postScriptName="NotoSansMalayalam-Regular" supportedAxes="wght">
             NotoSansMalayalam-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifMalayalam-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifMalayalam-Regular" supportedAxes="wght">
             NotoSerifMalayalam-VF.ttf
         </font>
     </family>
-    <family lang="und-Mlym" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansMalayalamUI-Regular">
+    <family lang="und-Mlym" variant="compact">
+        <font postScriptName="NotoSansMalayalamUI-Regular" supportedAxes="wght">
             NotoSansMalayalamUI-VF.ttf
         </font>
     </family>
-    <family lang="und-Beng" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansBengali-Regular">
+    <family lang="und-Beng" variant="elegant">
+        <font postScriptName="NotoSansBengali-Regular" supportedAxes="wght">
             NotoSansBengali-VF.ttf
         </font>
         <font fallbackFor="serif" postScriptName="NotoSerifBengali-Regular">
             NotoSerifBengali-VF.ttf
         </font>
     </family>
-    <family lang="und-Beng" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansBengaliUI-Regular">
+    <family lang="und-Beng" variant="compact">
+        <font postScriptName="NotoSansBengaliUI-Regular" supportedAxes="wght">
             NotoSansBengaliUI-VF.ttf
         </font>
     </family>
-    <family lang="und-Telu" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansTelugu-Regular">
+    <family lang="und-Telu" variant="elegant">
+        <font postScriptName="NotoSansTelugu-Regular" supportedAxes="wght">
             NotoSansTelugu-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifTelugu-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifTelugu-Regular" supportedAxes="wght">
             NotoSerifTelugu-VF.ttf
         </font>
     </family>
-    <family lang="und-Telu" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansTeluguUI-Regular">
+    <family lang="und-Telu" variant="compact">
+        <font postScriptName="NotoSansTeluguUI-Regular" supportedAxes="wght">
             NotoSansTeluguUI-VF.ttf
         </font>
     </family>
-    <family lang="und-Knda" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansKannada-Regular">
+    <family lang="und-Knda" variant="elegant">
+        <font postScriptName="NotoSansKannada-Regular" supportedAxes="wght">
             NotoSansKannada-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifKannada-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifKannada-Regular" supportedAxes="wght">
             NotoSerifKannada-VF.ttf
         </font>
     </family>
-    <family lang="und-Knda" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansKannadaUI-Regular">
+    <family lang="und-Knda" variant="compact">
+        <font postScriptName="NotoSansKannadaUI-Regular" supportedAxes="wght">
             NotoSansKannadaUI-VF.ttf
         </font>
     </family>
@@ -290,19 +350,20 @@
         </font>
         <font weight="700" style="normal">NotoSansOriyaUI-Bold.ttf</font>
     </family>
-    <family lang="und-Sinh" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansSinhala-Regular">
+    <family lang="und-Sinh" variant="elegant">
+        <font postScriptName="NotoSansSinhala-Regular" supportedAxes="wght">
             NotoSansSinhala-VF.ttf
         </font>
         <font fallbackFor="serif" postScriptName="NotoSerifSinhala-Regular">
             NotoSerifSinhala-VF.ttf
         </font>
     </family>
-    <family lang="und-Sinh" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansSinhalaUI-Regular">
+    <family lang="und-Sinh" variant="compact">
+        <font postScriptName="NotoSansSinhalaUI-Regular" supportedAxes="wght">
             NotoSansSinhalaUI-VF.ttf
         </font>
     </family>
+    <!-- TODO: NotoSansKhmer uses non-standard wght value, so cannot use auto-adjustment. -->
     <family lang="und-Khmr" variant="elegant">
         <font weight="100" style="normal" postScriptName="NotoSansKhmer-Regular">
             NotoSansKhmer-VF.ttf
@@ -398,8 +459,8 @@
     <family lang="und-Ahom">
         <font weight="400" style="normal">NotoSansAhom-Regular.otf</font>
     </family>
-    <family lang="und-Adlm" varFamilyType="1">
-        <font postScriptName="NotoSansAdlam-Regular">
+    <family lang="und-Adlm">
+        <font postScriptName="NotoSansAdlam-Regular" supportedAxes="wght">
             NotoSansAdlam-VF.ttf
         </font>
     </family>
@@ -686,8 +747,8 @@
             NotoSansTaiViet-Regular.ttf
         </font>
     </family>
-    <family lang="und-Tibt" varFamilyType="1">
-        <font postScriptName="NotoSerifTibetan-Regular">
+    <family lang="und-Tibt">
+        <font postScriptName="NotoSerifTibetan-Regular" supportedAxes="wght">
             NotoSerifTibetan-VF.ttf
         </font>
     </family>
@@ -865,27 +926,27 @@
     <family lang="und-Dogr">
         <font weight="400" style="normal">NotoSerifDogra-Regular.ttf</font>
     </family>
-    <family lang="und-Medf" varFamilyType="1">
-        <font postScriptName="NotoSansMedefaidrin-Regular">
+    <family lang="und-Medf">
+        <font postScriptName="NotoSansMedefaidrin-Regular" supportedAxes="wght">
             NotoSansMedefaidrin-VF.ttf
         </font>
     </family>
-    <family lang="und-Soyo" varFamilyType="1">
+    <family lang="und-Soyo" supportedAxes="wght">
         <font postScriptName="NotoSansSoyombo-Regular">
             NotoSansSoyombo-VF.ttf
         </font>
     </family>
-    <family lang="und-Takr" varFamilyType="1">
+    <family lang="und-Takr" supportedAxes="wght">
         <font postScriptName="NotoSansTakri-Regular">
             NotoSansTakri-VF.ttf
         </font>
     </family>
-    <family lang="und-Hmnp" varFamilyType="1">
+    <family lang="und-Hmnp" supportedAxes="wght">
         <font postScriptName="NotoSerifHmongNyiakeng-Regular">
             NotoSerifNyiakengPuachueHmong-VF.ttf
         </font>
     </family>
-    <family lang="und-Yezi" varFamilyType="1">
+    <family lang="und-Yezi" supportedAxes="wght">
         <font postScriptName="NotoSerifYezidi-Regular">
             NotoSerifYezidi-VF.ttf
         </font>
diff --git a/data/fonts/font_fallback_cjkvf.xml b/data/fonts/font_fallback_cjkvf.xml
index 75bc74ebb553..c1ca67ef456a 100644
--- a/data/fonts/font_fallback_cjkvf.xml
+++ b/data/fonts/font_fallback_cjkvf.xml
@@ -11,12 +11,84 @@
     effectively add 300 to the weight, this ensures that 900 is the bold
     paired with the 500 weight, ensuring adequate contrast.
 
-    TODO(rsheeter) update comment; ordering to match 800 to 900 is no longer required
+
+    The font_fallback.xml defines the list of font used by the system.
+
+    `familyset` node:
+      A `familyset` element must be a root node of the font_fallback.xml. No attributes are allowed
+      to `familyset` node.
+      The `familyset` node can contains `family` and `alias` nodes. Any other nodes will be ignored.
+
+    `family` node:
+      A `family` node defines a single font family definition.
+      A font family is a set of fonts for drawing text in various styles such as weight, slant.
+      There are three types of families, default family, named family and locale fallback family.
+
+      The default family is a special family node appeared the first node of the `familyset` node.
+      The default family is used as first priority fallback.
+      Only `name` attribute can be used for default family node. If the `name` attribute is
+      specified, This family will also works as named family.
+
+      The named family is a family that has name attribute. The named family defines a new fallback.
+      For example, if the name attribute is "serif", it creates serif fallback. Developers can
+      access the fallback by using Typeface#create API.
+      The named family can not have attribute other than `name` attribute. The `name` attribute
+      cannot be empty.
+
+      The locale fallback family is a font family that is used for fallback. The fallback family is
+      used when the named family or default family cannot be used. The locale fallback family can
+      have `lang` attribute and `variant` attribute. The `lang` attribute is an optional comma
+      separated BCP-47i language tag. The `variant` is an optional attribute that can be one one
+      `element`, `compact`. If a `variant` attribute is not specified, it is treated as default.
+
+    `alias` node:
+      An `alias` node defines a alias of named family with changing weight offset. An `alias` node
+      can have mandatory `name` and `to` attribute and optional `weight` attribute. This `alias`
+      defines new fallback that has the name of specified `name` attribute. The fallback list is
+      the same to the fallback that of the name specified with `to` attribute. If `weight` attribute
+      is specified, the base weight offset is shifted to the specified value. For example, if the
+      `weight` is 500, the output text is drawn with 500 of weight.
+
+    `font` node:
+      A `font` node defines a single font definition. There are two types of fonts, static font and
+      variable font.
+
+      A static font can have `weight`, `style`, `index` and `postScriptName` attributes. A `weight`
+      is a mandatory attribute that defines the weight of the font. Any number between 0 to 1000 is
+      valid. A `style` is a mandatory attribute that defines the style of the font. A 'style'
+      attribute can be `normal` or `italic`. An `index` is an optional attribute that defines the
+      index of the font collection. If this is not specified, it is treated as 0. If the font file
+      is not a font collection, this attribute is ignored. A `postScriptName` attribute is an
+      optional attribute. A PostScript name is used for identifying target of system font update.
+      If this is not specified, the system assumes the filename is same to PostScript name of the
+      font file. For example, if the font file is "Roboto-Regular.ttf", the system assume the
+      PostScript name of this font is "Roboto-Regular".
+
+      A variable font can be only defined for the variable font file. A variable font can have
+      `axis` child nodes for specifying axis values. A variable font can have all attribute of
+      static font and can have additional `supportedAxes` attribute. A `supportedAxes` attribute
+      is a comma separated supported axis tags. As of Android V, only `wght` and `ital` axes can
+      be specified.
+
+      If `supportedAxes` attribute is not specified, this `font` node works as static font of the
+      single instance of variable font specified with `axis` children.
+
+      If `supportedAxes` attribute is specified, the system dynamically create font instance for the
+      given weight and style value. If `wght` is specified in `supportedAxes` attribute the `weight`
+      attribute and `axis` child that has `wght` tag become optional and ignored because it is
+      determined by system at runtime. Similarly, if `ital` is specified in `supportedAxes`
+      attribute, the `style` attribute and `axis` child that has `ital` tag become optional and
+      ignored.
+
+    `axis` node:
+      An `axis` node defines a font variation value for a tag. An `axis` node can have two mandatory
+      attributes, `tag` and `value`. If the font is variable font and the same tag `axis` node is
+      specified in `supportedAxes` attribute, the style value works like a default instance.
 -->
-<familyset version="23">
+<familyset>
     <!-- first font is default -->
-    <family name="sans-serif" varFamilyType="2">
-        <font>Roboto-Regular.ttf
+    <family name="sans-serif">
+        <font supportedAxes="wght,ital">Roboto-Regular.ttf
           <axis tag="wdth" stylevalue="100" />
         </font>
    </family>
@@ -32,8 +104,8 @@
     <alias name="tahoma" to="sans-serif" />
     <alias name="verdana" to="sans-serif" />
 
-    <family name="sans-serif-condensed" varFamilyType="2">
-      <font>Roboto-Regular.ttf
+    <family name="sans-serif-condensed">
+      <font supportedAxes="wght,ital">Roboto-Regular.ttf
         <axis tag="wdth" stylevalue="75" />
       </font>
     </family>
@@ -72,8 +144,8 @@
         <font weight="400" style="normal" postScriptName="ComingSoon-Regular">ComingSoon.ttf</font>
     </family>
 
-    <family name="cursive" varFamilyType="1">
-      <font>DancingScript-Regular.ttf</font>
+    <family name="cursive">
+      <font supportedAxes="wght">DancingScript-Regular.ttf</font>
     </family>
 
     <family name="sans-serif-smallcaps">
@@ -90,8 +162,8 @@
     </family>
     <alias name="source-sans-pro-semi-bold" to="source-sans-pro" weight="600"/>
 
-    <family name="roboto-flex" varFamilyType="2">
-        <font>RobotoFlex-Regular.ttf
+    <family name="roboto-flex">
+        <font supportedAxes="wght">RobotoFlex-Regular.ttf
           <axis tag="wdth" stylevalue="100" />
         </font>
     </family>
@@ -109,11 +181,11 @@
         </font>
         <font weight="700" style="normal">NotoNaskhArabicUI-Bold.ttf</font>
     </family>
-    <family lang="und-Ethi" varFamilyType="1">
-        <font postScriptName="NotoSansEthiopic-Regular">
+    <family lang="und-Ethi">
+        <font postScriptName="NotoSansEthiopic-Regular" supportedAxes="wght">
             NotoSansEthiopic-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifEthiopic-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifEthiopic-Regular" supportedAxes="wght">
             NotoSerifEthiopic-VF.ttf
         </font>
     </family>
@@ -140,32 +212,32 @@
         </font>
         <font weight="700" style="normal">NotoSansThaiUI-Bold.ttf</font>
     </family>
-    <family lang="und-Armn" varFamilyType="1">
-        <font postScriptName="NotoSansArmenian-Regular">
+    <family lang="und-Armn">
+        <font postScriptName="NotoSansArmenian-Regular" supportedAxes="wght">
             NotoSansArmenian-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifArmenian-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifArmenian-Regular" supportedAxes="wght">
             NotoSerifArmenian-VF.ttf
         </font>
     </family>
-    <family lang="und-Geor,und-Geok" varFamilyType="1">
-        <font postScriptName="NotoSansGeorgian-Regular">
+    <family lang="und-Geor,und-Geok">
+        <font postScriptName="NotoSansGeorgian-Regular" supportedAxes="wght">
             NotoSansGeorgian-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifGeorgian-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifGeorgian-Regular" supportedAxes="wght">
             NotoSerifGeorgian-VF.ttf
         </font>
     </family>
-    <family lang="und-Deva" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansDevanagari-Regular">
+    <family lang="und-Deva" variant="elegant">
+        <font postScriptName="NotoSansDevanagari-Regular" supportedAxes="wght">
             NotoSansDevanagari-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifDevanagari-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifDevanagari-Regular" supportedAxes="wght">
             NotoSerifDevanagari-VF.ttf
         </font>
     </family>
-    <family lang="und-Deva" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansDevanagariUI-Regular">
+    <family lang="und-Deva" variant="compact">
+        <font postScriptName="NotoSansDevanagariUI-Regular" supportedAxes="wght">
             NotoSansDevanagariUI-VF.ttf
         </font>
     </family>
@@ -178,21 +250,9 @@
             NotoSansGujarati-Regular.ttf
         </font>
         <font weight="700" style="normal">NotoSansGujarati-Bold.ttf</font>
-        <font weight="400" style="normal" fallbackFor="serif"
-              postScriptName="NotoSerifGujarati-Regular">NotoSerifGujarati-VF.ttf
-            <axis tag="wght" stylevalue="400"/>
-        </font>
-        <font weight="500" style="normal" fallbackFor="serif"
-              postScriptName="NotoSerifGujarati-Regular">NotoSerifGujarati-VF.ttf
-            <axis tag="wght" stylevalue="500"/>
-        </font>
-        <font weight="600" style="normal" fallbackFor="serif"
-              postScriptName="NotoSerifGujarati-Regular">NotoSerifGujarati-VF.ttf
-            <axis tag="wght" stylevalue="600"/>
-        </font>
-        <font weight="700" style="normal" fallbackFor="serif"
-              postScriptName="NotoSerifGujarati-Regular">NotoSerifGujarati-VF.ttf
-            <axis tag="wght" stylevalue="700"/>
+        <font style="normal" fallbackFor="serif" postScriptName="NotoSerifGujarati-Regular"
+          supportedAxes="wght">
+          NotoSerifGujarati-VF.ttf
         </font>
     </family>
     <family lang="und-Gujr" variant="compact">
@@ -201,81 +261,81 @@
         </font>
         <font weight="700" style="normal">NotoSansGujaratiUI-Bold.ttf</font>
     </family>
-    <family lang="und-Guru" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansGurmukhi-Regular">
+    <family lang="und-Guru" variant="elegant">
+        <font postScriptName="NotoSansGurmukhi-Regular" supportedAxes="wght">
             NotoSansGurmukhi-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifGurmukhi-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifGurmukhi-Regular" supportedAxes="wght">
             NotoSerifGurmukhi-VF.ttf
         </font>
     </family>
-    <family lang="und-Guru" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansGurmukhiUI-Regular">
+    <family lang="und-Guru" variant="compact">
+        <font postScriptName="NotoSansGurmukhiUI-Regular" supportedAxes="wght">
             NotoSansGurmukhiUI-VF.ttf
         </font>
     </family>
-    <family lang="und-Taml" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansTamil-Regular">
+    <family lang="und-Taml" variant="elegant">
+        <font postScriptName="NotoSansTamil-Regular" supportedAxes="wght">
             NotoSansTamil-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifTamil-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifTamil-Regular" supportedAxes="wght">
             NotoSerifTamil-VF.ttf
         </font>
     </family>
-    <family lang="und-Taml" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansTamilUI-Regular">
+    <family lang="und-Taml" variant="compact">
+        <font postScriptName="NotoSansTamilUI-Regular" supportedAxes="wght">
             NotoSansTamilUI-VF.ttf
         </font>
     </family>
-    <family lang="und-Mlym" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansMalayalam-Regular">
+    <family lang="und-Mlym" variant="elegant">
+        <font postScriptName="NotoSansMalayalam-Regular" supportedAxes="wght">
             NotoSansMalayalam-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifMalayalam-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifMalayalam-Regular" supportedAxes="wght">
             NotoSerifMalayalam-VF.ttf
         </font>
     </family>
-    <family lang="und-Mlym" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansMalayalamUI-Regular">
+    <family lang="und-Mlym" variant="compact">
+        <font postScriptName="NotoSansMalayalamUI-Regular" supportedAxes="wght">
             NotoSansMalayalamUI-VF.ttf
         </font>
     </family>
-    <family lang="und-Beng" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansBengali-Regular">
+    <family lang="und-Beng" variant="elegant">
+        <font postScriptName="NotoSansBengali-Regular" supportedAxes="wght">
             NotoSansBengali-VF.ttf
         </font>
         <font fallbackFor="serif" postScriptName="NotoSerifBengali-Regular">
             NotoSerifBengali-VF.ttf
         </font>
     </family>
-    <family lang="und-Beng" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansBengaliUI-Regular">
+    <family lang="und-Beng" variant="compact">
+        <font postScriptName="NotoSansBengaliUI-Regular" supportedAxes="wght">
             NotoSansBengaliUI-VF.ttf
         </font>
     </family>
-    <family lang="und-Telu" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansTelugu-Regular">
+    <family lang="und-Telu" variant="elegant">
+        <font postScriptName="NotoSansTelugu-Regular" supportedAxes="wght">
             NotoSansTelugu-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifTelugu-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifTelugu-Regular" supportedAxes="wght">
             NotoSerifTelugu-VF.ttf
         </font>
     </family>
-    <family lang="und-Telu" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansTeluguUI-Regular">
+    <family lang="und-Telu" variant="compact">
+        <font postScriptName="NotoSansTeluguUI-Regular" supportedAxes="wght">
             NotoSansTeluguUI-VF.ttf
         </font>
     </family>
-    <family lang="und-Knda" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansKannada-Regular">
+    <family lang="und-Knda" variant="elegant">
+        <font postScriptName="NotoSansKannada-Regular" supportedAxes="wght">
             NotoSansKannada-VF.ttf
         </font>
-        <font fallbackFor="serif" postScriptName="NotoSerifKannada-Regular">
+        <font fallbackFor="serif" postScriptName="NotoSerifKannada-Regular" supportedAxes="wght">
             NotoSerifKannada-VF.ttf
         </font>
     </family>
-    <family lang="und-Knda" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansKannadaUI-Regular">
+    <family lang="und-Knda" variant="compact">
+        <font postScriptName="NotoSansKannadaUI-Regular" supportedAxes="wght">
             NotoSansKannadaUI-VF.ttf
         </font>
     </family>
@@ -290,19 +350,20 @@
         </font>
         <font weight="700" style="normal">NotoSansOriyaUI-Bold.ttf</font>
     </family>
-    <family lang="und-Sinh" variant="elegant" varFamilyType="1">
-        <font postScriptName="NotoSansSinhala-Regular">
+    <family lang="und-Sinh" variant="elegant">
+        <font postScriptName="NotoSansSinhala-Regular" supportedAxes="wght">
             NotoSansSinhala-VF.ttf
         </font>
         <font fallbackFor="serif" postScriptName="NotoSerifSinhala-Regular">
             NotoSerifSinhala-VF.ttf
         </font>
     </family>
-    <family lang="und-Sinh" variant="compact" varFamilyType="1">
-        <font postScriptName="NotoSansSinhalaUI-Regular">
+    <family lang="und-Sinh" variant="compact">
+        <font postScriptName="NotoSansSinhalaUI-Regular" supportedAxes="wght">
             NotoSansSinhalaUI-VF.ttf
         </font>
     </family>
+    <!-- TODO: NotoSansKhmer uses non-standard wght value, so cannot use auto-adjustment. -->
     <family lang="und-Khmr" variant="elegant">
         <font weight="100" style="normal" postScriptName="NotoSansKhmer-Regular">
             NotoSansKhmer-VF.ttf
@@ -398,8 +459,8 @@
     <family lang="und-Ahom">
         <font weight="400" style="normal">NotoSansAhom-Regular.otf</font>
     </family>
-    <family lang="und-Adlm" varFamilyType="1">
-        <font postScriptName="NotoSansAdlam-Regular">
+    <family lang="und-Adlm">
+        <font postScriptName="NotoSansAdlam-Regular" supportedAxes="wght">
             NotoSansAdlam-VF.ttf
         </font>
     </family>
@@ -686,8 +747,8 @@
             NotoSansTaiViet-Regular.ttf
         </font>
     </family>
-    <family lang="und-Tibt" varFamilyType="1">
-        <font postScriptName="NotoSerifTibetan-Regular">
+    <family lang="und-Tibt">
+        <font postScriptName="NotoSerifTibetan-Regular" supportedAxes="wght">
             NotoSerifTibetan-VF.ttf
         </font>
     </family>
@@ -707,123 +768,36 @@
         <font weight="400" style="normal">NotoSansSymbols-Regular-Subsetted.ttf</font>
     </family>
     <family lang="zh-Hans">
-        <font weight="100" style="normal" index="2" postScriptName="NotoSansCJKjp-Thin">
+        <font weight="400" style="normal" index="2" postScriptName="NotoSansCJKjp-Thin"
+            supportedAxes="wght">
             NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="100"/>
-        </font>
-        <font weight="200" style="normal" index="2" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="200"/>
-        </font>
-        <font weight="300" style="normal" index="2" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="300"/>
-        </font>
-        <font weight="400" style="normal" index="2" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="400"/>
-        </font>
-        <font weight="500" style="normal" index="2" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="500"/>
-        </font>
-        <font weight="600" style="normal" index="2" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="600"/>
-        </font>
-        <font weight="700" style="normal" index="2" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="700"/>
-        </font>
-        <font weight="800" style="normal" index="2" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="800"/>
-        </font>
-        <font weight="900" style="normal" index="2" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="900"/>
+            <!-- The default instance of NotoSansCJK-Regular.ttc is wght=100, so specify wght=400
+                 for making regular style as default. -->
+            <axis tag="wght" stylevalue="400" />
         </font>
         <font weight="400" style="normal" index="2" fallbackFor="serif"
               postScriptName="NotoSerifCJKjp-Regular">NotoSerifCJK-Regular.ttc
         </font>
     </family>
     <family lang="zh-Hant,zh-Bopo">
-        <font weight="100" style="normal" index="3" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="100"/>
-        </font>
-        <font weight="200" style="normal" index="3" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="200"/>
-        </font>
-        <font weight="300" style="normal" index="3" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="300"/>
-        </font>
-        <font weight="400" style="normal" index="3" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="400"/>
-        </font>
-        <font weight="500" style="normal" index="3" postScriptName="NotoSansCJKjp-Thin">
+        <font weight="400" style="normal" index="3" postScriptName="NotoSansCJKjp-Thin"
+            supportedAxes="wght">
             NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="500"/>
-        </font>
-        <font weight="600" style="normal" index="3" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="600"/>
-        </font>
-        <font weight="700" style="normal" index="3" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="700"/>
-        </font>
-        <font weight="800" style="normal" index="3" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="800"/>
-        </font>
-        <font weight="900" style="normal" index="3" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="900"/>
+            <!-- The default instance of NotoSansCJK-Regular.ttc is wght=100, so specify wght=400
+                 for making regular style as default. -->
+            <axis tag="wght" stylevalue="400" />
         </font>
         <font weight="400" style="normal" index="3" fallbackFor="serif"
               postScriptName="NotoSerifCJKjp-Regular">NotoSerifCJK-Regular.ttc
         </font>
     </family>
     <family lang="ja">
-        <font weight="100" style="normal" index="0" postScriptName="NotoSansCJKjp-Thin">
+        <font weight="400" style="normal" index="0" postScriptName="NotoSansCJKjp-Thin"
+            supportedAxes="wght">
             NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="100"/>
-        </font>
-        <font weight="200" style="normal" index="0" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="200"/>
-        </font>
-        <font weight="300" style="normal" index="0" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="300"/>
-        </font>
-        <font weight="400" style="normal" index="0" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="400"/>
-        </font>
-        <font weight="500" style="normal" index="0" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="500"/>
-        </font>
-        <font weight="600" style="normal" index="0" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="600"/>
-        </font>
-        <font weight="700" style="normal" index="0" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="700"/>
-        </font>
-        <font weight="800" style="normal" index="0" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="800"/>
-        </font>
-        <font weight="900" style="normal" index="0" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="900"/>
+            <!-- The default instance of NotoSansCJK-Regular.ttc is wght=100, so specify wght=400
+                 for making regular style as default. -->
+            <axis tag="wght" stylevalue="400" />
         </font>
         <font weight="400" style="normal" index="0" fallbackFor="serif"
               postScriptName="NotoSerifCJKjp-Regular">NotoSerifCJK-Regular.ttc
@@ -840,41 +814,12 @@
         </font>
     </family>
     <family lang="ko">
-        <font weight="100" style="normal" index="1" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="100"/>
-        </font>
-        <font weight="200" style="normal" index="1" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="200"/>
-        </font>
-        <font weight="300" style="normal" index="1" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="300"/>
-        </font>
-        <font weight="400" style="normal" index="1" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="400"/>
-        </font>
-        <font weight="500" style="normal" index="1" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="500"/>
-        </font>
-        <font weight="600" style="normal" index="1" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="600"/>
-        </font>
-        <font weight="700" style="normal" index="1" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="700"/>
-        </font>
-        <font weight="800" style="normal" index="1" postScriptName="NotoSansCJKjp-Thin">
-            NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="800"/>
-        </font>
-        <font weight="900" style="normal" index="1" postScriptName="NotoSansCJKjp-Thin">
+        <font weight="400" style="normal" index="1" postScriptName="NotoSansCJKjp-Thin"
+            supportedAxes="wght">
             NotoSansCJK-Regular.ttc
-            <axis tag="wght" stylevalue="900"/>
+            <!-- The default instance of NotoSansCJK-Regular.ttc is wght=100, so specify wght=400
+                 for making regular style as default. -->
+            <axis tag="wght" stylevalue="400" />
         </font>
         <font weight="400" style="normal" index="1" fallbackFor="serif"
               postScriptName="NotoSerifCJKjp-Regular">NotoSerifCJK-Regular.ttc
@@ -997,27 +942,27 @@
     <family lang="und-Dogr">
         <font weight="400" style="normal">NotoSerifDogra-Regular.ttf</font>
     </family>
-    <family lang="und-Medf" varFamilyType="1">
-        <font postScriptName="NotoSansMedefaidrin-Regular">
+    <family lang="und-Medf">
+        <font postScriptName="NotoSansMedefaidrin-Regular" supportedAxes="wght">
             NotoSansMedefaidrin-VF.ttf
         </font>
     </family>
-    <family lang="und-Soyo" varFamilyType="1">
+    <family lang="und-Soyo" supportedAxes="wght">
         <font postScriptName="NotoSansSoyombo-Regular">
             NotoSansSoyombo-VF.ttf
         </font>
     </family>
-    <family lang="und-Takr" varFamilyType="1">
+    <family lang="und-Takr" supportedAxes="wght">
         <font postScriptName="NotoSansTakri-Regular">
             NotoSansTakri-VF.ttf
         </font>
     </family>
-    <family lang="und-Hmnp" varFamilyType="1">
+    <family lang="und-Hmnp" supportedAxes="wght">
         <font postScriptName="NotoSerifHmongNyiakeng-Regular">
             NotoSerifNyiakengPuachueHmong-VF.ttf
         </font>
     </family>
-    <family lang="und-Yezi" varFamilyType="1">
+    <family lang="und-Yezi" supportedAxes="wght">
         <font postScriptName="NotoSerifYezidi-Regular">
             NotoSerifYezidi-VF.ttf
         </font>
diff --git a/graphics/java/android/graphics/FontListParser.java b/graphics/java/android/graphics/FontListParser.java
index 52b0b95d3e76..17c2dd94cd36 100644
--- a/graphics/java/android/graphics/FontListParser.java
+++ b/graphics/java/android/graphics/FontListParser.java
@@ -16,10 +16,6 @@
 
 package android.graphics;
 
-import static android.graphics.fonts.FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE;
-import static android.graphics.fonts.FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ITAL;
-import static android.graphics.fonts.FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ONLY;
-import static android.graphics.fonts.FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_TWO_FONTS_WGHT;
 import static android.text.FontConfig.NamedFamilyList;
 
 import android.annotation.NonNull;
@@ -32,7 +28,6 @@ import android.os.Build;
 import android.os.LocaleList;
 import android.text.FontConfig;
 import android.util.ArraySet;
-import android.util.Log;
 import android.util.Xml;
 
 import org.xmlpull.v1.XmlPullParser;
@@ -65,6 +60,7 @@ public class FontListParser {
     private static final String VARIANT_ELEGANT = "elegant";
 
     // XML constants for Font.
+    public static final String ATTR_SUPPORTED_AXES = "supportedAxes";
     public static final String ATTR_INDEX = "index";
     public static final String ATTR_WEIGHT = "weight";
     public static final String ATTR_POSTSCRIPT_NAME = "postScriptName";
@@ -78,6 +74,10 @@ public class FontListParser {
     public static final String ATTR_TAG = "tag";
     public static final String ATTR_STYLEVALUE = "stylevalue";
 
+    // The tag string for variable font type resolution.
+    private static final String TAG_WGHT = "wght";
+    private static final String TAG_ITAL = "ital";
+
     /* Parse fallback list (no names) */
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
     public static FontConfig parse(InputStream in) throws XmlPullParserException, IOException {
@@ -263,7 +263,6 @@ public class FontListParser {
         final String lang = parser.getAttributeValue("", "lang");
         final String variant = parser.getAttributeValue(null, "variant");
         final String ignore = parser.getAttributeValue(null, "ignore");
-        final String varFamilyTypeStr = parser.getAttributeValue(null, "varFamilyType");
         final List<FontConfig.Font> fonts = new ArrayList<>();
         while (keepReading(parser)) {
             if (parser.getEventType() != XmlPullParser.START_TAG) continue;
@@ -286,45 +285,12 @@ public class FontListParser {
                 intVariant = FontConfig.FontFamily.VARIANT_ELEGANT;
             }
         }
-        int varFamilyType = VARIABLE_FONT_FAMILY_TYPE_NONE;
-        if (varFamilyTypeStr != null) {
-            varFamilyType = Integer.parseInt(varFamilyTypeStr);
-            if (varFamilyType <= -1 || varFamilyType > 3) {
-                Log.e(TAG, "Error: unexpected varFamilyType value: " + varFamilyTypeStr);
-                varFamilyType = VARIABLE_FONT_FAMILY_TYPE_NONE;
-            }
-
-            // validation but don't read font content for performance reasons.
-            switch (varFamilyType) {
-                case VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ONLY:
-                    if (fonts.size() != 1) {
-                        Log.e(TAG, "Error: Single font support wght axis, but two or more fonts are"
-                                + " included in the font family.");
-                        varFamilyType = VARIABLE_FONT_FAMILY_TYPE_NONE;
-                    }
-                    break;
-                case VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ITAL:
-                    if (fonts.size() != 1) {
-                        Log.e(TAG, "Error: Single font support both ital and wght axes, but two or"
-                                + " more fonts are included in the font family.");
-                        varFamilyType = VARIABLE_FONT_FAMILY_TYPE_NONE;
-                    }
-                    break;
-                case VARIABLE_FONT_FAMILY_TYPE_TWO_FONTS_WGHT:
-                    if (fonts.size() != 2) {
-                        Log.e(TAG, "Error: two fonts that support wght axis, but one or three or"
-                                + " more fonts are included in the font family.");
-                        varFamilyType = VARIABLE_FONT_FAMILY_TYPE_NONE;
-                    }
-            }
-        }
 
         boolean skip = (ignore != null && (ignore.equals("true") || ignore.equals("1")));
         if (skip || fonts.isEmpty()) {
             return null;
         }
-        return new FontConfig.FontFamily(fonts, LocaleList.forLanguageTags(lang), intVariant,
-                varFamilyType);
+        return new FontConfig.FontFamily(fonts, LocaleList.forLanguageTags(lang), intVariant);
     }
 
     private static void throwIfAttributeExists(String attrName, XmlPullParser parser) {
@@ -407,6 +373,7 @@ public class FontListParser {
         boolean isItalic = STYLE_ITALIC.equals(parser.getAttributeValue(null, ATTR_STYLE));
         String fallbackFor = parser.getAttributeValue(null, ATTR_FALLBACK_FOR);
         String postScriptName = parser.getAttributeValue(null, ATTR_POSTSCRIPT_NAME);
+        final String supportedAxes = parser.getAttributeValue(null, ATTR_SUPPORTED_AXES);
         StringBuilder filename = new StringBuilder();
         while (keepReading(parser)) {
             if (parser.getEventType() == XmlPullParser.TEXT) {
@@ -422,6 +389,18 @@ public class FontListParser {
         }
         String sanitizedName = FILENAME_WHITESPACE_PATTERN.matcher(filename).replaceAll("");
 
+        int varTypeAxes = 0;
+        if (supportedAxes != null) {
+            for (String tag : supportedAxes.split(",")) {
+                String strippedTag = tag.strip();
+                if (strippedTag.equals(TAG_WGHT)) {
+                    varTypeAxes |= FontConfig.Font.VAR_TYPE_AXES_WGHT;
+                } else if (strippedTag.equals(TAG_ITAL)) {
+                    varTypeAxes |= FontConfig.Font.VAR_TYPE_AXES_ITAL;
+                }
+            }
+        }
+
         if (postScriptName == null) {
             // If post script name was not provided, assume the file name is same to PostScript
             // name.
@@ -462,7 +441,8 @@ public class FontListParser {
                 ),
                 index,
                 varSettings,
-                fallbackFor);
+                fallbackFor,
+                varTypeAxes);
     }
 
     private static String findUpdatedFontFile(String psName,
diff --git a/graphics/java/android/graphics/fonts/SystemFonts.java b/graphics/java/android/graphics/fonts/SystemFonts.java
index 3ef714ed8bdf..a90961eb6d2e 100644
--- a/graphics/java/android/graphics/fonts/SystemFonts.java
+++ b/graphics/java/android/graphics/fonts/SystemFonts.java
@@ -100,6 +100,71 @@ public final class SystemFonts {
         }
     }
 
+    /** @hide */
+    @VisibleForTesting
+    public static @FontFamily.Builder.VariableFontFamilyType int resolveVarFamilyType(
+            @NonNull FontConfig.FontFamily xmlFamily,
+            @Nullable String familyName) {
+        int wghtCount = 0;
+        int italCount = 0;
+        int targetFonts = 0;
+        boolean hasItalicFont = false;
+
+        List<FontConfig.Font> fonts = xmlFamily.getFontList();
+        for (int i = 0; i < fonts.size(); ++i) {
+            FontConfig.Font font = fonts.get(i);
+
+            if (familyName == null) {  // for default family
+                if (font.getFontFamilyName() != null) {
+                    continue;  // this font is not for the default family.
+                }
+            } else {  // for the specific family
+                if (!familyName.equals(font.getFontFamilyName())) {
+                    continue;  // this font is not for given family.
+                }
+            }
+
+            final int varTypeAxes = font.getVarTypeAxes();
+            if (varTypeAxes == 0) {
+                // If we see static font, we can immediately return as VAR_TYPE_NONE.
+                return FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE;
+            }
+
+            if ((varTypeAxes & FontConfig.Font.VAR_TYPE_AXES_WGHT) != 0) {
+                wghtCount++;
+            }
+
+            if ((varTypeAxes & FontConfig.Font.VAR_TYPE_AXES_ITAL) != 0) {
+                italCount++;
+            }
+
+            if (font.getStyle().getSlant() == FontStyle.FONT_SLANT_ITALIC) {
+                hasItalicFont = true;
+            }
+            targetFonts++;
+        }
+
+        if (italCount == 0) {  // No ital font.
+            if (targetFonts == 1 && wghtCount == 1) {
+                // If there is only single font that has wght, use it for regular style and
+                // use synthetic bolding for italic.
+                return FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ONLY;
+            } else if (targetFonts == 2 && wghtCount == 2 && hasItalicFont) {
+                // If there are two fonts and italic font is available, use them for regular and
+                // italic separately. (It is impossible to have two italic fonts. It will end up
+                // with Typeface creation failure.)
+                return FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_TWO_FONTS_WGHT;
+            }
+        } else if (italCount == 1) {
+            // If ital font is included, a single font should support both wght and ital.
+            if (wghtCount == 1 && targetFonts == 1) {
+                return FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_SINGLE_FONT_WGHT_ITAL;
+            }
+        }
+        // Otherwise, unsupported.
+        return FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE;
+    }
+
     private static void pushFamilyToFallback(@NonNull FontConfig.FontFamily xmlFamily,
             @NonNull ArrayMap<String, NativeFamilyListSet> fallbackMap,
             @NonNull Map<String, ByteBuffer> cache) {
@@ -126,7 +191,7 @@ public final class SystemFonts {
         }
 
         final FontFamily defaultFamily = defaultFonts.isEmpty() ? null : createFontFamily(
-                defaultFonts, languageTags, variant, xmlFamily.getVariableFontFamilyType(), false,
+                defaultFonts, languageTags, variant, resolveVarFamilyType(xmlFamily, null), false,
                 cache);
         // Insert family into fallback map.
         for (int i = 0; i < fallbackMap.size(); i++) {
@@ -145,7 +210,7 @@ public final class SystemFonts {
                 }
             } else {
                 final FontFamily family = createFontFamily(fallback, languageTags, variant,
-                        xmlFamily.getVariableFontFamilyType(), false, cache);
+                        resolveVarFamilyType(xmlFamily, name), false, cache);
                 if (family != null) {
                     familyListSet.familyList.add(family);
                 } else if (defaultFamily != null) {
@@ -217,7 +282,8 @@ public final class SystemFonts {
             final FontFamily family = createFontFamily(
                     xmlFamily.getFontList(),
                     xmlFamily.getLocaleList().toLanguageTags(), xmlFamily.getVariant(),
-                    xmlFamily.getVariableFontFamilyType(),
+                    resolveVarFamilyType(xmlFamily,
+                            null /* all fonts under named family should be treated as default */),
                     true, // named family is always default
                     bufferCache);
             if (family == null) {
diff --git a/services/core/java/com/android/server/graphics/fonts/UpdatableFontDir.java b/services/core/java/com/android/server/graphics/fonts/UpdatableFontDir.java
index 0f40ca082663..1715254a7403 100644
--- a/services/core/java/com/android/server/graphics/fonts/UpdatableFontDir.java
+++ b/services/core/java/com/android/server/graphics/fonts/UpdatableFontDir.java
@@ -16,8 +16,6 @@
 
 package com.android.server.graphics.fonts;
 
-import static android.graphics.fonts.FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE;
-
 import static com.android.server.graphics.fonts.FontManagerService.SystemFontException;
 
 import android.annotation.NonNull;
@@ -580,11 +578,11 @@ final class UpdatableFontDir {
                 return null;
             }
             resolvedFonts.add(new FontConfig.Font(info.mFile, null, info.getPostScriptName(),
-                    font.getFontStyle(), font.getIndex(), font.getFontVariationSettings(), null));
+                    font.getFontStyle(), font.getIndex(), font.getFontVariationSettings(),
+                    null /* family name */, FontConfig.Font.VAR_TYPE_AXES_NONE));
         }
         FontConfig.FontFamily family = new FontConfig.FontFamily(resolvedFonts,
-                LocaleList.getEmptyLocaleList(), FontConfig.FontFamily.VARIANT_DEFAULT,
-                VARIABLE_FONT_FAMILY_TYPE_NONE);
+                LocaleList.getEmptyLocaleList(), FontConfig.FontFamily.VARIANT_DEFAULT);
         return new FontConfig.NamedFamilyList(Collections.singletonList(family),
                 fontFamily.getName());
     }
diff --git a/services/tests/servicestests/src/com/android/server/graphics/fonts/UpdatableFontDirTest.java b/services/tests/servicestests/src/com/android/server/graphics/fonts/UpdatableFontDirTest.java
index 3de167e72ba0..dacff4c07759 100644
--- a/services/tests/servicestests/src/com/android/server/graphics/fonts/UpdatableFontDirTest.java
+++ b/services/tests/servicestests/src/com/android/server/graphics/fonts/UpdatableFontDirTest.java
@@ -23,7 +23,6 @@ import static org.junit.Assert.fail;
 
 import android.content.Context;
 import android.graphics.FontListParser;
-import android.graphics.fonts.FontFamily;
 import android.graphics.fonts.FontManager;
 import android.graphics.fonts.FontStyle;
 import android.graphics.fonts.FontUpdateRequest;
@@ -324,15 +323,16 @@ public final class UpdatableFontDirTest {
         Function<Map<String, File>, FontConfig> configSupplier = (map) -> {
             FontConfig.Font fooFont = new FontConfig.Font(
                     new File(mPreinstalledFontDirs.get(0), "foo.ttf"), null, "foo",
-                    new FontStyle(400, FontStyle.FONT_SLANT_UPRIGHT), 0, null, null);
+                    new FontStyle(400, FontStyle.FONT_SLANT_UPRIGHT), 0, null, null,
+                    FontConfig.Font.VAR_TYPE_AXES_NONE);
             FontConfig.Font barFont = new FontConfig.Font(
                     new File(mPreinstalledFontDirs.get(1), "bar.ttf"), null, "bar",
-                    new FontStyle(400, FontStyle.FONT_SLANT_UPRIGHT), 0, null, null);
+                    new FontStyle(400, FontStyle.FONT_SLANT_UPRIGHT), 0, null, null,
+                    FontConfig.Font.VAR_TYPE_AXES_NONE);
 
             FontConfig.FontFamily family = new FontConfig.FontFamily(
                     Arrays.asList(fooFont, barFont), null,
-                    FontConfig.FontFamily.VARIANT_DEFAULT,
-                    FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE);
+                    FontConfig.FontFamily.VARIANT_DEFAULT);
             return new FontConfig(Collections.emptyList(),
                     Collections.emptyList(),
                     Collections.singletonList(new FontConfig.NamedFamilyList(
@@ -492,10 +492,9 @@ public final class UpdatableFontDirTest {
                 mConfigFile, mCurrentTimeSupplier, (map) -> {
             FontConfig.Font font = new FontConfig.Font(
                     file, null, "bar", new FontStyle(400, FontStyle.FONT_SLANT_UPRIGHT),
-                    0, null, null);
+                    0, null, null, FontConfig.Font.VAR_TYPE_AXES_NONE);
             FontConfig.FontFamily family = new FontConfig.FontFamily(
-                    Collections.singletonList(font), null, FontConfig.FontFamily.VARIANT_DEFAULT,
-                    FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE);
+                    Collections.singletonList(font), null, FontConfig.FontFamily.VARIANT_DEFAULT);
             return new FontConfig(
                     Collections.emptyList(),
                     Collections.emptyList(),
@@ -647,10 +646,9 @@ public final class UpdatableFontDirTest {
                 mConfigFile, mCurrentTimeSupplier, (map) -> {
             FontConfig.Font font = new FontConfig.Font(
                     file, null, "test", new FontStyle(400, FontStyle.FONT_SLANT_UPRIGHT), 0, null,
-                    null);
+                    null, FontConfig.Font.VAR_TYPE_AXES_NONE);
             FontConfig.FontFamily family = new FontConfig.FontFamily(
-                    Collections.singletonList(font), null, FontConfig.FontFamily.VARIANT_DEFAULT,
-                    FontFamily.Builder.VARIABLE_FONT_FAMILY_TYPE_NONE);
+                    Collections.singletonList(font), null, FontConfig.FontFamily.VARIANT_DEFAULT);
             return new FontConfig(Collections.emptyList(), Collections.emptyList(),
                     Collections.singletonList(new FontConfig.NamedFamilyList(
                             Collections.singletonList(family), "sans-serif")),