Merge cherrypicks of ['android-review.googlesource.com/3032063'] into androidx-compose-release.

Change-Id: I8cbf783e5b48a837ccd011430426fd301a4eb072

2 files changed, 106 insertions, 66 deletions

diff --git a/compose/ui/ui-text/src/androidUnitTest/kotlin/androidx/compose/ui/text/SaversTest.kt b/compose/ui/ui-text/src/androidUnitTest/kotlin/androidx/compose/ui/text/SaversTest.kt
index 8365149116c..48a534f3f50 100644
--- a/compose/ui/ui-text/src/androidUnitTest/kotlin/androidx/compose/ui/text/SaversTest.kt
+++ b/compose/ui/ui-text/src/androidUnitTest/kotlin/androidx/compose/ui/text/SaversTest.kt
@@ -46,16 +46,17 @@ class SaversTest {
     @Test
     fun test_TextUnit() {
         val original = 2.sp
-        val saved = with(TextUnit.Saver) { defaultSaverScope.save(original) }
+        val saved = save(original, TextUnit.Saver, defaultSaverScope)
+        val restored: TextUnit? = restore(saved, TextUnit.Saver)
 
-        assertThat(TextUnit.Saver.restore(saved!!)).isEqualTo(original)
+        assertThat(restored).isEqualTo(original)
     }
 
     @Test
     fun test_TextUnit_unspecified() {
         val original = TextUnit.Unspecified
-        val saved = with(TextUnit.Saver) { defaultSaverScope.save(original) }
-        val restored = TextUnit.Saver.restore(saved!!)
+        val saved = save(original, TextUnit.Saver, defaultSaverScope)
+        val restored: TextUnit? = restore(saved, TextUnit.Saver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -63,16 +64,17 @@ class SaversTest {
     @Test
     fun test_Offset() {
         val original = Offset(10f, 10f)
-        val saved = with(Offset.Saver) { defaultSaverScope.save(original) }
+        val saved = save(original, Offset.Saver, defaultSaverScope)
+        val restored: Offset? = restore(saved, Offset.Saver)
 
-        assertThat(Offset.Saver.restore(saved!!)).isEqualTo(original)
+        assertThat(restored).isEqualTo(original)
     }
 
     @Test
     fun test_Offset_Unspecified() {
         val original = Offset.Unspecified
-        val saved = with(Offset.Saver) { defaultSaverScope.save(original) }
-        val restored = Offset.Saver.restore(saved!!)
+        val saved = save(original, Offset.Saver, defaultSaverScope)
+        val restored: Offset? = restore(saved, Offset.Saver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -80,8 +82,8 @@ class SaversTest {
     @Test
     fun test_Offset_Infinite() {
         val original = Offset.Infinite
-        val saved = with(Offset.Saver) { defaultSaverScope.save(original) }
-        val restored = Offset.Saver.restore(saved!!)
+        val saved = save(original, Offset.Saver, defaultSaverScope)
+        val restored: Offset? = restore(saved, Offset.Saver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -89,16 +91,17 @@ class SaversTest {
     @Test
     fun test_Color() {
         val original = Color.Yellow
-        val saved = with(Color.Saver) { defaultSaverScope.save(original) }
+        val saved = save(original, Color.Saver, defaultSaverScope)
+        val restored: Color? = restore(saved, Color.Saver)
 
-        assertThat(Color.Saver.restore(saved!!)).isEqualTo(original)
+        assertThat(restored).isEqualTo(original)
     }
 
     @Test
     fun test_Color_Unspecified() {
         val original = Color.Unspecified
-        val saved = with(Color.Saver) { defaultSaverScope.save(original) }
-        val restored = Color.Saver.restore(saved!!)
+        val saved = save(original, Color.Saver, defaultSaverScope)
+        val restored: Color? = restore(saved, Color.Saver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -106,8 +109,8 @@ class SaversTest {
     @Test
     fun test_Shadow() {
         val original = Shadow(color = Color.Blue, offset = Offset(5f, 5f), blurRadius = 2f)
-        val saved = with(Shadow.Saver) { defaultSaverScope.save(original) }
-        val restored = Shadow.Saver.restore(saved!!)
+        val saved = save(original, Shadow.Saver, defaultSaverScope)
+        val restored: Shadow? = restore(saved, Shadow.Saver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -115,8 +118,8 @@ class SaversTest {
     @Test
     fun test_Shadow_None() {
         val original = Shadow.None
-        val saved = with(Shadow.Saver) { defaultSaverScope.save(original) }
-        val restored = Shadow.Saver.restore(saved!!)
+        val saved = save(original, Shadow.Saver, defaultSaverScope)
+        val restored: Shadow? = restore(saved, Shadow.Saver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -124,8 +127,8 @@ class SaversTest {
     @Test
     fun test_ParagraphStyle() {
         val original = ParagraphStyle()
-        val saved = with(ParagraphStyleSaver) { defaultSaverScope.save(original) }
-        val restored = ParagraphStyleSaver.restore(saved!!)
+        val saved = save(original, ParagraphStyleSaver, defaultSaverScope)
+        val restored: ParagraphStyle? = restore(saved, ParagraphStyleSaver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -133,8 +136,8 @@ class SaversTest {
     @Test
     fun test_ParagraphStyle_with_a_nonnull_value() {
         val original = ParagraphStyle(textDirection = TextDirection.Rtl)
-        val saved = with(ParagraphStyleSaver) { defaultSaverScope.save(original) }
-        val restored = ParagraphStyleSaver.restore(saved!!)
+        val saved = save(original, ParagraphStyleSaver, defaultSaverScope)
+        val restored: ParagraphStyle? = restore(saved, ParagraphStyleSaver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -147,8 +150,8 @@ class SaversTest {
             lineHeight = 10.sp,
             textIndent = TextIndent(firstLine = 2.sp, restLine = 3.sp)
         )
-        val saved = with(ParagraphStyleSaver) { defaultSaverScope.save(original) }
-        val restored = ParagraphStyleSaver.restore(saved!!)
+        val saved = save(original, ParagraphStyleSaver, defaultSaverScope)
+        val restored: ParagraphStyle? = restore(saved, ParagraphStyleSaver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -156,8 +159,8 @@ class SaversTest {
     @Test
     fun test_SpanStyle() {
         val original = SpanStyle()
-        val saved = with(SpanStyleSaver) { defaultSaverScope.save(original) }
-        val restored = SpanStyleSaver.restore(saved!!)
+        val saved = save(original, SpanStyleSaver, defaultSaverScope)
+        val restored: SpanStyle? = restore(saved, SpanStyleSaver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -165,8 +168,8 @@ class SaversTest {
     @Test
     fun test_SpanStyle_with_a_nonnull_value() {
         val original = SpanStyle(baselineShift = BaselineShift.Subscript)
-        val saved = with(SpanStyleSaver) { defaultSaverScope.save(original) }
-        val restored = SpanStyleSaver.restore(saved!!)
+        val saved = save(original, SpanStyleSaver, defaultSaverScope)
+        val restored: SpanStyle? = restore(saved, SpanStyleSaver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -193,8 +196,8 @@ class SaversTest {
             textDecoration = TextDecoration.LineThrough,
             shadow = Shadow(color = Color.Red, offset = Offset(2f, 2f), blurRadius = 4f)
         )
-        val saved = with(SpanStyleSaver) { defaultSaverScope.save(original) }
-        val restored = SpanStyleSaver.restore(saved!!)
+        val saved = save(original, SpanStyleSaver, defaultSaverScope)
+        val restored: SpanStyle? = restore(saved, SpanStyleSaver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -202,33 +205,35 @@ class SaversTest {
     @Test
     fun test_FontWeight() {
         val original = FontWeight(123)
-        val saved = with(FontWeight.Saver) { defaultSaverScope.save(original) }
+        val saved = save(original, FontWeight.Saver, defaultSaverScope)
+        val restored: FontWeight? = restore(saved, FontWeight.Saver)
 
-        assertThat(FontWeight.Saver.restore(saved!!)).isEqualTo(original)
+        assertThat(restored).isEqualTo(original)
     }
 
     @Test
     fun test_FontWeight_w100() {
         val original = FontWeight.W100
-        val saved = with(FontWeight.Saver) { defaultSaverScope.save(original) }
+        val saved = save(original, FontWeight.Saver, defaultSaverScope)
+        val restored: FontWeight? = restore(saved, FontWeight.Saver)
 
-        val restored = FontWeight.Saver.restore(saved!!)
         assertThat(restored).isEqualTo(original)
     }
 
     @Test
     fun test_BaselineShift() {
         val original = BaselineShift(2f)
-        val saved = with(BaselineShift.Saver) { defaultSaverScope.save(original) }
+        val saved = save(original, BaselineShift.Saver, defaultSaverScope)
+        val restored: BaselineShift? = restore(saved, BaselineShift.Saver)
 
-        assertThat(BaselineShift.Saver.restore(saved!!)).isEqualTo(original)
+        assertThat(restored).isEqualTo(original)
     }
 
     @Test
     fun test_BaselineShift_None() {
         val original = BaselineShift.None
-        val saved = with(BaselineShift.Saver) { defaultSaverScope.save(original) }
-        val restored = BaselineShift.Saver.restore(saved!!)
+        val saved = save(original, BaselineShift.Saver, defaultSaverScope)
+        val restored: BaselineShift? = restore(saved, BaselineShift.Saver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -238,25 +243,26 @@ class SaversTest {
         val original = TextDecoration.combine(
             listOf(TextDecoration.LineThrough, TextDecoration.Underline)
         )
-        val saved = with(TextDecoration.Saver) { defaultSaverScope.save(original) }
+        val saved = save(original, TextDecoration.Saver, defaultSaverScope)
+        val restored: TextDecoration? = restore(saved, TextDecoration.Saver)
 
-        assertThat(TextDecoration.Saver.restore(saved!!)).isEqualTo(original)
+        assertThat(restored).isEqualTo(original)
     }
 
     @Test
     fun test_TextDecoration_None() {
         val original = TextDecoration.None
-        val saved = with(TextDecoration.Saver) { defaultSaverScope.save(original) }
+        val saved = save(original, TextDecoration.Saver, defaultSaverScope)
+        val restored: TextDecoration? = restore(saved, TextDecoration.Saver)
 
-        val restored = TextDecoration.Saver.restore(saved!!)
         assertThat(restored).isEqualTo(original)
     }
 
     @Test
     fun testSaveRestore_lineThrough() {
         val original = TextDecoration.LineThrough
-        val saved = with(TextDecoration.Saver) { defaultSaverScope.save(original) }
-        val restored = TextDecoration.Saver.restore(saved!!)
+        val saved = save(original, TextDecoration.Saver, defaultSaverScope)
+        val restored: TextDecoration? = restore(saved, TextDecoration.Saver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -264,8 +270,8 @@ class SaversTest {
     @Test
     fun testSaveRestore_underline() {
         val original = TextDecoration.Underline
-        val saved = with(TextDecoration.Saver) { defaultSaverScope.save(original) }
-        val restored = TextDecoration.Saver.restore(saved!!)
+        val saved = save(original, TextDecoration.Saver, defaultSaverScope)
+        val restored: TextDecoration? = restore(saved, TextDecoration.Saver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -273,16 +279,17 @@ class SaversTest {
     @Test
     fun test_TextGeometricTransform() {
         val original = TextGeometricTransform(1f, 2f)
-        val saved = with(TextGeometricTransform.Saver) { defaultSaverScope.save(original) }
+        val saved = save(original, TextGeometricTransform.Saver, defaultSaverScope)
+        val restored: TextGeometricTransform? = restore(saved, TextGeometricTransform.Saver)
 
-        assertThat(TextGeometricTransform.Saver.restore(saved!!)).isEqualTo(original)
+        assertThat(restored).isEqualTo(original)
     }
 
     @Test
     fun test_TextGeometricTransform_None() {
         val original = TextGeometricTransform.None
-        val saved = with(TextGeometricTransform.Saver) { defaultSaverScope.save(original) }
-        val restored = TextGeometricTransform.Saver.restore(saved!!)
+        val saved = save(original, TextGeometricTransform.Saver, defaultSaverScope)
+        val restored: TextGeometricTransform? = restore(saved, TextGeometricTransform.Saver)
 
         assertThat(restored).isEqualTo(original)
     }
@@ -290,16 +297,17 @@ class SaversTest {
     @Test
     fun test_TextIndent() {
         val original = TextIndent(1.sp, 2.sp)
-        val saved = with(TextIndent.Saver) { defaultSaverScope.save(original) }
+        val saved = save(original, TextIndent.Saver, defaultSaverScope)
+        val restored: TextIndent? = restore(saved, TextIndent.Saver)
 
-        assertThat(TextIndent.Saver.restore(saved!!)).isEqualTo(original)
+        assertThat(restored).isEqualTo(original)
     }
 
     @Test
     fun test_TextIndent_None() {
         val original = TextIndent.None
-        val saved = with(TextIndent.Saver) { defaultSaverScope.save(original) }
-        val restored = TextIndent.Saver.restore(saved!!)
+        val saved = save(original, TextIndent.Saver, defaultSaverScope)
+        val restored: TextIndent? = restore(saved, TextIndent.Saver)
 
         assertThat(restored).isEqualTo(original)
     }
diff --git a/compose/ui/ui-text/src/commonMain/kotlin/androidx/compose/ui/text/Savers.kt b/compose/ui/ui-text/src/commonMain/kotlin/androidx/compose/ui/text/Savers.kt
index 52ae36990dd..298553d6e4c 100644
--- a/compose/ui/ui-text/src/commonMain/kotlin/androidx/compose/ui/text/Savers.kt
+++ b/compose/ui/ui-text/src/commonMain/kotlin/androidx/compose/ui/text/Savers.kt
@@ -21,6 +21,8 @@ import androidx.compose.runtime.saveable.SaverScope
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.Shadow
+import androidx.compose.ui.graphics.isUnspecified
+import androidx.compose.ui.graphics.toArgb
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.intl.Locale
 import androidx.compose.ui.text.intl.LocaleList
@@ -28,7 +30,6 @@ import androidx.compose.ui.text.style.BaselineShift
 import androidx.compose.ui.text.style.TextDecoration
 import androidx.compose.ui.text.style.TextGeometricTransform
 import androidx.compose.ui.text.style.TextIndent
-import androidx.compose.ui.unit.ExperimentalUnitApi
 import androidx.compose.ui.unit.TextUnit
 import androidx.compose.ui.util.fastMap
 
@@ -52,11 +53,31 @@ internal inline fun <T : Saver<Original, Saveable>, Original, Saveable, reified
     value: Saveable?,
     saver: T
 ): Result? {
-    if (value == false) return null
+    // Most of the types we save are nullable. However, value classes are usually not but instead
+    // have a special Unspecified value. In that case we delegate handling of the "false"
+    // value restoration to the corresponding saver that will restore "false" as an Unspecified
+    // of the corresponding type.
+    if (value == false && saver !is NonNullValueClassSaver<*, *>) return null
     return value?.let { with(saver) { restore(value) } as Result }
 }
 
 /**
+ * Use for non-null value classes where the Unspecified value needs to be separately handled,
+ * for example as in the [OffsetSaver]
+ */
+private interface NonNullValueClassSaver<Original, Saveable : Any> : Saver<Original, Saveable>
+private fun <Original, Saveable : Any> NonNullValueClassSaver(
+    save: SaverScope.(value: Original) -> Saveable?,
+    restore: (value: Saveable) -> Original?
+): NonNullValueClassSaver<Original, Saveable> {
+    return object : NonNullValueClassSaver<Original, Saveable> {
+        override fun SaverScope.save(value: Original) = save.invoke(this, value)
+
+        override fun restore(value: Saveable) = restore.invoke(value)
+    }
+}
+
+/**
  * Utility function to save nullable values that does not require a Saver.
  */
 internal fun <T> save(value: T?): T? {
@@ -355,30 +376,41 @@ private val ShadowSaver = Saver<Shadow, Any>(
 internal val Color.Companion.Saver: Saver<Color, Any>
     get() = ColorSaver
 
-private val ColorSaver = Saver<Color, Any>(
-    save = { it.value },
-    restore = { Color(it as ULong) }
+private val ColorSaver = NonNullValueClassSaver<Color, Any>(
+    save = {
+        if (it.isUnspecified) { false } else { it.toArgb() }
+    },
+    restore = {
+        if (it == false) { Color.Unspecified } else { Color(it as Int) }
+    }
 )
 
 internal val TextUnit.Companion.Saver: Saver<TextUnit, Any>
     get() = TextUnitSaver
 
-@OptIn(ExperimentalUnitApi::class)
-private val TextUnitSaver = Saver<TextUnit, Any>(
+private val TextUnitSaver = NonNullValueClassSaver<TextUnit, Any>(
     save = {
-        arrayListOf(save(it.value), save(it.type))
+        if (it == TextUnit.Unspecified) {
+            false
+        } else {
+            arrayListOf(save(it.value), save(it.type))
+        }
     },
     restore = {
-        @Suppress("UNCHECKED_CAST")
-        val list = it as List<Any>
-        TextUnit(restore(list[0])!!, restore(list[1])!!)
+        if (it == false) {
+            TextUnit.Unspecified
+        } else {
+            @Suppress("UNCHECKED_CAST")
+            val list = it as List<Any>
+            TextUnit(restore(list[0])!!, restore(list[1])!!)
+        }
     }
 )
 
 internal val Offset.Companion.Saver: Saver<Offset, Any>
     get() = OffsetSaver
 
-private val OffsetSaver = Saver<Offset, Any>(
+private val OffsetSaver = NonNullValueClassSaver<Offset, Any>(
     save = {
         if (it == Offset.Unspecified) {
             false