Merge "Add easing parameter for fractionRange and timestampRange" into main
diff --git a/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/TransitionDsl.kt b/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/TransitionDsl.kt
index a30b780..79b3856 100644
--- a/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/TransitionDsl.kt
+++ b/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/TransitionDsl.kt
@@ -17,6 +17,8 @@
 package com.android.compose.animation.scene
 
 import androidx.compose.animation.core.AnimationSpec
+import androidx.compose.animation.core.Easing
+import androidx.compose.animation.core.LinearEasing
 import androidx.compose.animation.core.SpringSpec
 import androidx.compose.foundation.gestures.Orientation
 import androidx.compose.ui.geometry.Offset
@@ -140,6 +142,7 @@
     fun fractionRange(
         start: Float? = null,
         end: Float? = null,
+        easing: Easing = LinearEasing,
         builder: PropertyTransformationBuilder.() -> Unit,
     )
 }
@@ -182,6 +185,7 @@
     fun timestampRange(
         startMillis: Int? = null,
         endMillis: Int? = null,
+        easing: Easing = LinearEasing,
         builder: PropertyTransformationBuilder.() -> Unit,
     )
 
diff --git a/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/TransitionDslImpl.kt b/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/TransitionDslImpl.kt
index 6515cb8..a63b19a 100644
--- a/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/TransitionDslImpl.kt
+++ b/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/TransitionDslImpl.kt
@@ -18,6 +18,7 @@
 
 import androidx.compose.animation.core.AnimationSpec
 import androidx.compose.animation.core.DurationBasedAnimationSpec
+import androidx.compose.animation.core.Easing
 import androidx.compose.animation.core.Spring
 import androidx.compose.animation.core.SpringSpec
 import androidx.compose.animation.core.VectorConverter
@@ -163,9 +164,10 @@
     override fun fractionRange(
         start: Float?,
         end: Float?,
+        easing: Easing,
         builder: PropertyTransformationBuilder.() -> Unit
     ) {
-        range = TransformationRange(start, end)
+        range = TransformationRange(start, end, easing)
         builder()
         range = null
     }
@@ -251,6 +253,7 @@
     override fun timestampRange(
         startMillis: Int?,
         endMillis: Int?,
+        easing: Easing,
         builder: PropertyTransformationBuilder.() -> Unit
     ) {
         if (startMillis != null && (startMillis < 0 || startMillis > durationMillis)) {
@@ -263,7 +266,7 @@
 
         val start = startMillis?.let { it.toFloat() / durationMillis }
         val end = endMillis?.let { it.toFloat() / durationMillis }
-        fractionRange(start, end, builder)
+        fractionRange(start, end, easing, builder)
     }
 }
 
diff --git a/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/transformation/Transformation.kt b/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/transformation/Transformation.kt
index 77ec891..eda8ede 100644
--- a/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/transformation/Transformation.kt
+++ b/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/transformation/Transformation.kt
@@ -16,6 +16,8 @@
 
 package com.android.compose.animation.scene.transformation
 
+import androidx.compose.animation.core.Easing
+import androidx.compose.animation.core.LinearEasing
 import androidx.compose.ui.util.fastCoerceAtLeast
 import androidx.compose.ui.util.fastCoerceAtMost
 import androidx.compose.ui.util.fastCoerceIn
@@ -90,11 +92,13 @@
 data class TransformationRange(
     val start: Float,
     val end: Float,
+    val easing: Easing,
 ) {
     constructor(
         start: Float? = null,
-        end: Float? = null
-    ) : this(start ?: BoundUnspecified, end ?: BoundUnspecified)
+        end: Float? = null,
+        easing: Easing = LinearEasing,
+    ) : this(start ?: BoundUnspecified, end ?: BoundUnspecified, easing)
 
     init {
         require(!start.isSpecified() || (start in 0f..1f))
@@ -103,17 +107,20 @@
     }
 
     /** Reverse this range. */
-    fun reversed() = TransformationRange(start = reverseBound(end), end = reverseBound(start))
+    fun reversed() =
+        TransformationRange(start = reverseBound(end), end = reverseBound(start), easing = easing)
 
     /** Get the progress of this range given the global [transitionProgress]. */
     fun progress(transitionProgress: Float): Float {
-        return when {
-            start.isSpecified() && end.isSpecified() ->
-                ((transitionProgress - start) / (end - start)).fastCoerceIn(0f, 1f)
-            !start.isSpecified() && !end.isSpecified() -> transitionProgress
-            end.isSpecified() -> (transitionProgress / end).fastCoerceAtMost(1f)
-            else -> ((transitionProgress - start) / (1f - start)).fastCoerceAtLeast(0f)
-        }
+        val progress =
+            when {
+                start.isSpecified() && end.isSpecified() ->
+                    ((transitionProgress - start) / (end - start)).fastCoerceIn(0f, 1f)
+                !start.isSpecified() && !end.isSpecified() -> transitionProgress
+                end.isSpecified() -> (transitionProgress / end).fastCoerceAtMost(1f)
+                else -> ((transitionProgress - start) / (1f - start)).fastCoerceAtLeast(0f)
+            }
+        return easing.transform(progress)
     }
 
     private fun Float.isSpecified() = this != BoundUnspecified
diff --git a/packages/SystemUI/compose/scene/tests/src/com/android/compose/animation/scene/TransitionDslTest.kt b/packages/SystemUI/compose/scene/tests/src/com/android/compose/animation/scene/TransitionDslTest.kt
index 68240b5..bed6cef 100644
--- a/packages/SystemUI/compose/scene/tests/src/com/android/compose/animation/scene/TransitionDslTest.kt
+++ b/packages/SystemUI/compose/scene/tests/src/com/android/compose/animation/scene/TransitionDslTest.kt
@@ -16,6 +16,7 @@
 
 package com.android.compose.animation.scene
 
+import androidx.compose.animation.core.CubicBezierEasing
 import androidx.compose.animation.core.SpringSpec
 import androidx.compose.animation.core.TweenSpec
 import androidx.compose.animation.core.spring
@@ -107,6 +108,13 @@
                 fractionRange(start = 0.1f, end = 0.8f) { fade(TestElements.Foo) }
                 fractionRange(start = 0.2f) { fade(TestElements.Foo) }
                 fractionRange(end = 0.9f) { fade(TestElements.Foo) }
+                fractionRange(
+                    start = 0.1f,
+                    end = 0.8f,
+                    easing = CubicBezierEasing(0.1f, 0.1f, 0f, 1f)
+                ) {
+                    fade(TestElements.Foo)
+                }
             }
         }
 
@@ -118,6 +126,11 @@
                 TransformationRange(start = 0.1f, end = 0.8f),
                 TransformationRange(start = 0.2f, end = TransformationRange.BoundUnspecified),
                 TransformationRange(start = TransformationRange.BoundUnspecified, end = 0.9f),
+                TransformationRange(
+                    start = 0.1f,
+                    end = 0.8f,
+                    CubicBezierEasing(0.1f, 0.1f, 0f, 1f)
+                ),
             )
     }
 
@@ -130,6 +143,13 @@
                 timestampRange(startMillis = 100, endMillis = 300) { fade(TestElements.Foo) }
                 timestampRange(startMillis = 200) { fade(TestElements.Foo) }
                 timestampRange(endMillis = 400) { fade(TestElements.Foo) }
+                timestampRange(
+                    startMillis = 100,
+                    endMillis = 300,
+                    easing = CubicBezierEasing(0.1f, 0.1f, 0f, 1f)
+                ) {
+                    fade(TestElements.Foo)
+                }
             }
         }
 
@@ -141,6 +161,11 @@
                 TransformationRange(start = 100 / 500f, end = 300 / 500f),
                 TransformationRange(start = 200 / 500f, end = TransformationRange.BoundUnspecified),
                 TransformationRange(start = TransformationRange.BoundUnspecified, end = 400 / 500f),
+                TransformationRange(
+                    start = 100 / 500f,
+                    end = 300 / 500f,
+                    easing = CubicBezierEasing(0.1f, 0.1f, 0f, 1f)
+                ),
             )
     }
 
diff --git a/packages/SystemUI/compose/scene/tests/src/com/android/compose/animation/scene/transformation/EasingTest.kt b/packages/SystemUI/compose/scene/tests/src/com/android/compose/animation/scene/transformation/EasingTest.kt
new file mode 100644
index 0000000..07901f2
--- /dev/null
+++ b/packages/SystemUI/compose/scene/tests/src/com/android/compose/animation/scene/transformation/EasingTest.kt
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.compose.animation.scene.transformation
+
+import androidx.compose.animation.core.CubicBezierEasing
+import androidx.compose.animation.core.LinearEasing
+import androidx.compose.animation.core.tween
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.size
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.unit.dp
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.android.compose.animation.scene.TestElements
+import com.android.compose.animation.scene.testTransition
+import com.android.compose.test.assertSizeIsEqualTo
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class EasingTest {
+    @get:Rule val rule = createComposeRule()
+
+    @Test
+    fun testFractionRangeEasing() {
+        val easing = CubicBezierEasing(0.1f, 0.1f, 0f, 1f)
+        rule.testTransition(
+            fromSceneContent = { Box(Modifier.size(100.dp).element(TestElements.Foo)) },
+            toSceneContent = { Box(Modifier.size(100.dp).element(TestElements.Bar)) },
+            transition = {
+                // Scale during 4 frames.
+                spec = tween(16 * 4, easing = LinearEasing)
+                fractionRange(easing = easing) {
+                    scaleSize(TestElements.Foo, width = 0f, height = 0f)
+                    scaleSize(TestElements.Bar, width = 0f, height = 0f)
+                }
+            },
+        ) {
+            // Foo is entering, is 100dp x 100dp at rest and is scaled by (2, 0.5) during the
+            // transition so it starts at 200dp x 50dp.
+            before { onElement(TestElements.Bar).assertDoesNotExist() }
+            at(0) {
+                onElement(TestElements.Foo).assertSizeIsEqualTo(100.dp, 100.dp)
+                onElement(TestElements.Bar).assertSizeIsEqualTo(0.dp, 0.dp)
+            }
+            at(16) {
+                // 25% linear progress is mapped to 68.5% eased progress
+                onElement(TestElements.Foo).assertSizeIsEqualTo(31.5.dp, 31.5.dp)
+                onElement(TestElements.Bar).assertSizeIsEqualTo(68.5.dp, 68.5.dp)
+            }
+            at(32) {
+                // 50% linear progress is mapped to 89.5% eased progress
+                onElement(TestElements.Foo).assertSizeIsEqualTo(10.5.dp, 10.5.dp)
+                onElement(TestElements.Bar).assertSizeIsEqualTo(89.5.dp, 89.5.dp)
+            }
+            at(48) {
+                // 75% linear progress is mapped to 97.8% eased progress
+                onElement(TestElements.Foo).assertSizeIsEqualTo(2.2.dp, 2.2.dp)
+                onElement(TestElements.Bar).assertSizeIsEqualTo(97.8.dp, 97.8.dp)
+            }
+            after {
+                onElement(TestElements.Foo).assertDoesNotExist()
+                onElement(TestElements.Bar).assertSizeIsEqualTo(100.dp, 100.dp)
+            }
+        }
+    }
+
+    @Test
+    fun testTimestampRangeEasing() {
+        val easing = CubicBezierEasing(0.1f, 0.1f, 0f, 1f)
+        rule.testTransition(
+            fromSceneContent = { Box(Modifier.size(100.dp).element(TestElements.Foo)) },
+            toSceneContent = { Box(Modifier.size(100.dp).element(TestElements.Bar)) },
+            transition = {
+                // Scale during 4 frames.
+                spec = tween(16 * 4, easing = LinearEasing)
+                timestampRange(easing = easing) {
+                    scaleSize(TestElements.Foo, width = 0f, height = 0f)
+                    scaleSize(TestElements.Bar, width = 0f, height = 0f)
+                }
+            },
+        ) {
+            // Foo is entering, is 100dp x 100dp at rest and is scaled by (2, 0.5) during the
+            // transition so it starts at 200dp x 50dp.
+            before { onElement(TestElements.Bar).assertDoesNotExist() }
+            at(0) {
+                onElement(TestElements.Foo).assertSizeIsEqualTo(100.dp, 100.dp)
+                onElement(TestElements.Bar).assertSizeIsEqualTo(0.dp, 0.dp)
+            }
+            at(16) {
+                // 25% linear progress is mapped to 68.5% eased progress
+                onElement(TestElements.Foo).assertSizeIsEqualTo(31.5.dp, 31.5.dp)
+                onElement(TestElements.Bar).assertSizeIsEqualTo(68.5.dp, 68.5.dp)
+            }
+            at(32) {
+                // 50% linear progress is mapped to 89.5% eased progress
+                onElement(TestElements.Foo).assertSizeIsEqualTo(10.5.dp, 10.5.dp)
+                onElement(TestElements.Bar).assertSizeIsEqualTo(89.5.dp, 89.5.dp)
+            }
+            at(48) {
+                // 75% linear progress is mapped to 97.8% eased progress
+                onElement(TestElements.Foo).assertSizeIsEqualTo(2.2.dp, 2.2.dp)
+                onElement(TestElements.Bar).assertSizeIsEqualTo(97.8.dp, 97.8.dp)
+            }
+            after {
+                onElement(TestElements.Foo).assertDoesNotExist()
+                onElement(TestElements.Bar).assertSizeIsEqualTo(100.dp, 100.dp)
+            }
+        }
+    }
+}