[Motion] Open MotionUtils and update resolveThemeInterpolator to load…

… both new and legacy easing attributes.

PiperOrigin-RevId: 441806915

lib/java/com/google/android/material/motion/MotionUtils.java

@@ -15,24 +15,17 @@
  */
 package com.google.android.material.motion;
 
-import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP;
-
 import android.animation.TimeInterpolator;
 import android.content.Context;
 import android.util.TypedValue;
+import android.view.animation.AnimationUtils;
 import androidx.annotation.AttrRes;
 import androidx.annotation.NonNull;
-import androidx.annotation.RestrictTo;
 import androidx.core.graphics.PathParser;
 import androidx.core.view.animation.PathInterpolatorCompat;
 import com.google.android.material.resources.MaterialAttributes;
 
-/**
- * A utility class for motion system functions.
- *
- * @hide
- */
-@RestrictTo(LIBRARY_GROUP)
+/** A utility class for motion system functions. */
 public class MotionUtils {
 
   // Constants corresponding to motionEasing* theme attr values.
@@ -43,61 +36,96 @@ public class MotionUtils {
 
   private MotionUtils() {}
 
+  /**
+   * Resolve a duration from a material duration theme attribute.
+   *
+   * @param context the context from where the theme attribute will be resolved.
+   * @param attrResId the {@code motionDuration*} theme attribute to resolve
+   * @param defaultDuration the duration to be returned if unable to resolve {@code attrResId}
+   * @return the resolved {@code int} duration which {@code attrResId} points to or the {@code
+   *     defaultDuration} if resolution was unsuccessful.
+   */
   public static int resolveThemeDuration(
       @NonNull Context context, @AttrRes int attrResId, int defaultDuration) {
     return MaterialAttributes.resolveInteger(context, attrResId, defaultDuration);
   }
 
+  /**
+   * Load an interpolator from a material easing theme attribute.
+   *
+   * @param context context from where the theme attribute will be resolved
+   * @param attrResId the {@code motionEasing*} theme attribute to resolve
+   * @param defaultInterpolator the interpolator to be returned if unable to resolve {@code
+   *     attrResId}.
+   * @return the resolved {@link TimeInterpolator} which {@code attrResId} points to or the {@code
+   *     defaultInterpolator} if resolution was unsuccessful.
+   */
   @NonNull
   public static TimeInterpolator resolveThemeInterpolator(
       @NonNull Context context,
       @AttrRes int attrResId,
       @NonNull TimeInterpolator defaultInterpolator) {
     TypedValue easingValue = new TypedValue();
-    if (context.getTheme().resolveAttribute(attrResId, easingValue, true)) {
-      if (easingValue.type != TypedValue.TYPE_STRING) {
-        throw new IllegalArgumentException("Motion easing theme attribute must be a string");
-      }
+    if (!context.getTheme().resolveAttribute(attrResId, easingValue, true)) {
+      return defaultInterpolator;
+    }
 
-      String easingString = String.valueOf(easingValue.string);
+    if (easingValue.type != TypedValue.TYPE_STRING) {
+      throw new IllegalArgumentException(
+          "Motion easing theme attribute must be an @interpolator resource for"
+              + " ?attr/motionEasing*Interpolator attributes or a string for"
+              + " ?attr/motionEasing* attributes.");
+    }
 
-      if (isEasingType(easingString, EASING_TYPE_CUBIC_BEZIER)) {
-        String controlPointsString = getEasingContent(easingString, EASING_TYPE_CUBIC_BEZIER);
-        String[] controlPoints = controlPointsString.split(",");
-        if (controlPoints.length != 4) {
-          throw new IllegalArgumentException(
-              "Motion easing theme attribute must have 4 control points if using bezier curve"
-                  + " format; instead got: "
-                  + controlPoints.length);
-        }
+    String easingString = String.valueOf(easingValue.string);
+    if (isLegacyEasingAttribute(easingString)) {
+      return getLegacyThemeInterpolator(easingString);
+    }
+
+    return AnimationUtils.loadInterpolator(context, easingValue.resourceId);
+  }
 
-        float controlX1 = getControlPoint(controlPoints, 0);
-        float controlY1 = getControlPoint(controlPoints, 1);
-        float controlX2 = getControlPoint(controlPoints, 2);
-        float controlY2 = getControlPoint(controlPoints, 3);
-        return PathInterpolatorCompat.create(controlX1, controlY1, controlX2, controlY2);
-      } else if (isEasingType(easingString, EASING_TYPE_PATH)) {
-        String path = getEasingContent(easingString, EASING_TYPE_PATH);
-        return PathInterpolatorCompat.create(PathParser.createPathFromPathData(path));
-      } else {
-        throw new IllegalArgumentException("Invalid motion easing type: " + easingString);
+  private static TimeInterpolator getLegacyThemeInterpolator(String easingString) {
+    if (isLegacyEasingType(easingString, EASING_TYPE_CUBIC_BEZIER)) {
+      String controlPointsString = getLegacyEasingContent(easingString, EASING_TYPE_CUBIC_BEZIER);
+      String[] controlPoints = controlPointsString.split(",");
+      if (controlPoints.length != 4) {
+        throw new IllegalArgumentException(
+            "Motion easing theme attribute must have 4 control points if using bezier curve"
+                + " format; instead got: "
+                + controlPoints.length);
       }
+
+      float controlX1 = getLegacyControlPoint(controlPoints, 0);
+      float controlY1 = getLegacyControlPoint(controlPoints, 1);
+      float controlX2 = getLegacyControlPoint(controlPoints, 2);
+      float controlY2 = getLegacyControlPoint(controlPoints, 3);
+      return PathInterpolatorCompat.create(controlX1, controlY1, controlX2, controlY2);
+    } else if (isLegacyEasingType(easingString, EASING_TYPE_PATH)) {
+      String path = getLegacyEasingContent(easingString, EASING_TYPE_PATH);
+      return PathInterpolatorCompat.create(PathParser.createPathFromPathData(path));
+    } else {
+      throw new IllegalArgumentException("Invalid motion easing type: " + easingString);
     }
-    return defaultInterpolator;
   }
 
-  private static boolean isEasingType(String easingString, String easingType) {
+  private static boolean isLegacyEasingAttribute(String easingString) {
+    return isLegacyEasingType(easingString, EASING_TYPE_CUBIC_BEZIER)
+        || isLegacyEasingType(easingString, EASING_TYPE_PATH);
+  }
+
+  private static boolean isLegacyEasingType(String easingString, String easingType) {
     return easingString.startsWith(easingType + EASING_TYPE_FORMAT_START)
         && easingString.endsWith(EASING_TYPE_FORMAT_END);
   }
 
-  private static String getEasingContent(String easingString, String easingType) {
+  private static String getLegacyEasingContent(String easingString, String easingType) {
     return easingString.substring(
         easingType.length() + EASING_TYPE_FORMAT_START.length(),
         easingString.length() - EASING_TYPE_FORMAT_END.length());
   }
 
-  private static float getControlPoint(String[] controlPoints, int index) {
+  private static float getLegacyControlPoint(String[] controlPoints, int index) {
     float controlPoint = Float.parseFloat(controlPoints[index]);
     if (controlPoint < 0 || controlPoint > 1) {
       throw new IllegalArgumentException(

lib/javatests/com/google/android/material/motion/AndroidManifest.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Copyright 2022 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.
+  -->
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+  xmlns:tools="http://schemas.android.com/tools"
+  package="com.google.android.material.motion">
+
+  <uses-sdk
+    tools:overrideLibrary="androidx.test.core"/>
+
+  <application android:theme="@style/Theme.Material3.DayNight.NoActionBar"/>
+</manifest>

lib/javatests/com/google/android/material/motion/MotionUtilsTest.java

@@ -0,0 +1,150 @@
+/*
+ * Copyright (C) 2022 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.google.android.material.motion;
+
+import com.google.android.material.R;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.animation.TimeInterpolator;
+import android.os.Build.VERSION_CODES;
+import androidx.appcompat.app.AppCompatActivity;
+import android.view.animation.Interpolator;
+import android.view.animation.LinearInterpolator;
+import android.view.animation.PathInterpolator;
+import androidx.annotation.RequiresApi;
+import androidx.test.core.app.ApplicationProvider;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.junit.runner.RunWith;
+import org.robolectric.Robolectric;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.android.controller.ActivityController;
+import org.robolectric.annotation.Config;
+import org.robolectric.annotation.internal.DoNotInstrument;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(sdk = VERSION_CODES.LOLLIPOP)
+@DoNotInstrument
+@RequiresApi(api = VERSION_CODES.LOLLIPOP)
+public class MotionUtilsTest {
+
+  private ActivityController<AppCompatActivity> activityController;
+
+  @Rule public final ExpectedException thrown = ExpectedException.none();
+
+  @Test
+  public void testResolvesThemeInterpolator() {
+    assertThemeInterpolatorIsInstanceOf(
+        R.style.Theme_Material3_DayNight,
+        R.attr.motionEasingStandardInterpolator,
+        LinearInterpolator.class);
+  }
+
+  @Test
+  public void testCustomInterpolator_resolvesThemeInterpolator() {
+    assertThemeInterpolatorIsInstanceOf(
+        R.style.Theme_Material3_DayNight_CustomInterpolator,
+        R.attr.motionEasingStandardInterpolator,
+        LinearInterpolator.class);
+  }
+
+  @Test
+  public void testCustomAnimInterpolator_resolvesThemeInterpolator() {
+    assertThemeInterpolatorIsInstanceOf(
+        R.style.Theme_Material3_DayNight_CustomAnimInterpolator,
+        R.attr.motionEasingStandardInterpolator,
+        LinearInterpolator.class);
+  }
+
+  @Test
+  public void testResolvesLegacyInterpolator() {
+    assertThemeInterpolatorIsInstanceOf(
+        R.style.Theme_Material3_DayNight, R.attr.motionEasingStandard, PathInterpolator.class);
+  }
+
+  @Test
+  public void testMaterialComponentsTheme_resolveUnavailableInterpolatorReturnsDefault() {
+    createActivityAndSetTheme(R.style.Theme_MaterialComponents_DayNight);
+
+    DefaultDummyInterpolator defaultInterpolator = new DefaultDummyInterpolator();
+    TimeInterpolator standardInterpolator =
+        MotionUtils.resolveThemeInterpolator(
+            activityController.get().getApplicationContext(),
+            R.attr.motionEasingStandardInterpolator,
+            defaultInterpolator);
+    assertThat(standardInterpolator).isEqualTo(defaultInterpolator);
+  }
+
+  @Test
+  public void testMaterialComponentsTheme_resolvesLegacyInterpolator() {
+    assertThemeInterpolatorIsInstanceOf(
+        R.style.Theme_MaterialComponents_DayNight,
+        R.attr.motionEasingStandard,
+        PathInterpolator.class);
+  }
+
+  @Test
+  public void testMaterialComponentsThemeIncorrectLegacyAttrType_shouldThrowException() {
+    createActivityAndSetTheme(
+        R.style.Theme_MaterialComponents_DayNight_IncorrectLegacyEasingAttrType);
+
+    // ThrowingRunnable used by assertThrows is not available until gradle 4.13
+    thrown.expect(IllegalArgumentException.class);
+    MotionUtils.resolveThemeInterpolator(
+        activityController.get().getApplicationContext(),
+        R.attr.motionEasingStandard,
+        new DefaultDummyInterpolator());
+  }
+
+  @Test
+  public void testMaterialComponentsThemeIncorrectLegacyFormatting_shouldThrowException() {
+    createActivityAndSetTheme(
+        R.style.Theme_MaterialComponents_DayNight_IncorrectLegacyEasingFormat);
+
+    // ThrowingRunnable used by assertThrows is not available until gradle 4.13
+    thrown.expect(IllegalArgumentException.class);
+    MotionUtils.resolveThemeInterpolator(
+        activityController.get().getApplicationContext(),
+        R.attr.motionEasingStandard,
+        new DefaultDummyInterpolator());
+  }
+
+  private void createActivityAndSetTheme(int themeId) {
+    ApplicationProvider.getApplicationContext().setTheme(themeId);
+    activityController = Robolectric.buildActivity(AppCompatActivity.class).create();
+  }
+
+  private void assertThemeInterpolatorIsInstanceOf(int theme, int attrId, Class<?> expectedClass) {
+    createActivityAndSetTheme(theme);
+    DefaultDummyInterpolator defaultInterpolator = new DefaultDummyInterpolator();
+    TimeInterpolator themeInterpolator =
+        MotionUtils.resolveThemeInterpolator(
+            activityController.get().getApplicationContext(), attrId, defaultInterpolator);
+    assertThat(themeInterpolator).isNotEqualTo(defaultInterpolator);
+    // Robolectric's shadow of Android's AnimationUtils always returns a LinearInterpolator.
+    assertThat(themeInterpolator).isInstanceOf(expectedClass);
+  }
+
+  private static class DefaultDummyInterpolator implements Interpolator {
+    @Override
+    public float getInterpolation(float input) {
+      return 0;
+    }
+  }
+}

lib/javatests/com/google/android/material/motion/res/anim/custom_anim_interpolator.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  Copyright 2022 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.
+  -->
+
+<accelerateInterpolator
+  xmlns:android="http://schemas.android.com/apk/res/android"
+  android:factor="2" />

lib/javatests/com/google/android/material/motion/res/interpolator/custom_interpolator.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  Copyright 2022 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.
+  -->
+
+<pathInterpolator xmlns:android="http://schemas.android.com/apk/res/android"
+  android:controlX1="0.0"
+  android:controlX2="0.7"
+  android:controlY1="0.5"
+  android:controlY2="1.0" />

lib/javatests/com/google/android/material/motion/res/values/colors.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Copyright 2022 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.
+  -->
+<resources>
+  <color name="color_primary">#FFFFFF</color>
+</resources>