Add some stubs needed by android material library

src/api-impl/android/animation/TimeInterpolator.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2010 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 android.animation;
+
+/**
+ * A time interpolator defines the rate of change of an animation. This allows animations
+ * to have non-linear motion, such as acceleration and deceleration.
+ */
+public interface TimeInterpolator {
+	/**
+	 * Maps a value representing the elapsed fraction of an animation to a value that represents
+	 * the interpolated fraction. This interpolated value is then multiplied by the change in
+	 * value of an animation to derive the animated value at the current elapsed animation time.
+	 *
+	 * @param input A value between 0 and 1.0 indicating our current point
+	 *        in the animation where 0 represents the start and 1.0 represents
+	 *        the end
+	 * @return The interpolation value. This value can be more than 1.0 for
+	 *         interpolators which overshoot their targets, or less than 0 for
+	 *         interpolators that undershoot their targets.
+	 */
+	float getInterpolation(float input);
+}