From 3600fb7777921b24d39c34942c96553b669d73b7 Mon Sep 17 00:00:00 2001 From: Sunny Goyal Date: Wed, 4 Sep 2019 13:52:16 -0700 Subject: Adding support for building a "spring like animation" with precomputed values Bug: 138396187 Change-Id: Idba323090ecd9aca43c01414a32ab3b2e292e73e --- .../LauncherAppTransitionManagerImpl.java | 21 +- .../launcher3/anim/SpringAnimationBuilder.java | 229 +++++++++++++++++++++ 2 files changed, 238 insertions(+), 12 deletions(-) create mode 100644 src/com/android/launcher3/anim/SpringAnimationBuilder.java diff --git a/quickstep/recents_ui_overrides/src/com/android/launcher3/LauncherAppTransitionManagerImpl.java b/quickstep/recents_ui_overrides/src/com/android/launcher3/LauncherAppTransitionManagerImpl.java index 371161ebd..711594386 100644 --- a/quickstep/recents_ui_overrides/src/com/android/launcher3/LauncherAppTransitionManagerImpl.java +++ b/quickstep/recents_ui_overrides/src/com/android/launcher3/LauncherAppTransitionManagerImpl.java @@ -18,16 +18,11 @@ package com.android.launcher3; import static com.android.launcher3.LauncherAnimUtils.VIEW_TRANSLATE_X; import static com.android.launcher3.LauncherState.NORMAL; -import static com.android.launcher3.allapps.AllAppsTransitionController.ALL_APPS_PROGRESS; import static com.android.launcher3.anim.Interpolators.AGGRESSIVE_EASE; import static com.android.launcher3.anim.Interpolators.LINEAR; import static com.android.quickstep.TaskViewUtils.findTaskViewToLaunch; import static com.android.quickstep.TaskViewUtils.getRecentsWindowAnimator; -import static androidx.dynamicanimation.animation.DynamicAnimation.MIN_VISIBLE_CHANGE_PIXELS; -import static androidx.dynamicanimation.animation.SpringForce.DAMPING_RATIO_MEDIUM_BOUNCY; -import static androidx.dynamicanimation.animation.SpringForce.STIFFNESS_MEDIUM; - import android.animation.Animator; import android.animation.AnimatorListenerAdapter; import android.animation.AnimatorSet; @@ -35,18 +30,17 @@ import android.animation.ObjectAnimator; import android.content.Context; import android.view.View; -import androidx.annotation.NonNull; -import androidx.annotation.Nullable; - -import com.android.launcher3.allapps.AllAppsTransitionController; import com.android.launcher3.anim.AnimatorPlaybackController; import com.android.launcher3.anim.Interpolators; -import com.android.launcher3.anim.SpringObjectAnimator; +import com.android.launcher3.anim.SpringAnimationBuilder; import com.android.quickstep.util.ClipAnimationHelper; import com.android.quickstep.views.RecentsView; import com.android.quickstep.views.TaskView; import com.android.systemui.shared.system.RemoteAnimationTargetCompat; +import androidx.annotation.NonNull; +import androidx.annotation.Nullable; + /** * A {@link QuickstepAppTransitionManagerImpl} that also implements recents transitions from * {@link RecentsView}. @@ -156,8 +150,11 @@ public final class LauncherAppTransitionManagerImpl extends QuickstepAppTransiti return ObjectAnimator.ofFloat(mLauncher.getOverviewPanel(), RecentsView.CONTENT_ALPHA, values); case INDEX_RECENTS_TRANSLATE_X_ANIM: - return new SpringObjectAnimator<>(mLauncher.getOverviewPanel(), - VIEW_TRANSLATE_X, MIN_VISIBLE_CHANGE_PIXELS, 0.8f, 250, values); + return new SpringAnimationBuilder<>(mLauncher.getOverviewPanel(), VIEW_TRANSLATE_X) + .setDampingRatio(0.8f) + .setStiffness(250) + .setValues(values) + .build(mLauncher); default: return super.createStateElementAnimation(index, values); } diff --git a/src/com/android/launcher3/anim/SpringAnimationBuilder.java b/src/com/android/launcher3/anim/SpringAnimationBuilder.java new file mode 100644 index 000000000..0f34c1e97 --- /dev/null +++ b/src/com/android/launcher3/anim/SpringAnimationBuilder.java @@ -0,0 +1,229 @@ +/* + * Copyright (C) 2019 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.launcher3.anim; + +import android.animation.Animator; +import android.animation.ObjectAnimator; +import android.content.Context; +import android.util.FloatProperty; + +import com.android.launcher3.util.DefaultDisplay; + +import androidx.annotation.FloatRange; +import androidx.dynamicanimation.animation.SpringForce; + +/** + * Utility class to build an object animator which follows the same path as a spring animation for + * an underdamped spring. + */ +public class SpringAnimationBuilder extends FloatProperty { + + private final T mTarget; + private final FloatProperty mProperty; + + private float mStartValue; + private float mEndValue; + private float mVelocity = 0; + + private float mStiffness = SpringForce.STIFFNESS_MEDIUM; + private float mDampingRatio = SpringForce.DAMPING_RATIO_MEDIUM_BOUNCY; + private float mMinVisibleChange = 1; + + // Multiplier to the min visible change value for value threshold + private static final float THRESHOLD_MULTIPLIER = 0.65f; + + /** + * The spring equation is given as + * x = e^(-beta*t/2) * (a cos(gamma * t) + b sin(gamma * t) + * v = e^(-beta*t/2) * ((2 * a * gamma + beta * b) * sin(gamma * t) + * + (a * beta - 2 * b * gamma) * cos(gamma * t)) / 2 + * + * a = x(0) + * b = beta * x(0) / (2 * gamma) + v(0) / gamma + */ + private double beta; + private double gamma; + + private double a, b; + private double va, vb; + + // Threshold for velocity and value to determine when it's reasonable to assume that the spring + // is approximately at rest. + private double mValueThreshold; + private double mVelocityThreshold; + + private float mCurrentTime = 0; + + public SpringAnimationBuilder(T target, FloatProperty property) { + super("dynamic-spring-property"); + mTarget = target; + mProperty = property; + + mStartValue = mProperty.get(target); + } + + public SpringAnimationBuilder setEndValue(float value) { + mEndValue = value; + return this; + } + + public SpringAnimationBuilder setStartValue(float value) { + mStartValue = value; + return this; + } + + public SpringAnimationBuilder setValues(float... values) { + if (values.length > 1) { + mStartValue = values[0]; + mEndValue = values[values.length - 1]; + } else { + mEndValue = values[0]; + } + return this; + } + + public SpringAnimationBuilder setStiffness( + @FloatRange(from = 0.0, fromInclusive = false) float stiffness) { + if (stiffness <= 0) { + throw new IllegalArgumentException("Spring stiffness constant must be positive."); + } + mStiffness = stiffness; + return this; + } + + public SpringAnimationBuilder setDampingRatio( + @FloatRange(from = 0.0, to = 1.0, fromInclusive = false, toInclusive = false) + float dampingRatio) { + if (dampingRatio <= 0 || dampingRatio >= 1) { + throw new IllegalArgumentException("Damping ratio must be between 0 and 1"); + } + mDampingRatio = dampingRatio; + return this; + } + + public SpringAnimationBuilder setMinimumVisibleChange( + @FloatRange(from = 0.0, fromInclusive = false) float minimumVisibleChange) { + if (minimumVisibleChange <= 0) { + throw new IllegalArgumentException("Minimum visible change must be positive."); + } + mMinVisibleChange = minimumVisibleChange; + return this; + } + + public SpringAnimationBuilder setStartVelocity(float startVelocity) { + mVelocity = startVelocity; + return this; + } + + @Override + public void setValue(T object, float time) { + mCurrentTime = time; + mProperty.setValue( + object, (float) (exponentialComponent(time) * cosSinX(time)) + mEndValue); + } + + @Override + public Float get(T t) { + return mCurrentTime; + } + + public ObjectAnimator build(Context context) { + int singleFrameMs = DefaultDisplay.getSingleFrameMs(context); + double naturalFreq = Math.sqrt(mStiffness); + double dampedFreq = naturalFreq * Math.sqrt(1 - mDampingRatio * mDampingRatio); + + // All the calculations assume the stable position to be 0, shift the values accordingly. + beta = 2 * mDampingRatio * naturalFreq; + gamma = dampedFreq; + a = mStartValue - mEndValue; + b = beta * a / (2 * gamma) + mVelocity / gamma; + + va = a * beta / 2 - b * gamma; + vb = a * gamma + beta * b / 2; + + mValueThreshold = mMinVisibleChange * THRESHOLD_MULTIPLIER; + + // This multiplier is used to calculate the velocity threshold given a certain value + // threshold. The idea is that if it takes >= 1 frame to move the value threshold amount, + // then the velocity is a reasonable threshold. + mVelocityThreshold = mValueThreshold * 1000.0 / singleFrameMs; + + // Find the duration (in seconds) for the spring to reach equilibrium. + // equilibrium is reached when x = 0 + double duration = Math.atan2(-a, b) / gamma; + + // Keep moving ahead until the velocity reaches equilibrium. + double piByG = Math.PI / gamma; + while (duration < 0 || Math.abs(exponentialComponent(duration) * cosSinV(duration)) + >= mVelocityThreshold) { + duration += piByG; + } + + // Find the shortest time + double edgeTime = Math.max(0, duration - piByG / 2); + double minDiff = singleFrameMs / 2000.0; // Half frame time in seconds + + do { + if ((duration - edgeTime) < minDiff) { + break; + } + double mid = (edgeTime + duration) / 2; + if (isAtEquilibrium(mid)) { + duration = mid; + } else { + edgeTime = mid; + } + } while (true); + + + long durationMs = (long) (1000.0 * duration); + ObjectAnimator animator = ObjectAnimator.ofFloat(mTarget, this, 0, (float) duration); + animator.setDuration(durationMs).setInterpolator(Interpolators.LINEAR); + animator.addListener(new AnimationSuccessListener() { + @Override + public void onAnimationSuccess(Animator animator) { + mProperty.setValue(mTarget, mEndValue); + } + }); + return animator; + } + + private boolean isAtEquilibrium(double t) { + double ec = exponentialComponent(t); + + if (Math.abs(ec * cosSinX(t)) >= mValueThreshold) { + return false; + } + return Math.abs(ec * cosSinV(t)) < mVelocityThreshold; + } + + private double exponentialComponent(double t) { + return Math.pow(Math.E, - beta * t / 2); + } + + private double cosSinX(double t) { + return cosSin(t, a, b); + } + + private double cosSinV(double t) { + return cosSin(t, va, vb); + } + + private double cosSin(double t, double cosFactor, double sinFactor) { + double angle = t * gamma; + return cosFactor * Math.cos(angle) + sinFactor * Math.sin(angle); + } +} -- cgit v1.2.3