From 54a44d4c44de4407c6480ee8ebf76211e5fbb90b Mon Sep 17 00:00:00 2001
From: Hyunyoung Song <hyunyoungs@google.com>
Date: Mon, 14 Jun 2021 16:33:05 -0700
Subject: [PATCH] All apps motion

Bug: 189970327
Test: manual

TL;DR;;

equation: settleVelocity = releaseVelocity + interpolator 2nd deritive * t

Change-Id: I86fec339523fbc3bb347dec4affbd2d1c063d13d
---
 res/values/dimens.xml                         |  2 +-
 .../allapps/AllAppsContainerView.java         | 31 +++++++++----------
 .../allapps/AllAppsTransitionController.java  |  2 ++
 .../AbstractStateChangeTouchController.java   |  4 +--
 4 files changed, 18 insertions(+), 21 deletions(-)

diff --git a/res/values/dimens.xml b/res/values/dimens.xml
index 430a1abb90..542e062abc 100644
--- a/res/values/dimens.xml
+++ b/res/values/dimens.xml
@@ -98,7 +98,7 @@
     <dimen name="all_apps_header_tab_height">48dp</dimen>
     <dimen name="all_apps_tabs_indicator_height">2dp</dimen>
     <dimen name="all_apps_header_top_padding">36dp</dimen>
-    <dimen name="all_apps_header_bottom_padding">16dp</dimen>
+    <dimen name="all_apps_header_bottom_padding">6dp</dimen>
     <dimen name="all_apps_work_profile_tab_footer_top_padding">16dp</dimen>
     <dimen name="all_apps_work_profile_tab_footer_bottom_padding">20dp</dimen>
     <dimen name="all_apps_tabs_vertical_padding">6dp</dimen>
diff --git a/src/com/android/launcher3/allapps/AllAppsContainerView.java b/src/com/android/launcher3/allapps/AllAppsContainerView.java
index d749e02d73..555c911861 100644
--- a/src/com/android/launcher3/allapps/AllAppsContainerView.java
+++ b/src/com/android/launcher3/allapps/AllAppsContainerView.java
@@ -21,6 +21,8 @@ import static com.android.launcher3.model.BgDataModel.Callbacks.FLAG_HAS_SHORTCU
 import static com.android.launcher3.model.BgDataModel.Callbacks.FLAG_QUIET_MODE_CHANGE_PERMISSION;
 import static com.android.launcher3.model.BgDataModel.Callbacks.FLAG_QUIET_MODE_ENABLED;
 
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
 import android.animation.ValueAnimator;
 import android.content.Context;
 import android.content.res.Configuration;
@@ -82,10 +84,7 @@ public class AllAppsContainerView extends SpringRelativeLayout implements DragSo
         ScrimView.ScrimDrawingController {
 
     public static final float PULL_MULTIPLIER = .02f;
-    public static final float FLING_VELOCITY_MULTIPLIER = 2000f;
-
-    // Starts the springs after at least 25% of the animation has passed.
-    public static final float FLING_ANIMATION_THRESHOLD = 0.25f;
+    public static final float FLING_VELOCITY_MULTIPLIER = 1200f;
 
     private final Paint mHeaderPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
 
@@ -658,20 +657,18 @@ public class AllAppsContainerView extends SpringRelativeLayout implements DragSo
     /**
      * Adds an update listener to {@param animator} that adds springs to the animation.
      */
-    public void addSpringFromFlingUpdateListener(ValueAnimator animator, float velocity) {
-        animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
-            boolean shouldSpring = true;
-
+    public void addSpringFromFlingUpdateListener(ValueAnimator animator,
+            float velocity /* release velocity */,
+            float progress /* portion of the distance to travel*/) {
+        animator.addListener(new AnimatorListenerAdapter() {
             @Override
-            public void onAnimationUpdate(ValueAnimator valueAnimator) {
-                if (shouldSpring
-                        && valueAnimator.getAnimatedFraction() >= FLING_ANIMATION_THRESHOLD) {
-                    absorbSwipeUpVelocity(Math.max(100, Math.abs(
-                            Math.round(velocity * FLING_VELOCITY_MULTIPLIER))));
-                    // calculate the velocity of using the not user controlled interpolator
-                    // of when the container reach the end.
-                    shouldSpring = false;
-                }
+            public void onAnimationStart(Animator animator) {
+                float distance = (float) ((1 - progress) * getHeight()); // px
+                float settleVelocity = Math.min(0, distance
+                        / (AllAppsTransitionController.INTERP_COEFF * animator.getDuration())
+                        + velocity);
+                absorbSwipeUpVelocity(Math.max(1000, Math.abs(
+                        Math.round(settleVelocity * FLING_VELOCITY_MULTIPLIER))));
             }
         });
     }
diff --git a/src/com/android/launcher3/allapps/AllAppsTransitionController.java b/src/com/android/launcher3/allapps/AllAppsTransitionController.java
index 8ec8269ba0..a0551f019a 100644
--- a/src/com/android/launcher3/allapps/AllAppsTransitionController.java
+++ b/src/com/android/launcher3/allapps/AllAppsTransitionController.java
@@ -57,6 +57,8 @@ import com.android.launcher3.views.ScrimView;
  */
 public class AllAppsTransitionController
         implements StateHandler<LauncherState>, OnDeviceProfileChangeListener {
+    // This constant should match the second derivative of the animator interpolator.
+    public static final float INTERP_COEFF = 1.7f;
     private static final float CONTENT_VISIBLE_MAX_THRESHOLD = 0.5f;
 
     public static final FloatProperty<AllAppsTransitionController> ALL_APPS_PROGRESS =
diff --git a/src/com/android/launcher3/touch/AbstractStateChangeTouchController.java b/src/com/android/launcher3/touch/AbstractStateChangeTouchController.java
index a086635d57..90f37f3404 100644
--- a/src/com/android/launcher3/touch/AbstractStateChangeTouchController.java
+++ b/src/com/android/launcher3/touch/AbstractStateChangeTouchController.java
@@ -335,12 +335,10 @@ public abstract class AbstractStateChangeTouchController
         mCurrentAnimation.dispatchOnStart();
         if (targetState == LauncherState.ALL_APPS && !UNSTABLE_SPRINGS.get()) {
             if (mAllAppsOvershootStarted) {
-
                 mLauncher.getAppsView().onRelease();
                 mAllAppsOvershootStarted = false;
-
             } else {
-                mLauncher.getAppsView().addSpringFromFlingUpdateListener(anim, velocity);
+                mLauncher.getAppsView().addSpringFromFlingUpdateListener(anim, velocity, progress);
             }
         }
         anim.start();