Have responsive taskbar UI during swipe up gesture.

- Makes taskbar threshold an absolute Y threshold
  instead of a distance threshold.
- Moves handle, taskbar view, and taskbar background
  during the swipe up gesture

Next CL will address transforming the nav handle <-> taskbar
and ensuring that there's a clean handoff

Bug: 246631059
Test: swipe up on taskbar, release. see bounce
      swipe up on taskbar to go home, proper icon alignment
      swipe up on taskbar, pause for overview, see bounce
      -> further movement should not move taskbar
      test launcher3

Change-Id: I141236fd72428cda7edd0ff116de1d478d18c722

quickstep/src/com/android/launcher3/taskbar/TaskbarTranslationController.java

@@ -0,0 +1,197 @@
+/*
+ * 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.android.launcher3.taskbar;
+
+import static com.android.launcher3.anim.AnimatorListeners.forEndCallback;
+import static com.android.quickstep.AnimatedFloat.VALUE;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.animation.ObjectAnimator;
+import android.animation.ValueAnimator;
+
+import androidx.annotation.Nullable;
+import androidx.dynamicanimation.animation.SpringForce;
+
+import com.android.launcher3.anim.Interpolators;
+import com.android.launcher3.anim.SpringAnimationBuilder;
+import com.android.launcher3.util.DisplayController;
+import com.android.quickstep.AnimatedFloat;
+
+import java.io.PrintWriter;
+
+/**
+ * Class responsible for translating the transient taskbar UI during a swipe gesture.
+ *
+ * The translation is controlled, in priority order:
+ * - animation to home
+ * - a spring animation
+ * - controlled by user
+ *
+ * The spring animation will play start once the user lets go or when user pauses to go to overview.
+ * When the user goes home, the stash animation will play.
+ */
+public class TaskbarTranslationController implements TaskbarControllers.LoggableTaskbarController {
+
+    private final TaskbarActivityContext mContext;
+    private TaskbarControllers mControllers;
+    private final AnimatedFloat mTranslationYForSwipe = new AnimatedFloat(
+            this::updateTranslationYForSwipe);
+
+    private boolean mHasSprungOnceThisGesture;
+    private @Nullable ValueAnimator mSpringBounce;
+    private boolean mGestureEnded;
+    private boolean mAnimationToHomeRunning;
+
+    private final boolean mIsTransientTaskbar;
+
+    private final TransitionCallback mCallback;
+
+    public TaskbarTranslationController(TaskbarActivityContext context) {
+        mContext = context;
+        mIsTransientTaskbar = DisplayController.isTransientTaskbar(mContext);
+        mCallback = new TransitionCallback();
+    }
+
+    /**
+     * Initialization method.
+     */
+    public void init(TaskbarControllers controllers) {
+        mControllers = controllers;
+    }
+
+    /**
+     * Called to cancel any existing animations.
+     */
+    public void cancelAnimationIfExists() {
+        if (mSpringBounce != null) {
+            mSpringBounce.cancel();
+            mSpringBounce = null;
+        }
+        reset();
+    }
+
+    private void updateTranslationYForSwipe() {
+        if (!mIsTransientTaskbar) {
+            return;
+        }
+
+        float transY = mTranslationYForSwipe.value;
+        mControllers.stashedHandleViewController.setTranslationYForSwipe(transY);
+        mControllers.taskbarViewController.setTranslationYForSwipe(transY);
+        mControllers.taskbarDragLayerController.setTranslationYForSwipe(transY);
+    }
+
+    /**
+     * Starts a spring aniamtion to set the views back to the resting state.
+     */
+    public void startSpring() {
+        if (mHasSprungOnceThisGesture || mAnimationToHomeRunning) {
+            return;
+        }
+        mSpringBounce = new SpringAnimationBuilder(mContext)
+                .setStartValue(mTranslationYForSwipe.value)
+                .setEndValue(0)
+                .setDampingRatio(SpringForce.DAMPING_RATIO_MEDIUM_BOUNCY)
+                .setStiffness(SpringForce.STIFFNESS_LOW)
+                .build(mTranslationYForSwipe, VALUE);
+        mSpringBounce.addListener(forEndCallback(() -> {
+            if (mGestureEnded) {
+                reset();
+            }
+        }));
+        mSpringBounce.start();
+        mHasSprungOnceThisGesture = true;
+    }
+
+    private void reset() {
+        mGestureEnded = false;
+        mHasSprungOnceThisGesture = false;
+    }
+
+    /**
+     * Returns a callback to help monitor the swipe gesture.
+     */
+    public TransitionCallback getTransitionCallback() {
+        return mCallback;
+    }
+
+    /**
+     * Returns an animation to reset the taskbar translation for animation back to launcher.
+     */
+    public ObjectAnimator createAnimToLauncher(long duration) {
+        ObjectAnimator animator = ObjectAnimator.ofFloat(mTranslationYForSwipe, VALUE, 0);
+        animator.setInterpolator(Interpolators.LINEAR);
+        animator.setDuration(duration);
+        animator.addListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationStart(Animator animation) {
+                cancelAnimationIfExists();
+                mAnimationToHomeRunning = true;
+            }
+
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                mAnimationToHomeRunning = false;
+                reset();
+            }
+        });
+        return animator;
+    }
+
+    /**
+     * Helper class to communicate to/from  the input consumer.
+     */
+    public class TransitionCallback {
+
+        /**
+         * Called when there is movement to move the taskbar.
+         */
+        public void onActionMove(float dY) {
+            if (mAnimationToHomeRunning
+                    || (mHasSprungOnceThisGesture && !mGestureEnded)) {
+                return;
+            }
+
+            mTranslationYForSwipe.updateValue(dY);
+        }
+
+        /**
+         * Called when swipe gesture has ended.
+         */
+        public void onActionEnd() {
+            if (mHasSprungOnceThisGesture) {
+                reset();
+            } else {
+                mGestureEnded = true;
+                startSpring();
+            }
+        }
+    }
+
+    @Override
+    public void dumpLogs(String prefix, PrintWriter pw) {
+        pw.println(prefix + "TaskbarTranslationController:");
+
+        pw.println(prefix + "\tmTranslationYForSwipe=" + mTranslationYForSwipe.value);
+        pw.println(prefix + "\tmHasSprungOnceThisGesture=" + mHasSprungOnceThisGesture);
+        pw.println(prefix + "\tmAnimationToHomeRunning=" + mAnimationToHomeRunning);
+        pw.println(prefix + "\tmGestureEnded=" + mGestureEnded);
+        pw.println(prefix + "\tmSpringBounce is running=" + (mSpringBounce != null
+                && mSpringBounce.isRunning()));
+    }
+}
+