Fixing animation jump when dismissing paged task.

import android.content.Context;

import com.android.systemui.recents.events.EventBus;

import com.android.systemui.recents.misc.SystemServicesProxy;

/**

 * This is sent when we want to start screen pinning.

package com.android.systemui.recents.views;

import android.annotation.Nullable;

import android.app.ActivityManager;

import android.app.ActivityManager.StackId;

import android.app.ActivityOptions;

import android.content.Context;

import java.util.ArrayList;

import java.util.List;

import static android.app.ActivityManager.StackId.DOCKED_STACK_ID;

import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;

import static android.app.ActivityManager.StackId.FULLSCREEN_WORKSPACE_STACK_ID;

import static android.app.ActivityManager.StackId.INVALID_STACK_ID;

import android.os.Handler;

import android.util.ArraySet;

import android.util.AttributeSet;

import android.view.AppTransitionAnimationSpec;

import android.view.LayoutInflater;

import android.view.MotionEvent;

import android.view.View;

import android.view.WindowInsets;

import android.view.animation.AnimationUtils;

import android.view.animation.Interpolator;

import android.widget.FrameLayout;

import com.android.internal.annotations.GuardedBy;

import com.android.internal.logging.MetricsLogger;

import com.android.systemui.R;

import com.android.systemui.recents.Recents;

        mLayersDisabled = false;

        // Draw the freeform workspace background

        SystemServicesProxy ssp = Recents.getSystemServices();

        if (ssp.hasFreeformWorkspaceSupport()) {

            if (mFreeformWorkspaceBackground.getAlpha() > 0) {

                mFreeformWorkspaceBackground.draw(canvas);

            }

        }

        super.dispatchDraw(canvas);

    }

                mViewPool.returnViewToPool(tv);

            }

            // Get the stack scroll of the task to anchor to (since we are removing something, the front

            // most task will be our anchor task)

            // Get the stack scroll of the task to anchor to (since we are removing something, the

            // front most task will be our anchor task)

            Task anchorTask = null;

            float prevAnchorTaskScroll = 0;

            boolean pullStackForward = stack.getTaskCount() > 0;

                // to ensure that the new front most task is now fully visible

                mStackScroller.setStackScroll(mLayoutAlgorithm.mMaxScrollP);

            } else if (pullStackForward) {

                // Otherwise, offset the scroll by half the movement of the anchor task to allow the

                // tasks behind the removed task to move forward, and the tasks in front to move back

                // Otherwise, offset the scroll by the movement of the anchor task

                float anchorTaskScroll = mLayoutAlgorithm.getStackScrollForTask(anchorTask);

                mStackScroller.setStackScroll(mStackScroller.getStackScroll() + (anchorTaskScroll

                        - prevAnchorTaskScroll) / 2);

                float newStackScroll = mStackScroller.getStackScroll() +

                        (anchorTaskScroll - prevAnchorTaskScroll);

                if (mLayoutAlgorithm.getFocusState() != TaskStackLayoutAlgorithm.STATE_FOCUSED) {

                    // If we are focused, we don't want the front task to move, but otherwise, we

                    // allow the back task to move up, and the front task to move back

                    newStackScroll /= 2;

                }

                mStackScroller.setStackScroll(newStackScroll);

                mStackScroller.boundScroll();

            }

        // Remove the task from the stack

        mStack.removeTask(task);

        if (taskWasFocused || ssp.isTouchExplorationEnabled()) {

            // If the dismissed task was focused or if we are in touch exploration mode, then focus

            // the next task

            RecentsConfiguration config = Recents.getConfiguration();

            RecentsActivityLaunchState launchState = config.getLaunchState();

            boolean isFreeformTask = taskIndex > 0 ?

                    mStack.getTasks().get(taskIndex - 1).isFreeformTask() : false;

            setFocusedTask(taskIndex - 1, !isFreeformTask /* scrollToTask */,

                    launchState.launchedWithAltTab);

        }

    }

}

package com.android.systemui.recents.views;

import android.animation.Animator;

import android.animation.AnimatorListenerAdapter;

import android.animation.AnimatorSet;

import android.animation.ArgbEvaluator;

import android.animation.ObjectAnimator;

import android.animation.ValueAnimator;

import android.content.Context;

import android.content.res.ColorStateList;

import android.graphics.Canvas;