Moves Search results into a separate RV (take 2).

Bug: 206905515
Test: Manually verified b/230648542 did not resurface. Tested
on phone and tablet with and without work profile.

Change-Id: If724f635286b9dff2c64255f9ece3568a5cb4ea9
diff --git a/src/com/android/launcher3/FastScrollRecyclerView.java b/src/com/android/launcher3/FastScrollRecyclerView.java
new file mode 100644
index 0000000..f117069
--- /dev/null
+++ b/src/com/android/launcher3/FastScrollRecyclerView.java
@@ -0,0 +1,203 @@
+/*
+ * Copyright (C) 2015 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;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.accessibility.AccessibilityNodeInfo;
+
+import androidx.annotation.Nullable;
+import androidx.recyclerview.widget.RecyclerView;
+
+import com.android.launcher3.compat.AccessibilityManagerCompat;
+import com.android.launcher3.views.RecyclerViewFastScroller;
+
+
+/**
+ * A base {@link RecyclerView}, which does the following:
+ * <ul>
+ *   <li> NOT intercept a touch unless the scrolling velocity is below a predefined threshold.
+ *   <li> Enable fast scroller.
+ * </ul>
+ */
+public abstract class FastScrollRecyclerView extends RecyclerView  {
+
+    protected RecyclerViewFastScroller mScrollbar;
+
+    public FastScrollRecyclerView(Context context) {
+        this(context, null);
+    }
+
+    public FastScrollRecyclerView(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public FastScrollRecyclerView(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    @Override
+    protected void onAttachedToWindow() {
+        super.onAttachedToWindow();
+        bindFastScrollbar();
+    }
+
+    public void bindFastScrollbar() {
+        ViewGroup parent = (ViewGroup) getParent().getParent();
+        mScrollbar = parent.findViewById(R.id.fast_scroller);
+        mScrollbar.setRecyclerView(this, parent.findViewById(R.id.fast_scroller_popup));
+        onUpdateScrollbar(0);
+    }
+
+    @Nullable
+    public RecyclerViewFastScroller getScrollbar() {
+        return mScrollbar;
+    }
+
+    public int getScrollBarTop() {
+        return getPaddingTop();
+    }
+
+    /**
+     * Returns the height of the fast scroll bar
+     */
+    public int getScrollbarTrackHeight() {
+        return mScrollbar.getHeight() - getScrollBarTop() - getPaddingBottom();
+    }
+
+    /**
+     * Returns the available scroll height:
+     *   AvailableScrollHeight = Total height of the all items - last page height
+     */
+    protected abstract int getAvailableScrollHeight();
+
+    /**
+     * Returns the available scroll bar height:
+     *   AvailableScrollBarHeight = Total height of the visible view - thumb height
+     */
+    protected int getAvailableScrollBarHeight() {
+        int availableScrollBarHeight = getScrollbarTrackHeight() - mScrollbar.getThumbHeight();
+        return availableScrollBarHeight;
+    }
+
+    /**
+     * Updates the scrollbar thumb offset to match the visible scroll of the recycler view.  It does
+     * this by mapping the available scroll area of the recycler view to the available space for the
+     * scroll bar.
+     *
+     * @param scrollY the current scroll y
+     */
+    protected void synchronizeScrollBarThumbOffsetToViewScroll(int scrollY,
+            int availableScrollHeight) {
+        // Only show the scrollbar if there is height to be scrolled
+        if (availableScrollHeight <= 0) {
+            mScrollbar.setThumbOffsetY(-1);
+            return;
+        }
+
+        // Calculate the current scroll position, the scrollY of the recycler view accounts for the
+        // view padding, while the scrollBarY is drawn right up to the background padding (ignoring
+        // padding)
+        int scrollBarY =
+                (int) (((float) scrollY / availableScrollHeight) * getAvailableScrollBarHeight());
+
+        // Calculate the position and size of the scroll bar
+        mScrollbar.setThumbOffsetY(scrollBarY);
+    }
+
+    /**
+     * Returns whether the view itself will handle the touch event or not.
+     * @param ev MotionEvent in {@param eventSource}
+     */
+    public boolean shouldContainerScroll(MotionEvent ev, View eventSource) {
+        float[] point = new float[2];
+        point[0] = ev.getX();
+        point[1] = ev.getY();
+        Utilities.mapCoordInSelfToDescendant(mScrollbar, eventSource, point);
+        // IF the MotionEvent is inside the thumb, container should not be pulled down.
+        if (mScrollbar.shouldBlockIntercept((int) point[0], (int) point[1])) {
+            return false;
+        }
+
+        // IF scroller is at the very top OR there is no scroll bar because there is probably not
+        // enough items to scroll, THEN it's okay for the container to be pulled down.
+        if (getCurrentScrollY() == 0) {
+            return true;
+        }
+        return getAdapter() == null || getAdapter().getItemCount() == 0;
+    }
+
+    /**
+     * @return whether fast scrolling is supported in the current state.
+     */
+    public boolean supportsFastScrolling() {
+        return true;
+    }
+
+    /**
+     * Maps the touch (from 0..1) to the adapter position that should be visible.
+     * <p>Override in each subclass of this base class.
+     *
+     * @return the scroll top of this recycler view.
+     */
+    public abstract int getCurrentScrollY();
+
+    /**
+     * Maps the touch (from 0..1) to the adapter position that should be visible.
+     * <p>Override in each subclass of this base class.
+     */
+    public abstract String scrollToPositionAtProgress(float touchFraction);
+
+    /**
+     * Updates the bounds for the scrollbar.
+     * <p>Override in each subclass of this base class.
+     */
+    public abstract void onUpdateScrollbar(int dy);
+
+    /**
+     * <p>Override in each subclass of this base class.
+     */
+    public void onFastScrollCompleted() {}
+
+    @Override
+    public void onScrollStateChanged(int state) {
+        super.onScrollStateChanged(state);
+
+        if (state == SCROLL_STATE_IDLE) {
+            AccessibilityManagerCompat.sendScrollFinishedEventToTest(getContext());
+        }
+    }
+
+    @Override
+    public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
+        super.onInitializeAccessibilityNodeInfo(info);
+        if (isLayoutSuppressed()) info.setScrollable(false);
+    }
+
+    /**
+     * Scrolls this recycler view to the top.
+     */
+    public void scrollToTop() {
+        if (mScrollbar != null) {
+            mScrollbar.reattachThumbToScroll();
+        }
+        scrollToPosition(0);
+    }
+}