Merge "Fix selection from HOVER events in AppCompat popup menu" into androidx-main

diff --git a/appcompat/appcompat/src/androidTest/java/androidx/appcompat/widget/PopupMenuTest.java b/appcompat/appcompat/src/androidTest/java/androidx/appcompat/widget/PopupMenuTest.java
index 35cbe49..f725061 100644
--- a/appcompat/appcompat/src/androidTest/java/androidx/appcompat/widget/PopupMenuTest.java
+++ b/appcompat/appcompat/src/androidTest/java/androidx/appcompat/widget/PopupMenuTest.java

@@ -44,7 +44,6 @@
 import android.content.res.Resources;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
-import android.os.Build;
 import android.os.SystemClock;
 import android.text.TextUtils;
 import android.view.InputDevice;
@@ -601,9 +600,8 @@
         onView(withClassName(Matchers.is(DROP_DOWN_CLASS_NAME))).check(doesNotExist());
     }
 
-    // Broken on API 30 b/151920359
+    @SdkSuppress(minSdkVersion = 26) // Touch mode hides selection prior to SDK 26.
     @Test
-    @SdkSuppress(minSdkVersion = Build.VERSION_CODES.O, maxSdkVersion = 29)
     public void testHoverSelectsMenuItem() throws Throwable {
         Instrumentation instrumentation = InstrumentationRegistry.getInstrumentation();
 

diff --git a/appcompat/appcompat/src/main/java/androidx/appcompat/widget/DropDownListView.java b/appcompat/appcompat/src/main/java/androidx/appcompat/widget/DropDownListView.java
index cde1574..ff70a9c 100644
--- a/appcompat/appcompat/src/main/java/androidx/appcompat/widget/DropDownListView.java
+++ b/appcompat/appcompat/src/main/java/androidx/appcompat/widget/DropDownListView.java

@@ -16,15 +16,18 @@
 
 package androidx.appcompat.widget;
 
+import static android.os.Build.VERSION.SDK_INT;
+
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.graphics.Canvas;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
-import android.os.Build;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AbsListView;
+import android.widget.AdapterView;
 import android.widget.ListAdapter;
 import android.widget.ListView;
 
@@ -38,6 +41,8 @@
 import androidx.core.widget.ListViewAutoScrollHelper;
 
 import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 
 /**
  * <p>Wrapper class for a ListView. This wrapper can hijack the focus to
@@ -428,10 +433,9 @@
 
     @Override
     public boolean onHoverEvent(@NonNull MotionEvent ev) {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
-            // For SDK_INT prior to O the code below fails to change the selection.
-            // This is because prior to O mouse events used to enable touch mode, and
-            //  View.setSelectionFromTop does not do the right thing in touch mode.
+        if (SDK_INT < 26) {
+            // On SDK 26 and below, hover events force the UI into touch mode which does not show
+            // the selector. Don't bother trying to move selection.
             return super.onHoverEvent(ev);
         }
 
@@ -452,9 +456,17 @@
             if (position != INVALID_POSITION && position != getSelectedItemPosition()) {
                 final View hoveredItem = getChildAt(position - getFirstVisiblePosition());
                 if (hoveredItem.isEnabled()) {
-                    // Force a focus on the hovered item so that
-                    // the proper selector state gets used when we update.
-                    setSelectionFromTop(position, hoveredItem.getTop() - this.getTop());
+                    // Force a focus so that the proper selector state gets
+                    // used when we update.
+                    requestFocus();
+
+                    if (SDK_INT >= 30 && Api30Impl.canPositionSelectorForHoveredItem()) {
+                        // Starting in SDK 30, setSelectionFromTop does not move selection. Instead,
+                        // we'll reflect on the methods used by the platform DropDownListView.
+                        Api30Impl.positionSelectorForHoveredItem(this, position, hoveredItem);
+                    } else {
+                        setSelectionFromTop(position, hoveredItem.getTop() - this.getTop());
+                    }
                 }
                 updateSelectorStateCompat();
             }
@@ -648,7 +660,7 @@
         mDrawsInPressedState = true;
 
         // Ordering is essential. First, update the container's pressed state.
-        if (Build.VERSION.SDK_INT >= 21) {
+        if (SDK_INT >= 21) {
             Api21Impl.drawableHotspotChanged(this, x, y);
         }
         if (!isPressed()) {
@@ -671,7 +683,7 @@
         // Offset for child coordinates.
         final float childX = x - child.getLeft();
         final float childY = y - child.getTop();
-        if (Build.VERSION.SDK_INT >= 21) {
+        if (SDK_INT >= 21) {
             Api21Impl.drawableHotspotChanged(child, childX, childY);
         }
         if (!child.isPressed()) {
@@ -719,6 +731,67 @@
         }
     }
 
+    @SuppressWarnings("CatchAndPrintStackTrace")
+    @RequiresApi(30)
+    static class Api30Impl {
+        private static Method sPositionSelector;
+        private static Method sSetSelectedPositionInt;
+        private static Method sSetNextSelectedPositionInt;
+        private static boolean sHasMethods;
+
+        static {
+            try {
+                sPositionSelector = AbsListView.class.getDeclaredMethod(
+                        "positionSelector", int.class, View.class,
+                        boolean.class, float.class, float.class);
+                sPositionSelector.setAccessible(true);
+                sSetSelectedPositionInt  = AdapterView.class.getDeclaredMethod(
+                        "setSelectedPositionInt", int.class);
+                sSetSelectedPositionInt.setAccessible(true);
+                sSetNextSelectedPositionInt = AdapterView.class.getDeclaredMethod(
+                        "setNextSelectedPositionInt", int.class);
+                sSetNextSelectedPositionInt.setAccessible(true);
+                sHasMethods = true;
+            } catch (NoSuchMethodException e) {
+                e.printStackTrace();
+            }
+        }
+
+        private Api30Impl() {
+            // This class is not instantiable.
+        }
+
+        /**
+         * @return whether this class can access the methods required to position selection using
+         * hidden platform APIs
+         */
+        static boolean canPositionSelectorForHoveredItem() {
+            return sHasMethods;
+        }
+
+        /**
+         * Positions the selector for a hovered item using the same hidden platform APIs as the
+         * platform implementation of DropDownListView.
+         *
+         * @param view the drop-down list view handling the event
+         * @param position the position to select
+         * @param sel the view being selected
+         */
+        @SuppressWarnings("CatchAndPrintStackTrace")
+        @SuppressLint("BanUncheckedReflection") // No public APIs available.
+        static void positionSelectorForHoveredItem(DropDownListView view, int position, View sel) {
+            try {
+                sPositionSelector.invoke(view, position, sel, false, -1, -1);
+                sSetSelectedPositionInt.invoke(view, position);
+                sSetNextSelectedPositionInt.invoke(view, position);
+            } catch (IllegalAccessException e) {
+                e.printStackTrace();
+            } catch (InvocationTargetException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
     @RequiresApi(21)
     static class Api21Impl {
         private Api21Impl() {