Add an example of popup window

Bug: 194954154
Test: manual
Change-Id: Ifbd468ec38a2cb519e5f5343dde5e64c10d2a8aa

5 files changed, 198 insertions, 0 deletions

diff --git a/RotaryPlayground/res/layout/list_item.xml b/RotaryPlayground/res/layout/list_item.xml
new file mode 100644
index 0000000..dd36ec7
--- /dev/null
+++ b/RotaryPlayground/res/layout/list_item.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2021 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.
+  -->
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+          android:layout_width="match_parent"
+          android:layout_height="match_parent"
+          android:focusable="true"/>
diff --git a/RotaryPlayground/res/layout/popup_window_fragment.xml b/RotaryPlayground/res/layout/popup_window_fragment.xml
new file mode 100644
index 0000000..f3ba9d2
--- /dev/null
+++ b/RotaryPlayground/res/layout/popup_window_fragment.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2021 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.
+  -->
+<com.android.car.ui.FocusArea
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+    <Button
+        android:id="@+id/overflow"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Overflow Button"/>
+</com.android.car.ui.FocusArea>
diff --git a/RotaryPlayground/res/layout/rotary_menu.xml b/RotaryPlayground/res/layout/rotary_menu.xml
index e2a523a..53f17b7 100644
--- a/RotaryPlayground/res/layout/rotary_menu.xml
+++ b/RotaryPlayground/res/layout/rotary_menu.xml
@@ -77,6 +77,13 @@
         android:text="Custom FocusAreas"
         style="@style/tab" />
     <Button
+        android:id="@+id/popup_window"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:layout_weight="1"
+        android:text="Popup window"
+        style="@style/tab" />
+    <Button
         android:id="@+id/surface_view"
         android:layout_width="match_parent"
         android:layout_height="0dp"
diff --git a/RotaryPlayground/src/com/android/car/rotaryplayground/PopupWindowFragment.java b/RotaryPlayground/src/com/android/car/rotaryplayground/PopupWindowFragment.java
new file mode 100644
index 0000000..f2ae91a
--- /dev/null
+++ b/RotaryPlayground/src/com/android/car/rotaryplayground/PopupWindowFragment.java
@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) 2021 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.car.rotaryplayground;
+
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.ViewTreeObserver;
+import android.widget.ArrayAdapter;
+import android.widget.Button;
+import android.widget.ListPopupWindow;
+import android.widget.ListView;
+import android.widget.Toast;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.fragment.app.Fragment;
+
+import com.android.car.ui.FocusParkingView;
+
+/** Fragment to demo a popup window. */
+public class PopupWindowFragment extends Fragment {
+
+    private static final String[] ACTIONS = {"Action 1", "Action 2", "Action 3"};
+    private static final int WINDOW_WIDTH = 300;
+    private static final int WINDOW_HEIGHT = 400;
+
+    @NonNull
+    private ListPopupWindow mPopupWindow;
+    @Nullable
+    private ListView mListView;
+
+    @Override
+    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
+            @Nullable Bundle savedInstanceState) {
+        View view = inflater.inflate(R.layout.popup_window_fragment, container, false);
+        Button overflow = view.findViewById(R.id.overflow);
+
+        mPopupWindow = new ListPopupWindow(getActivity());
+        mPopupWindow.setAdapter(new ArrayAdapter<>(getActivity(), R.layout.list_item, ACTIONS));
+        mPopupWindow.setAnchorView(overflow);
+        mPopupWindow.setWidth(WINDOW_WIDTH);
+        mPopupWindow.setHeight(WINDOW_HEIGHT);
+        mPopupWindow.setModal(true);
+        mPopupWindow.setOnItemClickListener((parent, v, position, id) -> {
+            Toast.makeText(getActivity(), ACTIONS[position], Toast.LENGTH_SHORT).show();
+            mPopupWindow.dismiss();
+        });
+
+        overflow.setOnClickListener((v) -> {
+            mPopupWindow.show();
+            mListView = mPopupWindow.getListView();
+            if (mListView != null && mListView.isFocused()) {
+                initRotaryMode();
+            }
+        });
+
+        return view;
+    }
+
+    /**
+     * Initializes the popup window to support rotary controller rotations and nudges.
+     * <p>
+     * In rotary mode the first focusable element in the ListView should be focused automatically
+     * when the popup window shows up. However, in {@link ListPopupWindow#show}, Android framework
+     * creates the ListView, sets it focusable, then focuses on it automatically. What's worse,
+     * ListView doesn't handle focusSearch() properly, causing rotation fails once it's focused.
+     * To work around it, move focus to its first focusable element, then set the ListView
+     * to not be focusable.
+     */
+    private void initRotaryMode() {
+        if (mListView == null) {
+            return;
+        }
+
+        // Add a FocusParkingView to prevent rotary controller rotation wrap-around.
+        View root = mListView.getRootView();
+        if (root instanceof ViewGroup) {
+            ViewGroup rootView = (ViewGroup) root;
+            FocusParkingView fpv = new FocusParkingView(getActivity());
+
+            // This popup window can be dismissed by controller nudges.
+            fpv.setOnPopupWindowDismiss(() -> mPopupWindow.dismiss());
+
+            rootView.addView(fpv);
+        }
+
+        // At this time the elements in the list are not loaded yet. Because there is no callbacks
+        // to notify whether the elements are loaded, use an OnPreDrawListener as workaround.
+        ViewTreeObserver.OnPreDrawListener listeners[] =
+                new ViewTreeObserver.OnPreDrawListener[1];
+        listeners[0] = (() -> {
+            boolean focusInitialized = false;
+            for (int i = 0; i < mListView.getChildCount(); i++) {
+                View child = mListView.getChildAt(i);
+                if (child != null) {
+                    // Because the elements are set focusable, they'll steal click events from the
+                    // list, so they need to handle the events on their own.
+                    int position = i;
+                    child.setOnClickListener(v -> mPopupWindow.performItemClick(position));
+
+                    // Move focus to the first focusable element and set the list non-focussable.
+                    if (!focusInitialized) {
+                        focusInitialized = child.requestFocus();
+                        if (focusInitialized) {
+                            mListView.setFocusable(false);
+                            mListView.getViewTreeObserver().removeOnPreDrawListener(listeners[0]);
+                        }
+                    }
+                }
+            }
+            return true;
+        });
+        mListView.getViewTreeObserver().addOnPreDrawListener(listeners[0]);
+    }
+}
diff --git a/RotaryPlayground/src/com/android/car/rotaryplayground/RotaryMenu.java b/RotaryPlayground/src/com/android/car/rotaryplayground/RotaryMenu.java
index 4b8844d..f1ffe86 100644
--- a/RotaryPlayground/src/com/android/car/rotaryplayground/RotaryMenu.java
+++ b/RotaryPlayground/src/com/android/car/rotaryplayground/RotaryMenu.java
@@ -39,6 +39,7 @@ public class RotaryMenu extends Fragment {
     private Fragment mScrollFragment;
     private Fragment mWebViewFragment;
     private Fragment mCustomFocusAreasFragment;
+    private Fragment mPopupWindowFragment;
     private Fragment mSurfaceViewFragment;
 
     @Override
@@ -94,6 +95,12 @@ public class RotaryMenu extends Fragment {
             showCustomFocusAreasFragment();
         });
 
+        Button popupWindowButton = view.findViewById(R.id.popup_window);
+        popupWindowButton.setOnClickListener(v -> {
+            selectTab(v);
+            showPopupWindowFragment();
+        });
+
         Button surfaceViewButton = view.findViewById(R.id.surface_view);
         surfaceViewButton.setOnClickListener(v -> {
             selectTab(v);
@@ -169,6 +176,13 @@ public class RotaryMenu extends Fragment {
         showFragment(mCustomFocusAreasFragment);
     }
 
+    private void showPopupWindowFragment() {
+        if (mPopupWindowFragment == null) {
+            mPopupWindowFragment = new PopupWindowFragment();
+        }
+        showFragment(mPopupWindowFragment);
+    }
+
     private void showSurfaceViewFragment() {
         if (mSurfaceViewFragment == null) {
             mSurfaceViewFragment = new SurfaceViewFragment();