CTS: regression test for overlaying IME picker

Bug: 181660568
Test: atest InputMethodPickerTest
Change-Id: Id17ff13bebe88ac8ff07efe0155fe7acc3470c97
diff --git a/tests/framework/base/windowmanager/util/src/android/server/wm/WindowManagerStateHelper.java b/tests/framework/base/windowmanager/util/src/android/server/wm/WindowManagerStateHelper.java
index 56a98d0..a70f507 100644
--- a/tests/framework/base/windowmanager/util/src/android/server/wm/WindowManagerStateHelper.java
+++ b/tests/framework/base/windowmanager/util/src/android/server/wm/WindowManagerStateHelper.java
@@ -305,7 +305,7 @@
         }, windowName + "'s surface is disappeared");
     }
 
-    void waitAndAssertWindowSurfaceShown(String windowName, boolean shown) {
+    public void waitAndAssertWindowSurfaceShown(String windowName, boolean shown) {
         assertTrue(
                 waitForWithAmState(state -> state.isWindowSurfaceShown(windowName) == shown,
                         windowName + "'s  isWindowSurfaceShown to return " + shown));
diff --git a/tests/inputmethod/Android.bp b/tests/inputmethod/Android.bp
index 90a8c2f..4902be2 100644
--- a/tests/inputmethod/Android.bp
+++ b/tests/inputmethod/Android.bp
@@ -27,9 +27,11 @@
     compile_multilib: "both",
     libs: ["android.test.runner"],
     static_libs: [
+        "androidx.test.ext.junit",
         "androidx.test.rules",
         "androidx.test.uiautomator_uiautomator",
         "compatibility-device-util-axt",
+        "cts-wm-util",
         "ctstestrunner-axt",
         "CtsMockInputMethodLib",
         "CtsMockSpellCheckerLib",
diff --git a/tests/inputmethod/src/android/view/inputmethod/cts/InputMethodPickerTest.java b/tests/inputmethod/src/android/view/inputmethod/cts/InputMethodPickerTest.java
new file mode 100644
index 0000000..3064c30
--- /dev/null
+++ b/tests/inputmethod/src/android/view/inputmethod/cts/InputMethodPickerTest.java
@@ -0,0 +1,103 @@
+/*
+ * 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 android.view.inputmethod.cts;
+
+import static android.content.Intent.ACTION_CLOSE_SYSTEM_DIALOGS;
+import static android.content.Intent.FLAG_RECEIVER_FOREGROUND;
+import static android.content.pm.PackageManager.FEATURE_INPUT_METHODS;
+import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
+import static android.view.inputmethod.cts.util.TestUtils.waitOnMainUntil;
+
+import static androidx.test.platform.app.InstrumentationRegistry.getInstrumentation;
+
+import static org.junit.Assume.assumeTrue;
+
+import android.content.Intent;
+import android.platform.test.annotations.AppModeFull;
+import android.platform.test.annotations.SecurityTest;
+import android.server.wm.ActivityManagerTestBase;
+import android.view.View;
+import android.view.inputmethod.InputMethodManager;
+import android.view.inputmethod.cts.util.TestActivity;
+import android.widget.LinearLayout;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.MediumTest;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.util.concurrent.TimeUnit;
+
+@MediumTest
+@RunWith(AndroidJUnit4.class)
+public class InputMethodPickerTest extends ActivityManagerTestBase {
+
+    private static final long TIMEOUT = TimeUnit.SECONDS.toMillis(5);
+
+    private InputMethodManager mImManager;
+
+    @Before
+    public void setUp() throws Exception {
+        super.setUp();
+        mImManager = mContext.getSystemService(InputMethodManager.class);
+
+        closeSystemDialogsAndWait();
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        closeSystemDialogsAndWait();
+    }
+
+    @AppModeFull(reason = "Instant apps cannot rely on ACTION_CLOSE_SYSTEM_DIALOGS")
+    @SecurityTest(minPatchLevel = "unknown")
+    @Test
+    public void testInputMethodPicker_hidesUntrustedOverlays() throws Exception {
+        assumeTrue(mContext.getPackageManager().hasSystemFeature(FEATURE_INPUT_METHODS));
+        TestActivity testActivity = TestActivity.startSync(activity -> {
+            final View view = new View(activity);
+            view.setLayoutParams(new LinearLayout.LayoutParams(MATCH_PARENT, MATCH_PARENT));
+            return view;
+        });
+
+        // Test setup: Show overlay and verify that it worked.
+        getInstrumentation().runOnMainSync(() -> {
+            testActivity.showOverlayWindow();
+        });
+        mWmState.waitAndAssertWindowSurfaceShown(TestActivity.OVERLAY_WINDOW_NAME, true);
+
+        // Test setup: Show the IME picker and verify that it worked.
+        getInstrumentation().runOnMainSync(() -> {
+            mImManager.showInputMethodPicker();
+        });
+        waitOnMainUntil(() -> mImManager.isInputMethodPickerShown(), TIMEOUT,
+                "Test setup failed: InputMethod picker should be shown");
+
+        // Actual Test: Make sure the IME picker hides app overlays.
+        mWmState.waitAndAssertWindowSurfaceShown(TestActivity.OVERLAY_WINDOW_NAME, false);
+    }
+
+    private void closeSystemDialogsAndWait() throws Exception {
+        mContext.sendBroadcast(
+                new Intent(ACTION_CLOSE_SYSTEM_DIALOGS).setFlags(FLAG_RECEIVER_FOREGROUND));
+        waitOnMainUntil(() -> !mImManager.isInputMethodPickerShown(), TIMEOUT,
+                "Test assertion failed: InputMethod picker should be closed but isn't");
+    }
+}
diff --git a/tests/inputmethod/src/android/view/inputmethod/cts/util/TestActivity.java b/tests/inputmethod/src/android/view/inputmethod/cts/util/TestActivity.java
index 398e7b6..78d7835 100644
--- a/tests/inputmethod/src/android/view/inputmethod/cts/util/TestActivity.java
+++ b/tests/inputmethod/src/android/view/inputmethod/cts/util/TestActivity.java
@@ -16,14 +16,20 @@
 
 package android.view.inputmethod.cts.util;
 
+import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
+import static android.view.WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
 import static android.view.WindowManager.LayoutParams.SOFT_INPUT_STATE_UNCHANGED;
+import static android.view.WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY;
 
 import android.app.Activity;
+import android.content.Context;
 import android.content.Intent;
+import android.graphics.PixelFormat;
 import android.os.Bundle;
 import android.view.View;
 import android.view.Window;
 import android.view.WindowManager;
+import android.widget.TextView;
 
 import androidx.annotation.AnyThread;
 import androidx.annotation.NonNull;
@@ -36,6 +42,7 @@
 
 public class TestActivity extends Activity {
 
+    public static final String OVERLAY_WINDOW_NAME = "TestActivity.APP_OVERLAY_WINDOW";
     private static final AtomicReference<Function<TestActivity, View>> sInitializer =
             new AtomicReference<>();
 
@@ -45,6 +52,8 @@
 
     private long mOnBackPressedCallCount;
 
+    private TextView mOverlayView;
+
     /**
      * Controls how {@link #onBackPressed()} behaves.
      *
@@ -82,6 +91,16 @@
         setContentView(mInitializer.apply(this));
     }
 
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+        if (mOverlayView != null) {
+            mOverlayView.getContext()
+                    .getSystemService(WindowManager.class).removeView(mOverlayView);
+            mOverlayView = null;
+        }
+    }
+
     /**
      * {@inheritDoc}
      */
@@ -94,6 +113,23 @@
         super.onBackPressed();
     }
 
+    public void showOverlayWindow() {
+        if (mOverlayView != null) {
+            throw new IllegalStateException("can only show one overlay at a time.");
+        }
+        Context overlayContext = getApplicationContext().createWindowContext(getDisplay(),
+                TYPE_APPLICATION_OVERLAY, null);
+        mOverlayView = new TextView(overlayContext);
+        WindowManager.LayoutParams params =
+                new WindowManager.LayoutParams(MATCH_PARENT, MATCH_PARENT,
+                        TYPE_APPLICATION_OVERLAY, FLAG_NOT_FOCUSABLE, PixelFormat.TRANSLUCENT);
+        params.setTitle(OVERLAY_WINDOW_NAME);
+        mOverlayView.setLayoutParams(params);
+        mOverlayView.setText("IME CTS TestActivity OverlayView");
+        mOverlayView.setBackgroundColor(0x77FFFF00);
+        overlayContext.getSystemService(WindowManager.class).addView(mOverlayView, params);
+    }
+
     /**
      * Launches {@link TestActivity} with the given initialization logic for content view.
      *