Fix NPE in systemui when showing up toast on released display.

Bug: 265325338
Test: atest ToastTest ToastUITest
Change-Id: I3562040ce50a8550f7d9aac7c833e0dc2fd672ce

packages/SystemUI/src/com/android/systemui/toast/ToastLogger.kt

@@ -58,6 +58,16 @@ class ToastLogger @Inject constructor(
         })
     }
 
+    fun logOnSkipToastForInvalidDisplay(packageName: String, token: String, displayId: Int) {
+        log(DEBUG, {
+            str1 = packageName
+            str2 = token
+            int1 = displayId
+        }, {
+            "[$str2] Skip toast for [$str1] scheduled on unavailable display #$int1"
+        })
+    }
+
     private inline fun log(
         logLevel: LogLevel,
         initializer: LogMessage.() -> Unit,

packages/SystemUI/src/com/android/systemui/toast/ToastUI.java

@@ -32,6 +32,7 @@ import android.os.IBinder;
 import android.os.ServiceManager;
 import android.os.UserHandle;
 import android.util.Log;
+import android.view.Display;
 import android.view.accessibility.AccessibilityManager;
 import android.view.accessibility.IAccessibilityManager;
 import android.widget.ToastPresenter;
@@ -115,8 +116,14 @@ public class ToastUI implements CoreStartable, CommandQueue.Callbacks {
             Context context = mContext.createContextAsUser(userHandle, 0);
 
             DisplayManager mDisplayManager = mContext.getSystemService(DisplayManager.class);
-            Context displayContext = context.createDisplayContext(
-                    mDisplayManager.getDisplay(displayId));
+            Display display = mDisplayManager.getDisplay(displayId);
+            if (display == null) {
+                // Display for which this toast was scheduled for is no longer available.
+                mToastLogger.logOnSkipToastForInvalidDisplay(packageName, token.toString(),
+                        displayId);
+                return;
+            }
+            Context displayContext = context.createDisplayContext(display);
             mToast = mToastFactory.createToast(mContext /* sysuiContext */, text, packageName,
                     userHandle.getIdentifier(), mOrientation);
 

packages/SystemUI/tests/src/com/android/systemui/toast/ToastUITest.java

@@ -28,6 +28,7 @@ import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyZeroInteractions;
 import static org.mockito.Mockito.when;
 
 import android.app.Application;
@@ -36,6 +37,7 @@ import android.app.ITransientNotificationCallback;
 import android.content.Context;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
+import android.hardware.display.DisplayManager;
 import android.os.Binder;
 import android.os.Build;
 import android.os.Parcel;
@@ -74,6 +76,8 @@ import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 import org.mockito.stubbing.Answer;
 
+import java.util.Arrays;
+
 @SmallTest
 @RunWith(AndroidTestingRunner.class)
 @TestableLooper.RunWithLooper
@@ -400,6 +404,18 @@ public class ToastUITest extends SysuiTestCase {
         verify(mToastLogger, never()).logOnHideToast(PACKAGE_NAME_1, TOKEN_1.toString());
     }
 
+    @Test
+    public void testShowToast_invalidDisplayId_logsAndSkipsToast() {
+        int invalidDisplayId = getInvalidDisplayId();
+
+        mToastUI.showToast(UID_1, PACKAGE_NAME_1, TOKEN_1, TEXT, WINDOW_TOKEN_1, Toast.LENGTH_LONG,
+                mCallback, invalidDisplayId);
+
+        verify(mToastLogger).logOnSkipToastForInvalidDisplay(PACKAGE_NAME_1, TOKEN_1.toString(),
+                invalidDisplayId);
+        verifyZeroInteractions(mWindowManager);
+    }
+
     private View verifyWmAddViewAndAttachToParent() {
         ArgumentCaptor<View> viewCaptor = ArgumentCaptor.forClass(View.class);
         verify(mWindowManager).addView(viewCaptor.capture(), any());
@@ -416,4 +432,10 @@ public class ToastUITest extends SysuiTestCase {
             return null;
         };
     }
+
+    private int getInvalidDisplayId() {
+        return Arrays.stream(
+                mContext.getSystemService(DisplayManager.class).getDisplays())
+                .map(Display::getDisplayId).max(Integer::compare).get() + 1;
+    }
 }