From 9a28c009d937e060bb5c10034cb5370129b8ce81 Mon Sep 17 00:00:00 2001
From: Jan Tomljanovic <jtomljanovic@google.com>
Date: Fri, 6 Nov 2020 11:28:09 +0000
Subject: [PATCH] Don't try to show the current toast again while it's showing.

By doing this we avoid a few bad things:
 - mechanism that hides the current toast by trying to show it again
 - delaying the call to hide and remove the current toast from the queue
   when it's duration expires (which in the case of repeated calls can
   delay this indefinitely)

Test: atest NotificationManagerServiceTest
Test: atest android.widget.cts.ToastTest
Bug: 167672740
Change-Id: Ie4953109314113efae49fa0c5e0c236e6e0dbb23
---
 .../NotificationManagerService.java           | 13 ++++++++++
 .../NotificationManagerServiceTest.java       | 26 +++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/services/core/java/com/android/server/notification/NotificationManagerService.java b/services/core/java/com/android/server/notification/NotificationManagerService.java
index d769ff8e75055..7b1c0ac27ab30 100755
--- a/services/core/java/com/android/server/notification/NotificationManagerService.java
+++ b/services/core/java/com/android/server/notification/NotificationManagerService.java
@@ -437,6 +437,10 @@ public class NotificationManagerService extends SystemService {
 
     private KeyguardManager mKeyguardManager;
 
+    // True if the toast that's on top of the queue is being shown at the moment.
+    @GuardedBy("mToastQueue")
+    private boolean mIsCurrentToastShown = false;
+
     // The last key in this list owns the hardware.
     ArrayList<String> mLights = new ArrayList<>();
 
@@ -6482,12 +6486,17 @@ public void run() {
 
     @GuardedBy("mToastQueue")
     void showNextToastLocked() {
+        if (mIsCurrentToastShown) {
+            return; // Don't show the same toast twice.
+        }
+
         ToastRecord record = mToastQueue.get(0);
         while (record != null) {
             if (DBG) Slog.d(TAG, "Show pkg=" + record.pkg + " callback=" + record.callback);
             try {
                 record.callback.show(record.token);
                 scheduleDurationReachedLocked(record);
+                mIsCurrentToastShown = true;
                 return;
             } catch (RemoteException e) {
                 Slog.w(TAG, "Object died trying to show notification " + record.callback
@@ -6519,6 +6528,10 @@ void cancelToastLocked(int index) {
             // the list anyway
         }
 
+        if (index == 0) {
+            mIsCurrentToastShown = false;
+        }
+
         ToastRecord lastToast = mToastQueue.remove(index);
 
         mWindowManagerInternal.removeWindowToken(lastToast.token, false /* removeWindows */,
diff --git a/services/tests/uiservicestests/src/com/android/server/notification/NotificationManagerServiceTest.java b/services/tests/uiservicestests/src/com/android/server/notification/NotificationManagerServiceTest.java
index 4a0aa7c9e8e74..0e8cea43063b9 100755
--- a/services/tests/uiservicestests/src/com/android/server/notification/NotificationManagerServiceTest.java
+++ b/services/tests/uiservicestests/src/com/android/server/notification/NotificationManagerServiceTest.java
@@ -4415,6 +4415,32 @@ public void testAllowForegroundToasts() throws Exception {
     }
 
     @Test
+    public void testDontCallShowToastAgainOnTheSameTextToast() throws Exception {
+        final String testPackage = "testPackageName";
+        assertEquals(0, mService.mToastQueue.size());
+        mService.isSystemUid = false;
+
+        // package is not suspended
+        when(mPackageManager.isPackageSuspendedForUser(testPackage, UserHandle.getUserId(mUid)))
+                .thenReturn(false);
+
+        setAppInForegroundForToasts(mUid, true);
+
+        Binder token = new Binder();
+        INotificationManager nmService = (INotificationManager) mService.mService;
+
+        // first time trying to show the toast, showToast gets called
+        nmService.enqueueTextToast(testPackage, token, "Text", 2000, 0, null);
+        verify(mStatusBar, times(1))
+                .showToast(anyInt(), any(), any(), any(), any(), anyInt(), any());
+
+        // second time trying to show the same toast, showToast isn't called again (total number of
+        // invocations stays at one)
+        nmService.enqueueTextToast(testPackage, token, "Text", 2000, 0, null);
+        verify(mStatusBar, times(1))
+                .showToast(anyInt(), any(), any(), any(), any(), anyInt(), any());
+    }
+
     public void testDisallowToastsFromSuspendedPackages() throws Exception {
         final String testPackage = "testPackageName";
         assertEquals(0, mService.mToastQueue.size());