Merge "Prevent users from blocking certain system notifications."
diff --git a/packages/SettingsLib/src/com/android/settingslib/Utils.java b/packages/SettingsLib/src/com/android/settingslib/Utils.java
index 72df96d..fa2226d 100644
--- a/packages/SettingsLib/src/com/android/settingslib/Utils.java
+++ b/packages/SettingsLib/src/com/android/settingslib/Utils.java
@@ -2,7 +2,11 @@
 
 import android.content.Context;
 import android.content.Intent;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.pm.UserInfo;
+import android.content.pm.Signature;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
@@ -138,4 +142,33 @@
 
         return statusString;
     }
+
+    /**
+     * Determine whether a package is a "system package", in which case certain things (like
+     * disabling notifications or disabling the package altogether) should be disallowed.
+     */
+    public static boolean isSystemPackage(PackageManager pm, PackageInfo pkg) {
+        if (sSystemSignature == null) {
+            sSystemSignature = new Signature[]{ getSystemSignature(pm) };
+        }
+        return sSystemSignature[0] != null && sSystemSignature[0].equals(getFirstSignature(pkg));
+    }
+
+    private static Signature[] sSystemSignature;
+
+    private static Signature getFirstSignature(PackageInfo pkg) {
+        if (pkg != null && pkg.signatures != null && pkg.signatures.length > 0) {
+            return pkg.signatures[0];
+        }
+        return null;
+    }
+
+    private static Signature getSystemSignature(PackageManager pm) {
+        try {
+            final PackageInfo sys = pm.getPackageInfo("android", PackageManager.GET_SIGNATURES);
+            return getFirstSignature(sys);
+        } catch (NameNotFoundException e) {
+        }
+        return null;
+    }
 }
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/NotificationGuts.java b/packages/SystemUI/src/com/android/systemui/statusbar/NotificationGuts.java
index 20a6e7c..52326e3 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/NotificationGuts.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/NotificationGuts.java
@@ -16,10 +16,11 @@
 
 package com.android.systemui.statusbar;
 
-import android.annotation.IdRes;
 import android.app.INotificationManager;
 import android.app.Notification;
 import android.content.Context;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
 import android.graphics.Canvas;
 import android.graphics.drawable.Drawable;
 import android.os.RemoteException;
@@ -28,13 +29,12 @@
 import android.service.notification.StatusBarNotification;
 import android.util.AttributeSet;
 import android.view.View;
-import android.widget.FrameLayout;
 import android.widget.LinearLayout;
 import android.widget.RadioButton;
-import android.widget.RadioGroup;
 import android.widget.SeekBar;
 import android.widget.TextView;
 
+import com.android.settingslib.Utils;
 import com.android.systemui.R;
 
 /**
@@ -123,10 +123,27 @@
         final TextView topicSummary = ((TextView) row.findViewById(R.id.summary));
         final TextView topicTitle = ((TextView) row.findViewById(R.id.title));
         mSeekBar = (SeekBar) row.findViewById(R.id.seekbar);
-        mSeekBar.setMax(4);
+        boolean systemApp = false;
+        try {
+            final PackageManager pm = BaseStatusBar.getPackageManagerForUser(
+                    getContext(), sbn.getUser().getIdentifier());
+            final PackageInfo info =
+                    pm.getPackageInfo(sbn.getPackageName(), PackageManager.GET_SIGNATURES);
+            systemApp = Utils.isSystemPackage(pm, info);
+        } catch (PackageManager.NameNotFoundException e) {
+            // unlikely.
+        }
+        final int minProgress = systemApp ?
+                NotificationListenerService.Ranking.IMPORTANCE_LOW
+                : NotificationListenerService.Ranking.IMPORTANCE_NONE;
+        mSeekBar.setMax(NotificationListenerService.Ranking.IMPORTANCE_MAX);
         mSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
             @Override
             public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
+                if (progress < minProgress) {
+                    seekBar.setProgress(minProgress);
+                    progress = minProgress;
+                }
                 updateTitleAndSummary(progress);
                 if (fromUser) {
                     if (appUsesTopics) {