Merge "Clear clipboard after a defined period of inactivity"

services/core/java/com/android/server/clipboard/ClipboardService.java

@@ -50,6 +50,8 @@ import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.IBinder;
 import android.os.IUserManager;
+import android.os.Looper;
+import android.os.Message;
 import android.os.Parcel;
 import android.os.RemoteCallbackList;
 import android.os.RemoteException;
@@ -74,6 +76,8 @@ import android.widget.Toast;
 
 import com.android.internal.R;
 import com.android.internal.annotations.GuardedBy;
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.util.FrameworkStatsLog;
 import com.android.server.LocalServices;
 import com.android.server.SystemService;
 import com.android.server.UiThread;
@@ -99,6 +103,22 @@ public class ClipboardService extends SystemService {
     private static final boolean IS_EMULATOR =
             SystemProperties.getBoolean("ro.boot.qemu", false);
 
+    @VisibleForTesting
+    public static final long DEFAULT_CLIPBOARD_TIMEOUT_MILLIS = 3600000;
+
+    /**
+     * Device config property for whether clipboard auto clear is enabled on the device
+     **/
+    public static final String PROPERTY_AUTO_CLEAR_ENABLED =
+            "auto_clear_enabled";
+
+    /**
+     * Device config property for time period in milliseconds after which clipboard is auto
+     * cleared
+     **/
+    public static final String PROPERTY_AUTO_CLEAR_TIMEOUT =
+            "auto_clear_timeout";
+
     // DeviceConfig properties
     private static final String PROPERTY_MAX_CLASSIFICATION_LENGTH = "max_classification_length";
     private static final int DEFAULT_MAX_CLASSIFICATION_LENGTH = 400;
@@ -312,6 +332,10 @@ public class ClipboardService extends SystemService {
      * 'intendingUserId' and the uid is called 'intendingUid'.
      */
     private class ClipboardImpl extends IClipboard.Stub {
+
+        private final Handler mClipboardClearHandler = new ClipboardClearHandler(
+                mWorkerHandler.getLooper());
+
         @Override
         public boolean onTransact(int code, Parcel data, Parcel reply, int flags)
                 throws RemoteException {
@@ -352,10 +376,34 @@ public class ClipboardService extends SystemService {
             }
             checkDataOwner(clip, intendingUid);
             synchronized (mLock) {
+                scheduleAutoClear(userId);
                 setPrimaryClipInternalLocked(clip, intendingUid, sourcePackage);
             }
         }
 
+        private void scheduleAutoClear(@UserIdInt int userId) {
+            final long oldIdentity = Binder.clearCallingIdentity();
+            try {
+                if (DeviceConfig.getBoolean(DeviceConfig.NAMESPACE_CLIPBOARD,
+                        PROPERTY_AUTO_CLEAR_ENABLED, false)) {
+                    mClipboardClearHandler.removeEqualMessages(ClipboardClearHandler.MSG_CLEAR,
+                            userId);
+                    Message clearMessage = Message.obtain(mClipboardClearHandler,
+                            ClipboardClearHandler.MSG_CLEAR, userId, 0, userId);
+                    mClipboardClearHandler.sendMessageDelayed(clearMessage,
+                            getTimeoutForAutoClear());
+                }
+            } finally {
+                Binder.restoreCallingIdentity(oldIdentity);
+            }
+        }
+
+        private long getTimeoutForAutoClear() {
+            return DeviceConfig.getLong(DeviceConfig.NAMESPACE_CLIPBOARD,
+                    PROPERTY_AUTO_CLEAR_TIMEOUT,
+                    DEFAULT_CLIPBOARD_TIMEOUT_MILLIS);
+        }
+
         @Override
         public void clearPrimaryClip(String callingPackage, @UserIdInt int userId) {
             final int intendingUid = getIntendingUid(callingPackage, userId);
@@ -365,6 +413,8 @@ public class ClipboardService extends SystemService {
                 return;
             }
             synchronized (mLock) {
+                mClipboardClearHandler.removeEqualMessages(ClipboardClearHandler.MSG_CLEAR,
+                        userId);
                 setPrimaryClipInternalLocked(null, intendingUid, callingPackage);
             }
         }
@@ -391,6 +441,9 @@ public class ClipboardService extends SystemService {
                 PerUserClipboard clipboard = getClipboardLocked(intendingUserId);
                 showAccessNotificationLocked(pkg, intendingUid, intendingUserId, clipboard);
                 notifyTextClassifierLocked(clipboard, pkg, intendingUid);
+                if (clipboard.primaryClip != null) {
+                    scheduleAutoClear(userId);
+                }
                 return clipboard.primaryClip;
             }
         }
@@ -484,6 +537,32 @@ public class ClipboardService extends SystemService {
                 return null;
             }
         }
+
+        private class ClipboardClearHandler extends Handler {
+
+            public static final int MSG_CLEAR = 101;
+
+            ClipboardClearHandler(Looper looper) {
+                super(looper);
+            }
+
+            public void handleMessage(@NonNull Message msg) {
+                switch (msg.what) {
+                    case MSG_CLEAR:
+                        final int userId = msg.arg1;
+                        synchronized (mLock) {
+                            if (getClipboardLocked(userId).primaryClip != null) {
+                                FrameworkStatsLog.write(FrameworkStatsLog.CLIPBOARD_CLEARED,
+                                        FrameworkStatsLog.CLIPBOARD_CLEARED__SOURCE__AUTO_CLEAR);
+                                setPrimaryClipInternalLocked(null, Binder.getCallingUid(), null);
+                            }
+                        }
+                        break;
+                    default:
+                        Slog.wtf(TAG, "ClipboardClearHandler received unknown message " + msg.what);
+                }
+            }
+        }
     };
 
     @GuardedBy("mLock")