Update Samsung Print Recommendation Plugin (to support Mopria printers)

- Extract common part of MDNSFilterPlugin to common utils, MDNSFilteredDiscovery.java (other vendors can use it too)
- Refactor Samsung Print Recomendation Plugin to use MDNSFilteredDiscovery.java
- Add Mopria devices detection to Samsung Print Recomendation Plugin

*Samsung Print Service Plugin supports Mopria printers since v3.00.161011.

Test: Tested manually. Test app was developed to make sure that Samsung Print Recommendation plugin can find both Samsung and Mopria devices. Additionally MDNSFilterPlugin was tested on HP printers.
Change-Id: Idc0d311171495f879564336370a86f7a8890378b

13 files changed, 541 insertions, 762 deletions

diff --git a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/RecommendationServiceImpl.java b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/RecommendationServiceImpl.java
index ac60a88e5ca6..1fe5a2a4d40b 100644
--- a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/RecommendationServiceImpl.java
+++ b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/RecommendationServiceImpl.java
@@ -78,7 +78,7 @@ public class RecommendationServiceImpl extends RecommendationService
 
         try {
             mPlugins.add(new RemotePrintServicePlugin(new SamsungRecommendationPlugin(this), this,
-                    false));
+                    true));
         } catch (Exception e) {
             Log.e(LOG_TAG, "Could not initiate " + getString(R.string.plugin_vendor_samsung) +
                     " plugin", e);
diff --git a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/mdnsFilter/MDNSFilterPlugin.java b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/mdnsFilter/MDNSFilterPlugin.java
index a2c0485f3d0a..d60a25f54a22 100644
--- a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/mdnsFilter/MDNSFilterPlugin.java
+++ b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/mdnsFilter/MDNSFilterPlugin.java
@@ -16,30 +16,52 @@
 
 package com.android.printservice.recommendation.plugin.mdnsFilter;
 
-import android.annotation.NonNull;
-import android.annotation.Nullable;
-import android.annotation.StringRes;
 import android.content.Context;
-import android.net.nsd.NsdManager;
 import android.net.nsd.NsdServiceInfo;
-import android.util.Log;
-import com.android.internal.annotations.GuardedBy;
-import com.android.internal.util.Preconditions;
+import android.annotation.NonNull;
+import android.annotation.StringRes;
+
 import com.android.printservice.recommendation.PrintServicePlugin;
-import com.android.printservice.recommendation.util.DiscoveryListenerMultiplexer;
-import com.android.printservice.recommendation.util.NsdResolveQueue;
+import com.android.printservice.recommendation.util.MDNSFilteredDiscovery;
+import com.android.printservice.recommendation.util.MDNSUtils;
 
 import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 /**
  * A plugin listening for mDNS results and only adding the ones that {@link
  * MDNSUtils#isVendorPrinter match} configured list
  */
-public class MDNSFilterPlugin implements PrintServicePlugin, NsdManager.DiscoveryListener {
-    private static final String LOG_TAG = "MDNSFilterPlugin";
+public class MDNSFilterPlugin implements PrintServicePlugin {
 
-    private static final String PRINTER_SERVICE_TYPE = "_ipp._tcp";
+    /** The mDNS service types supported */
+    private static final Set<String> PRINTER_SERVICE_TYPES = new HashSet<String>() {{
+        add("_ipp._tcp");
+    }};
+
+    /**
+     * The printer filter for {@link MDNSFilteredDiscovery} passing only mDNS results
+     * that {@link MDNSUtils#isVendorPrinter match} configured list
+     */
+    private static class VendorNameFilter implements MDNSFilteredDiscovery.PrinterFilter {
+        /** mDNS names handled by the print service this plugin is for */
+        private final @NonNull Set<String> mMDNSNames;
+
+        /**
+         * Filter constructor
+         *
+         * @param vendorNames The vendor names to pass
+         */
+        VendorNameFilter(@NonNull Set<String> vendorNames) {
+            mMDNSNames = new HashSet<>(vendorNames);
+        }
+
+        @Override
+        public boolean matchesCriteria(NsdServiceInfo nsdServiceInfo) {
+            return MDNSUtils.isVendorPrinter(nsdServiceInfo, mMDNSNames);
+        }
+    }
 
     /** Name of the print service this plugin is for */
     private final @StringRes int mName;
@@ -47,26 +69,8 @@ public class MDNSFilterPlugin implements PrintServicePlugin, NsdManager.Discover
     /** Package name of the print service this plugin is for */
     private final @NonNull CharSequence mPackageName;
 
-    /** mDNS names handled by the print service this plugin is for */
-    private final @NonNull HashSet<String> mMDNSNames;
-
-    /** Printer identifiers of the mPrinters found. */
-    @GuardedBy("mLock")
-    private final @NonNull HashSet<String> mPrinters;
-
-    /** Context of the user of this plugin */
-    private final @NonNull Context mContext;
-
-    /**
-     * Call back to report the number of mPrinters found.
-     *
-     * We assume that {@link #start} and {@link #stop} are never called in parallel, hence it is
-     * safe to not synchronize access to this field.
-     */
-    private @Nullable PrinterDiscoveryCallback mCallback;
-
-    /** Queue used to resolve nsd infos */
-    private final @NonNull NsdResolveQueue mResolveQueue;
+    /** The mDNS filtered discovery */
+    private final MDNSFilteredDiscovery mMDNSFilteredDiscovery;
 
     /**
      * Create new stub that assumes that a print service can be used to print on all mPrinters
@@ -79,16 +83,11 @@ public class MDNSFilterPlugin implements PrintServicePlugin, NsdManager.Discover
      */
     public MDNSFilterPlugin(@NonNull Context context, @NonNull String name,
             @NonNull CharSequence packageName, @NonNull List<String> mDNSNames) {
-        mContext = Preconditions.checkNotNull(context, "context");
-        mName = mContext.getResources().getIdentifier(Preconditions.checkStringNotEmpty(name,
-                "name"), null, "com.android.printservice.recommendation");
-        mPackageName = Preconditions.checkStringNotEmpty(packageName);
-        mMDNSNames = new HashSet<>(Preconditions
-                .checkCollectionNotEmpty(Preconditions.checkCollectionElementsNotNull(mDNSNames,
-                        "mDNSNames"), "mDNSNames"));
-
-        mResolveQueue = NsdResolveQueue.getInstance();
-        mPrinters = new HashSet<>();
+        mName = context.getResources().getIdentifier(name, null,
+                "com.android.printservice.recommendation");
+        mPackageName = packageName;
+        mMDNSFilteredDiscovery = new MDNSFilteredDiscovery(context, PRINTER_SERVICE_TYPES,
+                new VendorNameFilter(new HashSet<>(mDNSNames)));
     }
 
     @Override
@@ -96,18 +95,9 @@ public class MDNSFilterPlugin implements PrintServicePlugin, NsdManager.Discover
         return mPackageName;
     }
 
-    /**
-     * @return The NDS manager
-     */
-    private NsdManager getNDSManager() {
-        return (NsdManager) mContext.getSystemService(Context.NSD_SERVICE);
-    }
-
     @Override
     public void start(@NonNull PrinterDiscoveryCallback callback) throws Exception {
-        mCallback = callback;
-
-        DiscoveryListenerMultiplexer.addListener(getNDSManager(), PRINTER_SERVICE_TYPE, this);
+        mMDNSFilteredDiscovery.start(callback);
     }
 
     @Override
@@ -117,82 +107,6 @@ public class MDNSFilterPlugin implements PrintServicePlugin, NsdManager.Discover
 
     @Override
     public void stop() throws Exception {
-        mCallback.onChanged(0);
-        mCallback = null;
-
-        DiscoveryListenerMultiplexer.removeListener(getNDSManager(), this);
-    }
-
-    @Override
-    public void onStartDiscoveryFailed(String serviceType, int errorCode) {
-        Log.w(LOG_TAG, "Failed to start network discovery for type " + serviceType + ": "
-                + errorCode);
-    }
-
-    @Override
-    public void onStopDiscoveryFailed(String serviceType, int errorCode) {
-        Log.w(LOG_TAG, "Failed to stop network discovery for type " + serviceType + ": "
-                + errorCode);
-    }
-
-    @Override
-    public void onDiscoveryStarted(String serviceType) {
-        // empty
-    }
-
-    @Override
-    public void onDiscoveryStopped(String serviceType) {
-        mPrinters.clear();
-    }
-
-    @Override
-    public void onServiceFound(NsdServiceInfo serviceInfo) {
-        mResolveQueue.resolve(getNDSManager(), serviceInfo,
-                new NsdManager.ResolveListener() {
-            @Override
-            public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode) {
-                Log.w(LOG_TAG, "Service found: could not resolve " + serviceInfo + ": " +
-                        errorCode);
-            }
-
-            @Override
-            public void onServiceResolved(NsdServiceInfo serviceInfo) {
-                if (MDNSUtils.isVendorPrinter(serviceInfo, mMDNSNames)) {
-                    if (mCallback != null) {
-                        boolean added = mPrinters.add(serviceInfo.getHost().getHostAddress());
-
-                        if (added) {
-                            mCallback.onChanged(mPrinters.size());
-                        }
-                    }
-                }
-            }
-        });
-    }
-
-    @Override
-    public void onServiceLost(NsdServiceInfo serviceInfo) {
-        mResolveQueue.resolve(getNDSManager(), serviceInfo,
-                new NsdManager.ResolveListener() {
-            @Override
-            public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode) {
-                Log.w(LOG_TAG, "Service lost: Could not resolve " + serviceInfo + ": "
-                        + errorCode);
-            }
-
-            @Override
-            public void onServiceResolved(NsdServiceInfo serviceInfo) {
-                if (MDNSUtils.isVendorPrinter(serviceInfo, mMDNSNames)) {
-                    if (mCallback != null) {
-                        boolean removed = mPrinters
-                                .remove(serviceInfo.getHost().getHostAddress());
-
-                        if (removed) {
-                            mCallback.onChanged(mPrinters.size());
-                        }
-                    }
-                }
-            }
-        });
+        mMDNSFilteredDiscovery.stop();
     }
 }
diff --git a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/MDnsUtils.java b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/MDnsUtils.java
deleted file mode 100644
index 963e09b25257..000000000000
--- a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/MDnsUtils.java
+++ /dev/null
@@ -1,74 +0,0 @@
-/*
- * Copyright (C) 2016 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 com.android.printservice.recommendation.plugin.samsung;
-
-import android.net.nsd.NsdServiceInfo;
-import android.text.TextUtils;
-
-import java.nio.charset.StandardCharsets;
-import java.util.Locale;
-import java.util.Map;
-
-public class MDnsUtils {
-    public static final String ATTRIBUTE__TY = "ty";
-    public static final String ATTRIBUTE__PRODUCT = "product";
-    public static final String ATTRIBUTE__USB_MFG = "usb_MFG";
-    public static final String ATTRIBUTE__MFG = "mfg";
-
-    public static String getString(byte[] value) {
-        if (value != null) return new String(value,StandardCharsets.UTF_8);
-        return null;
-    }
-
-    public static boolean isVendorPrinter(NsdServiceInfo networkDevice, String[] vendorValues) {
-
-        Map<String,byte[]> attributes = networkDevice.getAttributes();
-        String product = getString(attributes.get(ATTRIBUTE__PRODUCT));
-        String ty = getString(attributes.get(ATTRIBUTE__TY));
-        String usbMfg = getString(attributes.get(ATTRIBUTE__USB_MFG));
-        String mfg = getString(attributes.get(ATTRIBUTE__MFG));
-        return containsVendor(product, vendorValues) || containsVendor(ty, vendorValues) || containsVendor(usbMfg, vendorValues) || containsVendor(mfg, vendorValues);
-
-    }
-
-    public static String getVendor(NsdServiceInfo networkDevice) {
-        String vendor;
-
-        Map<String,byte[]> attributes = networkDevice.getAttributes();
-        vendor = getString(attributes.get(ATTRIBUTE__MFG));
-        if (!TextUtils.isEmpty(vendor)) return vendor;
-        vendor = getString(attributes.get(ATTRIBUTE__USB_MFG));
-        if (!TextUtils.isEmpty(vendor)) return vendor;
-
-        return null;
-    }
-
-    private static boolean containsVendor(String container, String[] vendorValues) {
-        if ((container == null) || (vendorValues == null)) return false;
-        for (String value : vendorValues) {
-            if (containsString(container, value)
-                || containsString(container.toLowerCase(Locale.US), value.toLowerCase(Locale.US))
-                || containsString(container.toUpperCase(Locale.US), value.toUpperCase(Locale.US)))
-                return true;
-        }
-        return false;
-    }
-
-    private static boolean containsString(String container, String contained) {
-        return (container != null) && (contained != null) && (container.equalsIgnoreCase(contained) || container.contains(contained + " "));
-    }
-}
diff --git a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/PrinterFilterMopria.java b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/PrinterFilterMopria.java
new file mode 100644
index 000000000000..d03bb1d76003
--- /dev/null
+++ b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/PrinterFilterMopria.java
@@ -0,0 +1,63 @@
+/*
+ * (c) Copyright 2016 Samsung Electronics
+ * (c) Copyright 2016 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 com.android.printservice.recommendation.plugin.samsung;
+
+import android.net.nsd.NsdServiceInfo;
+import android.text.TextUtils;
+import android.util.Log;
+
+import com.android.printservice.recommendation.util.MDNSFilteredDiscovery;
+import com.android.printservice.recommendation.util.MDNSUtils;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Printer filter for Mopria printer models supported by the print service plugin
+ */
+class PrinterFilterMopria implements MDNSFilteredDiscovery.PrinterFilter {
+    private static final String TAG = "PrinterFilterMopria";
+
+    static final Set<String> MOPRIA_MDNS_SERVICES = new HashSet<String>() {{
+        add("_ipp._tcp");
+        add("_ipps._tcp");
+    }};
+
+    private static final String PDL__PDF = "application/pdf";
+    private static final String PDL__PCLM = "application/PCLm";
+    private static final String PDL__PWG_RASTER = "image/pwg-raster";
+
+    private static final String PDL_ATTRIBUTE = "pdl";
+
+    @Override
+    public boolean matchesCriteria(NsdServiceInfo nsdServiceInfo) {
+        if (!MDNSUtils.isSupportedServiceType(nsdServiceInfo, MOPRIA_MDNS_SERVICES)) {
+            return false;
+        }
+
+        String pdls = MDNSUtils.getString(nsdServiceInfo.getAttributes().get(PDL_ATTRIBUTE));
+        boolean isMatch = !TextUtils.isEmpty(pdls)
+                && (pdls.contains(PDL__PDF)
+                || pdls.contains(PDL__PCLM)
+                || pdls.contains(PDL__PWG_RASTER));
+
+        if (isMatch) {
+            Log.d(TAG, "Mopria printer found: " + nsdServiceInfo.getServiceName());
+        }
+        return isMatch;
+    }
+}
diff --git a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/PrinterFilterSamsung.java b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/PrinterFilterSamsung.java
new file mode 100644
index 000000000000..5b049efcf514
--- /dev/null
+++ b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/PrinterFilterSamsung.java
@@ -0,0 +1,117 @@
+/*
+ * (c) Copyright 2016 Samsung Electronics
+ * (c) Copyright 2016 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 com.android.printservice.recommendation.plugin.samsung;
+
+import android.net.nsd.NsdServiceInfo;
+import android.annotation.NonNull;
+import android.text.TextUtils;
+import android.util.Log;
+
+import com.android.printservice.recommendation.util.MDNSFilteredDiscovery;
+import com.android.printservice.recommendation.util.MDNSUtils;
+
+import java.util.HashSet;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Printer filter for Samsung printer models supported by the print service plugin
+ */
+class PrinterFilterSamsung implements MDNSFilteredDiscovery.PrinterFilter {
+    private static final String TAG = "PrinterFilterSamsung";
+
+    static final Set<String> SAMSUNG_MDNS_SERVICES = new HashSet<String>() {{
+        add("_pdl-datastream._tcp");
+    }};
+
+    private static final String[] NOT_SUPPORTED_MODELS = new String[]{
+            "SCX-5x15",
+            "SF-555P",
+            "CF-555P",
+            "SCX-4x16",
+            "SCX-4214F",
+            "CLP-500",
+            "CJX-",
+            "MJC-"
+    };
+    private static final String ATTR_USB_MFG = "usb_MFG";
+    private static final String ATTR_MFG = "mfg";
+    private static final String ATTR_USB_MDL = "usb_MDL";
+    private static final String ATTR_MDL = "mdl";
+    private static final String ATTR_PRODUCT = "product";
+    private static final String ATTR_TY = "ty";
+
+    private static Set<String> SAMUNG_VENDOR_SET = new HashSet<String>() {{
+        add("samsung");
+    }};
+
+    @Override
+    public boolean matchesCriteria(NsdServiceInfo nsdServiceInfo) {
+        if (!MDNSUtils.isSupportedServiceType(nsdServiceInfo, SAMSUNG_MDNS_SERVICES)) {
+            return false;
+        }
+
+        if (!MDNSUtils.isVendorPrinter(nsdServiceInfo, SAMUNG_VENDOR_SET)) {
+            return false;
+        }
+
+        String modelName = getSamsungModelName(nsdServiceInfo);
+        if (modelName != null && isSupportedSamsungModel(modelName)) {
+            Log.d(TAG, "Samsung printer found: " + nsdServiceInfo.getServiceName());
+            return true;
+        }
+        return false;
+    }
+
+    private boolean isSupportedSamsungModel(String model) {
+        if (!TextUtils.isEmpty(model)) {
+            String modelToUpper = model.toUpperCase(Locale.US);
+            for (String unSupportedPrinter : NOT_SUPPORTED_MODELS) {
+                if (modelToUpper.contains(unSupportedPrinter)) {
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+
+    private String getSamsungModelName(@NonNull NsdServiceInfo resolvedDevice) {
+        Map<String,byte[]> attributes = resolvedDevice.getAttributes();
+        String usb_mfg = MDNSUtils.getString(attributes.get(ATTR_USB_MFG));
+        if (TextUtils.isEmpty(usb_mfg)) {
+            usb_mfg = MDNSUtils.getString(attributes.get(ATTR_MFG));
+        }
+
+        String usb_mdl = MDNSUtils.getString(attributes.get(ATTR_USB_MDL));
+        if (TextUtils.isEmpty(usb_mdl)) {
+            usb_mdl = MDNSUtils.getString(attributes.get(ATTR_MDL));
+        }
+
+        String modelName;
+        if (!TextUtils.isEmpty(usb_mfg) && !TextUtils.isEmpty(usb_mdl)) {
+            modelName = usb_mfg.trim() + " " + usb_mdl.trim();
+        } else {
+            modelName = MDNSUtils.getString(attributes.get(ATTR_PRODUCT));
+            if (TextUtils.isEmpty(modelName)) {
+                modelName = MDNSUtils.getString(attributes.get(ATTR_TY));
+            }
+        }
+
+        return modelName;
+    }
+}
diff --git a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/PrinterHashMap.java b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/PrinterHashMap.java
deleted file mode 100644
index 032fe22dd744..000000000000
--- a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/PrinterHashMap.java
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * Copyright (C) 2016 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 com.android.printservice.recommendation.plugin.samsung;
-
-import android.net.nsd.NsdServiceInfo;
-
-import java.util.HashMap;
-
-final class PrinterHashMap extends HashMap<String, NsdServiceInfo> {
-    public static String getKey(NsdServiceInfo serviceInfo) {
-        return serviceInfo.getServiceName();
-    }
-    public NsdServiceInfo addPrinter(NsdServiceInfo device) {
-        return put(getKey(device), device);
-    }
-    public NsdServiceInfo removePrinter(NsdServiceInfo device) {
-        return remove(getKey(device));
-    }
-}
diff --git a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/SamsungRecommendationPlugin.java b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/SamsungRecommendationPlugin.java
index e5b8a0f15f2e..eeb51229e7de 100644
--- a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/SamsungRecommendationPlugin.java
+++ b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/SamsungRecommendationPlugin.java
@@ -1,102 +1,69 @@
-/*

-(c) Copyright 2016 Samsung Electronics..

-

-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 com.android.printservice.recommendation.plugin.samsung;

-

-import android.content.Context;

-import android.net.nsd.NsdServiceInfo;

-import android.text.TextUtils;

-

-import java.util.Locale;

-import java.util.Map;

-

-import com.android.printservice.recommendation.R;

-

-public class SamsungRecommendationPlugin extends ServiceRecommendationPlugin {

-

-    private static final String TAG = "SamsungRecommendation";

-

-    private static final String ATTR_USB_MFG = "usb_MFG";

-    private static final String ATTR_MFG = "mfg";

-    private static final String ATTR_USB_MDL = "usb_MDL";

-    private static final String ATTR_MDL = "mdl";

-    private static final String ATTR_PRODUCT = "product";

-    private static final String ATTR_TY = "ty";

-

-    private static String[] mNotSupportedDevices = new String[]{

-            "SCX-5x15",

-            "SF-555P",

-            "CF-555P",

-            "SCX-4x16",

-            "SCX-4214F",

-            "CLP-500",

-            "CJX-",

-            "MJC-"

-    };

-

-    private static boolean isSupportedModel(String model) {

-        if (!TextUtils.isEmpty(model)) {

-            String modelToUpper = model.toUpperCase(Locale.US);

-            for (String unSupportedPrinter : mNotSupportedDevices) {

-                if (modelToUpper.contains(unSupportedPrinter)) {

-                    return  false;

-                }

-            }

-        }

-        return true;

-    }

-

-    public SamsungRecommendationPlugin(Context context) {

-        super(context, R.string.plugin_vendor_samsung, new VendorInfo(context.getResources(), R.array.known_print_vendor_info_for_samsung), new String[]{"_pdl-datastream._tcp"});

-    }

-

-    @Override

-    public boolean matchesCriteria(String vendor, NsdServiceInfo nsdServiceInfo) {

-        if (!TextUtils.equals(vendor, mVendorInfo.mVendorID)) return false;

-

-        String modelName = getModelName(nsdServiceInfo);

-        if (modelName != null) {

-            return (isSupportedModel(modelName));

-        }

-        return false;

-    }

-

-    private String getModelName(NsdServiceInfo resolvedDevice) {

-        Map<String,byte[]> attributes = resolvedDevice.getAttributes();

-        String usb_mfg = MDnsUtils.getString(attributes.get(ATTR_USB_MFG));

-        if (TextUtils.isEmpty(usb_mfg)) {

-            usb_mfg = MDnsUtils.getString(attributes.get(ATTR_MFG));

-        }

-

-        String usb_mdl = MDnsUtils.getString(attributes.get(ATTR_USB_MDL));

-        if (TextUtils.isEmpty(usb_mdl)) {

-            usb_mdl = MDnsUtils.getString(attributes.get(ATTR_MDL));

-        }

-

-        String modelName = null;

-        if (!TextUtils.isEmpty(usb_mfg) && !TextUtils.isEmpty(usb_mdl)) {

-            modelName = usb_mfg.trim() + " " + usb_mdl.trim();

-        } else {

-            modelName = MDnsUtils.getString(attributes.get(ATTR_PRODUCT));

-            if (TextUtils.isEmpty(modelName)) {

-                modelName = MDnsUtils.getString(attributes.get(ATTR_TY));

-            }

-        }

-

-        return modelName;

-    }

-}

+/*
+ * (c) Copyright 2016 Samsung Electronics
+ * (c) Copyright 2016 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 com.android.printservice.recommendation.plugin.samsung;
+
+import android.content.Context;
+import android.net.nsd.NsdServiceInfo;
+import android.annotation.NonNull;
+
+import com.android.printservice.recommendation.PrintServicePlugin;
+import com.android.printservice.recommendation.R;
+import com.android.printservice.recommendation.util.MDNSFilteredDiscovery;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class SamsungRecommendationPlugin implements PrintServicePlugin {
+    private static final Set<String> ALL_MDNS_SERVICES = new HashSet<String>() {{
+        addAll(PrinterFilterMopria.MOPRIA_MDNS_SERVICES);
+        addAll(PrinterFilterSamsung.SAMSUNG_MDNS_SERVICES);
+    }};
+
+    private final @NonNull Context mContext;
+    private final @NonNull MDNSFilteredDiscovery mMDNSFilteredDiscovery;
+
+    private final @NonNull PrinterFilterSamsung mPrinterFilterSamsung = new PrinterFilterSamsung();
+    private final @NonNull PrinterFilterMopria mPrinterFilterMopria = new PrinterFilterMopria();
+
+    public SamsungRecommendationPlugin(@NonNull Context context) {
+        mContext = context;
+        mMDNSFilteredDiscovery = new MDNSFilteredDiscovery(context, ALL_MDNS_SERVICES,
+                (NsdServiceInfo nsdServiceInfo) ->
+                        mPrinterFilterSamsung.matchesCriteria(nsdServiceInfo) ||
+                                mPrinterFilterMopria.matchesCriteria(nsdServiceInfo));
+    }
+
+    @Override
+    public int getName() {
+        return R.string.plugin_vendor_samsung;
+    }
+
+    @Override
+    public @NonNull CharSequence getPackageName() {
+        return mContext.getString(R.string.plugin_package_samsung);
+    }
+
+    @Override
+    public void start(@NonNull PrinterDiscoveryCallback callback) throws Exception {
+        mMDNSFilteredDiscovery.start(callback);
+    }
+
+    @Override
+    public void stop() throws Exception {
+        mMDNSFilteredDiscovery.stop();
+    }
+}
diff --git a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/ServiceListener.java b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/ServiceListener.java
deleted file mode 100644
index 7bb83c9384f7..000000000000
--- a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/ServiceListener.java
+++ /dev/null
@@ -1,186 +0,0 @@
-/*
- * Copyright (C) 2016 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 com.android.printservice.recommendation.plugin.samsung;
-
-import android.content.Context;
-import android.content.res.TypedArray;
-import android.net.nsd.NsdManager;
-import android.net.nsd.NsdServiceInfo;
-import android.text.TextUtils;
-import android.util.Pair;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
-import com.android.printservice.recommendation.R;
-import com.android.printservice.recommendation.util.DiscoveryListenerMultiplexer;
-
-public class ServiceListener implements ServiceResolveQueue.ResolveCallback {
-
-    private final NsdManager mNSDManager;
-    private final Map<String, VendorInfo> mVendorInfoHashMap;
-    private final String[] mServiceType;
-    private final Observer mObserver;
-    private final ServiceResolveQueue mResolveQueue;
-    private List<NsdManager.DiscoveryListener> mListeners = new ArrayList<>();
-    public HashMap<String, PrinterHashMap> mVendorHashMap = new HashMap<>();
-
-    public interface Observer {
-        boolean matchesCriteria(String vendor, NsdServiceInfo serviceInfo);
-        void dataSetChanged();
-    }
-
-    public ServiceListener(Context context, Observer observer, String[] serviceTypes) {
-        mObserver = observer;
-        mServiceType = serviceTypes;
-        mNSDManager = (NsdManager)context.getSystemService(Context.NSD_SERVICE);
-        mResolveQueue = ServiceResolveQueue.getInstance(mNSDManager);
-
-        Map<String, VendorInfo> vendorInfoMap = new HashMap<>();
-        TypedArray testArray = context.getResources().obtainTypedArray(R.array.known_print_plugin_vendors);
-        for(int i = 0; i < testArray.length(); i++) {
-            int arrayID = testArray.getResourceId(i, 0);
-            if (arrayID != 0) {
-                VendorInfo info = new VendorInfo(context.getResources(), arrayID);
-                vendorInfoMap.put(info.mVendorID, info);
-                vendorInfoMap.put(info.mPackageName, info);
-            }
-        }
-        testArray.recycle();
-        mVendorInfoHashMap = vendorInfoMap;
-    }
-
-    @Override
-    public void serviceResolved(NsdServiceInfo nsdServiceInfo) {
-        printerFound(nsdServiceInfo);
-    }
-
-    private synchronized void printerFound(NsdServiceInfo nsdServiceInfo) {
-        if (nsdServiceInfo == null) return;
-        if (TextUtils.isEmpty(PrinterHashMap.getKey(nsdServiceInfo))) return;
-        String vendor = MDnsUtils.getVendor(nsdServiceInfo);
-        if (vendor == null) vendor = "";
-        for(Map.Entry<String,VendorInfo> entry : mVendorInfoHashMap.entrySet()) {
-            for(String vendorValues : entry.getValue().mDNSValues) {
-                if (vendor.equalsIgnoreCase(vendorValues)) {
-                    vendor = entry.getValue().mVendorID;
-                    break;
-                }
-            }
-            // intentional pointer check
-            //noinspection StringEquality
-            if ((vendor != entry.getValue().mVendorID) &&
-                    MDnsUtils.isVendorPrinter(nsdServiceInfo, entry.getValue().mDNSValues)) {
-                vendor = entry.getValue().mVendorID;
-            }
-            // intentional pointer check
-            //noinspection StringEquality
-            if (vendor == entry.getValue().mVendorID) break;
-        }
-
-        if (TextUtils.isEmpty(vendor)) {
-            return;
-        }
-
-        if (!mObserver.matchesCriteria(vendor, nsdServiceInfo))
-            return;
-        boolean mapsChanged;
-
-        PrinterHashMap vendorHash = mVendorHashMap.get(vendor);
-        if (vendorHash == null) {
-            vendorHash = new PrinterHashMap();
-        }
-        mapsChanged = (vendorHash.addPrinter(nsdServiceInfo) == null);
-        mVendorHashMap.put(vendor, vendorHash);
-
-        if (mapsChanged) {
-            mObserver.dataSetChanged();
-        }
-    }
-
-    private synchronized void printerRemoved(NsdServiceInfo nsdServiceInfo) {
-        boolean wasRemoved = false;
-        Set<String> vendors = mVendorHashMap.keySet();
-        for(String vendor : vendors) {
-            PrinterHashMap map = mVendorHashMap.get(vendor);
-            wasRemoved |= (map.removePrinter(nsdServiceInfo) != null);
-            if (map.isEmpty()) wasRemoved |= (mVendorHashMap.remove(vendor) != null);
-        }
-        if (wasRemoved) {
-            mObserver.dataSetChanged();
-        }
-    }
-
-    public void start() {
-        stop();
-        for(final String service :mServiceType) {
-            NsdManager.DiscoveryListener listener = new NsdManager.DiscoveryListener() {
-                @Override
-                public void onStartDiscoveryFailed(String s, int i) {
-
-                }
-
-                @Override
-                public void onStopDiscoveryFailed(String s, int i) {
-
-                }
-
-                @Override
-                public void onDiscoveryStarted(String s) {
-
-                }
-
-                @Override
-                public void onDiscoveryStopped(String s) {
-
-                }
-
-                @Override
-                public void onServiceFound(NsdServiceInfo nsdServiceInfo) {
-                    mResolveQueue.queueRequest(nsdServiceInfo, ServiceListener.this);
-                }
-
-                @Override
-                public void onServiceLost(NsdServiceInfo nsdServiceInfo) {
-                    mResolveQueue.removeRequest(nsdServiceInfo, ServiceListener.this);
-                    printerRemoved(nsdServiceInfo);
-                }
-            };
-            DiscoveryListenerMultiplexer.addListener(mNSDManager, service, listener);
-            mListeners.add(listener);
-        }
-    }
-
-    public void stop() {
-        for(NsdManager.DiscoveryListener listener : mListeners) {
-            DiscoveryListenerMultiplexer.removeListener(mNSDManager, listener);
-        }
-        mVendorHashMap.clear();
-        mListeners.clear();
-    }
-
-    public Pair<Integer, Integer> getCount() {
-        int count = 0;
-        for (PrinterHashMap map : mVendorHashMap.values()) {
-            count += map.size();
-        }
-        return Pair.create(mVendorHashMap.size(), count);
-    }
-}
diff --git a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/ServiceRecommendationPlugin.java b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/ServiceRecommendationPlugin.java
deleted file mode 100644
index 9d15f3054ee2..000000000000
--- a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/ServiceRecommendationPlugin.java
+++ /dev/null
@@ -1,86 +0,0 @@
-/*
- * Copyright (C) 2016 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 com.android.printservice.recommendation.plugin.samsung;
-
-import android.content.Context;
-import android.net.nsd.NsdManager;
-import android.net.nsd.NsdServiceInfo;
-import android.annotation.NonNull;
-import android.text.TextUtils;
-import com.android.printservice.recommendation.PrintServicePlugin;
-
-public abstract class ServiceRecommendationPlugin implements PrintServicePlugin, ServiceListener.Observer {
-
-    protected static final String PDL_ATTRIBUTE = "pdl";
-
-    protected final Object mLock = new Object();
-    protected PrinterDiscoveryCallback mCallback = null;
-    protected final ServiceListener mListener;
-    protected final NsdManager mNSDManager;
-    protected final VendorInfo mVendorInfo;
-    private final int mVendorStringID;
-
-    protected ServiceRecommendationPlugin(Context context, int vendorStringID, VendorInfo vendorInfo, String[] services) {
-        mNSDManager = (NsdManager)context.getSystemService(Context.NSD_SERVICE);
-        mVendorStringID = vendorStringID;
-        mVendorInfo = vendorInfo;
-        mListener = new ServiceListener(context, this, services);
-    }
-
-    @Override
-    public int getName() {
-        return mVendorStringID;
-    }
-
-    @NonNull
-    @Override
-    public CharSequence getPackageName() {
-        return mVendorInfo.mPackageName;
-    }
-
-    @Override
-    public void start(@NonNull PrinterDiscoveryCallback callback) throws Exception {
-        synchronized (mLock) {
-            mCallback = callback;
-        }
-        mListener.start();
-    }
-
-    @Override
-    public void stop() throws Exception {
-        synchronized (mLock) {
-            mCallback = null;
-        }
-        mListener.stop();
-    }
-
-    @Override
-    public void dataSetChanged() {
-        synchronized (mLock) {
-            if (mCallback != null) mCallback.onChanged(getCount());
-        }
-    }
-
-    @Override
-    public boolean matchesCriteria(String vendor, NsdServiceInfo nsdServiceInfo) {
-        return TextUtils.equals(vendor, mVendorInfo.mVendorID);
-    }
-
-    public int getCount() {
-        return mListener.getCount().second;
-    }
-}
diff --git a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/ServiceResolveQueue.java b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/ServiceResolveQueue.java
deleted file mode 100644
index e5691b734416..000000000000
--- a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/ServiceResolveQueue.java
+++ /dev/null
@@ -1,109 +0,0 @@
-/*
- * Copyright (C) 2016 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 com.android.printservice.recommendation.plugin.samsung;
-
-import android.net.nsd.NsdManager;
-import android.net.nsd.NsdServiceInfo;
-import android.util.Pair;
-import com.android.printservice.recommendation.util.NsdResolveQueue;
-
-import java.util.LinkedList;
-
-final class ServiceResolveQueue {
-
-    private final NsdManager mNsdManager;
-    private final LinkedList<Pair<NsdServiceInfo, ResolveCallback>> mQueue = new LinkedList<>();
-    private final Object mLock = new Object();
-
-    private static Object sLock = new Object();
-    private static ServiceResolveQueue sInstance = null;
-    private final NsdResolveQueue mNsdResolveQueue;
-    private Pair<NsdServiceInfo, ResolveCallback> mCurrentRequest = null;
-
-    public static void createInstance(NsdManager nsdManager) {
-        if (sInstance == null) sInstance = new ServiceResolveQueue(nsdManager);
-    }
-
-    public static ServiceResolveQueue getInstance(NsdManager nsdManager) {
-        synchronized (sLock) {
-            createInstance(nsdManager);
-            return sInstance;
-        }
-    }
-
-    public static void destroyInstance() {
-        sInstance = null;
-    }
-
-    public interface ResolveCallback {
-        void serviceResolved(NsdServiceInfo nsdServiceInfo);
-    }
-
-    public ServiceResolveQueue(NsdManager nsdManager) {
-        mNsdManager = nsdManager;
-        mNsdResolveQueue = NsdResolveQueue.getInstance();
-    }
-
-    public void queueRequest(NsdServiceInfo serviceInfo, ResolveCallback callback) {
-        synchronized (mLock) {
-            Pair<NsdServiceInfo, ResolveCallback> newRequest = Pair.create(serviceInfo, callback);
-            if (mQueue.contains(newRequest)) return;
-            mQueue.add(newRequest);
-            makeNextRequest();
-        }
-    }
-
-    public void removeRequest(NsdServiceInfo serviceInfo, ResolveCallback callback) {
-        synchronized (mLock) {
-            Pair<NsdServiceInfo, ResolveCallback> newRequest = Pair.create(serviceInfo, callback);
-            mQueue.remove(newRequest);
-            if ((mCurrentRequest != null) && newRequest.equals(mCurrentRequest)) mCurrentRequest = null;
-        }
-    }
-
-    private void makeNextRequest() {
-        synchronized (mLock) {
-            if (mCurrentRequest != null) return;
-            if (mQueue.isEmpty()) return;
-            mCurrentRequest = mQueue.removeFirst();
-            mNsdResolveQueue.resolve(mNsdManager, mCurrentRequest.first,
-                    new NsdManager.ResolveListener() {
-                        @Override
-                        public void onResolveFailed(NsdServiceInfo nsdServiceInfo, int i) {
-                            synchronized (mLock) {
-                                if (mCurrentRequest != null) mQueue.add(mCurrentRequest);
-                                makeNextRequest();
-                            }
-                        }
-
-                        @Override
-                        public void onServiceResolved(NsdServiceInfo nsdServiceInfo) {
-                            synchronized (mLock) {
-                                if (mCurrentRequest != null) {
-                                    mCurrentRequest.second.serviceResolved(nsdServiceInfo);
-                                    mCurrentRequest = null;
-                                }
-                                makeNextRequest();
-                            }
-                        }
-                    });
-
-        }
-    }
-
-
-}
diff --git a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/VendorInfo.java b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/VendorInfo.java
deleted file mode 100644
index 0ebb4e441f11..000000000000
--- a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/samsung/VendorInfo.java
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * Copyright (C) 2016 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 com.android.printservice.recommendation.plugin.samsung;
-
-import android.content.res.Resources;
-
-import java.util.Arrays;
-
-public final class VendorInfo {
-
-    public final String mPackageName;
-    public final String mVendorID;
-    public final String[] mDNSValues;
-    public final int mID;
-
-    public VendorInfo(Resources resources, int vendor_info_id) {
-        mID = vendor_info_id;
-        String[] data = resources.getStringArray(vendor_info_id);
-        if ((data == null) || (data.length < 2)) {
-            data = new String[] { null, null };
-        }
-        mPackageName = data[0];
-        mVendorID = data[1];
-        mDNSValues = (data.length > 2) ? Arrays.copyOfRange(data, 2, data.length) : new String[]{};
-    }
-}
diff --git a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/util/MDNSFilteredDiscovery.java b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/util/MDNSFilteredDiscovery.java
new file mode 100644
index 000000000000..c5dbc8c32e91
--- /dev/null
+++ b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/util/MDNSFilteredDiscovery.java
@@ -0,0 +1,212 @@
+/*
+ * Copyright (C) 2016 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 com.android.printservice.recommendation.util;
+
+import android.content.Context;
+import android.net.nsd.NsdManager;
+import android.net.nsd.NsdServiceInfo;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.util.Log;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.util.Preconditions;
+import com.android.printservice.recommendation.PrintServicePlugin;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * A discovery listening for mDNS results and only adding the ones that {@link
+ * PrinterFilter#matchesCriteria match} configured list
+ */
+public class MDNSFilteredDiscovery implements NsdManager.DiscoveryListener  {
+    private static final String LOG_TAG = "MDNSFilteredDiscovery";
+
+    /**
+     * mDNS service filter interface.
+     * Implement {@link PrinterFilter#matchesCriteria} to filter out supported services
+     */
+    public interface PrinterFilter {
+        /**
+         * Main filter method. Should return true if mDNS service is supported
+         * by the print service plugin
+         *
+         * @param nsdServiceInfo The service info to check
+         *
+         * @return True if service is supported by the print service plugin
+         */
+        boolean matchesCriteria(NsdServiceInfo nsdServiceInfo);
+    }
+
+    /** Printer identifiers of the mPrinters found. */
+    @GuardedBy("mLock")
+    private final @NonNull HashSet<String> mPrinters;
+
+    /** Service types discovered by this plugin */
+    private final @NonNull HashSet<String> mServiceTypes;
+
+    /** Context of the user of this plugin */
+    private final @NonNull Context mContext;
+
+    /** mDNS services filter */
+    private final @NonNull PrinterFilter mPrinterFilter;
+
+    /**
+     * Call back to report the number of mPrinters found.
+     *
+     * We assume that {@link #start} and {@link #stop} are never called in parallel, hence it is
+     * safe to not synchronize access to this field.
+     */
+    private @Nullable PrintServicePlugin.PrinterDiscoveryCallback mCallback;
+
+    /** Queue used to resolve nsd infos */
+    private final @NonNull NsdResolveQueue mResolveQueue;
+
+    /**
+     * Create new stub that assumes that a print service can be used to print on all mPrinters
+     * matching some mDNS names.
+     *
+     * @param context       The context the plugin runs in
+     * @param serviceTypes  The mDNS service types to listen to.
+     * @param printerFilter The filter for mDNS services
+     */
+    public MDNSFilteredDiscovery(@NonNull Context context,
+            @NonNull Set<String> serviceTypes,
+            @NonNull PrinterFilter printerFilter) {
+        mContext = Preconditions.checkNotNull(context, "context");
+        mServiceTypes = new HashSet<>(Preconditions
+                .checkCollectionNotEmpty(Preconditions.checkCollectionElementsNotNull(serviceTypes,
+                        "serviceTypes"), "serviceTypes"));
+        mPrinterFilter = Preconditions.checkNotNull(printerFilter, "printerFilter");
+
+        mResolveQueue = NsdResolveQueue.getInstance();
+        mPrinters = new HashSet<>();
+    }
+
+    /**
+     * @return The NDS manager
+     */
+    private NsdManager getNDSManager() {
+        return (NsdManager) mContext.getSystemService(Context.NSD_SERVICE);
+    }
+
+    /**
+     * Start the discovery.
+     *
+     * @param callback Callbacks used by this plugin.
+     */
+    public void start(@NonNull PrintServicePlugin.PrinterDiscoveryCallback callback) {
+        mCallback = callback;
+        mCallback.onChanged(mPrinters.size());
+
+        for (String serviceType : mServiceTypes) {
+            DiscoveryListenerMultiplexer.addListener(getNDSManager(), serviceType, this);
+        }
+    }
+
+    /**
+     * Stop the discovery. This can only return once the plugin is completely finished and cleaned up.
+     */
+    public void stop() {
+        mCallback.onChanged(0);
+        mCallback = null;
+
+        for (int i = 0; i < mServiceTypes.size(); ++i) {
+            DiscoveryListenerMultiplexer.removeListener(getNDSManager(), this);
+        }
+    }
+
+    /**
+     *
+     * @return The number of discovered printers
+     */
+    public int getCount() {
+        return mPrinters.size();
+    }
+
+    @Override
+    public void onStartDiscoveryFailed(String serviceType, int errorCode) {
+        Log.w(LOG_TAG, "Failed to start network discovery for type " + serviceType + ": "
+                + errorCode);
+    }
+
+    @Override
+    public void onStopDiscoveryFailed(String serviceType, int errorCode) {
+        Log.w(LOG_TAG, "Failed to stop network discovery for type " + serviceType + ": "
+                + errorCode);
+    }
+
+    @Override
+    public void onDiscoveryStarted(String serviceType) {
+        // empty
+    }
+
+    @Override
+    public void onDiscoveryStopped(String serviceType) {
+        mPrinters.clear();
+    }
+
+    @Override
+    public void onServiceFound(NsdServiceInfo serviceInfo) {
+        mResolveQueue.resolve(getNDSManager(), serviceInfo,
+                new NsdManager.ResolveListener() {
+                    @Override
+                    public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode) {
+                        Log.w(LOG_TAG, "Service found: could not resolve " + serviceInfo + ": " +
+                                errorCode);
+                    }
+
+                    @Override
+                    public void onServiceResolved(NsdServiceInfo serviceInfo) {
+                        if (mPrinterFilter.matchesCriteria(serviceInfo)) {
+                            if (mCallback != null) {
+                                boolean added = mPrinters.add(serviceInfo.getHost().getHostAddress());
+                                if (added) {
+                                    mCallback.onChanged(mPrinters.size());
+                                }
+                            }
+                        }
+                    }
+                });
+    }
+
+    @Override
+    public void onServiceLost(NsdServiceInfo serviceInfo) {
+        mResolveQueue.resolve(getNDSManager(), serviceInfo,
+                new NsdManager.ResolveListener() {
+                    @Override
+                    public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode) {
+                        Log.w(LOG_TAG, "Service lost: Could not resolve " + serviceInfo + ": "
+                                + errorCode);
+                    }
+
+                    @Override
+                    public void onServiceResolved(NsdServiceInfo serviceInfo) {
+                        if (mPrinterFilter.matchesCriteria(serviceInfo)) {
+                            if (mCallback != null) {
+                                boolean removed = mPrinters
+                                        .remove(serviceInfo.getHost().getHostAddress());
+
+                                if (removed) {
+                                    mCallback.onChanged(mPrinters.size());
+                                }
+                            }
+                        }
+                    }
+                });
+    }
+}
\ No newline at end of file
diff --git a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/mdnsFilter/MDNSUtils.java b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/util/MDNSUtils.java
index 4c27a47e144f..a6df3c8f2c24 100644
--- a/packages/PrintRecommendationService/src/com/android/printservice/recommendation/plugin/mdnsFilter/MDNSUtils.java
+++ b/packages/PrintRecommendationService/src/com/android/printservice/recommendation/util/MDNSUtils.java
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package com.android.printservice.recommendation.plugin.mdnsFilter;
+package com.android.printservice.recommendation.util;
 
 import android.annotation.NonNull;
 import android.net.nsd.NsdServiceInfo;
@@ -27,12 +27,15 @@ import java.util.Set;
 /**
  * Utils for dealing with mDNS attributes
  */
-class MDNSUtils {
+public class MDNSUtils {
     public static final String ATTRIBUTE_TY = "ty";
     public static final String ATTRIBUTE_PRODUCT = "product";
     public static final String ATTRIBUTE_USB_MFG = "usb_mfg";
     public static final String ATTRIBUTE_MFG = "mfg";
 
+    private MDNSUtils() {
+    }
+
     /**
      * Check if the service has any of a set of vendor names.
      *
@@ -95,4 +98,35 @@ class MDNSUtils {
     private static boolean containsString(@NonNull String container, @NonNull String contained) {
         return container.equalsIgnoreCase(contained) || container.contains(contained + " ");
     }
+
+    /**
+     * Return String from mDNS attribute byte array
+     *
+     * @param value the byte array with string data
+     *
+     * @return constructed string
+     */
+    public static String getString(byte[] value) {
+        if (value != null) return new String(value, StandardCharsets.UTF_8);
+        return null;
+    }
+
+    /**
+     * Check if service has a type of supported types set
+     *
+     * @param serviceInfo   The service
+     * @param serviceTypes  The supported service types set
+     *
+     * @return true if service has a type of supported types set
+     */
+    public static boolean isSupportedServiceType(@NonNull NsdServiceInfo serviceInfo,
+            @NonNull Set<String> serviceTypes) {
+        String curType = serviceInfo.getServiceType().toLowerCase();
+        for (String type : serviceTypes) {
+            if (curType.contains(type.toLowerCase())) {
+                return true;
+            }
+        }
+        return false;
+    }
 }