Implemented #1162: Invoke NFC in Advanced View

- Extracted NFC code from ViewKeyActivity to NfcHelper to share code between classes
 - Changed the private anonymous Handler for NFC into a static private subclass, that uses WeakReference to avoid memory leaks
 - Added resources needed (retrieved from Graphics) for the NFC button inside ViewKeyAdvShareFragment.
 - Fixed the ripple boundary of the Share With... button to prevent it from bleeding to other buttons on the right (UX improvement)

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ViewKeyActivity.java

@@ -21,18 +21,12 @@ package org.sufficientlysecure.keychain.ui;
 import android.animation.ArgbEvaluator;
 import android.animation.ObjectAnimator;
 import android.annotation.SuppressLint;
-import android.annotation.TargetApi;
 import android.app.Activity;
 import android.app.ActivityOptions;
 import android.content.Intent;
-import android.content.pm.PackageManager;
 import android.database.Cursor;
 import android.graphics.Bitmap;
 import android.net.Uri;
-import android.nfc.NdefMessage;
-import android.nfc.NdefRecord;
-import android.nfc.NfcAdapter;
-import android.nfc.NfcEvent;
 import android.os.AsyncTask;
 import android.os.Build;
 import android.os.Bundle;
@@ -40,7 +34,6 @@ import android.os.Handler;
 import android.os.Message;
 import android.os.Messenger;
 import android.provider.ContactsContract;
-import android.provider.Settings;
 import android.support.v4.app.ActivityCompat;
 import android.support.v4.app.LoaderManager;
 import android.support.v4.content.CursorLoader;
@@ -58,9 +51,7 @@ import android.widget.ImageView;
 import android.widget.RelativeLayout;
 import android.widget.TextView;
 import android.widget.Toast;
-
 import com.getbase.floatingactionbutton.FloatingActionButton;
-
 import org.sufficientlysecure.keychain.Constants;
 import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.keyimport.ParcelableKeyRing;
@@ -84,6 +75,7 @@ import org.sufficientlysecure.keychain.ui.util.QrCodeUtils;
 import org.sufficientlysecure.keychain.util.ContactHelper;
 import org.sufficientlysecure.keychain.util.ExportHelper;
 import org.sufficientlysecure.keychain.util.Log;
+import org.sufficientlysecure.keychain.util.NfcHelper;
 import org.sufficientlysecure.keychain.util.Preferences;
 
 import java.util.ArrayList;
@@ -115,11 +107,7 @@ public class ViewKeyActivity extends BaseActivity implements
     private CardView mQrCodeLayout;
 
     // NFC
-    private NfcAdapter mNfcAdapter;
+    private NfcHelper mNfcHelper;
-    private NfcAdapter.CreateNdefMessageCallback mNdefCallback;
-    private NfcAdapter.OnNdefPushCompleteCallback mNdefCompleteCallback;
-    private byte[] mNfcKeyringBytes;
-    private static final int NFC_SENT = 1;
 
     private static final int LOADER_ID_UNIFIED = 0;
 
@@ -256,7 +244,7 @@ public class ViewKeyActivity extends BaseActivity implements
         mActionNfc.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
-                invokeNfcBeam();
+                mNfcHelper.invokeNfcBeam();
             }
         });
 
@@ -264,7 +252,8 @@ public class ViewKeyActivity extends BaseActivity implements
         // or start new ones.
         getSupportLoaderManager().initLoader(LOADER_ID_UNIFIED, null, this);
 
-        initNfc(mDataUri);
+        mNfcHelper = new NfcHelper(this, mProviderHelper);
+        mNfcHelper.initNfc(mDataUri);
 
         startFragment(savedInstanceState, mDataUri);
     }
@@ -375,41 +364,6 @@ public class ViewKeyActivity extends BaseActivity implements
         return true;
     }
 
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
-    private void invokeNfcBeam() {
-        // Check if device supports NFC
-        if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_NFC)) {
-            Notify.createNotify(this, R.string.no_nfc_support, Notify.LENGTH_LONG, Notify.Style.ERROR).show();
-            return;
-        }
-        // Check for available NFC Adapter
-        mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
-        if (mNfcAdapter == null || !mNfcAdapter.isEnabled()) {
-            Notify.createNotify(this, R.string.error_nfc_needed, Notify.LENGTH_LONG, Notify.Style.ERROR, new Notify.ActionListener() {
-                @Override
-                public void onAction() {
-                    Intent intentSettings = new Intent(Settings.ACTION_NFC_SETTINGS);
-                    startActivity(intentSettings);
-                }
-            }, R.string.menu_nfc_preferences).show();
-
-            return;
-        }
-
-        if (!mNfcAdapter.isNdefPushEnabled()) {
-            Notify.createNotify(this, R.string.error_beam_needed, Notify.LENGTH_LONG, Notify.Style.ERROR, new Notify.ActionListener() {
-                @Override
-                public void onAction() {
-                    Intent intentSettings = new Intent(Settings.ACTION_NFCSHARING_SETTINGS);
-                    startActivity(intentSettings);
-                }
-            }, R.string.menu_beam_preferences).show();
-
-            return;
-        }
-
-        mNfcAdapter.invokeBeam(this);
-    }
 
     private void scanQrCode() {
         Intent scanQrCode = new Intent(this, ImportKeysProxyActivity.class);
@@ -710,95 +664,6 @@ public class ViewKeyActivity extends BaseActivity implements
         loadTask.execute();
     }
 
-    /**
-     * NFC: Initialize NFC sharing if OS and device supports it
-     */
-    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
-    private void initNfc(final Uri dataUri) {
-        // check if NFC Beam is supported (>= Android 4.1)
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
-
-            // Implementation for the CreateNdefMessageCallback interface
-            mNdefCallback = new NfcAdapter.CreateNdefMessageCallback() {
-                @Override
-                public NdefMessage createNdefMessage(NfcEvent event) {
-                    /*
-                     * When a device receives a push with an AAR in it, the application specified in the AAR is
-                     * guaranteed to run. The AAR overrides the tag dispatch system. You can add it back in to
-                     * guarantee that this activity starts when receiving a beamed message. For now, this code
-                     * uses the tag dispatch system.
-                     */
-                    return new NdefMessage(NdefRecord.createMime(Constants.NFC_MIME,
-                            mNfcKeyringBytes), NdefRecord.createApplicationRecord(Constants.PACKAGE_NAME));
-                }
-            };
-
-            // Implementation for the OnNdefPushCompleteCallback interface
-            mNdefCompleteCallback = new NfcAdapter.OnNdefPushCompleteCallback() {
-                @Override
-                public void onNdefPushComplete(NfcEvent event) {
-                    // A handler is needed to send messages to the activity when this
-                    // callback occurs, because it happens from a binder thread
-                    mNfcHandler.obtainMessage(NFC_SENT).sendToTarget();
-                }
-            };
-
-            // Check for available NFC Adapter
-            mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
-            if (mNfcAdapter != null) {
-                /*
-                 * Retrieve mNfcKeyringBytes here asynchronously (to not block the UI)
-                 * and init nfc adapter afterwards.
-                 * mNfcKeyringBytes can not be retrieved in createNdefMessage, because this process
-                 * has no permissions to query the Uri.
-                 */
-                AsyncTask<Void, Void, Void> initTask =
-                        new AsyncTask<Void, Void, Void>() {
-                            protected Void doInBackground(Void... unused) {
-                                try {
-                                    Uri blobUri =
-                                            KeychainContract.KeyRingData.buildPublicKeyRingUri(dataUri);
-                                    mNfcKeyringBytes = (byte[]) mProviderHelper.getGenericData(
-                                            blobUri,
-                                            KeychainContract.KeyRingData.KEY_RING_DATA,
-                                            ProviderHelper.FIELD_TYPE_BLOB);
-                                } catch (ProviderHelper.NotFoundException e) {
-                                    Log.e(Constants.TAG, "key not found!", e);
-                                }
-
-                                // no AsyncTask return (Void)
-                                return null;
-                            }
-
-                            protected void onPostExecute(Void unused) {
-                                // Register callback to set NDEF message
-                                mNfcAdapter.setNdefPushMessageCallback(mNdefCallback,
-                                        ViewKeyActivity.this);
-                                // Register callback to listen for message-sent success
-                                mNfcAdapter.setOnNdefPushCompleteCallback(mNdefCompleteCallback,
-                                        ViewKeyActivity.this);
-                            }
-                        };
-
-                initTask.execute();
-            }
-        }
-    }
-
-    /**
-     * NFC: This handler receives a message from onNdefPushComplete
-     */
-    private final Handler mNfcHandler = new Handler() {
-        @Override
-        public void handleMessage(Message msg) {
-            switch (msg.what) {
-                case NFC_SENT:
-                    Notify.showNotify(
-                            ViewKeyActivity.this, R.string.nfc_successful, Notify.Style.INFO);
-                    break;
-            }
-        }
-    };
 
     // These are the rows that we will retrieve.
     static final String[] PROJECTION = new String[] {

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ViewKeyAdvShareFragment.java

@@ -52,6 +52,7 @@ import org.sufficientlysecure.keychain.ui.util.KeyFormattingUtils;
 import org.sufficientlysecure.keychain.ui.util.Notify;
 import org.sufficientlysecure.keychain.ui.util.QrCodeUtils;
 import org.sufficientlysecure.keychain.util.Log;
+import org.sufficientlysecure.keychain.util.NfcHelper;
 
 import java.io.IOException;
 
@@ -68,10 +69,12 @@ public class ViewKeyAdvShareFragment extends LoaderFragment implements
     private View mFingerprintClipboardButton;
     private View mKeyShareButton;
     private View mKeyClipboardButton;
+    private View mKeyNfcButton;
     private ImageButton mKeySafeSlingerButton;
     private View mKeyUploadButton;
 
     ProviderHelper mProviderHelper;
+    NfcHelper mNfcHelper;
 
     private static final int LOADER_ID_UNIFIED = 0;
 
@@ -83,6 +86,7 @@ public class ViewKeyAdvShareFragment extends LoaderFragment implements
         View view = inflater.inflate(R.layout.view_key_adv_share_fragment, getContainer());
 
         mProviderHelper = new ProviderHelper(ViewKeyAdvShareFragment.this.getActivity());
+        mNfcHelper = new NfcHelper(getActivity(), mProviderHelper);
 
         mFingerprint = (TextView) view.findViewById(R.id.view_key_fingerprint);
         mQrCode = (ImageView) view.findViewById(R.id.view_key_qr_code);
@@ -90,6 +94,7 @@ public class ViewKeyAdvShareFragment extends LoaderFragment implements
         mFingerprintShareButton = view.findViewById(R.id.view_key_action_fingerprint_share);
         mFingerprintClipboardButton = view.findViewById(R.id.view_key_action_fingerprint_clipboard);
         mKeyShareButton = view.findViewById(R.id.view_key_action_key_share);
+        mKeyNfcButton = view.findViewById(R.id.view_key_action_key_nfc);
         mKeyClipboardButton = view.findViewById(R.id.view_key_action_key_clipboard);
         mKeySafeSlingerButton = (ImageButton) view.findViewById(R.id.view_key_action_key_safeslinger);
         mKeyUploadButton = view.findViewById(R.id.view_key_action_upload);
@@ -128,6 +133,14 @@ public class ViewKeyAdvShareFragment extends LoaderFragment implements
                 share(mDataUri, mProviderHelper, false, true);
             }
         });
+
+        mKeyNfcButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                mNfcHelper.invokeNfcBeam();
+            }
+        });
+
         mKeySafeSlingerButton.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
@@ -255,6 +268,9 @@ public class ViewKeyAdvShareFragment extends LoaderFragment implements
         // Prepare the loaders. Either re-connect with an existing ones,
         // or start new ones.
         getLoaderManager().initLoader(LOADER_ID_UNIFIED, null, this);
+
+        // Prepare the NfcHelper
+        mNfcHelper.initNfc(mDataUri);
     }
 
     static final String[] UNIFIED_PROJECTION = new String[] {
@@ -362,4 +378,5 @@ public class ViewKeyAdvShareFragment extends LoaderFragment implements
         startActivityForResult(uploadIntent, 0);
     }
 
+
 }

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/NfcHelper.java

@@ -0,0 +1,204 @@
+package org.sufficientlysecure.keychain.util;
+
+import android.annotation.TargetApi;
+import android.app.Activity;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.net.Uri;
+import android.nfc.NdefMessage;
+import android.nfc.NdefRecord;
+import android.nfc.NfcAdapter;
+import android.nfc.NfcEvent;
+import android.os.AsyncTask;
+import android.os.Build;
+import android.os.Handler;
+import android.os.Message;
+import android.provider.Settings;
+import org.sufficientlysecure.keychain.Constants;
+import org.sufficientlysecure.keychain.R;
+import org.sufficientlysecure.keychain.provider.KeychainContract;
+import org.sufficientlysecure.keychain.provider.ProviderHelper;
+import org.sufficientlysecure.keychain.ui.util.Notify;
+
+import java.lang.ref.WeakReference;
+
+/**
+ * This class contains NFC functionality that can be shared across Fragments or Activities.
+ * <p/>
+ * Created on Mar 20, 2015.
+ *
+ * @author Kent
+ */
+
+public class NfcHelper {
+
+    private Activity mActivity;
+    private ProviderHelper mProviderHelper;
+
+    /**
+     * NFC: This handler receives a message from onNdefPushComplete
+     */
+    private static NfcHandler mNfcHandler;
+
+    private NfcAdapter mNfcAdapter;
+    private NfcAdapter.CreateNdefMessageCallback mNdefCallback;
+    private NfcAdapter.OnNdefPushCompleteCallback mNdefCompleteCallback;
+    private byte[] mNfcKeyringBytes;
+    private static final int NFC_SENT = 1;
+
+    /**
+     * Initializes the NfcHelper.
+     */
+    public NfcHelper(final Activity activity, final ProviderHelper providerHelper) {
+        mActivity = activity;
+        mProviderHelper = providerHelper;
+
+        mNfcHandler = new NfcHandler(mActivity);
+    }
+
+    /**
+     * Return true if the NFC Adapter of this Helper has any features enabled.
+     *
+     * @return true if this NFC Adapter has any features enabled
+     */
+    public boolean isEnabled() {
+        return mNfcAdapter.isEnabled();
+    }
+
+    /**
+     * NFC: Initialize NFC sharing if OS and device supports it
+     */
+    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
+    public void initNfc(final Uri dataUri) {
+        // check if NFC Beam is supported (>= Android 4.1)
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
+
+            // Implementation for the CreateNdefMessageCallback interface
+            mNdefCallback = new NfcAdapter.CreateNdefMessageCallback() {
+                @Override
+                public NdefMessage createNdefMessage(NfcEvent event) {
+                    /*
+                     * When a device receives a push with an AAR in it, the application specified in the AAR is
+                     * guaranteed to run. The AAR overrides the tag dispatch system. You can add it back in to
+                     * guarantee that this activity starts when receiving a beamed message. For now, this code
+                     * uses the tag dispatch system.
+                     */
+                    return new NdefMessage(NdefRecord.createMime(Constants.NFC_MIME,
+                            mNfcKeyringBytes), NdefRecord.createApplicationRecord(Constants.PACKAGE_NAME));
+                }
+            };
+
+            // Implementation for the OnNdefPushCompleteCallback interface
+            mNdefCompleteCallback = new NfcAdapter.OnNdefPushCompleteCallback() {
+                @Override
+                public void onNdefPushComplete(NfcEvent event) {
+                    // A handler is needed to send messages to the activity when this
+                    // callback occurs, because it happens from a binder thread
+                    mNfcHandler.obtainMessage(NFC_SENT).sendToTarget();
+                }
+            };
+
+            // Check for available NFC Adapter
+            mNfcAdapter = NfcAdapter.getDefaultAdapter(mActivity);
+            if (mNfcAdapter != null) {
+                /*
+                 * Retrieve mNfcKeyringBytes here asynchronously (to not block the UI)
+                 * and init nfc adapter afterwards.
+                 * mNfcKeyringBytes can not be retrieved in createNdefMessage, because this process
+                 * has no permissions to query the Uri.
+                 */
+                AsyncTask<Void, Void, Void> initTask =
+                        new AsyncTask<Void, Void, Void>() {
+                            protected Void doInBackground(Void... unused) {
+                                try {
+                                    Uri blobUri =
+                                            KeychainContract.KeyRingData.buildPublicKeyRingUri(dataUri);
+                                    mNfcKeyringBytes = (byte[]) mProviderHelper.getGenericData(
+                                            blobUri,
+                                            KeychainContract.KeyRingData.KEY_RING_DATA,
+                                            ProviderHelper.FIELD_TYPE_BLOB);
+                                } catch (ProviderHelper.NotFoundException e) {
+                                    Log.e(Constants.TAG, "key not found!", e);
+                                }
+
+                                // no AsyncTask return (Void)
+                                return null;
+                            }
+
+                            protected void onPostExecute(Void unused) {
+                                // Register callback to set NDEF message
+                                mNfcAdapter.setNdefPushMessageCallback(mNdefCallback,
+                                        mActivity);
+                                // Register callback to listen for message-sent success
+                                mNfcAdapter.setOnNdefPushCompleteCallback(mNdefCompleteCallback,
+                                        mActivity);
+                            }
+                        };
+
+                initTask.execute();
+            }
+        }
+    }
+
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    public void invokeNfcBeam() {
+        // Check if device supports NFC
+        if (!mActivity.getPackageManager().hasSystemFeature(PackageManager.FEATURE_NFC)) {
+            Notify.createNotify(mActivity, R.string.no_nfc_support, Notify.LENGTH_LONG, Notify.Style.ERROR).show();
+            return;
+        }
+        // Check for available NFC Adapter
+        mNfcAdapter = NfcAdapter.getDefaultAdapter(mActivity);
+        if (mNfcAdapter == null || !mNfcAdapter.isEnabled()) {
+            Notify.createNotify(mActivity, R.string.error_nfc_needed, Notify.LENGTH_LONG, Notify.Style.ERROR, new Notify.ActionListener() {
+                @Override
+                public void onAction() {
+                    Intent intentSettings = new Intent(Settings.ACTION_NFC_SETTINGS);
+                    mActivity.startActivity(intentSettings);
+                }
+            }, R.string.menu_nfc_preferences).show();
+
+            return;
+        }
+
+        if (!mNfcAdapter.isNdefPushEnabled()) {
+            Notify.createNotify(mActivity, R.string.error_beam_needed, Notify.LENGTH_LONG, Notify.Style.ERROR, new Notify.ActionListener() {
+                @Override
+                public void onAction() {
+                    Intent intentSettings = new Intent(Settings.ACTION_NFCSHARING_SETTINGS);
+                    mActivity.startActivity(intentSettings);
+                }
+            }, R.string.menu_beam_preferences).show();
+
+            return;
+        }
+
+        mNfcAdapter.invokeBeam(mActivity);
+    }
+
+    /**
+     * A static subclass of {@link Handler} with a {@link WeakReference} to an {@link Activity} to avoid memory leaks.
+     */
+    private static class NfcHandler extends Handler {
+        private final WeakReference<Activity> mActivityReference;
+
+        public NfcHandler(Activity activity) {
+            mActivityReference = new WeakReference<>(activity);
+        }
+
+        @Override
+        public void handleMessage(Message msg) {
+            Activity activity = mActivityReference.get();
+
+            if (activity != null) {
+                switch (msg.what) {
+                    case NFC_SENT:
+                        Notify.showNotify(
+                                activity, R.string.nfc_successful, Notify.Style.INFO);
+                        break;
+                }
+            }
+        }
+    }
+
+}

OpenKeychain/src/main/res/layout/view_key_adv_share_fragment.xml

@@ -99,14 +99,12 @@
             android:layout_weight="1" />
 
         <LinearLayout
-            android:id="@+id/view_key_action_key_share"
             android:layout_width="match_parent"
             android:layout_height="?android:attr/listPreferredItemHeight"
-            android:clickable="true"
-            android:background="?android:selectableItemBackground"
             android:orientation="horizontal">
 
             <TextView
+                android:id="@+id/view_key_action_key_share"
                 android:paddingLeft="8dp"
                 android:paddingRight="8dp"
                 android:textAppearance="?android:attr/textAppearanceMedium"
@@ -116,7 +114,25 @@
                 android:layout_weight="1"
                 android:drawableRight="@drawable/ic_share_grey_24dp"
                 android:drawablePadding="8dp"
-                android:gravity="center_vertical" />
+                android:gravity="center_vertical"
+                android:background="?android:selectableItemBackground"/>
+
+            <View
+                android:layout_width="1dip"
+                android:layout_height="match_parent"
+                android:gravity="right"
+                android:layout_marginBottom="8dp"
+                android:layout_marginTop="8dp"
+                android:background="?android:attr/listDivider" />
+
+            <ImageButton
+                android:id="@+id/view_key_action_key_nfc"
+                android:layout_width="wrap_content"
+                android:layout_height="match_parent"
+                android:padding="8dp"
+                android:src="@drawable/ic_nfc_grey_24dp"
+                android:layout_gravity="center_vertical"
+                android:background="?android:selectableItemBackground" />
 
             <View
                 android:layout_width="1dip"
@@ -154,6 +170,7 @@
 
         </LinearLayout>
 
+
         <View
             android:layout_width="match_parent"
             android:layout_height="1dip"