Add the ability to show qr codes of stored accounts

Signed-off-by: Tilo Spannagel <development@tilosp.de>

app/src/main/java/org/shadowice/flocke/andotp/Database/Entry.java

@@ -276,6 +276,46 @@ public class Entry {
         return jsonObj;
     }
 
+    public Uri toUri() {
+        String type;
+        switch (this.type) {
+            case TOTP:
+                type = "totp";
+                break;
+            case HOTP:
+                type = "hotp";
+                break;
+            default:
+                return null;
+        }
+        Uri.Builder builder = new Uri.Builder()
+                .scheme("otpauth")
+                .authority(type)
+                .appendPath(this.label)
+                .appendQueryParameter("secret", new Base32().encodeAsString(this.secret));
+        if (this.issuer != null) {
+            builder.appendQueryParameter("issuer", this.issuer);
+        }
+        switch (this.type) {
+            case HOTP:
+                builder.appendQueryParameter("counter", Long.toString(this.counter));
+            case TOTP:
+                if (this.period != TokenCalculator.TOTP_DEFAULT_PERIOD)
+                    builder.appendQueryParameter("period", Integer.toString(this.period));
+                break;
+        }
+        if (this.digits != TokenCalculator.TOTP_DEFAULT_DIGITS) {
+            builder.appendQueryParameter("digits", Integer.toString(this.digits));
+        }
+        if (this.algorithm != TokenCalculator.DEFAULT_ALGORITHM) {
+            builder.appendQueryParameter("algorithm", this.algorithm.name());
+        }
+        for (String tag : this.tags) {
+            builder.appendQueryParameter("tags", tag);
+        }
+        return builder.build();
+    }
+
     public boolean isTimeBased() {
         return type == OTPType.TOTP || type == OTPType.STEAM;
     }

app/src/main/java/org/shadowice/flocke/andotp/View/EntriesCardAdapter.java

@@ -27,6 +27,8 @@ import android.content.ClipData;
 import android.content.ClipboardManager;
 import android.content.Context;
 import android.content.DialogInterface;
+import android.graphics.Bitmap;
+import android.graphics.drawable.BitmapDrawable;
 import android.net.Uri;
 import android.os.Handler;
 import androidx.annotation.NonNull;
@@ -46,9 +48,13 @@ import android.widget.Filter;
 import android.widget.Filterable;
 import android.widget.FrameLayout;
 import android.widget.GridView;
+import android.widget.ImageView;
 import android.widget.LinearLayout;
 import android.widget.Toast;
 
+import com.google.zxing.BarcodeFormat;
+import com.journeyapps.barcodescanner.BarcodeEncoder;
+
 import org.shadowice.flocke.andotp.Activities.MainActivity;
 import org.shadowice.flocke.andotp.Database.Entry;
 import org.shadowice.flocke.andotp.Dialogs.TagsDialog;
@@ -681,6 +687,35 @@ public class EntriesCardAdapter extends RecyclerView.Adapter<EntryViewHolder>
                 .show();
     }
 
+    private void showQRCode(final int pos) {
+        Uri uri = displayedEntries.get(pos).toUri();
+        if (uri != null) {
+            Bitmap bitmap;
+            try {
+                bitmap = new BarcodeEncoder().encodeBitmap(uri.toString(), BarcodeFormat.QR_CODE, 0, 0);
+            } catch(Exception ignored) {
+                Toast.makeText(context, R.string.toast_qr_failed_to_generate, Toast.LENGTH_LONG).show();
+                return;
+            }
+            BitmapDrawable drawable = new BitmapDrawable(context.getResources(), bitmap);
+            drawable.setFilterBitmap(false);
+
+            ImageView image = new ImageView(context);
+            image.setAdjustViewBounds(true);
+            image.setScaleType(ImageView.ScaleType.FIT_CENTER);
+            image.setImageDrawable(drawable);
+
+            new AlertDialog.Builder(context)
+                    .setTitle(R.string.dialog_title_qr_code)
+                    .setPositiveButton(android.R.string.ok, (dialog, which) -> {})
+                    .setView(image)
+                    .create()
+                    .show();
+        } else {
+            Toast.makeText(context, R.string.toast_qr_unsuported, Toast.LENGTH_LONG).show();
+        }
+    }
+
     private void showPopupMenu(View view, final int pos) {
         View menuItemView = view.findViewById(R.id.menuButton);
         PopupMenu popup = new PopupMenu(view.getContext(), menuItemView);
@@ -707,6 +742,9 @@ public class EntriesCardAdapter extends RecyclerView.Adapter<EntryViewHolder>
                 } else if (id == R.id.menu_popup_remove) {
                     removeItem(pos);
                     return true;
+                } else if (id == R.id.menu_popup_show_qr_code) {
+                    showQRCode(pos);
+                    return true;
                 } else {
                     return false;
                 }

app/src/main/res/menu/menu_popup.xml

@@ -20,4 +20,8 @@
         android:id="@+id/menu_popup_remove"
         android:title="@string/menu_popup_remove" />
 
+    <item
+        android:id="@+id/menu_popup_show_qr_code"
+        android:title="@string/menu_popup_show_qr_code" />
+
 </menu>

app/src/main/res/values/strings_main.xml

@@ -57,6 +57,7 @@
     <string name="menu_popup_change_image">Change image</string>
     <string name="menu_popup_edit_tags">Edit tags</string>
     <string name="menu_popup_remove">Remove</string>
+    <string name="menu_popup_show_qr_code">Show QR Code</string>
 
     <!-- Toast messages -->
     <string name="toast_auth_failed">Authentication failed, please try again!</string>
@@ -71,6 +72,8 @@
     <string name="toast_qr_error">Could not find/confirm QR code</string>
     <string name="toast_qr_checksum_exception">Checksum verification failed while decoding QR code</string>
     <string name="toast_qr_format_error">Format error in QR code</string>
+    <string name="toast_qr_unsuported">QR Code not supported</string>
+    <string name="toast_qr_failed_to_generate">Failed to generate QR Code</string>
 
     <!-- Dialogs -->
     <string name="dialog_title_auth">Authenticate</string>
@@ -80,6 +83,7 @@
     <string name="dialog_title_counter">Counter</string>
     <string name="dialog_title_used_tokens">Used tokens</string>
     <string name="dialog_title_keystore_error">KeyStore error</string>
+    <string name="dialog_title_qr_code">QR Code</string>
 
     <string name="dialog_title_enter_password">Enter password</string>