Integrate QR Code library instead of requiring the app to be installed, also due to security reasons

OpenKeychain/build.gradle

@@ -10,8 +10,6 @@ dependencies {
     compile project(':extern:openkeychain-api-lib')
     compile project(':extern:html-textview')
     compile project(':extern:StickyListHeaders:library')
-    compile project(':extern:zxing-qr-code')
-    compile project(':extern:zxing-android-integration')
     compile project(':extern:spongycastle:core')
     compile project(':extern:spongycastle:pg')
     compile project(':extern:spongycastle:pkix')
@@ -22,6 +20,11 @@ dependencies {
     compile project(':extern:TokenAutoComplete:library')
     compile project(':extern:safeslinger-exchange')
     compile project(':extern:android-lockpattern:code')
+
+    // TODO: include as submodule?:
+    compile 'com.journeyapps:zxing-android-embedded:2.0.1@aar'
+    compile 'com.journeyapps:zxing-android-integration:2.0.1@aar'
+    compile 'com.google.zxing:core:3.0.1'
 }
 
 android {

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

@@ -78,7 +78,11 @@ public class QrCodeScanActivity extends FragmentActivity {
             // scan using xzing's Barcode Scanner and return result parcel in OpenKeychain
 
             returnResult = true;
-            new IntentIntegrator(this).initiateScan();
+            IntentIntegrator integrator = new IntentIntegrator(this);
+            integrator.setDesiredBarcodeFormats(IntentIntegrator.QR_CODE_TYPES)
+                    .setPrompt(getString(R.string.import_qr_code_text))
+                    .setResultDisplayDuration(0)
+                    .initiateScan();
         } else if (ACTION_QR_CODE_API.equals(action)) {
             // scan using xzing's Barcode Scanner from outside OpenKeychain
 
@@ -168,7 +172,7 @@ public class QrCodeScanActivity extends FragmentActivity {
                         return;
                     }
 
-                    if ( ! result.success()) {
+                    if (!result.success()) {
                         // only return if no success...
                         Intent data = new Intent();
                         data.putExtras(returnData);

OpenKeychain/src/main/res/values/strings.xml

@@ -395,6 +395,7 @@
     <string name="import_qr_code_wrong">"QR Code malformed! Please try again!"</string>
     <string name="import_qr_code_too_short_fingerprint">"Fingerprint is too short (&lt; 16 characters)"</string>
     <string name="import_qr_code_button">"Scan QR Code"</string>
+    <string name="import_qr_code_text">"Place your camera over the QR Code!"</string>
 
     <!-- Generic result toast -->
     <string name="view_log">"View Log"</string>