add qr scanning support

build.gradle

@@ -12,6 +12,8 @@ sourceCompatibility = 1.9
 
 repositories {
     mavenCentral()
+    maven { url 'https://oss.sonatype.org/content/groups/public' }
+    maven { url 'https://mymavenrepo.com/repo/29EACwkkGcoOKnbx3bxN/' }
 }
 
 javafx {
@@ -38,6 +40,10 @@ dependencies {
         exclude group: 'org.slf4j'
     }
     implementation('co.nstant.in:cbor:0.9')
+    implementation('com.nativelibs4java:bridj:0.7-20200803')
+    implementation('com.github.sarxos:webcam-capture:0.3.13-SNAPSHOT') {
+        exclude group: 'com.nativelibs4java', module: 'bridj'
+    }
     implementation('de.codecentric.centerdevice:centerdevice-nsmenufx:2.1.7')
     implementation('org.controlsfx:controlsfx:11.0.1' ) {
         exclude group: 'org.openjfx', module: 'javafx-base'

drongo

@@ -1 +1 @@
-Subproject commit 8d49cebcaca6ccb2ea699fe8141554d1470d0a97
+Subproject commit 97cf49276a5c87425682a3fd0e48ffe081ff71bb

src/main/java/com/sparrowwallet/sparrow/AppController.java

@@ -409,6 +409,28 @@ public class AppController implements Initializable {
         }
     }
 
+    public void openTransactionFromQR(ActionEvent event) {
+        QRScanDialog qrScanDialog = new QRScanDialog();
+        Optional<QRScanDialog.Result> optionalResult = qrScanDialog.showAndWait();
+        if(optionalResult.isPresent()) {
+            QRScanDialog.Result result = optionalResult.get();
+            if(result.transaction != null) {
+                Tab tab = addTransactionTab(null, result.transaction);
+                tabs.getSelectionModel().select(tab);
+            }
+            if(result.psbt != null) {
+                Tab tab = addTransactionTab(null, result.psbt);
+                tabs.getSelectionModel().select(tab);
+            }
+            if(result.error != null) {
+                showErrorDialog("Invalid QR Code", result.error);
+            }
+            if(result.exception != null) {
+                showErrorDialog("Error opening webcam", result.exception.getMessage());
+            }
+        }
+    }
+
     public void saveTransaction(ActionEvent event) {
         Tab selectedTab = tabs.getSelectionModel().getSelectedItem();
         TabData tabData = (TabData)selectedTab.getUserData();
@@ -784,7 +806,10 @@ public class AppController implements Initializable {
                     //As per BIP174, combine PSBTs with matching transactions so long as they are not yet finalized
                     if(transactionTabData.getPsbt() != null && psbt != null && !transactionTabData.getPsbt().isFinalized() && !psbt.isFinalized()) {
                         transactionTabData.getPsbt().combine(psbt);
+                        if(name != null && !name.isEmpty()) {
                             tab.setText(name);
+                        }
+
                         EventManager.get().post(new PSBTCombinedEvent(transactionTabData.getPsbt()));
                     }
 
@@ -1012,4 +1037,9 @@ public class AppController implements Initializable {
     public void requestTransactionOpen(RequestTransactionOpenEvent event) {
         openTransactionFromFile(null);
     }
+
+    @Subscribe
+    public void requestQRScan(RequestQRScanEvent event) {
+        openTransactionFromQR(null);
+    }
 }

src/main/java/com/sparrowwallet/sparrow/control/QRScanDialog.java

@@ -0,0 +1,191 @@
+package com.sparrowwallet.sparrow.control;
+
+import com.github.sarxos.webcam.WebcamResolution;
+import com.sparrowwallet.drongo.Utils;
+import com.sparrowwallet.drongo.protocol.Base43;
+import com.sparrowwallet.drongo.protocol.Transaction;
+import com.sparrowwallet.drongo.psbt.PSBT;
+import com.sparrowwallet.sparrow.ur.ResultType;
+import com.sparrowwallet.sparrow.ur.UR;
+import com.sparrowwallet.sparrow.ur.URDecoder;
+import javafx.application.Platform;
+import javafx.beans.value.ChangeListener;
+import javafx.beans.value.ObservableValue;
+import javafx.scene.control.ButtonBar;
+import javafx.scene.control.ButtonType;
+import javafx.scene.control.Dialog;
+import javafx.scene.control.DialogPane;
+import javafx.scene.layout.StackPane;
+import org.controlsfx.tools.Borders;
+
+public class QRScanDialog extends Dialog<QRScanDialog.Result> {
+    private final URDecoder decoder;
+    private final WebcamService webcamService;
+
+    private boolean isUr;
+    private QRScanDialog.Result result;
+
+    public QRScanDialog() {
+        this.decoder = new URDecoder();
+
+        this.webcamService = new WebcamService(WebcamResolution.VGA);
+        WebcamView webcamView = new WebcamView(webcamService);
+
+        final DialogPane dialogPane = getDialogPane();
+
+        StackPane stackPane = new StackPane();
+        stackPane.getChildren().add(webcamView.getView());
+
+        dialogPane.setContent(Borders.wrap(stackPane).lineBorder().outerPadding(0).innerPadding(0).buildAll());
+
+        webcamService.resultProperty().addListener(new QRResultListener());
+        webcamService.setOnFailed(failedEvent -> {
+            Platform.runLater(() -> setResult(new Result(failedEvent.getSource().getException())));
+        });
+        webcamService.start();
+        setOnCloseRequest(event -> {
+            Platform.runLater(webcamService::cancel);
+        });
+
+        final ButtonType cancelButtonType = new javafx.scene.control.ButtonType("Cancel", ButtonBar.ButtonData.CANCEL_CLOSE);
+        dialogPane.getButtonTypes().addAll(cancelButtonType);
+        dialogPane.setPrefWidth(660);
+        dialogPane.setPrefHeight(550);
+
+        setResultConverter(dialogButton -> dialogButton != cancelButtonType ? result : null);
+    }
+
+    private class QRResultListener implements ChangeListener<com.google.zxing.Result> {
+        @Override
+        public void changed(ObservableValue<? extends com.google.zxing.Result> observable, com.google.zxing.Result oldValue, com.google.zxing.Result qrResult) {
+            if(result != null) {
+                Platform.runLater(() -> setResult(result));
+            }
+
+            //Try text first
+            String qrtext = qrResult.getText();
+            if(isUr || qrtext.toLowerCase().startsWith(UR.UR_PREFIX)) {
+                isUr = true;
+                decoder.receivePart(qrtext);
+
+                if(decoder.getResult() != null) {
+                    URDecoder.Result urResult = decoder.getResult();
+                    if(urResult.type == ResultType.SUCCESS) {
+                        if(urResult.ur.getType().equals(UR.BYTES_TYPE)) {
+                            try {
+                                PSBT psbt = new PSBT(urResult.ur.toBytes());
+                                result = new Result(psbt);
+                                return;
+                            } catch(Exception e) {
+                                //ignore, bytes not parsable as PSBT
+                            }
+
+                            try {
+                                Transaction transaction = new Transaction(urResult.ur.toBytes());
+                                result = new Result(transaction);
+                                return;
+                            } catch(Exception e) {
+                                //ignore, bytes not parsable as tx
+                            }
+
+                            result = new Result("Parsed UR of type " + urResult.ur.getType() + " was not a PSBT or transaction");
+                        } else {
+                            result = new Result("Cannot parse UR type of " + urResult.ur.getType());
+                        }
+                    } else {
+                        result = new Result(urResult.error);
+                    }
+                }
+            } else {
+                PSBT psbt;
+                Transaction transaction;
+                try {
+                    psbt = PSBT.fromString(qrtext);
+                    result = new Result(psbt);
+                    return;
+                } catch(Exception e) {
+                    //Ignore, not parseable as Base64 or hex
+                }
+
+                try {
+                    psbt = new PSBT(qrResult.getRawBytes());
+                    result = new Result(psbt);
+                    return;
+                } catch(Exception e) {
+                    //Ignore, not parseable as raw bytes
+                }
+
+                try {
+                    transaction = new Transaction(Utils.hexToBytes(qrtext));
+                    result = new Result(transaction);
+                    return;
+                } catch(Exception e) {
+                    //Ignore, not parseable as hex
+                }
+
+                try {
+                    transaction = new Transaction(qrResult.getRawBytes());
+                    result = new Result(transaction);
+                    return;
+                } catch(Exception e) {
+                    //Ignore, not parseable as raw bytes
+                }
+
+                //Try Base43 used by Electrum
+                byte[] base43 = Base43.decode(qrResult.getText());
+                try {
+                    psbt = new PSBT(base43);
+                    result = new Result(psbt);
+                    return;
+                } catch(Exception e) {
+                    //Ignore, not parseable as base43 decoded bytes
+                }
+
+                try {
+                    transaction = new Transaction(base43);
+                    result = new Result(transaction);
+                    return;
+                } catch(Exception e) {
+                    //Ignore, not parseable as base43 decoded bytes
+                }
+
+                result = new Result("Cannot parse QR code into a PSBT or transaction");
+            }
+        }
+    }
+
+    public static class Result {
+        public final Transaction transaction;
+        public final PSBT psbt;
+        public final String error;
+        public final Throwable exception;
+
+        public Result(Transaction transaction) {
+            this.transaction = transaction;
+            this.psbt = null;
+            this.error = null;
+            this.exception = null;
+        }
+
+        public Result(PSBT psbt) {
+            this.transaction = null;
+            this.psbt = psbt;
+            this.error = null;
+            this.exception = null;
+        }
+
+        public Result(String error) {
+            this.transaction = null;
+            this.psbt = null;
+            this.error = error;
+            this.exception = null;
+        }
+
+        public Result(Throwable exception) {
+            this.transaction = null;
+            this.psbt = null;
+            this.error = null;
+            this.exception = exception;
+        }
+    }
+}

src/main/java/com/sparrowwallet/sparrow/control/WebcamService.java

@@ -0,0 +1,81 @@
+package com.sparrowwallet.sparrow.control;
+
+import com.github.sarxos.webcam.Webcam;
+import com.github.sarxos.webcam.WebcamResolution;
+import com.google.zxing.*;
+import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
+import com.google.zxing.common.HybridBinarizer;
+import javafx.beans.property.ObjectProperty;
+import javafx.beans.property.SimpleObjectProperty;
+import javafx.concurrent.Service;
+import javafx.concurrent.Task;
+import javafx.embed.swing.SwingFXUtils;
+import javafx.scene.image.Image;
+
+import java.awt.image.BufferedImage;
+import java.util.concurrent.TimeUnit;
+
+public class WebcamService extends Service<Image> {
+    private final WebcamResolution resolution ;
+
+    private final ObjectProperty<Result> resultProperty = new SimpleObjectProperty<>(null);
+
+    public WebcamService(WebcamResolution resolution) {
+        this.resolution = resolution;
+    }
+
+    @Override
+    public Task<Image> createTask() {
+        return new Task<Image>() {
+            @Override
+            protected Image call() throws Exception {
+                Webcam cam = Webcam.getWebcams(1, TimeUnit.MINUTES).get(0);
+                try {
+                    cam.setCustomViewSizes(resolution.getSize());
+                    cam.setViewSize(resolution.getSize());
+
+                    cam.open();
+                    while(!isCancelled()) {
+                        if(cam.isImageNew()) {
+                            BufferedImage bimg = cam.getImage();
+                            updateValue(SwingFXUtils.toFXImage(bimg, null));
+                            readQR(bimg);
+                        }
+                    }
+                    cam.close();
+                    return getValue();
+                } finally {
+                    cam.close();
+                }
+            }
+        };
+    }
+
+    private void readQR(BufferedImage bufferedImage) {
+        LuminanceSource source = new BufferedImageLuminanceSource(bufferedImage);
+        BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
+
+        try {
+            Result result = new MultiFormatReader().decode(bitmap);
+            resultProperty.set(result);
+        } catch(NotFoundException e) {
+            // fall thru, it means there is no QR code in image
+        }
+    }
+
+    public Result getResult() {
+        return resultProperty.get();
+    }
+
+    public ObjectProperty<Result> resultProperty() {
+        return resultProperty;
+    }
+
+    public int getCamWidth() {
+        return resolution.getSize().width;
+    }
+
+    public int getCamHeight() {
+        return resolution.getSize().height;
+    }
+}

src/main/java/com/sparrowwallet/sparrow/control/WebcamView.java

@@ -0,0 +1,96 @@
+package com.sparrowwallet.sparrow.control;
+
+import javafx.scene.Node;
+import javafx.scene.control.Label;
+import javafx.scene.image.ImageView;
+import javafx.scene.layout.Region;
+
+public class WebcamView {
+    private final ImageView imageView;
+    private final WebcamService service;
+    private final Region view;
+
+    private final Label statusPlaceholder ;
+
+    public WebcamView(WebcamService service) {
+        this.service = service ;
+        this.imageView = new ImageView();
+        imageView.setPreserveRatio(true);
+        // make the cam behave like a mirror:
+        imageView.setScaleX(-1);
+
+        this.statusPlaceholder = new Label();
+        this.view = new Region() {
+            {
+                service.stateProperty().addListener((obs, oldState, newState) -> {
+                    switch (newState) {
+                        case READY:
+                            statusPlaceholder.setText("Initializing");
+                            getChildren().setAll(statusPlaceholder);
+                            break ;
+                        case SCHEDULED:
+                            statusPlaceholder.setText("Waiting");
+                            getChildren().setAll(statusPlaceholder);
+                            break ;
+                        case RUNNING:
+                            imageView.imageProperty().unbind();
+                            imageView.imageProperty().bind(service.valueProperty());
+                            getChildren().setAll(imageView);
+                            break ;
+                        case CANCELLED:
+                            imageView.imageProperty().unbind();
+                            imageView.setImage(null);
+                            statusPlaceholder.setText("Stopped");
+                            getChildren().setAll(statusPlaceholder);
+                            break;
+                        case FAILED:
+                            imageView.imageProperty().unbind();
+                            statusPlaceholder.setText("Error");
+                            getChildren().setAll(statusPlaceholder);
+                            service.getException().printStackTrace();
+                            break;
+                        case SUCCEEDED:
+                            // unreachable...
+                            imageView.imageProperty().unbind();
+                            statusPlaceholder.setText("");
+                            getChildren().clear();
+                    }
+                    requestLayout();
+                });
+            }
+
+            @Override
+            protected void layoutChildren() {
+                super.layoutChildren();
+                double w = getWidth();
+                double h = getHeight();
+                if (service.isRunning()) {
+                    imageView.setFitWidth(w);
+                    imageView.setFitHeight(h);
+                    imageView.resizeRelocate(0, 0, w, h);
+                } else {
+                    double labelHeight = statusPlaceholder.prefHeight(w);
+                    double labelWidth = statusPlaceholder.prefWidth(labelHeight);
+                    statusPlaceholder.resizeRelocate((w - labelWidth)/2, (h-labelHeight)/2, labelWidth, labelHeight);
+                }
+            }
+
+            @Override
+            protected double computePrefWidth(double height) {
+                return service.getCamWidth();
+            }
+            @Override
+            protected double computePrefHeight(double width) {
+                return service.getCamHeight();
+            }
+        };
+    }
+
+    public WebcamService getService() {
+        return service;
+    }
+
+    public Node getView() {
+        return view;
+    }
+}

src/main/java/com/sparrowwallet/sparrow/event/RequestQRScanEvent.java

@@ -0,0 +1,5 @@
+package com.sparrowwallet.sparrow.event;
+
+public class RequestQRScanEvent {
+    //Empty event class used to request the QRScanDialog is opened
+}

src/main/java/com/sparrowwallet/sparrow/event/RequestTransactionOpenEvent.java

@@ -1,5 +1,5 @@
 package com.sparrowwallet.sparrow.event;
 
 public class RequestTransactionOpenEvent {
-    //Empty event class used to request the transaction open dialog
+    //Empty event class used to request the transaction open file dialog
 }

src/main/java/com/sparrowwallet/sparrow/transaction/HeadersController.java

@@ -537,6 +537,8 @@ public class HeadersController extends TransactionFormController implements Init
     public void scanPSBT(ActionEvent event) {
         ToggleButton toggleButton = (ToggleButton)event.getSource();
         toggleButton.setSelected(false);
+
+        EventManager.get().post(new RequestQRScanEvent());
     }
 
     public void savePSBT(ActionEvent event) {

src/main/java/com/sparrowwallet/sparrow/ur/UR.java

@@ -1,12 +1,25 @@
 package com.sparrowwallet.sparrow.ur;
 
+import co.nstant.in.cbor.CborBuilder;
+import co.nstant.in.cbor.CborDecoder;
+import co.nstant.in.cbor.CborEncoder;
+import co.nstant.in.cbor.CborException;
+import co.nstant.in.cbor.model.ByteString;
+import co.nstant.in.cbor.model.DataItem;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.util.Arrays;
+import java.util.List;
 import java.util.Objects;
 
 /**
  * Ported from https://github.com/BlockchainCommons/URKit
  */
 public class UR {
+    public static final String UR_PREFIX = "ur";
+    public static final String BYTES_TYPE = "bytes";
+
     private final String type;
     private final byte[] data;
 
@@ -27,6 +40,16 @@ public class UR {
         return data;
     }
 
+    public byte[] toBytes() throws InvalidTypeException, CborException {
+        if(!BYTES_TYPE.equals(getType())) {
+            throw new InvalidTypeException("Not a " + BYTES_TYPE + " type");
+        }
+
+        ByteArrayInputStream bais = new ByteArrayInputStream(getCbor());
+        List<DataItem> dataItems = new CborDecoder(bais).decode();
+        return ((ByteString)dataItems.get(0)).getBytes();
+    }
+
     public static boolean isURType(String type) {
         for(char c : type.toCharArray()) {
             if('a' <= c && c <= 'z') {
@@ -45,8 +68,14 @@ public class UR {
 
     public static UR fromBytes(byte[] data) {
         try {
-            return new UR("bytes", data);
-        } catch(UR.InvalidTypeException e) {
+            ByteArrayOutputStream baos = new ByteArrayOutputStream();
+            new CborEncoder(baos).encode(new CborBuilder()
+                    .add(data)
+                    .build());
+            byte[] cbor = baos.toByteArray();
+
+            return new UR("bytes", cbor);
+        } catch(InvalidTypeException | CborException e) {
             return null;
         }
     }

src/main/java/com/sparrowwallet/sparrow/ur/UREncoder.java

@@ -53,7 +53,7 @@ public class UREncoder {
     }
 
     private static String encodeUR(String... pathComponents) {
-        return encodeURI("ur", pathComponents);
+        return encodeURI(UR.UR_PREFIX, pathComponents);
     }
 
     private static String encodeURI(String scheme, String... pathComponents) {

src/main/java/module-info.java

@@ -18,6 +18,7 @@ open module com.sparrowwallet.sparrow {
     requires org.jetbrains.annotations;
     requires com.fasterxml.jackson.databind;
     requires cbor;
+    requires webcam.capture;
     requires centerdevice.nsmenufx;
     requires javafx.swing;
 }

src/main/resources/com/sparrowwallet/sparrow/app.fxml

@@ -21,6 +21,7 @@
                                 <MenuItem text="File..." onAction="#openTransactionFromFile"/>
                                 <MenuItem fx:id="openTransactionIdItem" text="From ID..." onAction="#openTransactionFromId"/>
                                 <MenuItem text="From Text..." onAction="#openTransactionFromText"/>
+                                <MenuItem text="From QR..." onAction="#openTransactionFromQR"/>
                                 <MenuItem text="Examples" onAction="#openExamples"/>
                             </items>
                         </Menu>