add pdf export of wallet output descriptor from qr display dialog

build.gradle

@@ -97,6 +97,7 @@ dependencies {
     implementation('io.reactivex.rxjava2:rxjavafx:2.2.2')
     implementation('org.apache.commons:commons-lang3:3.7')
     implementation('net.sourceforge.streamsupport:streamsupport:1.7.0')
+    implementation('com.github.librepdf:openpdf:1.3.27')
     testImplementation('junit:junit:4.12')
 }
 

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

@@ -0,0 +1,73 @@
+package com.sparrowwallet.sparrow.control;
+
+import com.lowagie.text.*;
+import com.lowagie.text.Font;
+import com.lowagie.text.Image;
+import com.lowagie.text.pdf.PdfWriter;
+import com.sparrowwallet.hummingbird.UR;
+import com.sparrowwallet.hummingbird.UREncoder;
+import com.sparrowwallet.sparrow.AppServices;
+import javafx.embed.swing.SwingFXUtils;
+import javafx.event.ActionEvent;
+import javafx.scene.control.*;
+import javafx.scene.control.Button;
+import javafx.stage.FileChooser;
+import javafx.stage.Stage;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.awt.*;
+import java.io.File;
+import java.io.FileOutputStream;
+
+public class DescriptorQRDisplayDialog extends QRDisplayDialog {
+    private static final Logger log = LoggerFactory.getLogger(DescriptorQRDisplayDialog.class);
+
+    public DescriptorQRDisplayDialog(String walletName, String outputDescriptor, UR ur) {
+        super(ur);
+
+        DialogPane dialogPane = getDialogPane();
+        final ButtonType pdfButtonType = new javafx.scene.control.ButtonType("Save PDF...", ButtonBar.ButtonData.HELP_2);
+        dialogPane.getButtonTypes().add(pdfButtonType);
+
+        Button pdfButton = (Button)dialogPane.lookupButton(pdfButtonType);
+        pdfButton.addEventFilter(ActionEvent.ACTION, event -> {
+            savePdf(walletName, outputDescriptor, ur);
+            event.consume();
+        });
+    }
+
+    private void savePdf(String walletName, String outputDescriptor, UR ur) {
+        Stage window = new Stage();
+        FileChooser fileChooser = new FileChooser();
+        fileChooser.setTitle("Save PDF");
+        fileChooser.setInitialFileName(walletName + ".pdf");
+        AppServices.moveToActiveWindowScreen(window, 800, 450);
+        File file = fileChooser.showSaveDialog(window);
+        if(file != null) {
+            try(Document document = new Document()) {
+                document.setMargins(36, 36, 48, 36);
+                PdfWriter.getInstance(document, new FileOutputStream(file));
+                document.open();
+
+                Font titleFont = FontFactory.getFont(FontFactory.HELVETICA_BOLD, 16, Color.BLACK);
+                Chunk title = new Chunk("Output descriptor for " + walletName, titleFont);
+                document.add(title);
+
+                UREncoder urEncoder = new UREncoder(ur, 2000, 10, 0);
+                String fragment = urEncoder.nextPart();
+                if(urEncoder.isSinglePart()) {
+                    Image image = Image.getInstance(SwingFXUtils.fromFXImage(getQrCode(fragment), null), Color.WHITE);
+                    document.add(image);
+                }
+
+                Font descriptorFont = FontFactory.getFont(FontFactory.COURIER, 14, Color.BLACK);
+                Paragraph descriptor = new Paragraph(outputDescriptor, descriptorFont);
+                document.add(descriptor);
+            } catch(Exception e) {
+                log.error("Error creating descriptor PDF", e);
+                AppServices.showErrorDialog("Error creating PDF", e.getMessage());
+            }
+        }
+    }
+}

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

@@ -137,7 +137,7 @@ public class QRDisplayDialog extends Dialog<UR> {
         }
     }
 
-    private Image getQrCode(String fragment) {
+    protected Image getQrCode(String fragment) {
         try {
             QRCodeWriter qrCodeWriter = new QRCodeWriter();
             BitMatrix qrMatrix = qrCodeWriter.encode(fragment, BarcodeFormat.QR_CODE, QR_WIDTH, QR_HEIGHT);

src/main/java/com/sparrowwallet/sparrow/wallet/SettingsController.java

@@ -324,6 +324,7 @@ public class SettingsController extends WalletFormController implements Initiali
             return;
         }
 
+        OutputDescriptor outputDescriptor = OutputDescriptor.getOutputDescriptor(walletForm.getWallet(), KeyPurpose.DEFAULT_PURPOSES, null);
         List<ScriptExpression> scriptExpressions = getScriptExpressions(walletForm.getWallet().getScriptType());
 
         CryptoOutput cryptoOutput;
@@ -341,7 +342,7 @@ public class SettingsController extends WalletFormController implements Initiali
         }
 
         UR cryptoOutputUR = cryptoOutput.toUR();
-        QRDisplayDialog qrDisplayDialog = new QRDisplayDialog(cryptoOutputUR);
+        QRDisplayDialog qrDisplayDialog = new DescriptorQRDisplayDialog(walletForm.getWallet().getFullDisplayName(), outputDescriptor.toString(true), cryptoOutputUR);
         qrDisplayDialog.showAndWait();
     }
 

src/main/java/module-info.java

@@ -44,4 +44,5 @@ open module com.sparrowwallet.sparrow {
     requires org.apache.commons.lang3;
     requires net.sourceforge.streamsupport;
     requires co.nstant.in.cbor;
+    requires com.github.librepdf.openpdf;
 }