From 69cce41f9e93170f95da913f28f2e2c46ea3f7ee Mon Sep 17 00:00:00 2001
From: Jakob Heher <jakob.heher@iaik.tugraz.at>
Date: Thu, 22 Feb 2024 15:26:02 +0100
Subject: [PATCH] Properly shutdown during A-Trust communication (#113)

This properly winds down A-Trust communication and exits cleanly if the
main window is closed while waiting for user input.
---
 .../MobileBKUEnterNumberComposite.java        | 13 +----
 .../gui/workflow/states/MobileBKUState.java   | 52 +++++++------------
 2 files changed, 20 insertions(+), 45 deletions(-)

diff --git a/pdf-over-gui/src/main/java/at/asit/pdfover/gui/composites/mobilebku/MobileBKUEnterNumberComposite.java b/pdf-over-gui/src/main/java/at/asit/pdfover/gui/composites/mobilebku/MobileBKUEnterNumberComposite.java
index 6afedf56..e9c6e85c 100644
--- a/pdf-over-gui/src/main/java/at/asit/pdfover/gui/composites/mobilebku/MobileBKUEnterNumberComposite.java
+++ b/pdf-over-gui/src/main/java/at/asit/pdfover/gui/composites/mobilebku/MobileBKUEnterNumberComposite.java
@@ -81,17 +81,6 @@ public void widgetSelected(SelectionEvent e) {
 		}
 	};
 
-	/**
-	 *
-	 */
-	private final SelectionListener cancelListener = new SelectionAdapter() {
-		@Override
-		public void widgetSelected(SelectionEvent e) {
-			MobileBKUEnterNumberComposite.this.userCancel = true;
-		}
-	};
-
-
 	String mobileNumber;
 
 	String mobilePassword;
@@ -195,7 +184,7 @@ public MobileBKUEnterNumberComposite(Composite parent, int style, State state) {
 
 		this.btn_cancel = new Button(containerComposite, SWT.NATIVE);
 		SWTUtils.anchor(btn_cancel).bottom(100, -20).right(btn_ok, -10);
-		this.btn_cancel.addSelectionListener(this.cancelListener);
+		SWTUtils.addSelectionListener(btn_cancel, () -> { this.userCancel = true; });
 
 		this.lbl_error = new Label(containerComposite, SWT.WRAP | SWT.NATIVE );
 		SWTUtils.anchor(lbl_error).bottom(103, -20).left(5, 0).right(btn_cancel, -10);
diff --git a/pdf-over-gui/src/main/java/at/asit/pdfover/gui/workflow/states/MobileBKUState.java b/pdf-over-gui/src/main/java/at/asit/pdfover/gui/workflow/states/MobileBKUState.java
index 4e105ab8..932091a1 100644
--- a/pdf-over-gui/src/main/java/at/asit/pdfover/gui/workflow/states/MobileBKUState.java
+++ b/pdf-over-gui/src/main/java/at/asit/pdfover/gui/workflow/states/MobileBKUState.java
@@ -19,6 +19,7 @@
 import java.net.ConnectException;
 import java.net.URI;
 import java.net.UnknownHostException;
+import java.util.function.Supplier;
 
 // Imports
 import at.asit.pdfover.signer.UserCancelledException;
@@ -34,6 +35,7 @@
 import org.apache.hc.core5.http.io.entity.EntityUtils;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.widgets.Display;
+import org.eclipse.swt.widgets.Shell;
 
 import at.asit.pdfover.gui.MainWindow.Buttons;
 import at.asit.pdfover.gui.MainWindowBehavior;
@@ -270,6 +272,17 @@ private void updateRememberPasswordSetting(boolean enabled, boolean allowEnablin
 		}
 	}
 
+	public void readAndDispatchSWTUntil(Supplier<Boolean> pred) throws UserCancelledException {
+		Shell shell = getStateMachine().getMainShell();
+		Display display = shell.getDisplay();
+		while (!pred.get()) {
+			if (!display.readAndDispatch())
+				display.sleep();
+			if (shell.isDisposed())
+				throw new UserCancelledException();
+		}
+	}
+
 	public void getCredentialsFromUserTo(@NonNull UsernameAndPassword credentials, String errorMessage) throws UserCancelledException {
 		Display.getDefault().syncCall(() -> {
 			MobileBKUEnterNumberComposite ui = this.getMobileBKUEnterNumberComposite();
@@ -291,12 +304,7 @@ public void getCredentialsFromUserTo(@NonNull UsernameAndPassword credentials, S
 				ui.enableButton();
 				getStateMachine().display(ui);
 
-				Display display = getStateMachine().getMainShell().getDisplay();
-				while (!ui.userAck && !ui.userCancel) {
-					if (!display.readAndDispatch()) {
-						display.sleep();
-					}
-				}
+				readAndDispatchSWTUntil(() -> (ui.userAck || ui.userCancel));
 			}
 
 			updateRememberPasswordSetting(ui.isRememberPassword(), !ui.userCancel);
@@ -340,12 +348,7 @@ public static enum ResultType { TO_FIDO2, SMSTAN };
 			tan.setFIDO2Enabled(showFido2);
 			getStateMachine().display(tan);
 
-			Display display = getStateMachine().getMainShell().getDisplay();
-			while (!tan.isDone()) {
-				if (!display.readAndDispatch()) {
-					display.sleep();
-				}
-			}
+			readAndDispatchSWTUntil(() -> tan.isDone());
 			getStateMachine().display(getWaitingComposite());
 
 			if (tan.isUserCancel())
@@ -400,12 +403,7 @@ public enum QRResult {
 		return Display.getDefault().syncCall(() -> {
 			MobileBKUQRComposite qr = getMobileBKUQRComposite();
 
-			Display display = getStateMachine().getMainShell().getDisplay();
-			while (!qr.isDone()) {
-				if (!display.readAndDispatch()) {
-					display.sleep();
-				}
-			}
+			readAndDispatchSWTUntil(() -> qr.isDone());
 
 			getStateMachine().display(this.getWaitingComposite());
 
@@ -460,11 +458,7 @@ public enum AppOpenResult {
 		return Display.getDefault().syncCall(() -> {
 			WaitingForAppComposite wfa = getWaitingForAppComposite();
 
-			Display display = wfa.getDisplay();
-			while (!wfa.isDone()) {
-				if (!display.readAndDispatch())
-					display.sleep();
-			}
+			readAndDispatchSWTUntil(() -> wfa.isDone());
 
 			getStateMachine().display(this.getWaitingComposite());
 
@@ -520,11 +514,7 @@ public enum AppBiometryResult {
 		return Display.getDefault().syncCall(() -> {
 			MobileBKUFingerprintComposite bio = getMobileBKUFingerprintComposite();
 
-			Display display = bio.getDisplay();
-			while (!bio.isDone()) {
-				if (!display.readAndDispatch())
-					display.sleep();
-			}
+			readAndDispatchSWTUntil(() -> bio.isDone());
 
 			getStateMachine().display(this.getWaitingComposite());
 
@@ -571,11 +561,7 @@ public static enum ResultType { TO_SMS, CREDENTIAL };
 			
 			getStateMachine().display(fido2);
 
-			Display display = fido2.getDisplay();
-			while (!fido2.isDone()) {
-				if (!display.readAndDispatch())
-					display.sleep();
-			}
+			readAndDispatchSWTUntil(() -> fido2.isDone());
 
 			getStateMachine().display(this.getWaitingComposite());