Remember last used key within SigningDialog.

src/main/java/com/blackberry/jwteditor/presenter/EditorPresenter.java

@@ -58,6 +58,7 @@ public class EditorPresenter {
     private final Logging logging;
     private final MessageDialogFactory messageDialogFactory;
     private final EditorModel model;
+    private final LastSigningKeys lastSigningKeys;
 
     private boolean selectionChanging;
 
@@ -72,6 +73,7 @@ public EditorPresenter(
         this.keysRepository = keysRepository;
         this.model = new EditorModel();
         this.messageDialogFactory = new MessageDialogFactory(view.uiComponent());
+        this.lastSigningKeys = new LastSigningKeys();
     }
 
     /**
@@ -271,7 +273,8 @@ private void signingDialog(SigningDialog.Mode mode) {
                 logging,
                 keysRepository.getSigningKeys(),
                 getJWS(),
-                mode
+                mode,
+                lastSigningKeys
         );
 
         showDialogAndUpdateJWS(signDialog);

src/main/java/com/blackberry/jwteditor/view/dialog/operations/LastSigningKeys.java

@@ -0,0 +1,20 @@
+package com.blackberry.jwteditor.view.dialog.operations;
+
+import com.blackberry.jwteditor.model.keys.Key;
+import com.blackberry.jwteditor.view.dialog.operations.SigningDialog.Mode;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+
+public class LastSigningKeys {
+    private final Map<Mode, Key> lastKeyMap = new HashMap<>();
+
+    Optional<Key> lastKeyFor(Mode mode) {
+        return Optional.ofNullable(lastKeyMap.get(mode));
+    }
+
+    void recordKeyUse(Mode mode, Key key) {
+        lastKeyMap.put(mode, key);
+    }
+}

src/main/java/com/blackberry/jwteditor/view/dialog/operations/SigningDialog.java

@@ -61,15 +61,18 @@ public enum Mode {
     private JRadioButton radioButtonUpdateGenerateNone;
 
     private final Mode mode;
+    private final LastSigningKeys lastSigningKeys;
 
     public SigningDialog(
             Window parent,
             Logging logging,
             List<Key> signingKeys,
             JWS jws,
-            Mode mode) {
+            Mode mode,
+            LastSigningKeys lastSigningKeys) {
         super(parent, logging, mode.titleResourceId, jws, "error_title_unable_to_sign");
         this.mode = mode;
+        this.lastSigningKeys = lastSigningKeys;
 
         configureUI(contentPane, buttonOK, buttonCancel);
 
@@ -88,8 +91,9 @@ public SigningDialog(
             buttonOK.setEnabled(true);
         });
 
-        // Set the signing key to the first entry, also triggering the event handler
-        comboBoxSigningKey.setSelectedIndex(0);
+        int lastUsedKeyIndex = lastSigningKeys.lastKeyFor(mode).map(signingKeys::indexOf).orElse(-1);
+        lastUsedKeyIndex = lastUsedKeyIndex == -1 ? 0 : lastUsedKeyIndex;
+        comboBoxSigningKey.setSelectedIndex(lastUsedKeyIndex);
 
         // If the dialog is being used for the embedded JWK attack, hide the Header Options
         if (mode != Mode.NORMAL) {
@@ -103,6 +107,8 @@ JWS performOperation() throws SigningException, NoSuchFieldException, IllegalAcc
         JWKKey selectedKey = (JWKKey) comboBoxSigningKey.getSelectedItem();
         JWSAlgorithm selectedAlgorithm = (JWSAlgorithm) comboBoxSigningAlgorithm.getSelectedItem();
 
+        lastSigningKeys.recordKeyUse(mode, selectedKey);
+
         // Get the header update mode based on the selected radio button, convert to the associated enum value
         SigningUpdateMode signingUpdateMode;