Improve auxiliary keys window, make it easier to copy a key to clipboard

Change the auxiliary key window to:
- show the keys in a QLineEdit widget which allow copying the text on all systems
- show one key at a time, select the key index in a QSpinBox (allowed range: 0 - 1000)
- reuse that dialog when generating a delegated key in the delegation editor, to allow choosing from more than one key

electroncash_gui/qt/avalanche/delegation_editor.py

@@ -16,9 +16,7 @@
 from electroncash.bitcoin import is_private_key
 from electroncash.wallet import Deterministic_Wallet
 
-from .util import CachedWalletPasswordWidget, get_privkey_suggestion
-
-DELEGATED_KEY_INDEX = 1
+from .util import AuxiliaryKeysDialog, CachedWalletPasswordWidget
 
 
 class AvaDelegationWidget(CachedWalletPasswordWidget):
@@ -146,26 +144,15 @@ def on_generate_key_clicked(self):
         """
         if not self.wallet.is_deterministic() or not self.wallet.can_export():
             return
-        wif_pk = ""
-        if not self.wallet.has_password() or self.pwd is not None:
-            wif_pk = get_privkey_suggestion(
-                self.wallet,
-                key_index=DELEGATED_KEY_INDEX,
-                pwd=self.pwd,
-            )
-        if not wif_pk:
-            # This should only happen if the pwd dialog was cancelled
-            self.pubkey_edit.setText("")
-            return
-        QtWidgets.QMessageBox.information(
-            self,
-            "Delegated key",
-            f"This key is derived from the change_index = 2 branch of this wallet's "
-            f"derivation path.<br><br>"
-            f"Please save the following private key:<br><b>{wif_pk}</b><br><br>"
-            f"You will need it to use your delegation with a Bitcoin ABC node.",
+        additional_info = (
+            "Please save the private key. You will need it to use your delegation with "
+            "a Bitcoin ABC node."
         )
-        self.pubkey_edit.setText(Key.from_wif(wif_pk).get_pubkey().to_hex())
+        d = AuxiliaryKeysDialog(self.wallet, self.pwd, self, additional_info)
+        d.set_index(1)
+        d.exec_()
+
+        self.pubkey_edit.setText(d.get_hex_public_key())
 
     def on_generate_clicked(self):
         dg_hex = self._build()

electroncash_gui/qt/avalanche/proof_editor.py

@@ -24,7 +24,7 @@
 from electroncash.wallet import AddressNotFoundError, Deterministic_Wallet
 
 from .delegation_editor import AvaDelegationDialog
-from .util import CachedWalletPasswordWidget, get_privkey_suggestion
+from .util import CachedWalletPasswordWidget, get_auxiliary_privkey
 
 PROOF_MASTER_KEY_INDEX = 0
 
@@ -379,7 +379,7 @@ def _get_privkey_suggestion(self) -> str:
             return ""
         wif_pk = ""
         if not self.wallet.has_password() or self.pwd is not None:
-            wif_pk = get_privkey_suggestion(
+            wif_pk = get_auxiliary_privkey(
                 self.wallet, key_index=PROOF_MASTER_KEY_INDEX, pwd=self.pwd
             )
         return wif_pk

electroncash_gui/qt/avalanche/util.py

@@ -4,12 +4,15 @@
 
 from PyQt5 import QtWidgets
 
+from electroncash.address import PublicKey
+from electroncash.bitcoin import is_private_key
 from electroncash.wallet import Deterministic_Wallet
 
 from ..password_dialog import PasswordDialog
+from ..util import ButtonsLineEdit
 
 
-def get_privkey_suggestion(
+def get_auxiliary_privkey(
     wallet: Deterministic_Wallet,
     key_index: int = 0,
     pwd: Optional[str] = None,
@@ -68,3 +71,126 @@ def pwd(self) -> Optional[str]:
                 return self._pwd
             except Exception as e:
                 QtWidgets.QMessageBox.critical(self, "Invalid password", str(e))
+
+
+class KeyWidget(QtWidgets.QWidget):
+    """A widget to view a private key - public key pair"""
+
+    def __init__(self, parent: Optional[QtWidgets.QWidget] = None):
+        super().__init__(parent)
+
+        layout = QtWidgets.QVBoxLayout()
+        self.setLayout(layout)
+        layout.setContentsMargins(0, 0, 0, 0)
+
+        layout.addWidget(QtWidgets.QLabel("Private key"))
+        self.privkey_view = ButtonsLineEdit()
+        self.privkey_view.setReadOnly(True)
+        self.privkey_view.addCopyButton()
+        layout.addWidget(self.privkey_view)
+
+        layout.addWidget(QtWidgets.QLabel("Public key"))
+        self.pubkey_view = ButtonsLineEdit()
+        self.pubkey_view.setReadOnly(True)
+        self.pubkey_view.addCopyButton()
+        layout.addWidget(self.pubkey_view)
+
+    def setPrivkey(self, wif_privkey: str):
+        assert is_private_key(wif_privkey)
+        self.privkey_view.setText(wif_privkey)
+        pub = PublicKey.from_WIF_privkey(wif_privkey)
+        self.pubkey_view.setText(pub.to_ui_string())
+
+
+class AuxiliaryKeysWidget(CachedWalletPasswordWidget):
+    """A widget to show private-public key pairs derived from the BIP44 change_index 2
+    derivation path.
+    """
+
+    def __init__(
+        self,
+        wallet: Deterministic_Wallet,
+        pwd: Optional[str] = None,
+        parent: Optional[QtWidgets.QWidget] = None,
+        additional_info: Optional[str] = None,
+    ):
+        super().__init__(wallet, pwd, parent)
+
+        layout = QtWidgets.QVBoxLayout()
+        self.setLayout(layout)
+
+        info_label = QtWidgets.QLabel(
+            "These keys are not used to generate addresses and can be used for other "
+            "purposes, such as building Avalanche Proofs and Delegations.<br><br>"
+            "They are derived from the change_index = 2 branch of this wallet's "
+            "derivation path.<br><br>"
+            "<b>Do not share your private keys with anyone!</b><br>"
+        )
+        info_label.setWordWrap(True)
+        layout.addWidget(info_label)
+        if additional_info is not None:
+            info_label2 = QtWidgets.QLabel(additional_info)
+            info_label2.setWordWrap(True)
+            layout.addWidget(info_label2)
+
+        index_layout = QtWidgets.QHBoxLayout()
+        layout.addLayout(index_layout)
+
+        index_layout.addWidget(QtWidgets.QLabel("Key index"))
+        self.index_spinbox = QtWidgets.QSpinBox()
+        self.index_spinbox.setRange(0, 1000)
+        index_layout.addWidget(self.index_spinbox)
+        index_layout.addStretch(1)
+
+        self.key_widget = KeyWidget()
+        layout.addWidget(self.key_widget)
+
+        self.set_index(self.index_spinbox.value())
+        self.index_spinbox.valueChanged.connect(self.set_index)
+
+    def set_index(self, index: int):
+        wif_key = get_auxiliary_privkey(self.wallet, index, self.pwd)
+        self.key_widget.setPrivkey(wif_key)
+
+        was_blocked = self.index_spinbox.blockSignals(True)
+        self.index_spinbox.setValue(index)
+        self.index_spinbox.blockSignals(was_blocked)
+
+    def get_wif_private_key(self) -> str:
+        return self.key_widget.privkey_view.text()
+
+    def get_hex_public_key(self) -> str:
+        return self.key_widget.pubkey_view.text()
+
+
+class AuxiliaryKeysDialog(QtWidgets.QDialog):
+    def __init__(
+        self,
+        wallet: Deterministic_Wallet,
+        pwd: Optional[str] = None,
+        parent: QtWidgets.QWidget = None,
+        additional_info: Optional[str] = None,
+    ):
+        super().__init__(parent)
+        self.setWindowTitle("Auxiliary keys")
+        self.setMinimumWidth(650)
+
+        layout = QtWidgets.QVBoxLayout()
+        self.setLayout(layout)
+
+        self.aux_keys_widget = AuxiliaryKeysWidget(wallet, pwd, self, additional_info)
+        layout.addWidget(self.aux_keys_widget)
+
+        self.ok_button = QtWidgets.QPushButton("OK")
+        layout.addWidget(self.ok_button)
+
+        self.ok_button.clicked.connect(self.accept)
+
+    def set_index(self, index: int):
+        self.aux_keys_widget.set_index(index)
+
+    def get_hex_public_key(self) -> str:
+        return self.aux_keys_widget.get_hex_public_key()
+
+    def get_wif_private_key(self) -> str:
+        return self.aux_keys_widget.get_wif_private_key()

electroncash_gui/qt/main_window.py

@@ -82,6 +82,7 @@
 from .amountedit import AmountEdit, XECAmountEdit, MyLineEdit, XECSatsByteEdit
 from .avalanche.delegation_editor import AvaDelegationDialog
 from .avalanche.proof_editor import AvaProofDialog
+from .avalanche.util import AuxiliaryKeysDialog
 from .qrcodewidget import QRCodeWidget, QRDialog
 from .qrtextedit import ShowQRTextEdit, ScanQRTextEdit
 from .sign_verify_dialog import SignVerifyDialog
@@ -4115,25 +4116,9 @@ def import_addr(addr):
     def show_auxiliary_keys(self, password):
         if not self.wallet.is_deterministic() or not self.wallet.can_export():
             return
-        infomsg = (
-            f"These keys are not used to generate addresses and can be used for other "
-            f"purposes, such as building Avalanche Proofs and Delegations.<br><br>"
-            f"<b>Do not share your private keys with anyone!</b><br>"
-            f"<ul>"
-        )
-        for i in range(10):
-            wif = self.wallet.export_private_key_for_index((2, i), password)
-            pub = PublicKey.from_WIF_privkey(wif)
-            infomsg += (
-                f"<li>Key {i}:"
-                f"  <ul>"
-                f"    <li>Private key: <b>{wif}</b></li>"
-                f"    <li>Public key: <b>{pub.to_ui_string()}</b></li>"
-                f"  </ul>"
-                f"</li>"
-            )
-        infomsg += f"</ul><br>"
-        QtWidgets.QMessageBox.information(self, "Auxiliary Keys", infomsg)
+
+        d = AuxiliaryKeysDialog(self.wallet, password, self)
+        d.show()
 
     @protected
     def do_import_privkey(self, password):