hw plugins: (cleanup) Plugin objects should not have a Handler field

Handlers are per-client (connected device), plugins are ~singletons.
These were mostly remnants of old code.

electrum/plugins/bitbox02/bitbox02.py

@@ -22,7 +22,7 @@ from electrum.bitcoin import OnchainOutputType
 import electrum.bitcoin as bitcoin
 import electrum.ecc as ecc
 
-from ..hw_wallet import HW_PluginBase, HardwareClientBase
+from ..hw_wallet import HW_PluginBase, HardwareClientBase, HardwareHandlerBase
 
 
 _logger = get_logger(__name__)
@@ -47,7 +47,7 @@ except ImportError as e:
 
 class BitBox02Client(HardwareClientBase):
     # handler is a BitBox02_Handler, importing it would lead to a circular dependency
-    def __init__(self, handler: Any, device: Device, config: SimpleConfig, *, plugin: HW_PluginBase):
+    def __init__(self, handler: HardwareHandlerBase, device: Device, config: SimpleConfig, *, plugin: HW_PluginBase):
         HardwareClientBase.__init__(self, plugin=plugin)
         self.bitbox02_device = None  # type: Optional[bitbox02.BitBox02]
         self.handler = handler
@@ -653,11 +653,8 @@ class BitBox02Plugin(HW_PluginBase):
         else:
             raise ImportError()
 
-    # handler is a BitBox02_Handler
     @runs_in_hwd_thread
-    def create_client(self, device: Device, handler: Any) -> BitBox02Client:
-        if not handler:
-            self.handler = handler
+    def create_client(self, device, handler) -> BitBox02Client:
         return BitBox02Client(handler, device, self.config, plugin=self)
 
     def setup_device(

electrum/plugins/digitalbitbox/digitalbitbox.py

@@ -32,7 +32,7 @@ from electrum.network import Network
 from electrum.logging import get_logger
 from electrum.plugin import runs_in_hwd_thread, run_in_hwd_thread
 
-from ..hw_wallet import HW_PluginBase, HardwareClientBase
+from ..hw_wallet import HW_PluginBase, HardwareClientBase, HardwareHandlerBase
 
 
 _logger = get_logger(__name__)
@@ -597,7 +597,7 @@ class DigitalBitbox_KeyStore(Hardware_KeyStore):
 
                 if self.plugin.is_mobile_paired() and tx_dbb_serialized is not None:
                     reply['tx'] = tx_dbb_serialized
-                    self.plugin.comserver_post_notification(reply)
+                    self.plugin.comserver_post_notification(reply, handler=self.handler)
 
                 if steps > 1:
                     self.handler.show_message(_("Signing large transaction. Please be patient ...") + "\n\n" +
@@ -683,8 +683,6 @@ class DigitalBitboxPlugin(HW_PluginBase):
 
     def create_client(self, device, handler):
         if device.interface_number == 0 or device.usage_page == 0xffff:
-            if handler:
-                self.handler = handler
             client = self.get_dbb_device(device)
             if client is not None:
                 client = DigitalBitbox_Client(self, client)
@@ -707,7 +705,7 @@ class DigitalBitboxPlugin(HW_PluginBase):
         return ENCRYPTION_PRIVKEY_KEY in self.digitalbitbox_config
 
 
-    def comserver_post_notification(self, payload):
+    def comserver_post_notification(self, payload, *, handler: 'HardwareHandlerBase'):
         assert self.is_mobile_paired(), "unexpected mobile pairing error"
         url = 'https://digitalbitbox.com/smartverification/index.php'
         key_s = base64.b64decode(self.digitalbitbox_config[ENCRYPTION_PRIVKEY_KEY])
@@ -719,7 +717,8 @@ class DigitalBitboxPlugin(HW_PluginBase):
             text = Network.send_http_on_proxy('post', url, body=args.encode('ascii'), headers={'content-type': 'application/x-www-form-urlencoded'})
             _logger.info(f'digitalbitbox reply from server {text}')
         except Exception as e:
-            self.handler.show_error(repr(e)) # repr because str(Exception()) == ''
+            _logger.exception("")
+            handler.show_error(repr(e))  # repr because str(Exception()) == ''
 
 
     def get_xpub(self, device_id, derivation, xtype, wizard):
@@ -763,4 +762,4 @@ class DigitalBitboxPlugin(HW_PluginBase):
             "type": 'p2pkh',
             "echo": xpub['echo'],
         }
-        self.comserver_post_notification(verify_request_payload)
+        self.comserver_post_notification(verify_request_payload, handler=keystore.handler)

electrum/plugins/ledger/ledger.py

@@ -687,9 +687,6 @@ class LedgerPlugin(HW_PluginBase):
 
     @runs_in_hwd_thread
     def create_client(self, device, handler):
-        if handler:
-            self.handler = handler
-
         client = self.get_btchip_device(device)
         if client is not None:
             client = Ledger_Client(client, product_key=device.product_key, plugin=self)