config: abstract away mempool depth format str "%.1f MB from tip"

related: 4dd94172a6
(as that commit introduced depth targets that need more precision to display)

electrum/gui/kivy/uix/dialogs/tx_dialog.py

@@ -125,6 +125,7 @@ class TxDialog(Factory.Popup):
         self.app = app  # type: ElectrumWindow
         self.wallet = self.app.wallet
         self.tx = tx  # type: Transaction
+        self.config = self.app.electrum_config
 
         # If the wallet can populate the inputs with more info, do it now.
         # As a result, e.g. we might learn an imported address tx is segwit,
@@ -154,7 +155,7 @@ class TxDialog(Factory.Popup):
             self.date_str = datetime.fromtimestamp(tx_mined_status.timestamp).isoformat(' ')[:-3]
         elif exp_n is not None:
             self.date_label = _('Mempool depth')
-            self.date_str = _('{} from tip').format('%.2f MB'%(exp_n/1000000))
+            self.date_str = self.config.depth_tooltip(exp_n)
         else:
             self.date_label = ''
             self.date_str = ''

electrum/gui/qt/transaction_dialog.py

@@ -476,8 +476,10 @@ class BaseTxDialog(QDialog, MessageBoxMixin):
             self.date_label.setText(_("Date: {}").format(time_str))
             self.date_label.show()
         elif exp_n is not None:
-            text = '%.2f MB'%(exp_n/1000000)
-            self.date_label.setText(_('Position in mempool: {} from tip').format(text))
+            text = "{}: {}".format(
+                _('Position in mempool'),
+                self.config.depth_tooltip(exp_n))
+            self.date_label.setText(text)
             self.date_label.show()
         else:
             self.date_label.hide()

electrum/simple_config.py

@@ -437,11 +437,17 @@ class SimpleConfig(Logger):
             min_target = -1
         return min_target
 
+    def get_depth_mb_str(self, depth: int) -> str:
+        # e.g. 500_000 -> "0.50 MB"
+        depth_mb = "{:.2f}".format(depth / 1_000_000)  # maybe .rstrip("0") ?
+        return f"{depth_mb} MB"
+
     def depth_tooltip(self, depth: Optional[int]) -> str:
         """Returns text tooltip for given mempool depth (in vbytes)."""
         if depth is None:
             return "unknown from tip"
-        return "%.1f MB from tip" % (depth/1_000_000)
+        depth_mb = self.get_depth_mb_str(depth)
+        return _("{} from tip").format(depth_mb)
 
     def eta_tooltip(self, x):
         if x < 0:

electrum/wallet.py

@@ -1198,7 +1198,7 @@ class Abstract_Wallet(AddressSynchronizer, ABC):
                and self.config.has_fee_mempool():
                 exp_n = self.config.fee_to_depth(fee_per_byte)
                 if exp_n is not None:
-                    extra.append('%.2f MB'%(exp_n/1000000))
+                    extra.append(self.config.get_depth_mb_str(exp_n))
             if height == TX_HEIGHT_LOCAL:
                 status = 3
             elif height == TX_HEIGHT_UNCONF_PARENT: