Flip to `open_order_mode()` as ctx mngr

We need a subtask to compute the current pp PnL in real-time but really
only if a pp exists - a spawnable subtask would be ideal for this. Stage
a tick streaming task using a stream bcaster; no actual pnl calc yet.

Since we're going to need subtasks anyway might as well stick the order
mode UI processing loop in a task as well and then just give the whole
thing a ctx mngr api. This'll probably be handy for when we have
auto-strats that need to dynamically use the mode's api as well.

Oh, and move the time -> index mapper to a chart method for now.

piker/ui/_chart.py

@@ -71,7 +71,7 @@ from .. import brokers
 from ..log import get_logger
 from ._exec import run_qtractor
 from ._interaction import ChartView
-from .order_mode import run_order_mode
+from .order_mode import open_order_mode
 from .. import fsp
 from ._forms import (
     FieldsForm,
@@ -1084,6 +1084,22 @@ class ChartPlotWidget(pg.PlotWidget):
         self.sig_mouse_leave.emit(self)
         self.scene().leaveEvent(ev)
 
+    def get_index(self, time: float) -> int:
+
+        # TODO: this should go onto some sort of
+        # data-view strimg thinger..right?
+        ohlc = self._shm.array
+        # ohlc = chart._shm.array
+
+        # XXX: not sure why the time is so off here
+        # looks like we're gonna have to do some fixing..
+        indexes = ohlc['time'] >= time
+
+        if any(indexes):
+            return ohlc['index'][indexes][-1]
+        else:
+            return ohlc['index'][-1]
+
 
 _clear_throttle_rate: int = 60  # Hz
 _book_throttle_rate: int = 16  # Hz
@@ -1695,19 +1711,6 @@ async def display_symbol_data(
         ) as feed,
         trio.open_nursery() as n,
     ):
-        # async def print_quotes():
-        #     async with feed.stream.subscribe() as bstream:
-        #         last_tick = time.time()
-        #         async for quotes in bstream:
-        #             now = time.time()
-        #             period = now - last_tick
-        #             for sym, quote in quotes.items():
-        #                 ticks = quote.get('ticks', ())
-        #                 if ticks:
-        #                     # print(f'{1/period} Hz')
-        #                     last_tick = time.time()
-
-        # n.start_soon(print_quotes)
 
         ohlcv: ShmArray = feed.shm
         bars = ohlcv.array
@@ -1833,12 +1836,37 @@ async def display_symbol_data(
                 linkedsplits
             )
 
-            await run_order_mode(
+            async with (
+
+                open_order_mode(
                     chart,
                     symbol,
                     provider,
                     order_mode_started
-            )
+                ) as order_mode,
+            ):
+                pp = order_mode.pp
+                live = pp.live_pp
+
+                # real-time update pnl on the  order mode
+                async with feed.stream.subscribe() as bstream:
+                    last_tick = time.time()
+                    async for quotes in bstream:
+
+                        now = time.time()
+                        period = now - last_tick
+
+                        for sym, quote in quotes.items():
+
+                            ticks = quote.get('ticks', ())
+                            if ticks:
+                                print(f'{1/period} Hz')
+
+                                if live.size:
+                                    # compute and display pnl
+                                    pass
+
+                                last_tick = time.time()
 
 
 async def load_provider_search(

piker/ui/order_mode.py

@@ -18,6 +18,7 @@
 Chart trading, the only way to scalp.
 
 """
+from contextlib import asynccontextmanager
 from dataclasses import dataclass, field
 from functools import partial
 from pprint import pformat
@@ -36,7 +37,7 @@ from ..data._source import Symbol
 from ..log import get_logger
 from ._editors import LineEditor, ArrowEditor
 from ._lines import order_line, LevelLine
-from ._position import PositionTracker, OrderModePane, Allocator, _size_units
+from ._position import PositionTracker, SettingsPane, Allocator, _size_units
 from ._window import MultiStatus
 from ..clearing._messages import Order
 from ._forms import open_form_input_handling
@@ -91,7 +92,7 @@ class OrderMode:
     multistatus: MultiStatus
     pp: PositionTracker
     allocator: 'Allocator'  # noqa
-    pane: OrderModePane
+    pane: SettingsPane
 
     active: bool = False
 
@@ -462,7 +463,8 @@ class OrderMode:
         return ids
 
 
-async def run_order_mode(
+@asynccontextmanager
+async def open_order_mode(
 
     chart: 'ChartPlotWidget',  # noqa
     symbol: Symbol,
@@ -493,6 +495,7 @@ async def run_order_mode(
             trades_stream,
             positions
         ),
+        trio.open_nursery() as n,
 
     ):
         log.info(f'Opening order mode for {brokername}.{symbol.key}')
@@ -521,7 +524,7 @@ async def run_order_mode(
         pp_tracker.hide()
 
         # order pane widgets and allocation model
-        order_pane = OrderModePane(
+        order_pane = SettingsPane(
             tracker=pp_tracker,
             form=form,
             alloc=alloc,
@@ -574,21 +577,6 @@ async def run_order_mode(
         # make fill bar and positioning snapshot
         order_pane.init_status_ui()
 
-        # TODO: this should go onto some sort of
-        # data-view strimg thinger..right?
-        def get_index(time: float):
-
-            # XXX: not sure why the time is so off here
-            # looks like we're gonna have to do some fixing..
-
-            ohlc = chart._shm.array
-            indexes = ohlc['time'] >= time
-
-            if any(indexes):
-                return ohlc['index'][indexes][-1]
-            else:
-                return ohlc['index'][-1]
-
         # Begin order-response streaming
         done()
 
@@ -611,6 +599,27 @@ async def run_order_mode(
             # to handle input since the ems connection is ready
             started.set()
 
+            n.start_soon(
+                process_trades_and_update_ui,
+                mode,
+                trades_stream,
+                book,
+            )
+            yield mode
+            # await trio.sleep_forever()
+
+
+async def process_trades_and_update_ui(
+
+    mode: OrderMode,
+    trades_stream: tractor.MsgStream,
+    book: OrderBook,
+
+) -> None:
+
+    get_index = mode.chart.get_index
+    tracker = mode.pp
+
     # this is where we receive **back** messages
     # about executions **from** the EMS actor
     async for msg in trades_stream:
@@ -626,7 +635,7 @@ async def run_order_mode(
 
             sym = mode.chart.linked.symbol
             if msg['symbol'].lower() in sym.key:
-                        pp_tracker.update(msg)
+                tracker.update(msg)
 
                 # update order pane widgets
                 mode.pane.update_status_ui()
@@ -717,4 +726,4 @@ async def run_order_mode(
                 arrow_index=get_index(details['broker_time']),
             )
 
-                    pp_tracker.live_pp.fills.append(msg)
+            tracker.live_pp.fills.append(msg)