Initial dynamic option chain UI draft

There's still a ton to polish (and some bugs to fix) but this is a first
working draft of a real-time option chain!

Insights and todos:
- `kivy` widgets need to be cached and reused (eg. rows, cells, etc.)
  for speed since it seems creating new ones constantly is quite taxing
  on the CPU
- the chain will tear down and re-setup the option data feed stream each
  time a different contract expiry button set is clicked
- there's still some weird bug with row highlighting where it seems rows
  added from a new expiry set (which weren't previously rendered) aren't
  being highlighted reliably

piker/ui/monitor.py

@@ -304,6 +304,9 @@ class Row(GridLayout, HoverBehavior):
                 cell.key = key
                 self._cell_widgets[key] = cell
 
+    def iter_cells(self):
+        return self._cell_widgets.items()
+
     def get_cell(self, key):
         return self._cell_widgets.get(key)
 
@@ -356,7 +359,7 @@ class Row(GridLayout, HoverBehavior):
         """Highlight layout on enter.
         """
         log.debug(
-            f"Entered row {type(self)} through {self.border_point}")
+            f"Entered row {self} through {self.border_point}")
         # don't highlight header row
         if getattr(self, 'is_header', None):
             self.hovered = False
@@ -365,7 +368,7 @@ class Row(GridLayout, HoverBehavior):
         """Un-highlight layout on exit.
         """
         log.debug(
-            f"Left row {type(self)} through {self.border_point}")
+            f"Left row {self} through {self.border_point}")
 
 
 class TickerTable(GridLayout):
@@ -424,7 +427,7 @@ class TickerTable(GridLayout):
         symbol name. Most naive algo possible for the moment.
         """
         for symbol, row in self.symbols2rows.items():
-           if patt in symbol:
+            if patt in symbol:
                 yield symbol, row
 
     def get_row(self, symbol: str) -> Row:
@@ -442,10 +445,12 @@ async def update_quotes(
     widgets: dict,
     agen: AsyncGeneratorType,
     symbol_data: dict,
-    first_quotes: dict
+    first_quotes: dict,
+    task_status: trio._core._run._TaskStatus = trio.TASK_STATUS_IGNORED,
 ):
     """Process live quotes by updating ticker rows.
     """
+    log.debug("Initializing UI update loop")
     table = widgets['table']
     flash_keys = {'low', 'high'}
 
@@ -521,9 +526,8 @@ async def update_quotes(
         color_row(row, record, {})
         cache[sym] = row
 
-    # render all rows once up front
+    log.debug("Finished initializing update loop")
-    table.render_rows(cache)
+    task_status.started()
-
     # real-time cell update loop
     async for quotes in agen:  # new quotes data only
         for symbol, quote in quotes.items():
@@ -538,6 +542,7 @@ async def update_quotes(
         log.debug("Waiting on quotes")
 
     log.warn("Data feed connection dropped")
+    # XXX: if we're cancelled this should never get called
     nursery.cancel_scope.cancel()
 
 
@@ -617,7 +622,8 @@ async def _async_main(
     for ticker_record in first_quotes:
         table.append_row(
             ticker_record['symbol'],
-            Row(ticker_record, headers=('symbol',), bidasks=bidasks, table=table)
+            Row(ticker_record, headers=('symbol',),
+                bidasks=bidasks, table=table)
         )
 
     # associate the col headers row with the ticker table even though

piker/ui/option_chain.py

@@ -5,8 +5,11 @@ Launch with ``piker options <symbol>``.
 """
 import types
 from functools import partial
+from typing import Dict, List
+# import typing
 
 import trio
+from async_generator import asynccontextmanager
 import tractor
 from kivy.uix.boxlayout import BoxLayout
 from kivy.lang import Builder
@@ -27,129 +30,328 @@ async def modify_symbol(symbol):
     pass
 
 
-class ExpiryButton(HeaderCell):
-    def on_press(self, value=None):
-        log.info(f"Clicked {self}")
-
-
 class StrikeCell(Cell):
     """Strike cell"""
 
 
 _no_display = ['symbol', 'contract_type', 'strike', 'time', 'open']
+_strike_row_cache = {}
+_strike_cell_cache = {}
 
 
 class StrikeRow(BoxLayout):
     """A 'row' composed of two ``Row``s sandwiching a
     ``StrikeCell`.
     """
+    _row_cache = {}
+
     def __init__(self, strike, **kwargs):
         super().__init__(orientation='horizontal', **kwargs)
         self.strike = strike
         # store 2 rows: 1 for call, 1 for put
         self._sub_rows = {}
-        self.table = None
+        self._widgets_added = False
 
     def append_sub_row(
         self,
         record: dict,
+        displayable: dict,
         bidasks=None,
         headers=(),
         table=None,
         **kwargs,
     ) -> None:
-        if self.is_populated():
+        # if self.is_populated():
-            raise TypeError(f"{self} can only append two sub-rows?")
+        #     raise TypeError(f"{self} can only append two sub-rows?")
 
         # the 'contract_type' determines whether this
         # is a put or call row
         contract_type = record['contract_type']
 
-        # reverse order of call side cells
+        # We want to only create a few ``Row`` widgets as possible to
-        if contract_type == 'call':
+        # speed up rendering; we cache sub rows after creation.
-            record = dict(list(reversed(list(record.items()))))
+        row = self._row_cache.get((self.strike, contract_type))
+        if not row:
+            # reverse order of call side cells
+            if contract_type == 'call':
+                record = dict(list(reversed(list(record.items()))))
+            row = Row(
+                record,
+                bidasks=bidasks,
+                headers=headers,
+                table=table,
+                no_cell=_no_display,
+                **kwargs
+            )
+            self._row_cache[(self.strike, contract_type)] = row
+        else:
+            # must update the internal cells
+            row.update(record, displayable)
 
-        row = Row(
-            record,
-            bidasks=bidasks,
-            headers=headers,
-            table=table,
-            no_cell=_no_display,
-            **kwargs
-        )
         # reassign widget for when rendered in the update loop
         row.widget = self
         self._sub_rows[contract_type] = row
-        if self.is_populated():
+
+        if self.is_populated() and not self._widgets_added:
             # calls on the left
             self.add_widget(self._sub_rows['call'])
-            # strikes in the middle
+            strike_cell = _strike_cell_cache.setdefault(
-            self.add_widget(
+                self.strike, StrikeCell(
-                StrikeCell(
                     key=self.strike,
                     text=str(self.strike),
                     is_header=True,
                     # make centre strike cell nice and small
-                    size_hint=(1/8., 1),
+                    size_hint=(1/10., 1),
                 )
             )
+            # strikes in the middle
+            self.add_widget(strike_cell)
             # puts on the right
             self.add_widget(self._sub_rows['put'])
+            self._widgets_added = True
 
     def is_populated(self):
         """Bool determing if both a put and call subrow have beed appended.
         """
         return len(self._sub_rows) == 2
 
+    def has_widgets(self):
+        return self._widgets_added
+
     def update(self, record, displayable):
         self._sub_rows[record['contract_type']].update(
             record, displayable)
 
 
-async def _async_main(
+class ExpiryButton(HeaderCell):
-    symbol: str,
+    def on_press(self, value=None):
+        log.info(f"Clicked {self}")
+        if self.chain.sub[1] == self.key:
+            log.info(f"Clicked {self} is already selected")
+            return
+        log.info(f"Subscribing for {self.chain.sub}")
+        self.chain.start_displaying(self.chain.sub[0], self.key)
+
+
+class DataFeed(object):
+    """Data feed client for streaming symbol data from a remote
+    broker data source.
+    """
+    def __init__(self, portal, brokermod):
+        self.portal = portal
+        self.brokermod = brokermod
+        self.sub = None
+        self.quote_gen = None
+
+    async def open_stream(self, symbols, rate=3, test=None):
+        if self.quote_gen is not None and symbols != self.sub:
+            log.info(f"Stopping existing subscription for {self.sub}")
+            await self.quote_gen.aclose()
+            self.sub = symbols
+
+        if test:
+            # stream from a local test file
+            quote_gen = await self.portal.run(
+                "piker.brokers.data", 'stream_from_file',
+                filename=test
+            )
+        else:
+            # start live streaming from broker daemon
+            quote_gen = await self.portal.run(
+                "piker.brokers.data",
+                'start_quote_stream',
+                broker=self.brokermod.name,
+                symbols=symbols,
+                feed_type='option',
+                rate=rate,
+            )
+
+        # get first quotes response
+        log.debug(f"Waiting on first quote for {symbols}...")
+        quotes = await quote_gen.__anext__()
+
+        self.quote_gen = quote_gen
+        self.first_quotes = quotes
+        # self.records = records
+        # self.displayables = displayables
+        return quote_gen, quotes
+
+
+class OptionChain(object):
+    """A real-time options chain UI.
+    """
+    def __init__(
+        self,
+        symbol: str,
+        expiry: str,
+        widgets: dict,
+        bidasks: Dict[str, List[str]],
+        feed: DataFeed,
+        rate: int = 1,
+    ):
+        self.sub = (symbol, expiry)
+        self.widgets = widgets
+        self.bidasks = bidasks
+        self._strikes2rows = {}
+        self._nursery = None
+        self.feed = feed
+        self._update_cs = None
+        # TODO: this should be moved down to the data feed layer
+        # right now it's only needed for the UI uupdate loop to cancel itself
+        self._first_quotes = None
+
+    @asynccontextmanager
+    async def open_scope(self):
+        """Open an internal resource and update task scope required
+        to allow for dynamic real-time operation.
+        """
+        # assign us to each expiry button
+        for key, button in (
+            self.widgets['expiry_buttons']._cell_widgets.items()
+        ):
+            button.chain = self
+
+        async with trio.open_nursery() as n:
+            self._nursery = n
+            n.start_soon(self.start_updating)
+            yield self
+
+        self._nursery = None
+        await self.feed.quote_gen.aclose()
+
+    def clear(self):
+        """Clear the strike rows from the internal table.
+        """
+        table = self.widgets['table']
+        table.clear_widgets()
+        for strike in self._strikes2rows.copy():
+            self._strikes2rows.pop(strike)
+
+    def render_rows(self, records, displayables):
+        """Render all strike rows in the internal table.
+        """
+        log.debug("Rendering rows")
+        table = self.widgets['table']
+        for record, display in zip(
+            sorted(records, key=lambda q: q['strike']),
+            displayables
+        ):
+            strike = record['strike']
+            strike_row = _strike_row_cache.setdefault(
+                strike, StrikeRow(strike))
+            strike_row.append_sub_row(
+                record,
+                display,
+                bidasks=self.bidasks,
+                table=table,
+            )
+            if strike_row.is_populated():
+                # We must fill out the the table's symbol2rows manually
+                # using each contracts "symbol" so that the quote updater
+                # task can look up the right row to update easily
+                # See update_quotes() and ``Row`` internals for details.
+                for contract_type, row in strike_row._sub_rows.items():
+                    symbol = row._last_record['symbol']
+                    table.symbols2rows[symbol] = row
+
+                if strike not in self._strikes2rows:
+                    # readding widgets is an error
+                    table.add_widget(strike_row)
+                    self._strikes2rows[strike] = strike_row
+
+        log.debug("Finished rendering rows!")
+
+    async def start_feed(
+        self,
+        symbol: str,
+        expiry: str,
+        # max QT rate per API customer is approx 4 rps
+        # and usually 3 rps is allocated to the stock monitor
+        rate: int = 1,
+        test: str = None
+    ):
+        if self.feed.sub != self.sub:
+            return await self.feed.open_stream([(symbol, expiry)], rate=rate)
+        else:
+            feed = self.feed
+            return feed.quote_gen, feed.first_quotes
+
+    async def start_updating(self):
+        if self._update_cs:
+            self._update_cs.cancel()
+            await trio.sleep(0)
+
+        self.clear()
+
+        if self._nursery is None:
+            raise RuntimeError(
+                "You must call await `start()` first!")
+
+        n = self._nursery
+        log.debug(f"Waiting on first_quotes for {self.sub}")
+        quote_gen, first_quotes = await self.start_feed(*self.sub)
+        log.debug(f"Got first_quotes for {self.sub}")
+
+        # redraw the UI
+        records, displayables = zip(*[
+            self.feed.brokermod.format_option_quote(quote, {})
+            for quote in first_quotes.values()
+        ])
+        self.render_rows(records, displayables)
+
+        with trio.open_cancel_scope() as cs:
+            self._update_cs = cs
+            # start quote update loop
+            await n.start(
+                partial(
+                    update_quotes,
+                    self._nursery,
+                    self.feed.brokermod.format_option_quote,
+                    self.widgets,
+                    quote_gen,
+                    symbol_data={},
+                    first_quotes=first_quotes,
+                )
+            )
+
+    def start_displaying(self, symbol, expiry):
+        self.sub = (symbol, expiry)
+        self._nursery.start_soon(self.start_updating)
+
+
+async def new_chain_ui(
     portal: tractor._portal.Portal,
+    symbol: str,
+    expiry: str,
+    contracts,
     brokermod: types.ModuleType,
-    rate: int = 4,
+    nursery: trio._core._run.Nursery,
-    test: bool = False
+    rate: int = 1,
 ) -> None:
-    '''Launch kivy app + all other related tasks.
+    """Create and return a new option chain UI.
-
+    """
-    This is started with cli cmd `piker options`.
+    widgets = {}
-    '''
-    # retreive all contracts
-    all_contracts = await contracts(brokermod, symbol)
-    first_expiry = next(iter(all_contracts)).expiry
-
-    if test:
-        # stream from a local test file
-        quote_gen = await portal.run(
-            "piker.brokers.data", 'stream_from_file',
-            filename=test
-        )
-    else:
-        # start live streaming from broker daemon
-        quote_gen = await portal.run(
-            "piker.brokers.data",
-            'start_quote_stream',
-            broker=brokermod.name,
-            symbols=[(symbol, first_expiry)],
-            feed_type='option',
-        )
-
-    # get first quotes response
-    log.debug("Waiting on first quote...")
-    quotes = await quote_gen.__anext__()
-    records, displayables = zip(*[
-        brokermod.format_option_quote(quote, {})
-        for quote in quotes.values()
-    ])
-
     # define bid-ask "stacked" cells
     # (TODO: needs some rethinking and renaming for sure)
     bidasks = brokermod._option_bidasks
 
-    # build out UI
+    feed = DataFeed(portal, brokermod)
+    chain = OptionChain(
+        symbol,
+        expiry,
+        widgets,
+        bidasks,
+        feed,
+        rate=rate,
+    )
+
+    quote_gen, first_quotes = await chain.start_feed(symbol, expiry)
+    records, displayables = zip(*[
+        brokermod.format_option_quote(quote, {})
+        for quote in first_quotes.values()
+    ])
+
+    # build out root UI
     title = f"option chain: {symbol}\t(press ? for help)"
     Window.set_title(title)
 
@@ -163,7 +365,7 @@ async def _async_main(
     # TODO: figure out how to compact these buttons
     expiries = {
         key.expiry: key.expiry[:key.expiry.find('T')]
-        for key in all_contracts
+        for key in contracts
     }
     expiry_buttons = Row(
         record=expiries,
@@ -182,94 +384,77 @@ async def _async_main(
     header_record['contract_type'] = 'put'
     header_row.append_sub_row(
         header_record,
-        headers=headers,
-        bidasks=bidasks,
-        is_header=True,
-        size_hint=(1, None),
-
-    )
-    header_record['contract_type'] = 'call'
-    header_row.append_sub_row(
         header_record,
         headers=headers,
         bidasks=bidasks,
         is_header=True,
         size_hint=(1, None),
-
+    )
+    header_record['contract_type'] = 'call'
+    header_row.append_sub_row(
+        header_record,
+        header_record,
+        headers=headers,
+        bidasks=bidasks,
+        is_header=True,
+        size_hint=(1, None),
     )
     container.add_widget(header_row)
-
     table = TickerTable(
         sort_key='strike',
         cols=1,
         size_hint=(1, None),
     )
     header_row.table = table
+    table.bind(minimum_height=table.setter('height'))
+    pager = PagerView(
+        container=container,
+        contained=table,
+        nursery=nursery
+    )
+    container.add_widget(pager)
+    widgets.update({
+        'root': container,
+        'container': container,
+        'table': table,
+        'expiry_buttons': expiry_buttons,
+        'pager': pager,
+    })
+    return chain
 
-    strike_rows = {}
-    for record, display in zip(sorted(
-        records,
-        key=lambda q: q['strike'],
-    ), displayables):
-        strike = record['strike']
-        strike_row = strike_rows.setdefault(
-            strike, StrikeRow(strike))
-        strike_row.append_sub_row(
-            record,
-            bidasks=bidasks,
-            table=table,
-        )
-        if strike_row.is_populated():
-            # We must fill out the the table's symbol2rows manually
-            # using each contracts "symbol" so that the quote updater
-            # task can look up the right row to update easily
-            # See update_quotes() and ``Row`` for details.
-            for contract_type, row in strike_row._sub_rows.items():
-                table.symbols2rows[row._last_record['symbol']] = row
 
-            table.append_row(symbol, strike_row)
+async def _async_main(
+    symbol: str,
+    portal: tractor._portal.Portal,
+    brokermod: types.ModuleType,
+    rate: int = 1,
+    test: bool = False
+) -> None:
+    '''Launch kivy app + all other related tasks.
+
+    This is started with cli cmd `piker options`.
+    '''
+    # retreive all contracts just because we need a default when the
+    # UI starts up
+    all_contracts = await contracts(brokermod, symbol)
+    # start streaming soonest contract by default
+    first_expiry = next(iter(all_contracts)).expiry
 
     async with trio.open_nursery() as nursery:
         # set up a pager view for large ticker lists
-        table.bind(minimum_height=table.setter('height'))
+        chain = await new_chain_ui(
-        pager = PagerView(
+            portal,
-            container=container,
+            symbol,
-            contained=table,
+            first_expiry,
-            nursery=nursery
+            all_contracts,
+            brokermod,
+            nursery,
+            rate=rate,
         )
-        container.add_widget(pager)
+        async with chain.open_scope():
-        widgets = {
+            try:
-            'root': container,
+                # Trio-kivy entry point.
-            'container': container,
+                await async_runTouchApp(chain.widgets['root'])  # run kivy
-            'table': table,
+            finally:
-            'expiry_buttons': expiry_buttons,
+                # cancel GUI update task
-            'pager': pager,
+                nursery.cancel_scope.cancel()
-        }
-        nursery.start_soon(
-            partial(
-                update_quotes,
-                nursery,
-                brokermod.format_option_quote,
-                widgets,
-                quote_gen,
-                symbol_data={},
-                first_quotes=quotes,
-            )
-        )
-        try:
-            # Trio-kivy entry point.
-            await async_runTouchApp(widgets['root'])  # run kivy
-        finally:
-            await quote_gen.aclose()  # cancel aysnc gen call
-            # un-subscribe from symbols stream (cancel if brokerd
-            # was already torn down - say by SIGINT)
-            with trio.move_on_after(0.2):
-                await portal.run(
-                    "piker.brokers.data", 'modify_quote_stream',
-                    broker=brokermod.name,
-                    feed_type='option',
-                    symbols=[]
-                )
-
-            # cancel GUI update task
-            nursery.cancel_scope.cancel()