Add history chart and "linear region" for syncing

Add a first draft of a working `pyqtgraph.LinearRegionItem` link between
a history view chart (+ data set) and the normal real-time "HFT" chart
set.

Add the history view (aka more downsampled data view) chart set to the
rt/hft set's splitter as it's "first widget". Hook up linear region
callbacks to enable syncing between charts including compenstating for
the downsampling rate ration (in this case hardcoded 60 since 1s to 1M,
but we'll actually compute it going forward obvs).

More to come dawgys..

piker/ui/_display.py

@@ -29,7 +29,7 @@ from typing import Optional, Any, Callable
 import numpy as np
 import tractor
 import trio
-import pendulum
+# import pendulum
 import pyqtgraph as pg
 
 # from .. import brokers
@@ -720,12 +720,15 @@ async def display_symbol_data(
 
     ) as feed:
         ohlcv: ShmArray = feed.rt_shm
-        bars = ohlcv.array
+        hist_ohlcv: ShmArray = feed.hist_shm
+        end_index = hist_ohlcv.index
+
+        # bars = ohlcv.array
         symbol = feed.symbols[sym]
         fqsn = symbol.front_fqsn()
 
-        times = feed.hist_shm.array['time']
+        # times = feed.hist_shm.array['time']
-        end = pendulum.from_timestamp(times[-1])
+        # end = pendulum.from_timestamp(times[-1])
         # start = pendulum.from_timestamp(times[times != times[-1]][-1])
         # step_size_s = (end - start).seconds
 
@@ -739,7 +742,7 @@ async def display_symbol_data(
             f'step:{tf_key} '
         )
 
-        linked = godwidget.linkedsplits
+        linked = godwidget.rt_linked
         linked._symbol = symbol
 
         # generate order mode side-pane UI
@@ -749,10 +752,27 @@ async def display_symbol_data(
         # add as next-to-y-axis singleton pane
         godwidget.pp_pane = pp_pane
 
+        # create top history view chart above the "main rt chart".
+        hist_linked = godwidget.hist_linked
+        hist_linked._symbol = symbol
+        hist_chart = hist_linked.plot_ohlc_main(
+            symbol,
+            feed.hist_shm,
+            # in the case of history chart we explicitly set `False`
+            # to avoid internal pane creation.
+            sidepane=False,
+        )
+        hist_chart.default_view(
+            bars_from_y=int(len(hist_ohlcv.array)),  # size to data
+            y_offset=6116*2,  # push it a little away from the y-axis
+        )
+
         # create main OHLC chart
         chart = linked.plot_ohlc_main(
             symbol,
             ohlcv,
+            # in the case of history chart we explicitly set `False`
+            # to avoid internal pane creation.
             sidepane=pp_pane,
         )
 
@@ -760,13 +780,13 @@ async def display_symbol_data(
         chart._feeds[symbol.key] = feed
         chart.setFocus()
 
+        # XXX: FOR SOME REASON THIS IS CAUSING HANGZ!?!
         # plot historical vwap if available
         wap_in_history = False
-
+        # if (
-        # XXX: FOR SOME REASON THIS IS CAUSING HANGZ!?!
+        #     brokermod._show_wap_in_history
-        # if brokermod._show_wap_in_history:
+        #     and 'bar_wap' in bars.dtype.fields
-
+        # ):
-        #     if 'bar_wap' in bars.dtype.fields:
         #     wap_in_history = True
         #     chart.draw_curve(
         #         name='bar_wap',
@@ -775,39 +795,51 @@ async def display_symbol_data(
         #         add_label=False,
         #     )
 
-        # size view to data once at outset
-        # chart.cv._set_yrange()
-
         # Add the LinearRegionItem to the ViewBox, but tell the ViewBox
         # to exclude this item when doing auto-range calculations.
-        hist_pi = chart.plotItem
+        rt_pi = chart.plotItem
+        hist_pi = hist_chart.plotItem
         region = pg.LinearRegionItem()
         region.setZValue(10)
-        # hist_pi.addItem(region, ignoreBounds=True)
+        hist_pi.addItem(region, ignoreBounds=True)
-        flow = chart._flows[chart.name]
+        flow = chart._flows[hist_chart.name]
-        region.setClipItem(flow.graphics)
+        assert flow
+        # XXX: no idea why this doesn't work but it's causing
+        # a weird placement of the region on the way-far-left..
+        # region.setClipItem(flow.graphics)
 
         def update():
             region.setZValue(10)
-            minX, maxX = region.getRegion()
+            mn, mx = region.getRegion()
-            # p1.setXRange(minX, maxX, padding=0)
+            # print(f'region_x: {(mn, mx)}')
+
+            # XXX: seems to cause a real perf hit?
+            rt_pi.setXRange(
+                (mn - end_index) * 60,
+                (mx - end_index) * 60,
+                padding=0,
+            )
 
         region.sigRegionChanged.connect(update)
 
         def update_region_from_pi(
             window,
             viewRange: tuple[tuple, tuple],
+
         ) -> None:
             # set the region on the history chart
             # to the range currently viewed in the
             # HFT/real-time chart.
             rgn = viewRange[0]
-            # region.setRegion(rgn)
+            # print(f'rt_view_range: {rgn}')
+            mn, mx = rgn
+            region.setRegion((
+                mn/60 + end_index,
+                mx/60 + end_index,
+            ))
 
         # connect region to be updated on plotitem interaction.
-        hist_pi.sigRangeChanged.connect(update_region_from_pi)
+        rt_pi.sigRangeChanged.connect(update_region_from_pi)
-        # causes recursion error right now!?..
-        # region.setRegion([l, r])
 
         # NOTE: we must immediately tell Qt to show the OHLC chart
         # to avoid a race where the subplots get added/shown to
@@ -816,6 +848,11 @@ async def display_symbol_data(
         linked.focus()
         await trio.sleep(0)
 
+        linked.splitter.insertWidget(0, hist_linked)
+        # XXX: if we wanted it at the bottom?
+        # linked.splitter.addWidget(hist_linked)
+        linked.focus()
+
         vlm_chart: Optional[ChartPlotWidget] = None
         async with trio.open_nursery() as ln:
 
@@ -851,8 +888,9 @@ async def display_symbol_data(
             )
 
             await trio.sleep(0)
+
+            # size view to data prior to order mode init
             chart.default_view()
-            l, lbar, rbar, r = chart.bars_range()
 
             async with (
                 open_order_mode(
@@ -863,12 +901,14 @@ async def display_symbol_data(
                 )
             ):
                 if not vlm_chart:
+                    # trigger another view reset if no sub-chart
                     chart.default_view()
 
                 # let Qt run to render all widgets and make sure the
                 # sidepanes line up vertically.
                 await trio.sleep(0)
                 linked.resize_sidepanes()
+                linked.set_split_sizes()
 
                 # NOTE: we pop the volume chart from the subplots set so
                 # that it isn't double rendered in the display loop