Flip contents label stuff into a type

piker/ui/_chart.py

@@ -2,6 +2,7 @@
 High level Qt chart widgets.
 """
 from typing import Tuple, Dict, Any, Optional
+from functools import partial
 
 from PyQt5 import QtCore, QtGui
 import numpy as np
@@ -15,6 +16,7 @@ from ._axes import (
 )
 from ._graphics import (
     CrossHair,
+    ContentsLabel,
     BarItems,
     h_line,
 )
@@ -27,7 +29,6 @@ from ._style import (
     _min_points_to_show,
     _bars_from_right_in_follow_mode,
     _bars_to_left_in_follow_mode,
-    _font,
 )
 from ..data._source import Symbol
 from .. import brokers
@@ -326,7 +327,7 @@ class ChartPlotWidget(pg.PlotWidget):
         self.showAxis('right')
 
         # show background grid
-        self.showGrid(x=True, y=True, alpha=0.4)
+        self.showGrid(x=True, y=True, alpha=0.5)
 
         # use cross-hair for cursor?
         # self.setCursor(QtCore.Qt.CrossCursor)
@@ -344,10 +345,12 @@ class ChartPlotWidget(pg.PlotWidget):
     def last_bar_in_view(self) -> bool:
         self._array[-1]['index']
 
-    def _update_contents_label(self, index: int) -> None:
+    def update_contents_labels(self, index: int) -> None:
         if index >= 0 and index < len(self._array):
+            array = self._array
+
             for name, (label, update) in self._labels.items():
-                update(index)
+                update(index, array)
 
     def _set_xlimits(
         self,
@@ -375,54 +378,6 @@ class ChartPlotWidget(pg.PlotWidget):
         rbar = min(r, len(self._array))
         return l, lbar, rbar, r
 
-    def draw_ohlc(
-        self,
-        name: str,
-        data: np.ndarray,
-        # XXX: pretty sure this is dumb and we don't need an Enum
-        style: pg.GraphicsObject = BarItems,
-    ) -> pg.GraphicsObject:
-        """Draw OHLC datums to chart.
-        """
-        graphics = style(self.plotItem)
-        # adds all bar/candle graphics objects for each data point in
-        # the np array buffer to be drawn on next render cycle
-        self.addItem(graphics)
-
-        # draw after to allow self.scene() to work...
-        graphics.draw_from_data(data)
-
-        self._graphics[name] = graphics
-
-        # XXX: How to stack labels vertically?
-        # Ogi says: "use ..."
-        label = pg.LabelItem(
-            justify='left',
-            size=f'{_font.pixelSize()}px',
-        )
-        label.setParentItem(self._vb)
-        self.scene().addItem(label)
-
-        # keep close to top
-        label.anchor(itemPos=(0, 0), parentPos=(0, 0), offset=(0, -4))
-
-        def update(index: int) -> None:
-            label.setText(
-                "{name}[{index}] -> O:{} H:{} L:{} C:{} V:{}".format(
-                    *self._array[index].item()[2:8],
-                    name=name,
-                    index=index,
-                )
-            )
-
-        self._labels[name] = (label, update)
-        self._update_contents_label(len(data) - 1)
-        label.show()
-
-        self._add_sticky(name)
-
-        return graphics
-
     def default_view(
         self,
         index: int = -1,
@@ -456,6 +411,34 @@ class ChartPlotWidget(pg.PlotWidget):
             padding=0,
         )
 
+    def draw_ohlc(
+        self,
+        name: str,
+        data: np.ndarray,
+        # XXX: pretty sure this is dumb and we don't need an Enum
+        style: pg.GraphicsObject = BarItems,
+    ) -> pg.GraphicsObject:
+        """Draw OHLC datums to chart.
+        """
+        graphics = style(self.plotItem)
+        # adds all bar/candle graphics objects for each data point in
+        # the np array buffer to be drawn on next render cycle
+        self.addItem(graphics)
+
+        # draw after to allow self.scene() to work...
+        graphics.draw_from_data(data)
+
+        self._graphics[name] = graphics
+
+        label = ContentsLabel(chart=self, anchor_at=('top', 'left'))
+        self._labels[name] = (label, partial(label.update_from_ohlc, name))
+        label.show()
+        self.update_contents_labels(len(data) - 1)
+
+        self._add_sticky(name)
+
+        return graphics
+
     def draw_curve(
         self,
         name: str,
@@ -482,37 +465,21 @@ class ChartPlotWidget(pg.PlotWidget):
         # register overlay curve with name
         self._graphics[name] = curve
 
-        # XXX: How to stack labels vertically?
-        label = pg.LabelItem(
-            justify='left',
-            size=f'{_font.pixelSize()}px',
-        )
-
-        # anchor to the viewbox
-        label.setParentItem(self._vb)
-        # label.setParentItem(self.getPlotItem())
-
         if overlay:
-            # position bottom left if an overlay
+            anchor_at = ('bottom', 'right')
-            label.anchor(itemPos=(1, 1), parentPos=(1, 1), offset=(0, 3))
             self._overlays[name] = curve
 
         else:
-            label.anchor(itemPos=(0, 0), parentPos=(0, 0), offset=(0, -4))
+            anchor_at = ('top', 'right')
 
             # TODO: something instead of stickies for overlays
             # (we need something that avoids clutter on x-axis).
             self._add_sticky(name)
 
-        def update(index: int) -> None:
+        label = ContentsLabel(chart=self, anchor_at=anchor_at)
-            data = self._array[index][name]
+        self._labels[name] = (label, partial(label.update_from_value, name))
-            label.setText(f"{name}: {data:.2f}")
-
         label.show()
-        self.scene().addItem(label)
+        self.update_contents_labels(len(data) - 1)
-
-        self._labels[name] = (label, update)
-        self._update_contents_label(len(data) - 1)
 
         if self._cursor:
             self._cursor.add_curve_cursor(self, curve)
@@ -909,7 +876,7 @@ async def chart_from_fsp(
         )
 
         # display contents labels asap
-        chart._update_contents_label(len(shm.array) - 1)
+        chart.update_contents_labels(len(shm.array) - 1)
 
         array = shm.array
         value = array[fsp_func_name][-1]

piker/ui/_graphics.py

@@ -6,10 +6,11 @@ from typing import List
 
 import numpy as np
 import pyqtgraph as pg
+# from numba import jit, float64, optional, int64
 from PyQt5 import QtCore, QtGui
 from PyQt5.QtCore import QLineF, QPointF
 
-# from .quantdom.utils import timeit
+# from .._profile import timeit
 from ._style import _xaxis_at, hcolor, _font
 from ._axes import YAxisLabel, XAxisLabel
 
@@ -56,6 +57,78 @@ class LineDot(pg.CurvePoint):
         self.setFlag(self.ItemIgnoresTransformations)
 
 
+_corner_anchors = {
+    'top': 0,
+    'left': 0,
+    'bottom': 1,
+    'right': 1,
+}
+# XXX: fyi naming here is confusing / opposite to coords
+_corner_margins = {
+    ('top', 'left'): (-4, -5),
+    ('top', 'right'): (4, -5),
+    ('bottom', 'left'): (-4, 5),
+    ('bottom', 'right'): (4, 5),
+}
+
+
+class ContentsLabel(pg.LabelItem):
+    """Label anchored to a ``ViewBox`` typically for displaying
+    datum-wise points from the "viewed" contents.
+
+    """
+    def __init__(
+        self,
+        chart: 'ChartPlotWidget',  # noqa
+        anchor_at: str = ('top', 'right'),
+        justify_text: str = 'left',
+        size: str = f'{_font.pixelSize()}px',
+    ) -> None:
+
+        super().__init__(justify=justify_text, size=size)
+
+        # anchor to viewbox
+        self.setParentItem(chart._vb)
+        chart.scene().addItem(self)
+        self.chart = chart
+
+        v, h = anchor_at
+        index = (_corner_anchors[h], _corner_anchors[v])
+        margins = _corner_margins[(v, h)]
+
+        self.anchor(itemPos=index, parentPos=index, offset=margins)
+
+    def update_from_ohlc(
+        self,
+        name: str,
+        index: int,
+        array: np.ndarray,
+    ) -> None:
+        # this being "html" is the dumbest shit :eyeroll:
+        self.setText(
+            "<b>i</b>:{index}<br/>"
+            "<b>O</b>:{}<br/>"
+            "<b>H</b>:{}<br/>"
+            "<b>L</b>:{}<br/>"
+            "<b>C</b>:{}<br/>"
+            "<b>V</b>:{}".format(
+                # *self._array[index].item()[2:8],
+                *array[index].item()[2:8],
+                name=name,
+                index=index,
+            )
+        )
+
+    def update_from_value(
+        self,
+        name: str,
+        index: int,
+        array: np.ndarray,
+    ) -> None:
+        data = array[index][name]
+        self.setText(f"{name}: {data:.2f}")
+
+
 class CrossHair(pg.GraphicsObject):
 
     def __init__(
@@ -208,7 +281,7 @@ class CrossHair(pg.GraphicsObject):
                 opts['vl'].setX(ix)
 
                 # update the chart's "contents" label
-                plot._update_contents_label(ix)
+                plot.update_contents_labels(ix)
 
                 # update all subscribed curve dots
                 for cursor in opts.get('cursors', ()):
@@ -235,6 +308,15 @@ class CrossHair(pg.GraphicsObject):
             return self.plots[0].boundingRect()
 
 
+# @jit(
+#     # float64[:](
+#     #     float64[:],
+#     #     optional(float64),
+#     #     optional(int16)
+#     # ),
+#     nopython=True,
+#     nogil=True
+# )
 def _mk_lines_array(data: List, size: int) -> np.ndarray:
     """Create an ndarray to hold lines graphics objects.
     """
@@ -246,6 +328,16 @@ def _mk_lines_array(data: List, size: int) -> np.ndarray:
 
 
 # TODO: `numba` this?
+
+# @jit(
+#     # float64[:](
+#     #     float64[:],
+#     #     optional(float64),
+#     #     optional(int16)
+#     # ),
+#     nopython=True,
+#     nogil=True
+# )
 def bars_from_ohlc(
     data: np.ndarray,
     w: float,