pikers
/
piker
3
0
Fork 0
Code Issues 4 Pull Requests 6 Packages Projects Releases Wiki Activity

Support updating bars graphics from array 

This makes a OHLC graphics "sequence" update very similar (actually API
compatible) with `pg.PlotCurveItem.setData()`. The difference here is
that only latest OHLC datum is used to update the charts last bar.
its_happening
Tyler Goodlet 2020-06-19 07:53:06 -04:00
parent b14cb66d7c
commit b328457f3b
1 changed files with 23 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
piker/ui/_graphics.py
View File

@ -185,10 +185,10 @@ class BarItems(pg.GraphicsObject):
def __init__(self): def __init__(self):
super().__init__() super().__init__()
self.picture = QtGui.QPicture() self.picture = QtGui.QPicture()
self.lines = None # lines container
self._last_quote = {} self.lines: np.ndarray = None
# TODO: this is the routine to be retriggered for redraw # TODO: can we be faster just dropping this?
@contextmanager @contextmanager
def painter(self): def painter(self):
# pre-computing a QPicture object allows paint() to run much # pre-computing a QPicture object allows paint() to run much
@ -221,8 +221,6 @@ class BarItems(pg.GraphicsObject):
QtCore.QLineF( QtCore.QLineF(
q['index'] + self.w, q['close'], q['index'], q['close']) q['index'] + self.w, q['close'], q['index'], q['close'])
) )
else:
self._last_quote = q
# if not _tina_mode: # piker mode # if not _tina_mode: # piker mode
p.setPen(self.bull_brush) p.setPen(self.bull_brush)
p.drawLines(*lines) p.drawLines(*lines)
@ -245,17 +243,24 @@ class BarItems(pg.GraphicsObject):
# p.setPen(self.bear_brush) # p.setPen(self.bear_brush)
# p.drawLines(*downs) # p.drawLines(*downs)
def update_last_bar( def update_from_array(
self, self,
quote: Dict[str, Any], array: np.ndarray,
) -> None: ) -> None:
"""Update the last datum's bar graphic from a quote ``dict``. """Update the last datum's bar graphic from input data array.
This routine should be interface compatible with
``pg.PlotCurveItem.setData()``. Normally this method in
``pyqtgraph`` seems to update all the data passed to the
graphics object, and then update/rerender, but here we're
assuming the prior graphics havent changed (OHLC history rarely
does) so this "should" be simpler and faster.
""" """
last = quote['last'] # do we really need to verify the entire past data set?
body, larm, rarm = self.lines[-3:] # close line is absolute last last = array['close'][-1]
body, larm, rarm = self.lines[-3:]
# XXX: is there a faster way to modify this? # XXX: is there a faster way to modify this?
# update right arm # update right arm
rarm.setLine(rarm.x1(), last, rarm.x2(), last) rarm.setLine(rarm.x1(), last, rarm.x2(), last)
@ -270,23 +275,27 @@ class BarItems(pg.GraphicsObject):
body.setLine(body.x1(), low, body.x2(), high) body.setLine(body.x1(), low, body.x2(), high)
# draw the pic
with self.painter() as p: with self.painter() as p:
p.setPen(self.bull_brush) p.setPen(self.bull_brush)
p.drawLines(*self.lines) p.drawLines(*self.lines)
# trigger re-draw # trigger re-render
self.update() self.update()
# be compat with ``pg.PlotCurveItem``
setData = update_from_array
# XXX: From the customGraphicsItem.py example: # XXX: From the customGraphicsItem.py example:
# The only required methods are paint() and boundingRect() # The only required methods are paint() and boundingRect()
def paint(self, p, *args): def paint(self, p, opt, widget):
p.drawPicture(0, 0, self.picture) p.drawPicture(0, 0, self.picture)
def boundingRect(self): def boundingRect(self):
# boundingRect _must_ indicate the entire area that will be # boundingRect _must_ indicate the entire area that will be
# drawn on or else we will get artifacts and possibly crashing. # drawn on or else we will get artifacts and possibly crashing.
# (in this case, QPicture does all the work of computing the # (in this case, QPicture does all the work of computing the
# bouning rect for us) # bounding rect for us)
return QtCore.QRectF(self.picture.boundingRect()) return QtCore.QRectF(self.picture.boundingRect())