Add initial y-axis zoom

piker/ui/_chart.py

@@ -384,7 +384,6 @@ class ChartPlotWidget(pg.PlotWidget):
 
         # self.setViewportMargins(0, 0, 0, 0)
         self._ohlc = array  # readonly view of ohlc data
-        self.default_view()
 
         self._arrays = {}  # readonly view of overlays
         self._graphics = {}  # registry of underlying graphics
@@ -406,6 +405,8 @@ class ChartPlotWidget(pg.PlotWidget):
         # show background grid
         self.showGrid(x=True, y=True, alpha=0.5)
 
+        self.default_view()
+
         # TODO: stick in config
         # use cross-hair for cursor?
         # self.setCursor(QtCore.Qt.CrossCursor)
@@ -478,10 +479,13 @@ class ChartPlotWidget(pg.PlotWidget):
 
         """
         xlast = self._ohlc[index]['index']
-        print(xlast)
         begin = xlast - _bars_to_left_in_follow_mode
         end = xlast + _bars_from_right_in_follow_mode
 
+        # remove any custom user yrange setttings
+        if self._static_yrange == 'axis':
+            self._static_yrange = None
+
         self.plotItem.vb.setXRange(
             min=begin,
             max=end,
@@ -697,7 +701,12 @@ class ChartPlotWidget(pg.PlotWidget):
         data set.
 
         """
-        if self._static_yrange is not None:
+        set_range = True
+
+        if self._static_yrange == 'axis':
+            set_range = False
+
+        elif self._static_yrange is not None:
             ylow, yhigh = self._static_yrange
 
         elif yrange is not None:
@@ -761,11 +770,19 @@ class ChartPlotWidget(pg.PlotWidget):
                 ylow = np.nanmin(bars)
                 yhigh = np.nanmax(bars)
 
+        if set_range:
             # view margins: stay within a % of the "true range"
             diff = yhigh - ylow
             ylow = ylow - (diff * 0.04)
             yhigh = yhigh + (diff * 0.04)
 
+            self.setLimits(
+                yMin=ylow,
+                yMax=yhigh,
+            )
+            self.setYRange(ylow, yhigh)
+
+    # def _label_h(self, yhigh: float, ylow: float) -> float:
     #     # compute contents label "height" in view terms
     #     # to avoid having data "contents" overlap with them
     #     if self._labels:
@@ -791,14 +808,8 @@ class ChartPlotWidget(pg.PlotWidget):
 
     #     if label_h > yhigh - ylow:
     #         label_h = 0
-        # print(f"bounds (ylow, yhigh): {(ylow, yhigh)}")
-        label_h = 0
 
-        self.setLimits(
+    #     print(f"bounds (ylow, yhigh): {(ylow, yhigh)}")
-            yMin=ylow,
-            yMax=yhigh + label_h,
-        )
-        self.setYRange(ylow, yhigh + label_h)
 
     def enterEvent(self, ev):  # noqa
         # pg.PlotWidget.enterEvent(self, ev)
@@ -1137,7 +1148,7 @@ async def spawn_fsps(
                     """Start an fsp subactor async.
 
                     """
-                    print(f'FSP NAME: {fsp_name}')
+                    # print(f'FSP NAME: {fsp_name}')
                     portal = await n.run_in_actor(
 
                         # subactor entrypoint

piker/ui/_interaction.py

@@ -17,6 +17,8 @@
 """
 UX interaction customs.
 """
+from typing import Optional
+
 import pyqtgraph as pg
 from pyqtgraph import ViewBox, Point, QtCore, QtGui
 from pyqtgraph import functions as fn
@@ -144,7 +146,7 @@ class SelectRect(QtGui.QGraphicsRectItem):
         x1, x2 = start_pos.x(), end_pos.x()
 
         # TODO: heh, could probably use a max-min streamin algo here too
-        ymn, xmn = min(y1, y2), min(x1, x2)
+        _, xmn = min(y1, y2), min(x1, x2)
         ymx, xmx = max(y1, y2), max(x1, x2)
 
         pchng = (y2 - y1) / y1 * 100
@@ -277,7 +279,11 @@ class ChartView(ViewBox):
         ev.accept()
         self.sigRangeChangedManually.emit(mask)
 
-    def mouseDragEvent(self, ev, axis=None):
+    def mouseDragEvent(
+        self,
+        ev,
+        axis: Optional[int] = None,
+    ) -> None:
         #  if axis is specified, event will only affect that axis.
         ev.accept()  # we accept all buttons
 
@@ -295,6 +301,18 @@ class ChartView(ViewBox):
         # Scale or translate based on mouse button
         if ev.button() & (QtCore.Qt.LeftButton | QtCore.Qt.MidButton):
 
+            # zoom only y-axis when click-n-drag on it
+            if axis == 1:
+                # set a static y range special value on chart widget to
+                # prevent sizing to data in view.
+                self._chart._static_yrange = 'axis'
+
+                scale_y = 1.3 ** (dif.y() * -1 / 20)
+                self.setLimits(yMin=None, yMax=None)
+
+                # print(scale_y)
+                self.scaleBy((0, scale_y))
+
             if self.state['mouseMode'] == ViewBox.RectMode:
 
                 down_pos = ev.buttonDownPos()
@@ -333,6 +351,7 @@ class ChartView(ViewBox):
                 self.sigRangeChangedManually.emit(self.state['mouseEnabled'])
 
         elif ev.button() & QtCore.Qt.RightButton:
+
             # print "vb.rightDrag"
             if self.state['aspectLocked'] is not False:
                 mask[0] = 0