fix: intermediate plotting of first event whenever a slot is added

CHANGELOG

@@ -1,4 +1,6 @@
 2.14.3
+ - fix: intermediate plotting of first event whenever a slot is added
+ - fix: catch zero-division warning when plotting empty image
  - enh: avoid showing first dataset event when user clicks in QuickView
  - setup: bump dclab from 0.55.7 to 0.56.3 (enhanced basin support)
 2.14.2

shapeout2/gui/main.py

@@ -941,6 +941,7 @@ def on_quickview(self, view=True):
     @QtCore.pyqtSlot()
     def on_quickview_refresh(self):
         """Refresh quickview with the currently shown dataset"""
+        print("REFRESH", self.sender())
         slot_index, filt_index = self.block_matrix.get_quickview_indices()
         if slot_index is not None:
             self.on_quickview_show_dataset(slot_index, filt_index,
@@ -964,6 +965,7 @@ def on_quickview_show_dataset(self, slot_index, filt_index,
             the one where QuickView is currently set active. If
             False, nothing is changed.
         """
+        print("SHOW", self.sender())
         ds = self.pipeline.get_dataset(slot_index=slot_index,
                                        filt_index=filt_index,
                                        apply_filter=True)

shapeout2/gui/quick_view/qv_main.py

@@ -263,7 +263,7 @@ def get_event_image(self, ds, event):
         # automatic contrast
         if state["event"]["image auto contrast"]:
             vmin, vmax = cellimg.min(), cellimg.max()
-            cellimg = (cellimg - vmin) / (vmax - vmin) * 255
+            cellimg = (cellimg - vmin) / max(vmax - vmin, 1) * 255
         # convert to RGB
         cellimg = cellimg.reshape(
             cellimg.shape[0], cellimg.shape[1], 1)
@@ -692,6 +692,7 @@ def show_event(self, event):
             self.tableWidget_feats.set_key_vals(keys, vals)
 
     @show_wait_cursor
+    @QtCore.pyqtSlot(object, object)
     def show_rtdc(self, rtdc_ds, slot):
         """Display an RT-DC measurement given by `path` and `filters`"""
         # Create a hierarchy child so that the user can browse
@@ -742,7 +743,6 @@ def show_rtdc(self, rtdc_ds, slot):
         self.spinBox_event.blockSignals(True)
         self.spinBox_event.setMaximum(event_count)
         self.spinBox_event.setToolTip("total: {}".format(event_count))
-        self.spinBox_event.setValue(1)
         self.spinBox_event.blockSignals(False)
 
         # set quick view state