ENH: Timeplot auto scrolling

pydm/widgets/archiver_time_plot.py

@@ -16,7 +16,8 @@
 logger = logging.getLogger(__name__)
 
 DEFAULT_ARCHIVE_BUFFER_SIZE = 18000
-DEFAULT_TIME_SPAN = 5.0
+DEFAULT_TIME_SPAN = 3600.0
+MIN_TIME_SPAN = 5.0
 
 
 class ArchivePlotCurveItem(TimePlotCurveItem):
@@ -80,7 +81,7 @@ def address(self, new_address: str) -> None:
             return
 
         # Prepare new address to use the archiver plugin and create the new channel
-        archive_address = "archiver://pv=" + remove_protocol(new_address)
+        archive_address = "archiver://pv=" + remove_protocol(new_address.strip())
         self.archive_channel = PyDMChannel(
             address=archive_address, value_slot=self.receiveArchiveData, value_signal=self.archive_data_request_signal
         )
@@ -250,6 +251,35 @@ def channels(self) -> List[PyDMChannel]:
         """Return the list of channels this curve is connected to"""
         return [self.channel, self.archive_channel]
 
+    def min_archiver_x(self):
+        """
+        Provide the the oldest valid timestamp from the archiver data buffer.
+
+        Returns
+        -------
+        float
+            The timestamp of the oldest data point in the archiver data buffer.
+        """
+        if self.archive_points_accumulated:
+            return self.archive_data_buffer[0, -self.archive_points_accumulated]
+        else:
+            return self.min_x()
+
+    def max_archiver_x(self):
+        """
+        Provide the the most recent timestamp from the archiver data buffer.
+        This is useful for scaling the x-axis.
+
+        Returns
+        -------
+        float
+            The timestamp of the most recent data point in the archiver data buffer.
+        """
+        if self.archive_points_accumulated:
+            return self.archive_data_buffer[0, -1]
+        else:
+            return self.min_x()
+
     def receiveNewValue(self, new_value):
         """ """
         if self._liveData:
@@ -297,12 +327,12 @@ def __init__(
     def updateXAxis(self, update_immediately: bool = False) -> None:
         """Manages the requests to archiver appliance. When the user pans or zooms the x axis to the left,
         a request will be made for backfill data"""
-        if len(self._curves) == 0:
+        if len(self._curves) == 0 or self.auto_scroll_timer.isActive():
             return
 
         min_x = self.plotItem.getAxis("bottom").range[0]  # Gets the leftmost timestamp displayed on the x-axis
-        max_x = max([curve.max_x() for curve in self._curves])
-        max_range = self.plotItem.getAxis("bottom").range[1]
+        max_x = self.plotItem.getAxis("bottom").range[1]
+        max_point = max([curve.max_x() for curve in self._curves])
         if min_x == 0:  # This is zero when the plot first renders
             min_x = time.time()
             self._min_x = min_x
@@ -312,11 +342,13 @@ def updateXAxis(self, update_immediately: bool = False) -> None:
                 self._min_x = self._min_x - self.getTimeSpan()
                 self._archive_request_queued = True
                 self.requestDataFromArchiver()
-            self.plotItem.setXRange(self._min_x, time.time(), padding=0.0, update=update_immediately)
+            self.plotItem.setXRange(
+                time.time() - DEFAULT_TIME_SPAN, time.time(), padding=0.0, update=update_immediately
+            )
         elif min_x < self._min_x and not self.plotItem.isAnyXAutoRange():
             # This means the user has manually scrolled to the left, so request archived data
             self._min_x = min_x
-            self.setTimeSpan(max_x - min_x)
+            self.setTimeSpan(max_point - min_x)
             if not self._archive_request_queued:
                 # Letting the user pan or scroll the plot is convenient, but can generate a lot of events in under
                 # a second that would trigger a request for data. By using a timer, we avoid this burst of events
@@ -325,13 +357,15 @@ def updateXAxis(self, update_immediately: bool = False) -> None:
                 QTimer.singleShot(1000, self.requestDataFromArchiver)
         # Here we only update the x-axis if the user hasn't asked for autorange and they haven't zoomed in (as
         # detected by the max range showing on the plot being less than the data available)
-        elif not self.plotItem.isAnyXAutoRange() and not max_range < max_x - 10:
+        elif not self.plotItem.isAnyXAutoRange() and max_x >= max_point - 10:
             if min_x > (self._prev_x + 15) or min_x < (self._prev_x - 15):
                 # The plus/minus 15 just makes sure we don't do this on every update tick of the graph
-                self.setTimeSpan(max_x - min_x)
+                self.setTimeSpan(max_point - min_x)
             else:
                 # Keep the plot moving with a rolling window based on the current timestamp
-                self.plotItem.setXRange(max_x - self.getTimeSpan(), max_x, padding=0.0, update=update_immediately)
+                self.plotItem.setXRange(
+                    max_point - self.getTimeSpan(), max_point, padding=0.0, update=update_immediately
+                )
         self._prev_x = min_x
 
     def requestDataFromArchiver(self, min_x: Optional[float] = None, max_x: Optional[float] = None) -> None:
@@ -348,10 +382,11 @@ def requestDataFromArchiver(self, min_x: Optional[float] = None, max_x: Optional
            to the timestamp of the oldest live data point in the buffer if available. If no live points are
            recorded yet, then defaults to the timestamp at which the plot was first rendered.
         """
-        processing_command = ""
+        req_queued = False
         if min_x is None:
             min_x = self._min_x
         for curve in self._curves:
+            processing_command = ""
             if curve.use_archive_data:
                 if max_x is None:
                     if curve.points_accumulated > 0:
@@ -360,13 +395,38 @@ def requestDataFromArchiver(self, min_x: Optional[float] = None, max_x: Optional
                         max_x = self._starting_timestamp
                 requested_seconds = max_x - min_x
                 if requested_seconds <= 5:
-                    self._archive_request_queued = False
                     continue  # Avoids noisy requests when first rendering the plot
                 # Max amount of raw data to return before using optimized data
                 max_data_request = int(0.80 * self.getArchiveBufferSize())
                 if requested_seconds > max_data_request:
                     processing_command = "optimized_" + str(self.optimized_data_bins)
                 curve.archive_data_request_signal.emit(min_x, max_x - 1, processing_command)
+                req_queued |= True
+
+        if not req_queued:
+            self._archive_request_queued = False
+
+    def setAutoScroll(self, enable: bool = False, timespan: float = 60, padding: float = 0.1, refresh_rate: int = 5000):
+        """Enable/Disable autoscrolling along the x-axis. This will (un)pause
+        the autoscrolling QTimer, which calls the auto_scroll slot when time is up.
+
+        Parameters
+        ----------
+        enable : bool, optional
+            Whether or not to start the autoscroll QTimer, by default False
+        timespan : float, optional
+            The timespan to set for autoscrolling along the x-axis in seconds, by default 60
+        padding : float, optional
+            The size of the empty space between the data and the sides of the plot, by default 0.1
+        refresh_rate : int, optional
+            How often the scroll should occur in milliseconds, by default 5000
+        """
+        super().setAutoScroll(enable, timespan, padding, refresh_rate)
+
+        self._min_x = min(self._min_x, self.getViewBox().viewRange()[0][0])
+        if self._min_x != self._prev_x:
+            self.requestDataFromArchiver()
+            self._prev_x = self._min_x
 
     def getArchiveBufferSize(self) -> int:
         """Returns the size of the data buffer used to store archived data"""
@@ -383,14 +443,17 @@ def createCurveItem(self, *args, **kwargs) -> ArchivePlotCurveItem:
     @Slot()
     def archive_data_received(self):
         """Take any action needed when this plot receives new data from archiver appliance"""
+        self._archive_request_queued = False
+        if self.auto_scroll_timer.isActive():
+            return
+
         max_x = max([curve.max_x() for curve in self._curves])
         # Assure the user sees all data available whenever the request data is returned
         self.plotItem.setXRange(max_x - self.getTimeSpan(), max_x, padding=0.0, update=True)
-        self._archive_request_queued = False
 
     def setTimeSpan(self, value):
         """Set the value of the plot's timespan"""
-        if value < DEFAULT_TIME_SPAN:  # Less than 5 seconds will break the plot
+        if value < MIN_TIME_SPAN:  # Less than 5 seconds will break the plot
             return
         self._time_span = value
 

pydm/widgets/timeplot.py

@@ -489,6 +489,9 @@ def __init__(
         for channel in init_y_channels:
             self.addYChannel(channel)
 
+        self.auto_scroll_timer = QTimer()
+        self.auto_scroll_timer.timeout.connect(self.auto_scroll)
+
     def initialize_for_designer(self):
         # If we are in Qt Designer, don't update the plot continuously.
         # This function gets called by PyDMTimePlot's designer plugin.
@@ -653,7 +656,7 @@ def updateXAxis(self, update_immediately=False):
             Update the axis range(s) immediately if True, or defer until the
             next rendering.
         """
-        if len(self._curves) == 0:
+        if len(self._curves) == 0 or self.auto_scroll_timer.isActive():
             return
 
         if self._plot_by_timestamps:
@@ -783,6 +786,41 @@ def refreshCurve(self, curve):
                 yAxisName=curve.y_axis_name,
             )
 
+    def setAutoScroll(self, enable: bool = False, timespan: float = 60, padding: float = 0.1, refresh_rate: int = 5000):
+        """Enable/Disable autoscrolling along the x-axis. This will (un)pause
+        the autoscrolling QTimer, which calls the auto_scroll slot when time is up.
+
+        Parameters
+        ----------
+        enable : bool, optional
+            Whether or not to start the autoscroll QTimer, by default False
+        timespan : float, optional
+            The timespan to set for autoscrolling along the x-axis in seconds, by default 60
+        padding : float, optional
+            The size of the empty space between the data and the sides of the plot, by default 0.1
+        refresh_rate : int, optional
+            How often the scroll should occur in milliseconds, by default 5000
+        """
+        if not enable:
+            self.auto_scroll_timer.stop()
+            return
+
+        self.setAutoRangeX(False)
+        if timespan <= 0:
+            min_x, max_x = self.getViewBox().viewRange()[0]
+            timespan = max_x - min_x
+        self.scroll_timespan = timespan
+        self.scroll_padding = max(padding * timespan, refresh_rate / 1000)
+
+        self.auto_scroll_timer.start(refresh_rate)
+        self.auto_scroll()
+
+    def auto_scroll(self):
+        """Autoscrolling slot to be called by the autoscroll QTimer."""
+        curr = time.time()
+        # Only include padding on the right
+        self.plotItem.setXRange(curr - self.scroll_timespan, curr + self.scroll_padding)
+
     def addLegendItem(self, item, pv_name, force_show_legend=False):
         """
         Add an item into the graph's legend.