Merge pull request #813 from danielhrisca/axisitem_tweak

AxisItem performance improvements

pyqtgraph/graphicsItems/AxisItem.py

@@ -17,7 +17,7 @@ class AxisItem(GraphicsWidget):
     If maxTickLength is negative, ticks point into the plot.
     """
 
-    def __init__(self, orientation, pen=None, linkView=None, parent=None, maxTickLength=-5, showValues=True):
+    def __init__(self, orientation, pen=None, linkView=None, parent=None, maxTickLength=-5, showValues=True, text='', units='', unitPrefix='', **args):
         """
         ==============  ===============================================================
         **Arguments:**
@@ -28,6 +28,14 @@ class AxisItem(GraphicsWidget):
                         to be linked to the visible range of a ViewBox.
         showValues      (bool) Whether to display values adjacent to ticks
         pen             (QPen) Pen used when drawing ticks.
+        text            The text (excluding units) to display on the label for this
+                        axis.
+        units           The units for this axis. Units should generally be given
+                        without any scaling prefix (eg, 'V' instead of 'mV'). The
+                        scaling prefix will be automatically prepended based on the
+                        range of data displayed.
+        **args          All extra keyword arguments become CSS style options for
+                        the <span> tag which will surround the axis label and units.
         ==============  ===============================================================
         """
 
@@ -67,10 +75,10 @@ class AxisItem(GraphicsWidget):
         self.fixedWidth = None
         self.fixedHeight = None
 
-        self.labelText = ''
-        self.labelUnits = ''
-        self.labelUnitPrefix=''
-        self.labelStyle = {}
+        self.labelText = text
+        self.labelUnits = units
+        self.labelUnitPrefix = unitPrefix
+        self.labelStyle = args
         self.logMode = False
         self.tickFont = None
 
@@ -80,6 +88,8 @@ class AxisItem(GraphicsWidget):
         self.autoSIPrefix = True
         self.autoSIPrefixScale = 1.0
 
+        self.showLabel(False)
+
         self.setRange(0, 1)
 
         if pen is None:
@@ -91,8 +101,6 @@ class AxisItem(GraphicsWidget):
         if linkView is not None:
             self.linkToView(linkView)
 
-        self.showLabel(False)
-        
         self.grid = False
         #self.setCacheMode(self.DeviceCoordinateCache)
 
@@ -256,11 +264,14 @@ class AxisItem(GraphicsWidget):
             axis.setLabel('label text', units='V', **labelStyle)
 
         """
+        show_label = False
         if text is not None:
             self.labelText = text
-            self.showLabel()
+            show_label = True
         if units is not None:
             self.labelUnits = units
+            show_label = True
+        if show_label:
             self.showLabel()
         if unitPrefix is not None:
             self.labelUnitPrefix = unitPrefix