cleanup: docs, default args

examples/plottingItems.py

@@ -16,20 +16,27 @@ win.resize(1000,600)
 # Enable antialiasing for prettier plots
 pg.setConfigOptions(antialias=True)
 
+# Create a plot with some random data
 p1 = win.addPlot(title="Plot Items example", y=np.random.normal(size=100, scale=10), pen=0.5)
 p1.setYRange(-40, 40)
+
+# Add three infinite lines with labels
 inf1 = pg.InfiniteLine(movable=True, angle=90, label='x={value:0.2f}', 
                        labelOpts={'position':0.1, 'color': (200,200,100), 'fill': (200,200,200,50), 'movable': True})
 inf2 = pg.InfiniteLine(movable=True, angle=0, pen=(0, 0, 200), bounds = [-20, 20], hoverPen=(0,200,0), label='y={value:0.2f}mm', 
                        labelOpts={'color': (200,0,0), 'movable': True, 'fill': (0, 0, 200, 100)})
-inf3 = pg.InfiniteLine(movable=True, angle=45, pen='g', label='diagonal', labelOpts={'rotateAxis': [1, 0], 'fill': (0, 200, 0, 100), 'movable': True})
+inf3 = pg.InfiniteLine(movable=True, angle=45, pen='g', label='diagonal',
+                       labelOpts={'rotateAxis': [1, 0], 'fill': (0, 200, 0, 100), 'movable': True})
 inf1.setPos([2,2])
 p1.addItem(inf1)
 p1.addItem(inf2)
 p1.addItem(inf3)
 
+# Add a linear region with a label
 lr = pg.LinearRegionItem(values=[70, 80])
 p1.addItem(lr)
+label = pg.InfLineLabel(lr.lines[1], "region 1", position=0.95, rotateAxis=(1,0), anchor=(1, 1))
+
 
 ## Start Qt event loop unless running in interactive mode or using pyside.
 if __name__ == '__main__':

pyqtgraph/graphicsItems/InfiniteLine.py

@@ -8,7 +8,7 @@ import numpy as np
 import weakref
 
 
-__all__ = ['InfiniteLine']
+__all__ = ['InfiniteLine', 'InfLineLabel']
 
 
 class InfiniteLine(GraphicsObject):
@@ -310,7 +310,9 @@ class InfLineLabel(TextItem):
                     along the line.
     =============== ==================================================================
     
-    All extra keyword arguments are passed to TextItem.
+    All extra keyword arguments are passed to TextItem. A particularly useful
+    option here is to use `rotateAxis=(1, 0)`, which will cause the text to
+    be automatically rotated parallel to the line.
     """
     def __init__(self, line, text="", movable=False, position=0.5, **kwds):
         self.line = line

pyqtgraph/graphicsItems/TextItem.py

@@ -10,7 +10,7 @@ class TextItem(GraphicsObject):
     GraphicsItem displaying unscaled text (the text will always appear normal even inside a scaled ViewBox). 
     """
     def __init__(self, text='', color=(200,200,200), html=None, anchor=(0,0),
-                 border=None, fill=None, angle=0, rotateAxis=(1, 0)):
+                 border=None, fill=None, angle=0, rotateAxis=None):
         """
         ==============  =================================================================================
         **Arguments:**
@@ -30,6 +30,15 @@ class TextItem(GraphicsObject):
                         Allows text to follow both the position and orientation of its parent while still
                         discarding any scale and shear factors.
         ==============  =================================================================================
+
+
+        The effects of the `rotateAxis` and `angle` arguments are added independently. So for example:
+
+        * rotateAxis=None, angle=0 -> normal horizontal text
+        * rotateAxis=None, angle=90 -> normal vertical text
+        * rotateAxis=(1, 0), angle=0 -> text aligned with x axis of its parent
+        * rotateAxis=(0, 1), angle=0 -> text aligned with y axis of its parent
+        * rotateAxis=(1, 0), angle=90 -> text orthogonal to x axis of its parent        
         """
                      
         self.anchor = Point(anchor)