Merge pull request #861 from ixjlyons/errorbaritem-set-path

Set path attr in case ErrorBarItem initialized without data

pyqtgraph/graphicsItems/ErrorBarItem.py

@@ -23,6 +23,7 @@ class ErrorBarItem(GraphicsObject):
             beam=None,
             pen=None
         )
+        self.setVisible(False)
         self.setData(**opts)
 
     def setData(self, **opts):
@@ -45,6 +46,7 @@ class ErrorBarItem(GraphicsObject):
         This method was added in version 0.9.9. For prior versions, use setOpts.
         """
         self.opts.update(opts)
+        self.setVisible(all(self.opts[ax] is not None for ax in ['x', 'y']))
         self.path = None
         self.update()
         self.prepareGeometryChange()
@@ -59,6 +61,7 @@ class ErrorBarItem(GraphicsObject):
         
         x, y = self.opts['x'], self.opts['y']
         if x is None or y is None:
+            self.path = p
             return
         
         beam = self.opts['beam']

pyqtgraph/graphicsItems/tests/test_ErrorBarItem.py

@@ -0,0 +1,37 @@
+import pyqtgraph as pg
+import numpy as np
+
+app = pg.mkQApp()
+
+
+def test_ErrorBarItem_defer_data():
+    plot = pg.PlotWidget()
+    plot.show()
+
+    # plot some data away from the origin to set the view rect
+    x = np.arange(5) + 10
+    curve = pg.PlotCurveItem(x=x, y=x)
+    plot.addItem(curve)
+    app.processEvents()
+    r_no_ebi = plot.viewRect()
+
+    # ErrorBarItem with no data shouldn't affect the view rect
+    err = pg.ErrorBarItem()
+    plot.addItem(err)
+    app.processEvents()
+    r_empty_ebi = plot.viewRect()
+
+    assert r_no_ebi == r_empty_ebi
+
+    err.setData(x=x, y=x, bottom=x, top=x)
+    app.processEvents()
+    r_ebi = plot.viewRect()
+
+    assert r_empty_ebi != r_ebi
+
+    # unset data, ErrorBarItem disappears and view rect goes back to original
+    err.setData(x=None, y=None)
+    app.processEvents()
+    r_clear_ebi = plot.viewRect()
+
+    assert r_clear_ebi == r_no_ebi