Fixes to make crashing less likely on PySide

Merge branch 'clear_cycles' into develop

pyqtgraph/Qt.py

@@ -32,6 +32,23 @@ else:
 if USE_PYSIDE:
     from PySide import QtGui, QtCore, QtOpenGL, QtSvg
     import PySide
+    try:
+        from PySide import shiboken
+        isQObjectAlive = shiboken.isValid
+    except ImportError:
+        def isQObjectAlive(obj):
+            try:
+                if hasattr(obj, 'parent'):
+                    obj.parent()
+                elif hasattr(obj, 'parentItem'):
+                    obj.parentItem()
+                else:
+                    raise Exception("Cannot determine whether Qt object %s is still alive." % obj)
+            except RuntimeError:
+                return False
+            else:
+                return True
+    
     VERSION_INFO = 'PySide ' + PySide.__version__
     
     # Make a loadUiType function like PyQt has
@@ -78,6 +95,9 @@ else:
         pass
 
 
+    import sip
+    def isQObjectAlive(obj):
+        return not sip.isdeleted(obj)
     loadUiType = uic.loadUiType
 
     QtCore.Signal = QtCore.pyqtSignal

pyqtgraph/__init__.py

@@ -56,6 +56,7 @@ CONFIG_OPTIONS = {
     'weaveDebug': False,    ## Print full error message if weave compile fails
     'exitCleanup': True,    ## Attempt to work around some exit crash bugs in PyQt and PySide
     'enableExperimental': False, ## Enable experimental features (the curious can search for this key in the code)
+    'crashWarning': False,  # If True, print warnings about situations that may result in a crash
 } 
 
 
@@ -256,6 +257,7 @@ from .graphicsWindows import *
 from .SignalProxy import *
 from .colormap import *
 from .ptime import time
+from pyqtgraph.Qt import isQObjectAlive
 
 
 ##############################################################
@@ -284,7 +286,12 @@ def cleanup():
     s = QtGui.QGraphicsScene()
     for o in gc.get_objects():
         try:
-            if isinstance(o, QtGui.QGraphicsItem) and o.scene() is None:
+            if isinstance(o, QtGui.QGraphicsItem) and isQObjectAlive(o) and o.scene() is None:
+                if getConfigOption('crashWarning'):
+                    sys.stderr.write('Error: graphics item without scene. '
+                        'Make sure ViewBox.close() and GraphicsView.close() '
+                        'are properly called before app shutdown (%s)\n' % (o,))
+                
                 s.addItem(o)
         except RuntimeError:  ## occurs if a python wrapper no longer has its underlying C++ object
             continue

pyqtgraph/graphicsItems/PlotItem/PlotItem.py

@@ -18,6 +18,7 @@ This class is very heavily featured:
 """
 from ...Qt import QtGui, QtCore, QtSvg, USE_PYSIDE
 from ... import pixmaps
+import sys
 
 if USE_PYSIDE:
     from .plotConfigTemplate_pyside import *
@@ -193,14 +194,6 @@ class PlotItem(GraphicsWidget):
         self.layout.setColumnStretchFactor(1, 100)
         
 
-        ## Wrap a few methods from viewBox
-        for m in [
-            'setXRange', 'setYRange', 'setXLink', 'setYLink', 'setAutoPan', 'setAutoVisible',
-            'setRange', 'autoRange', 'viewRect', 'viewRange', 'setMouseEnabled', 'setLimits',
-            'enableAutoRange', 'disableAutoRange', 'setAspectLocked', 'invertY',
-            'register', 'unregister']:  ## NOTE: If you update this list, please update the class docstring as well.
-            setattr(self, m, getattr(self.vb, m))
-            
         self.items = []
         self.curves = []
         self.itemMeta = weakref.WeakKeyDictionary()
@@ -298,7 +291,24 @@ class PlotItem(GraphicsWidget):
         """Return the :class:`ViewBox <pyqtgraph.ViewBox>` contained within."""
         return self.vb
     
+    ## Wrap a few methods from viewBox. 
     
+    #Important: don't use a settattr(m, getattr(self.vb, m)) as we'd be leaving the viebox alive
+    #because we had a reference to an instance method (creating wrapper methods at runtime instead).
+    for m in [
+        'setXRange', 'setYRange', 'setXLink', 'setYLink', 'setAutoPan', 'setAutoVisible',
+        'setRange', 'autoRange', 'viewRect', 'viewRange', 'setMouseEnabled', 'setLimits',
+        'enableAutoRange', 'disableAutoRange', 'setAspectLocked', 'invertY',
+        'register', 'unregister']:  ## NOTE: If you update this list, please update the class docstring as well.
+        def _create_method(name):
+            def method(self, *args, **kwargs):
+                return getattr(self.vb, name)(*args, **kwargs)
+            method.__name__ = name
+            return method
+        
+        locals()[m] = _create_method(m)
+        
+    del _create_method
     
     def setLogMode(self, x=None, y=None):
         """
@@ -356,10 +366,8 @@ class PlotItem(GraphicsWidget):
         self.ctrlMenu.setParent(None)
         self.ctrlMenu = None
         
-        #self.ctrlBtn.setParent(None)
-        #self.ctrlBtn = None
-        #self.autoBtn.setParent(None)
-        #self.autoBtn = None
+        self.autoBtn.setParent(None)
+        self.autoBtn = None
         
         for k in self.axes:
             i = self.axes[k]['item']

pyqtgraph/graphicsItems/ViewBox/ViewBox.py

@@ -5,11 +5,12 @@ from ...Point import Point
 from ... import functions as fn
 from .. ItemGroup import ItemGroup
 from .. GraphicsWidget import GraphicsWidget
-from ...GraphicsScene import GraphicsScene
 import weakref
 from copy import deepcopy
 from ... import debug as debug
 from ... import getConfigOption
+import sys
+from pyqtgraph.Qt import isQObjectAlive
 
 __all__ = ['ViewBox']
 
@@ -240,6 +241,7 @@ class ViewBox(GraphicsWidget):
             del ViewBox.NamedViews[self.name]
 
     def close(self):
+        self.clear()
         self.unregister()
 
     def implements(self, interface):
@@ -1653,6 +1655,9 @@ class ViewBox(GraphicsWidget):
         ## called when the application is about to exit.
         ## this disables all callbacks, which might otherwise generate errors if invoked during exit.
         for k in ViewBox.AllViews:
+            if isQObjectAlive(k) and getConfigOption('crashWarning'):
+                sys.stderr.write('Warning: ViewBox should be closed before application exit.\n')
+                
             try:
                 k.destroyed.disconnect()
             except RuntimeError:  ## signal is already disconnected.

pyqtgraph/graphicsItems/tests/test_GraphicsItem.py

@@ -0,0 +1,47 @@
+import gc
+import weakref
+try:
+    import faulthandler
+    faulthandler.enable()
+except ImportError:
+    pass
+
+import pyqtgraph as pg
+pg.mkQApp()
+
+def test_getViewWidget():
+    view = pg.PlotWidget()
+    vref = weakref.ref(view)
+    item = pg.InfiniteLine()
+    view.addItem(item)
+    assert item.getViewWidget() is view
+    del view
+    gc.collect()
+    assert vref() is None
+    assert item.getViewWidget() is None
+
+def test_getViewWidget_deleted():
+    view = pg.PlotWidget()
+    item = pg.InfiniteLine()
+    view.addItem(item)
+    assert item.getViewWidget() is view
+    
+    # Arrange to have Qt automatically delete the view widget
+    obj = pg.QtGui.QWidget()
+    view.setParent(obj)
+    del obj
+    gc.collect()
+
+    assert not pg.Qt.isQObjectAlive(view)
+    assert item.getViewWidget() is None
+
+
+#if __name__ == '__main__':
+    #view = pg.PlotItem()
+    #vref = weakref.ref(view)
+    #item = pg.InfiniteLine()
+    #view.addItem(item)
+    #del view
+    #gc.collect()
+    
+    

pyqtgraph/tests/test_qt.py

@@ -0,0 +1,10 @@
+import pyqtgraph as pg
+import gc
+
+def test_isQObjectAlive():
+    o1 = pg.QtCore.QObject()
+    o2 = pg.QtCore.QObject()
+    o2.setParent(o1)
+    del o1
+    gc.collect()
+    assert not pg.Qt.isQObjectAlive(o2)