Expanded ref checks

Fixed ref cycle in ImageItem -> HistogramLutItem

pyqtgraph/graphicsItems/HistogramLUTItem.py

@@ -17,6 +17,7 @@ from .. import functions as fn
 import numpy as np
 from .. import debug as debug
 
+import weakref
 
 __all__ = ['HistogramLUTItem']
 
@@ -42,7 +43,7 @@ class HistogramLUTItem(GraphicsWidget):
         """
         GraphicsWidget.__init__(self)
         self.lut = None
-        self.imageItem = None
+        self.imageItem = lambda: None  # fake a dead weakref
         
         self.layout = QtGui.QGraphicsGridLayout()
         self.setLayout(self.layout)
@@ -138,7 +139,7 @@ class HistogramLUTItem(GraphicsWidget):
         #self.region.setBounds([vr.top(), vr.bottom()])
 
     def setImageItem(self, img):
-        self.imageItem = img
+        self.imageItem = weakref.ref(img)
         img.sigImageChanged.connect(self.imageChanged)
         img.setLookupTable(self.getLookupTable)  ## send function pointer, not the result
         #self.gradientChanged()
@@ -150,11 +151,11 @@ class HistogramLUTItem(GraphicsWidget):
         self.update()
     
     def gradientChanged(self):
-        if self.imageItem is not None:
+        if self.imageItem() is not None:
             if self.gradient.isLookupTrivial():
-                self.imageItem.setLookupTable(None) #lambda x: x.astype(np.uint8))
+                self.imageItem().setLookupTable(None) #lambda x: x.astype(np.uint8))
             else:
-                self.imageItem.setLookupTable(self.getLookupTable)  ## send function pointer, not the result
+                self.imageItem().setLookupTable(self.getLookupTable)  ## send function pointer, not the result
             
         self.lut = None
         #if self.imageItem is not None:
@@ -178,14 +179,14 @@ class HistogramLUTItem(GraphicsWidget):
         #self.update()
 
     def regionChanging(self):
-        if self.imageItem is not None:
+        if self.imageItem() is not None:
-            self.imageItem.setLevels(self.region.getRegion())
+            self.imageItem().setLevels(self.region.getRegion())
         self.sigLevelsChanged.emit(self)
         self.update()
 
     def imageChanged(self, autoLevel=False, autoRange=False):
         profiler = debug.Profiler()
-        h = self.imageItem.getHistogram()
+        h = self.imageItem().getHistogram()
         profiler('get histogram')
         if h[0] is None:
             return

pyqtgraph/tests/test_ref_cycles.py

@@ -7,54 +7,42 @@ import numpy as np
 import gc, weakref
 app = pg.mkQApp()
 
-def processEvents():
+def assert_alldead(refs):
-    for i in range(3):
+    for ref in refs:
-        gc.collect()
+        assert ref() is None
-        app.processEvents()
-        # processEvents ignored DeferredDelete events; we must process these
-        # manually.
-        app.sendPostedEvents(None, pg.QtCore.QEvent.DeferredDelete)
 
-#def test_PlotItem():
+def mkrefs(*objs):
-    #for i in range(10):
+    return map(weakref.ref, objs)
-        #plt = pg.PlotItem()
-        #plt.plot(np.random.normal(size=10000))
-    #processEvents()
-    
-    #ot = pg.debug.ObjTracker()
-    
-    #plots = []
-    #for i in range(10):
-        #plt = pg.PlotItem()
-        #plt.plot(np.random.normal(size=10000))
-        #plots.append(plt)
-    #processEvents()
-
-    #ot.diff()
-    
-    #del plots
-    #processEvents()
-    
-    #ot.diff()
-    
-    
-    #return ot
 
 def test_PlotWidget():
-    def mkref(*args, **kwds):
+    def mkobjs(*args, **kwds):
-        iv = pg.PlotWidget(*args, **kwds)
+        w = pg.PlotWidget(*args, **kwds)
-        return weakref.ref(iv)
+        data = pg.np.array([1,5,2,4,3])
+        c = w.plot(data, name='stuff')
+        w.addLegend()
+        
+        # test that connections do not keep objects alive
+        w.plotItem.vb.sigRangeChanged.connect(mkrefs)
+        app.focusChanged.connect(w.plotItem.vb.invertY)
+        
+        # return weakrefs to a bunch of objects that should die when the scope exits.
+        return mkrefs(w, c, data, w.plotItem, w.plotItem.vb, w.plotItem.getMenu(), w.plotItem.getAxis('left'))
     
     for i in range(5):
-        assert mkref()() is None
+        assert_alldead(mkobjs())
     
 def test_ImageView():
-    def mkref(*args, **kwds):
+    def mkobjs():
-        iv = pg.ImageView(*args, **kwds)
+        iv = pg.ImageView()
-        return weakref.ref(iv)
+        data = np.zeros((10,10,5))
+        iv.setImage(data)
+        
+        return mkrefs(iv, iv.imageItem, iv.view, iv.ui.histogram, data)
     
     for i in range(5):
-        assert mkref()() is None
+        assert_alldead(mkobjs())
+
+
     
 if __name__ == '__main__':
     ot = test_PlotItem()