"""
Test for unwanted reference cycles

"""
import pyqtgraph as pg
import numpy as np
import gc, weakref
app = pg.mkQApp()

def processEvents():
    for i in range(3):
        gc.collect()
        app.processEvents()
        # processEvents ignored DeferredDelete events; we must process these
        # manually.
        app.sendPostedEvents(None, pg.QtCore.QEvent.DeferredDelete)

#def test_PlotItem():
    #for i in range(10):
        #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):
        iv = pg.PlotWidget(*args, **kwds)
        return weakref.ref(iv)
    
    for i in range(100):
        assert mkref()() is None
    
def test_ImageView():
    def mkref(*args, **kwds):
        iv = pg.ImageView(*args, **kwds)
        return weakref.ref(iv)
    
    for i in range(100):
        assert mkref()() is None
    
if __name__ == '__main__':
    ot = test_PlotItem()