enhance context menu, draw object center, recenter if image out of view

pyqtUsrObj.py

@@ -461,6 +461,15 @@ class FixTargetFrame(pg.ROI):
           lh=QLineF(x-rx, y, x+rx, y)
           lv=QLineF(x, y-ry, x, y+ry)
           p.drawLines(lh, lv)
+
+      #plot center of all feducials
+      ctr=np.array(f['pos']).mean(axis=0)
+      x, y=ctr  # ;print(x,y)
+      lh=QLineF(x-rx, y, x+rx, y)
+      lv=QLineF(x, y-ry, x, y+ry)
+      p.drawLines(lh, lv)
+      p.drawEllipse(x-rx/2, y-ry/2, rx, ry)
+
     else:
       assert('unknown feducial type')
 
@@ -741,6 +750,8 @@ if __name__=='__main__':
   #viRoi.addTranslateHandle([.7, .5], axes=None, item=None, name=None, index=None) #quadrat
   vb.addItem(viRoi)
 
+  #autorange not working, as all rois are in ItemGroup
+  vb.setRange(QtCore.QRectF(-300, -400, 900+300, 500+400))
 
   childTree(vb)