Fix PySide compatibility for signal defs

skimage/viewer/plugins/base.py

@@ -6,7 +6,7 @@ from warnings import warn
 import numpy as np
 
 from ..qt import QtGui
-from ..qt.QtCore import Qt, pyqtSignal
+from ..qt.QtCore import Qt, Signal
 from ..utils import RequiredAttr, init_qtapp
 
 
@@ -75,8 +75,8 @@ class Plugin(QtGui.QDialog):
     image_viewer = RequiredAttr("%s is not attached to ImageViewer" % name)
 
     # Signals used when viewers are linked to the Plugin output.
-    image_updated = pyqtSignal(np.ndarray)
-    _started = pyqtSignal(int)
+    image_updated = Signal(np.ndarray)
+    _started = Signal(int)
 
     def __init__(self, image_filter=None, height=0, width=400, useblit=True,
                  dock='bottom'):

skimage/viewer/qt/QtCore.py

@@ -4,6 +4,9 @@ if qt_api == 'pyside':
     from PySide.QtCore import *
 elif qt_api == 'pyqt':
     from PyQt4.QtCore import *
+    # Use pyside names for signals and slots
+    Signal = pyqtSignal
+    Slot = pyqtSlot
 else:
     # Mock objects for buildbot (which doesn't have Qt, but imports viewer).
     class Qt(object):
@@ -12,5 +15,8 @@ else:
         LeftDockWidgetArea = None
         RightDockWidgetArea = None
 
-    def pyqtSignal(*args, **kwargs):
+    def Signal(*args, **kwargs):
+        pass
+
+    def Slot(*args, **kwargs):
         pass