Added version check for PySide >= 1.0.3.

Author: gstorer

lib/matplotlib/backends/backend_qt4.py

@@ -20,11 +20,8 @@
 except ImportError:
     figureoptions = None
 
-try:
-    from qt4_compat import QtCore, QtGui, _getSaveFileName, __version__
-except ImportError:
-    raise ImportError("Qt4 backend requires that PyQt4 or PySide is installed.")
-	
+from qt4_compat import QtCore, QtGui, _getSaveFileName, __version__
+    
 backend_version = __version__
 def fn_name(): return sys._getframe(1).f_code.co_name
 

lib/matplotlib/backends/qt4_compat.py

@@ -12,8 +12,10 @@
 QT_API = os.environ.get('QT_API', QT_API_PYQT)
 
 if QT_API == QT_API_PYQT:
-    from PyQt4 import QtCore, QtGui
-
+    try:
+        from PyQt4 import QtCore, QtGui
+    except ImportError:
+        raise ImportError("Qt4 backend requires that PyQt4 is installed.")
     # Alias PyQt-specific functions for PySide compatibility.
     try:
         QtCore.Slot = QtCore.pyqtSlot
@@ -39,8 +41,13 @@
         _getSaveFileName = QtGui.QFileDialog.getSaveFileName
 
 elif QT_API == QT_API_PYSIDE:
-    from PySide import QtCore, QtGui, __version__
-    
+    try:
+        from PySide import QtCore, QtGui, __version__, __version_info__
+    except ImportError:
+        raise ImportError("Qt4 backend requires that PySide is installed.")
+    if __version_info__ < (1,0,3):
+        raise ImportError("Matplotlib backend_qt4 and backend_qt4agg require PySide >=1.0.3")
+
     # Alias PySide-specific function for PyQt compatibilty
     QtCore.pyqtProperty = QtCore.Property
     QtCore.pyqtSignature = QtCore.Slot # Not a perfect match but