MCEDockWidget has an optional fade in/out when mouse enters/leaves.

src/mcedit2/widgets/mcedockwidget.py

@@ -2,7 +2,7 @@
     mcedockwidget
 """
 from __future__ import absolute_import, division, print_function, unicode_literals
-from PySide import QtGui
+from PySide import QtGui, QtCore
 import logging
 
 log = logging.getLogger(__name__)
@@ -11,5 +11,31 @@ log = logging.getLogger(__name__)
 class MCEDockWidget(QtGui.QDockWidget):
     def __init__(self, *a, **kw):
         super(MCEDockWidget, self).__init__(*a, **kw)
+        self._unfocusedOpacity = 1.0
 
-        
+    def setUnfocusedOpacity(self, value):
+        self._unfocusedOpacity = value
+
+    def animate(self, value):
+        log.info("ANIMATION")
+        self.setWindowOpacity(value)
+
+    def enterEvent(self, event):
+        if self._unfocusedOpacity == 1.0:
+           return
+        self.animation = animation = QtCore.QPropertyAnimation(self, 'windowOpacity')
+        animation.setDuration(100)
+        animation.setStartValue(self.windowOpacity())
+        animation.setEndValue(1.0)
+        animation.valueChanged.connect(self.animate)
+        animation.start()
+
+    def leaveEvent(self, event):
+        if self._unfocusedOpacity == 1.0:
+           return
+        self.animation = animation = QtCore.QPropertyAnimation(self, 'windowOpacity')
+        animation.setDuration(250)
+        animation.setStartValue(self.windowOpacity())
+        animation.setEndValue(self._unfocusedOpacity)
+        animation.valueChanged.connect(self.animate)
+        animation.start()