Merge pull request matplotlib#1705 from tacaswell/qt_closeevent_v1.2

Qt closeevent fixes for  v1.2.x

Author: mdboom

lib/matplotlib/__init__.py

@@ -1122,6 +1122,7 @@ def tk_window_focus():
     'matplotlib.tests.test_triangulation',
     'matplotlib.tests.test_transforms',
     'matplotlib.tests.test_arrow_patches',
+    'matplotlib.tests.test_backend_qt4',
     ]
 
 

lib/matplotlib/backends/backend_qt4.py

@@ -367,11 +367,14 @@ def idle_draw(*args):
             self._idle = True
         if d: QtCore.QTimer.singleShot(0, idle_draw)
 
+
 class MainWindow(QtGui.QMainWindow):
     def closeEvent(self, event):
         self.emit(QtCore.SIGNAL('closing()'))
+        QtGui.QMainWindow.closeEvent(self, event)
+
 
-class FigureManagerQT( FigureManagerBase ):
+class FigureManagerQT(FigureManagerBase):
     """
     Public attributes
 
@@ -381,29 +384,31 @@ class FigureManagerQT( FigureManagerBase ):
     window      : The qt.QMainWindow
     """
 
-    def __init__( self, canvas, num ):
-        if DEBUG: print('FigureManagerQT.%s' % fn_name())
-        FigureManagerBase.__init__( self, canvas, num )
+    def __init__(self, canvas, num):
+        if DEBUG:
+            print('FigureManagerQT.%s' % fn_name())
+        FigureManagerBase.__init__(self, canvas, num)
         self.canvas = canvas
         self.window = MainWindow()
         self.window.connect(self.window, QtCore.SIGNAL('closing()'),
-            canvas.close_event)
+                            canvas.close_event)
+        self.window.connect(self.window, QtCore.SIGNAL('closing()'),
+                            self._widgetclosed)
 
         self.window.setWindowTitle("Figure %d" % num)
-        image = os.path.join( matplotlib.rcParams['datapath'],'images','matplotlib.png' )
-        self.window.setWindowIcon(QtGui.QIcon( image ))
+        image = os.path.join(matplotlib.rcParams['datapath'], 'images', 'matplotlib.png')
+        self.window.setWindowIcon(QtGui.QIcon(image))
 
         # Give the keyboard focus to the figure instead of the
         # manager; StrongFocus accepts both tab and click to focus and
         # will enable the canvas to process event w/o clicking.
         # ClickFocus only takes the focus is the window has been
         # clicked
-        # on. http://developer.qt.nokia.com/doc/qt-4.8/qt.html#FocusPolicy-enum
-        self.canvas.setFocusPolicy( QtCore.Qt.StrongFocus )
+        # on. http://qt-project.org/doc/qt-4.8/qt.html#FocusPolicy-enum or
+        # http://doc.qt.digia.com/qt/qt.html#FocusPolicy-enum
+        self.canvas.setFocusPolicy(QtCore.Qt.StrongFocus)
         self.canvas.setFocus()
 
-        QtCore.QObject.connect( self.window, QtCore.SIGNAL( 'destroyed()' ),
-                            self._widgetclosed )
         self.window._destroying = False
 
         self.toolbar = self._get_toolbar(self.canvas, self.window)
@@ -419,7 +424,7 @@ def __init__( self, canvas, num ):
         # requested size:
         cs = canvas.sizeHint()
         sbs = self.window.statusBar().sizeHint()
-        self._status_and_tool_height = tbs_height+sbs.height()
+        self._status_and_tool_height = tbs_height + sbs.height()
         height = cs.height() + self._status_and_tool_height
         self.window.resize(cs.width(), height)
 
@@ -428,14 +433,14 @@ def __init__( self, canvas, num ):
         if matplotlib.is_interactive():
             self.window.show()
 
-        def notify_axes_change( fig ):
+        def notify_axes_change(fig):
             # This will be called whenever the current axes is changed
             if self.toolbar is not None:
                 self.toolbar.update()
-        self.canvas.figure.add_axobserver( notify_axes_change )
+        self.canvas.figure.add_axobserver(notify_axes_change)
 
     @QtCore.Slot()
-    def _show_message(self,s):
+    def _show_message(self, s):
         # Fixes a PySide segfault.
         self.window.statusBar().showMessage(s)
 
@@ -445,8 +450,9 @@ def full_screen_toggle(self):
         else:
             self.window.showFullScreen()
 
-    def _widgetclosed( self ):
-        if self.window._destroying: return
+    def _widgetclosed(self):
+        if self.window._destroying:
+            return
         self.window._destroying = True
         try:
             Gcf.destroy(self.num)
@@ -474,15 +480,19 @@ def resize(self, width, height):
     def show(self):
         self.window.show()
 
-    def destroy( self, *args ):
+    def destroy(self, *args):
         # check for qApp first, as PySide deletes it in its atexit handler
-        if QtGui.QApplication.instance() is None: return
-        if self.window._destroying: return
+        if QtGui.QApplication.instance() is None:
+            return
+        if self.window._destroying:
+            return
         self.window._destroying = True
-        QtCore.QObject.disconnect( self.window, QtCore.SIGNAL( 'destroyed()' ),
-                                   self._widgetclosed )
-        if self.toolbar: self.toolbar.destroy()
-        if DEBUG: print("destroy figure manager")
+        QtCore.QObject.disconnect(self.window, QtCore.SIGNAL('destroyed()'),
+                                  self._widgetclosed)
+        if self.toolbar:
+                self.toolbar.destroy()
+        if DEBUG:
+                print("destroy figure manager")
         self.window.close()
 
     def get_window_title(self):

lib/matplotlib/tests/test_backend_qt4.py

@@ -0,0 +1,32 @@
+from matplotlib import pyplot as plt
+from matplotlib.testing.decorators import cleanup
+from matplotlib.testing.decorators import knownfailureif
+from matplotlib._pylab_helpers import Gcf
+import copy
+
+try:
+    import matplotlib.backends.qt4_compat
+    HAS_QT = True
+except ImportError:
+    HAS_QT = False
+
+
+@cleanup
+@knownfailureif(not HAS_QT)
+def test_fig_close():
+    # force switch to the Qt4 backend
+    plt.switch_backend('Qt4Agg')
+
+    #save the state of Gcf.figs
+    init_figs = copy.copy(Gcf.figs)
+
+    # make a figure using pyplot interface
+    fig = plt.figure()
+
+    # simulate user clicking the close button by reaching in
+    # and calling close on the underlying Qt object
+    fig.canvas.manager.window.close()
+
+    # assert that we have removed the reference to the FigureManager
+    # that got added by plt.figure()
+    assert(init_figs == Gcf.figs)