Merge pull request #8867 from anntzer/eventloop

efiring · tacaswell · commit 35af6c02cfea · 2017-09-18T15:08:42.000-04:00
Remove start_event_loop_default.  Let pause() run the event loop for all backends.
diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -2414,55 +2414,27 @@ def new_timer(self, *args, **kwargs):
         return TimerBase(*args, **kwargs)
 
     def flush_events(self):
-        """
-        Flush the GUI events for the figure. Implemented only for
-        backends with GUIs.
-        """
-        raise NotImplementedError
+        """Flush the GUI events for the figure.
 
-    def start_event_loop(self, timeout):
+        Interactive backends need to reimplement this method.
         """
-        Start an event loop.  This is used to start a blocking event
-        loop so that interactive functions, such as ginput and
-        waitforbuttonpress, can wait for events.  This should not be
-        confused with the main GUI event loop, which is always running
-        and has nothing to do with this.
 
-        This is implemented only for backends with GUIs.
-        """
-        raise NotImplementedError
+    def start_event_loop(self, timeout=0):
+        """Start a blocking event loop.
 
-    def stop_event_loop(self):
-        """
-        Stop an event loop.  This is used to stop a blocking event
-        loop so that interactive functions, such as ginput and
-        waitforbuttonpress, can wait for events.
+        Such an event loop is used by interactive functions, such as `ginput`
+        and `waitforbuttonpress`, to wait for events.
 
-        This is implemented only for backends with GUIs.
-        """
-        raise NotImplementedError
+        The event loop blocks until a callback function triggers
+        `stop_event_loop`, or *timeout* is reached.
 
-    def start_event_loop_default(self, timeout=0):
-        """
-        Start an event loop.  This is used to start a blocking event
-        loop so that interactive functions, such as ginput and
-        waitforbuttonpress, can wait for events.  This should not be
-        confused with the main GUI event loop, which is always running
-        and has nothing to do with this.
+        If *timeout* is negative, never timeout.
 
-        This function provides default event loop functionality based
-        on time.sleep that is meant to be used until event loop
-        functions for each of the GUI backends can be written.  As
-        such, it throws a deprecated warning.
+        Only interactive backends need to reimplement this method and it relies
+        on `flush_events` being properly implemented.
 
-        This call blocks until a callback function triggers
-        stop_event_loop() or *timeout* is reached.  If *timeout* is
-        <=0, never timeout.
+        Interactive backends should implement this in a more native way.
         """
-        str = "Using default event loop until function specific"
-        str += " to this GUI is implemented"
-        warnings.warn(str, mplDeprecation)
-
         if timeout <= 0:
             timeout = np.inf
         timestep = 0.01
@@ -2473,15 +2445,19 @@ def start_event_loop_default(self, timeout=0):
             time.sleep(timestep)
             counter += 1
 
-    def stop_event_loop_default(self):
-        """
-        Stop an event loop.  This is used to stop a blocking event
-        loop so that interactive functions, such as ginput and
-        waitforbuttonpress, can wait for events.
+    def stop_event_loop(self):
+        """Stop the current blocking event loop.
 
+        Interactive backends need to reimplement this to match
+        `start_event_loop`
         """
         self._looping = False
 
+    start_event_loop_default = cbook.deprecated(
+        "2.1", name="start_event_loop_default")(start_event_loop)
+    stop_event_loop_default = cbook.deprecated(
+        "2.1", name="stop_event_loop_default")(stop_event_loop)
+
 
 def key_press_handler(event, canvas, toolbar=None):
     """
diff --git a/lib/matplotlib/backends/backend_gtk.py b/lib/matplotlib/backends/backend_gtk.py
@@ -480,13 +480,6 @@ def flush_events(self):
         gtk.gdk.flush()
         gtk.gdk.threads_leave()
 
-    def start_event_loop(self,timeout):
-        FigureCanvasBase.start_event_loop_default(self,timeout)
-    start_event_loop.__doc__=FigureCanvasBase.start_event_loop_default.__doc__
-
-    def stop_event_loop(self):
-        FigureCanvasBase.stop_event_loop_default(self)
-    stop_event_loop.__doc__=FigureCanvasBase.stop_event_loop_default.__doc__
 
 
 class FigureManagerGTK(FigureManagerBase):
diff --git a/lib/matplotlib/backends/backend_gtk3.py b/lib/matplotlib/backends/backend_gtk3.py
@@ -333,14 +333,6 @@ def flush_events(self):
         Gdk.flush()
         Gdk.threads_leave()
 
-    def start_event_loop(self,timeout):
-        FigureCanvasBase.start_event_loop_default(self,timeout)
-    start_event_loop.__doc__=FigureCanvasBase.start_event_loop_default.__doc__
-
-    def stop_event_loop(self):
-        FigureCanvasBase.stop_event_loop_default(self)
-    stop_event_loop.__doc__=FigureCanvasBase.stop_event_loop_default.__doc__
-
 
 class FigureManagerGTK3(FigureManagerBase):
     """
diff --git a/lib/matplotlib/backends/backend_tkagg.py b/lib/matplotlib/backends/backend_tkagg.py
@@ -464,14 +464,6 @@ def new_timer(self, *args, **kwargs):
     def flush_events(self):
         self._master.update()
 
-    def start_event_loop(self,timeout):
-        FigureCanvasBase.start_event_loop_default(self,timeout)
-    start_event_loop.__doc__=FigureCanvasBase.start_event_loop_default.__doc__
-
-    def stop_event_loop(self):
-        FigureCanvasBase.stop_event_loop_default(self)
-    stop_event_loop.__doc__=FigureCanvasBase.stop_event_loop_default.__doc__
-
 
 class FigureManagerTkAgg(FigureManagerBase):
     """
diff --git a/lib/matplotlib/backends/backend_webagg.py b/lib/matplotlib/backends/backend_webagg.py
@@ -59,17 +59,6 @@ def show(self):
     def new_timer(self, *args, **kwargs):
         return TimerTornado(*args, **kwargs)
 
-    def start_event_loop(self, timeout):
-        backend_bases.FigureCanvasBase.start_event_loop_default(
-            self, timeout)
-    start_event_loop.__doc__ = \
-        backend_bases.FigureCanvasBase.start_event_loop_default.__doc__
-
-    def stop_event_loop(self):
-        backend_bases.FigureCanvasBase.stop_event_loop_default(self)
-    stop_event_loop.__doc__ = \
-        backend_bases.FigureCanvasBase.stop_event_loop_default.__doc__
-
 
 class WebAggApplication(tornado.web.Application):
     initialized = False
diff --git a/lib/matplotlib/backends/backend_webagg_core.py b/lib/matplotlib/backends/backend_webagg_core.py
@@ -359,17 +359,6 @@ def handle_set_dpi_ratio(self, event):
     def send_event(self, event_type, **kwargs):
         self.manager._send_event(event_type, **kwargs)
 
-    def start_event_loop(self, timeout):
-        backend_bases.FigureCanvasBase.start_event_loop_default(
-            self, timeout)
-    start_event_loop.__doc__ = \
-        backend_bases.FigureCanvasBase.start_event_loop_default.__doc__
-
-    def stop_event_loop(self):
-        backend_bases.FigureCanvasBase.stop_event_loop_default(self)
-    stop_event_loop.__doc__ = \
-        backend_bases.FigureCanvasBase.stop_event_loop_default.__doc__
-
 
 _JQUERY_ICON_CLASSES = {
     'home': 'ui-icon ui-icon-home',
diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
@@ -75,8 +75,7 @@ def _backend_selection():
         loop, and if not switches to a compatible one.
     """
     backend = rcParams['backend']
-    if not rcParams['backend_fallback'] or \
-                     backend not in _interactive_bk:
+    if not rcParams['backend_fallback'] or backend not in _interactive_bk:
         return
     is_agg_backend = rcParams['backend'].endswith('Agg')
     if 'wx' in sys.modules and not backend in ('WX', 'WXAgg'):
@@ -275,33 +274,24 @@ def pause(interval):
     """
     Pause for *interval* seconds.
 
-    If there is an active figure it will be updated and displayed,
-    and the GUI event loop will run during the pause.
+    If there is an active figure, it will be updated and displayed before the
+    pause, and the GUI event loop (if any) will run during the pause.
 
-    If there is no active figure, or if a non-interactive backend
-    is in use, this executes time.sleep(interval).
-
-    This can be used for crude animation. For more complex
-    animation, see :mod:`matplotlib.animation`.
-
-    This function is experimental; its behavior may be changed
-    or extended in a future release.
+    This can be used for crude animation.  For more complex animation, see
+    :mod:`matplotlib.animation`.
 
+    This function is experimental; its behavior may be changed or extended in a
+    future release.
     """
-    backend = rcParams['backend']
-    if backend in _interactive_bk:
-        figManager = _pylab_helpers.Gcf.get_active()
-        if figManager is not None:
-            canvas = figManager.canvas
-            if canvas.figure.stale:
-                canvas.draw_idle()
-            show(block=False)
-            canvas.start_event_loop(interval)
-            return
-
-    # No on-screen figure is active, so sleep() is all we need.
-    import time
-    time.sleep(interval)
+    manager = _pylab_helpers.Gcf.get_active()
+    if manager is not None:
+        canvas = manager.canvas
+        if canvas.figure.stale:
+            canvas.draw_idle()
+        show(block=False)
+        canvas.start_event_loop(interval)
+    else:
+        time.sleep(interval)
 
 
 @docstring.copy_dedent(matplotlib.rc)
