Standardize creation of FigureManager from a given FigureCanvas class.

anntzer · anntzer · commit 04368ed39dfa · 2022-02-03T19:47:41.000+01:00
The `new_manager` classmethod may appear to belong more naturally to the
FigureManager class rather than the FigureCanvas class, but putting it
on FigureCanvas has multiple advantages:

- One may want to create managers at times where all one has is a
  FigureCanvas instance, which may not even have a corresponding manager
  (e.g. `subplot_tool`).
- A given FigureManager class can be associated with many different
  FigureCanvas classes (indeed, FigureManagerQT can manage both
  FigureCanvasQTAgg and FigureCanvasQTCairo and also the mplcairo Qt
  canvas classes), whereas we don't have multiple FigureManager classes
  for a given FigureCanvas class.
diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -1660,6 +1660,16 @@ def _fix_ipython_backend2gui(cls):
             if _is_non_interactive_terminal_ipython(ip):
                 ip.enable_gui(backend2gui_rif)
 
+    @classmethod
+    def new_manager(cls, figure, num):
+        """
+        Create a new figure manager for *figure*, using this canvas class.
+
+        Backends should override this method to instantiate the correct figure
+        manager subclass, and perform any additional setup that may be needed.
+        """
+        return FigureManagerBase(cls(figure), num)
+
     @contextmanager
     def _idle_draw_cntx(self):
         self._is_idle_drawing = True
@@ -3223,11 +3233,10 @@ def configure_subplots(self, *args):
         if hasattr(self, "subplot_tool"):
             self.subplot_tool.figure.canvas.manager.show()
             return
-        plt = _safe_pyplot_import()
+        # This import needs to happen here due to circular imports.
+        from matplotlib.figure import Figure
         with mpl.rc_context({"toolbar": "none"}):  # No navbar for the toolfig.
-            # Use new_figure_manager() instead of figure() so that the figure
-            # doesn't get registered with pyplot.
-            manager = plt.new_figure_manager(-1, (6, 3))
+            manager = type(self.canvas).new_manager(Figure(figsize=(6, 3)), -1)
         manager.set_window_title("Subplot configuration tool")
         tool_fig = manager.canvas.figure
         tool_fig.subplots_adjust(top=0.9)
@@ -3455,9 +3464,7 @@ def new_figure_manager(cls, num, *args, **kwargs):
     @classmethod
     def new_figure_manager_given_figure(cls, num, figure):
         """Create a new figure manager instance for the given figure."""
-        canvas = cls.FigureCanvas(figure)
-        manager = cls.FigureManager(canvas, num)
-        return manager
+        return cls.FigureCanvas.new_manager(figure, num)
 
     @classmethod
     def draw_if_interactive(cls):
diff --git a/lib/matplotlib/backends/_backend_tk.py b/lib/matplotlib/backends/_backend_tk.py
@@ -227,6 +227,43 @@ def _update_device_pixel_ratio(self, event=None):
             w, h = self.get_width_height(physical=True)
             self._tkcanvas.configure(width=w, height=h)
 
+    @classmethod
+    def new_manager(cls, figure, num):
+        # docstring inherited
+        with _restore_foreground_window_at_end():
+            if cbook._get_running_interactive_framework() is None:
+                cbook._setup_new_guiapp()
+                _c_internal_utils.Win32_SetProcessDpiAwareness_max()
+            window = tk.Tk(className="matplotlib")
+            window.withdraw()
+
+            # Put a Matplotlib icon on the window rather than the default tk
+            # icon. See https://www.tcl.tk/man/tcl/TkCmd/wm.html#M50
+            #
+            # `ImageTk` can be replaced with `tk` whenever the minimum
+            # supported Tk version is increased to 8.6, as Tk 8.6+ natively
+            # supports PNG images.
+            icon_fname = str(cbook._get_data_path(
+                'images/matplotlib.png'))
+            icon_img = ImageTk.PhotoImage(file=icon_fname, master=window)
+
+            icon_fname_large = str(cbook._get_data_path(
+                'images/matplotlib_large.png'))
+            icon_img_large = ImageTk.PhotoImage(
+                file=icon_fname_large, master=window)
+            try:
+                window.iconphoto(False, icon_img_large, icon_img)
+            except Exception as exc:
+                # log the failure (due e.g. to Tk version), but carry on
+                _log.info('Could not load matplotlib icon: %s', exc)
+
+            canvas = cls.FigureCanvas(figure, master=window)
+            manager = cls.FigureManager(canvas, num, window)
+            if mpl.is_interactive():
+                manager.show()
+                canvas.draw_idle()
+            return manager
+
     def resize(self, event):
         width, height = event.width, event.height
         if self._resize_callback is not None:
@@ -910,45 +947,6 @@ def trigger(self, *args):
 class _BackendTk(_Backend):
     FigureManager = FigureManagerTk
 
-    @classmethod
-    def new_figure_manager_given_figure(cls, num, figure):
-        """
-        Create a new figure manager instance for the given figure.
-        """
-        with _restore_foreground_window_at_end():
-            if cbook._get_running_interactive_framework() is None:
-                cbook._setup_new_guiapp()
-                _c_internal_utils.Win32_SetProcessDpiAwareness_max()
-            window = tk.Tk(className="matplotlib")
-            window.withdraw()
-
-            # Put a Matplotlib icon on the window rather than the default tk
-            # icon. See https://www.tcl.tk/man/tcl/TkCmd/wm.html#M50
-            #
-            # `ImageTk` can be replaced with `tk` whenever the minimum
-            # supported Tk version is increased to 8.6, as Tk 8.6+ natively
-            # supports PNG images.
-            icon_fname = str(cbook._get_data_path(
-                'images/matplotlib.png'))
-            icon_img = ImageTk.PhotoImage(file=icon_fname, master=window)
-
-            icon_fname_large = str(cbook._get_data_path(
-                'images/matplotlib_large.png'))
-            icon_img_large = ImageTk.PhotoImage(
-                file=icon_fname_large, master=window)
-            try:
-                window.iconphoto(False, icon_img_large, icon_img)
-            except Exception as exc:
-                # log the failure (due e.g. to Tk version), but carry on
-                _log.info('Could not load matplotlib icon: %s', exc)
-
-            canvas = cls.FigureCanvas(figure, master=window)
-            manager = cls.FigureManager(canvas, num, window)
-            if mpl.is_interactive():
-                manager.show()
-                canvas.draw_idle()
-            return manager
-
     @staticmethod
     def mainloop():
         managers = Gcf.get_all_fig_managers()
diff --git a/lib/matplotlib/backends/backend_gtk3.py b/lib/matplotlib/backends/backend_gtk3.py
@@ -117,6 +117,11 @@ def __init__(self, figure=None):
         style_ctx.add_provider(css, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION)
         style_ctx.add_class("matplotlib-canvas")
 
+    @classmethod
+    def new_manager(cls, figure, num):
+        # docstring inherited
+        return FigureManagerGTK3(cls(figure), num)
+
     def destroy(self):
         self.close_event()
 
diff --git a/lib/matplotlib/backends/backend_gtk4.py b/lib/matplotlib/backends/backend_gtk4.py
@@ -80,6 +80,11 @@ def __init__(self, figure=None):
         style_ctx.add_provider(css, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION)
         style_ctx.add_class("matplotlib-canvas")
 
+    @classmethod
+    def new_manager(cls, figure, num):
+        # docstring inherited
+        return FigureManagerGTK4(cls(figure), num)
+
     def pick(self, mouseevent):
         # GtkWidget defines pick in GTK4, so we need to override here to work
         # with the base implementation we want.
diff --git a/lib/matplotlib/backends/backend_macosx.py b/lib/matplotlib/backends/backend_macosx.py
@@ -31,6 +31,11 @@ def __init__(self, figure):
         width, height = self.get_width_height()
         _macosx.FigureCanvas.__init__(self, width, height)
 
+    @classmethod
+    def new_manager(cls, figure, num):
+        # docstring inherited
+        return FigureManagerMac(cls(figure), num)
+
     def set_cursor(self, cursor):
         # docstring inherited
         _macosx.set_cursor(cursor)
diff --git a/lib/matplotlib/backends/backend_nbagg.py b/lib/matplotlib/backends/backend_nbagg.py
@@ -143,7 +143,20 @@ def remove_comm(self, comm_id):
 
 
 class FigureCanvasNbAgg(FigureCanvasWebAggCore):
-    pass
+    @classmethod
+    def new_manager(cls, figure, num):
+        canvas = cls(figure)
+        manager = FigureManagerNbAgg(canvas, num)
+        if is_interactive():
+            manager.show()
+            figure.canvas.draw_idle()
+
+        def destroy(event):
+            canvas.mpl_disconnect(cid)
+            Gcf.destroy(manager)
+
+        cid = canvas.mpl_connect('close_event', destroy)
+        return manager
 
 
 class CommSocket:
@@ -228,21 +241,6 @@ class _BackendNbAgg(_Backend):
     FigureCanvas = FigureCanvasNbAgg
     FigureManager = FigureManagerNbAgg
 
-    @staticmethod
-    def new_figure_manager_given_figure(num, figure):
-        canvas = FigureCanvasNbAgg(figure)
-        manager = FigureManagerNbAgg(canvas, num)
-        if is_interactive():
-            manager.show()
-            figure.canvas.draw_idle()
-
-        def destroy(event):
-            canvas.mpl_disconnect(cid)
-            Gcf.destroy(manager)
-
-        cid = canvas.mpl_connect('close_event', destroy)
-        return manager
-
     @staticmethod
     def show(block=None):
         ## TODO: something to do when keyword block==False ?
diff --git a/lib/matplotlib/backends/backend_qt.py b/lib/matplotlib/backends/backend_qt.py
@@ -235,6 +235,11 @@ def __init__(self, figure=None):
         palette = QtGui.QPalette(QtGui.QColor("white"))
         self.setPalette(palette)
 
+    @classmethod
+    def new_manager(cls, figure, num):
+        # docstring inherited
+        return FigureManagerQT(cls(figure), num)
+
     def _update_pixel_ratio(self):
         if self._set_device_pixel_ratio(_devicePixelRatioF(self)):
             # The easiest way to resize the canvas is to emit a resizeEvent
diff --git a/lib/matplotlib/backends/backend_webagg.py b/lib/matplotlib/backends/backend_webagg.py
@@ -48,7 +48,10 @@ def run(self):
 
 
 class FigureCanvasWebAgg(core.FigureCanvasWebAggCore):
-    pass
+    @classmethod
+    def new_manager(cls, figure, num):
+        # docstring inherited
+        return core.FigureManagerWebAgg(cls(figure), num)
 
 
 class WebAggApplication(tornado.web.Application):
diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
@@ -68,6 +68,15 @@ def error_msg_wx(msg, parent=None):
     return None
 
 
+# lru_cache holds a reference to the App and prevents it from being gc'ed.
+@functools.lru_cache(1)
+def _create_wxapp():
+    wxapp = wx.App(False)
+    wxapp.SetExitOnFrameDelete(True)
+    cbook._setup_new_guiapp()
+    return wxapp
+
+
 class TimerWx(TimerBase):
     """Subclass of `.TimerBase` using wx.Timer events."""
 
@@ -533,6 +542,17 @@ def __init__(self, parent, id, figure=None):
         self.SetBackgroundStyle(wx.BG_STYLE_PAINT)  # Reduce flicker.
         self.SetBackgroundColour(wx.WHITE)
 
+    @classmethod
+    def new_manager(cls, figure, num):
+        # docstring inherited
+        wxapp = wx.GetApp() or _create_wxapp()
+        frame = FigureFrameWx(num, figure, canvas_class=cls)
+        figmgr = frame.get_figure_manager()
+        if mpl.is_interactive():
+            figmgr.frame.Show()
+            figure.canvas.draw_idle()
+        return figmgr
+
     def Copy_to_Clipboard(self, event=None):
         """Copy bitmap of canvas to system clipboard."""
         bmp_obj = wx.BitmapDataObject()
@@ -1355,24 +1375,6 @@ class _BackendWx(_Backend):
     FigureCanvas = FigureCanvasWx
     FigureManager = FigureManagerWx
 
-    @classmethod
-    def new_figure_manager_given_figure(cls, num, figure):
-        # Create a wx.App instance if it has not been created so far.
-        wxapp = wx.GetApp()
-        if wxapp is None:
-            wxapp = wx.App()
-            wxapp.SetExitOnFrameDelete(True)
-            cbook._setup_new_guiapp()
-            # Retain a reference to the app object so that it does not get
-            # garbage collected.
-            _BackendWx._theWxApp = wxapp
-        # Attaches figure.canvas, figure.canvas.manager.
-        frame = FigureFrameWx(num, figure, canvas_class=cls.FigureCanvas)
-        if mpl.is_interactive():
-            frame.Show()
-            figure.canvas.draw_idle()
-        return figure.canvas.manager
-
     @staticmethod
     def mainloop():
         if not wx.App.IsMainLoopRunning():
