ENH: try to mimic pyplot's number management

Closes #4

Author: tacaswell

mpl_gui/__init__.py

@@ -165,6 +165,15 @@ def by_label(self):
             )
         return mapping
 
+    @property
+    def by_number(self):
+        """
+        Return a dictionary of the current mapping number -> figures.
+
+        """
+        self._promote_and_number()
+        return {fig.canvas.manager.num: fig for fig in self.figures}
+
     @functools.wraps(figure)
     def figure(self, *args, **kwargs):
         fig = figure(*args, **kwargs)
@@ -180,6 +189,18 @@ def subplot_mosaic(self, *args, **kwargs):
         fig, axd = subplot_mosaic(*args, **kwargs)
         return self._register_fig(fig), axd
 
+    def _promote_and_number(self):
+        promoted_figures = []
+        unpromotod_figures = []
+        for f in self.figures:
+            if f.canvas.manager is not None:
+                promoted_figures.append(f)
+            else:
+                unpromotod_figures.append(f)
+        next_num = max([f.canvas.manager.num for f in promoted_figures], default=0) + 1
+        for num, fig in enumerate(unpromotod_figures, start=next_num):
+            promote_figure(fig, num=num)
+
     def show_all(self, *, block=None, timeout=None):
         """
         Show all of the Figures that the FigureRegistry knows about.
@@ -211,7 +232,7 @@ def show_all(self, *, block=None, timeout=None):
 
         if timeout is None:
             timeout = self._timeout
-
+        self._promote_and_number()
         show(self.figures, block=self._block, timeout=self._timeout)
 
     # alias to easy pyplot compatibility

mpl_gui/_promotion.py

@@ -37,7 +37,7 @@ def _auto_draw_if_interactive(fig, val):
             fig.canvas.draw_idle()
 
 
-def promote_figure(fig, *, auto_draw=True):
+def promote_figure(fig, *, auto_draw=True, num=None):
     """Create a new figure manager instance."""
     _backend_mod = current_backend_module()
 
@@ -57,7 +57,10 @@ def promote_figure(fig, *, auto_draw=True):
             return fig.canvas.manager
     # TODO: do we want to make sure we poison / destroy / decouple the existing
     # canavs?
-    manager = _backend_mod.new_figure_manager_given_figure(next(_figure_count), fig)
+    next_num = next(_figure_count)
+    manager = _backend_mod.new_figure_manager_given_figure(
+        num if num is not None else next_num, fig
+    )
     if fig.get_label():
         manager.set_window_title(fig.get_label())
 

mpl_gui/registry.py

@@ -20,6 +20,15 @@
 for k in _fr_exports:
     locals()[k] = getattr(_fr, k)
 
+
+def get_figlabels():
+    return list(_fr.by_label)
+
+
+def get_fignums():
+    return sorted(_fr.by_number)
+
+
 # if one must.  `from foo import *` is a language miss-feature, but provide
 # sensible behavior anyway.
 __all__ = _fr_exports + [