move context manager into a common place

src/plopp/graphics/fig.py

@@ -3,33 +3,15 @@
 
 from ..core.utils import number_to_variable, name_with_unit
 from ..core import View
-from .io import fig_to_bytes
+from .utils import fig_to_bytes, silent_mpl_figure
 from .mesh import Mesh
 from .line import Line
 
-from contextlib import contextmanager
-import matplotlib as mpl
 import matplotlib.pyplot as plt
 from scipp import DataArray, to_unit
 from typing import Any, Tuple
 
 
-@contextmanager
-def silent_mpl_figure():
- """
- Context manager to prevent automatic generation of figures in Jupyter.
- """
- backend_ = mpl.get_backend()
- revert = False
- if 'inline' in backend_:
- mpl.use("Agg")
- revert = True
- with plt.ioff():
- yield
- if revert:
- mpl.use(backend_)
-
-
 class Figure(View):
 
  def __init__(self,

src/plopp/graphics/point_cloud.py

@@ -4,7 +4,7 @@
 from ..core.limits import find_limits, fix_empty_range
 from ..core.utils import name_with_unit
 from .color_mapper import ColorMapper
-from .io import fig_to_bytes
+from .utils import fig_to_bytes, silent_mpl_figure
 from ..widgets import ToggleTool
 
 import numpy as np
@@ -90,7 +90,8 @@ def _set_points_colors(self):
  def _update_colorbar(self):
  dpi = 96
  height_inches = 0.89 * self._figsize[1] / dpi
- cbar_fig = plt.figure(figsize=(height_inches * 0.2, height_inches), dpi=dpi)
+ with silent_mpl_figure():
+ cbar_fig = plt.figure(figsize=(height_inches * 0.2, height_inches), dpi=dpi)
  cbar_ax = cbar_fig.add_axes([0.05, 0.02, 0.25, 1.0])
  _ = ColorbarBase(cbar_ax,
  cmap=self.color_mapper.cmap,

src/plopp/graphics/static.py

@@ -2,7 +2,7 @@
 # Copyright (c) 2022 Scipp contributors (https://github.com/scipp)
 
 from .fig import Figure
-from .io import fig_to_bytes
+from .utils import fig_to_bytes
 
 
 class StaticFig(Figure):

src/plopp/graphics/utils.py

@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (c) 2022 Scipp contributors (https://github.com/scipp)
+
+from contextlib import contextmanager
+from io import BytesIO
+import matplotlib as mpl
+
+
+def fig_to_bytes(fig, form='png'):
+ """
+ Convert a Matplotlib figure to png (default) or svg bytes.
+ """
+ buf = BytesIO()
+ fig.savefig(buf, format=form, bbox_inches='tight')
+ buf.seek(0)
+ return buf.getvalue()
+
+
+@contextmanager
+def silent_mpl_figure():
+ """
+ Context manager to prevent automatic generation of figures in Jupyter.
+ """
+ backend_ = mpl.get_backend()
+ revert = False
+ if 'inline' in backend_:
+ mpl.use("Agg")
+ revert = True
+ with mpl.pyplot.ioff():
+ yield
+ if revert:
+ mpl.use(backend_)