_pylab_helpers.py 4.4 KB

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  1. """
  2. Manage figures for the pyplot interface.
  3. """
  4. import atexit
  5. from collections import OrderedDict
  6. import gc
  7. class Gcf:
  8. """
  9. Singleton to maintain the relation between figures and their managers, and
  10. keep track of and "active" figure and manager.
  11. The canvas of a figure created through pyplot is associated with a figure
  12. manager, which handles the interaction between the figure and the backend.
  13. pyplot keeps track of figure managers using an identifier, the "figure
  14. number" or "manager number" (which can actually be any hashable value);
  15. this number is available as the :attr:`number` attribute of the manager.
  16. This class is never instantiated; it consists of an `OrderedDict` mapping
  17. figure/manager numbers to managers, and a set of class methods that
  18. manipulate this `OrderedDict`.
  19. Attributes
  20. ----------
  21. figs : OrderedDict
  22. `OrderedDict` mapping numbers to managers; the active manager is at the
  23. end.
  24. """
  25. figs = OrderedDict()
  26. @classmethod
  27. def get_fig_manager(cls, num):
  28. """
  29. If manager number *num* exists, make it the active one and return it;
  30. otherwise return *None*.
  31. """
  32. manager = cls.figs.get(num, None)
  33. if manager is not None:
  34. cls.set_active(manager)
  35. return manager
  36. @classmethod
  37. def destroy(cls, num):
  38. """
  39. Destroy manager *num* -- either a manager instance or a manager number.
  40. In the interactive backends, this is bound to the window "destroy" and
  41. "delete" events.
  42. It is recommended to pass a manager instance, to avoid confusion when
  43. two managers share the same number.
  44. """
  45. if all(hasattr(num, attr) for attr in ["num", "_cidgcf", "destroy"]):
  46. manager = num
  47. if cls.figs.get(manager.num) is manager:
  48. cls.figs.pop(manager.num)
  49. else:
  50. return
  51. else:
  52. try:
  53. manager = cls.figs.pop(num)
  54. except KeyError:
  55. return
  56. manager.canvas.mpl_disconnect(manager._cidgcf)
  57. manager.destroy()
  58. gc.collect(1)
  59. @classmethod
  60. def destroy_fig(cls, fig):
  61. """Destroy figure *fig*."""
  62. num = next((manager.num for manager in cls.figs.values()
  63. if manager.canvas.figure == fig), None)
  64. if num is not None:
  65. cls.destroy(num)
  66. @classmethod
  67. def destroy_all(cls):
  68. """Destroy all figures."""
  69. # Reimport gc in case the module globals have already been removed
  70. # during interpreter shutdown.
  71. import gc
  72. for manager in list(cls.figs.values()):
  73. manager.canvas.mpl_disconnect(manager._cidgcf)
  74. manager.destroy()
  75. cls.figs.clear()
  76. gc.collect(1)
  77. @classmethod
  78. def has_fignum(cls, num):
  79. """Return whether figure number *num* exists."""
  80. return num in cls.figs
  81. @classmethod
  82. def get_all_fig_managers(cls):
  83. """Return a list of figure managers."""
  84. return list(cls.figs.values())
  85. @classmethod
  86. def get_num_fig_managers(cls):
  87. """Return the number of figures being managed."""
  88. return len(cls.figs)
  89. @classmethod
  90. def get_active(cls):
  91. """Return the active manager, or *None* if there is no manager."""
  92. return next(reversed(cls.figs.values())) if cls.figs else None
  93. @classmethod
  94. def _set_new_active_manager(cls, manager):
  95. """Adopt *manager* into pyplot and make it the active manager."""
  96. if not hasattr(manager, "_cidgcf"):
  97. manager._cidgcf = manager.canvas.mpl_connect(
  98. "button_press_event", lambda event: cls.set_active(manager))
  99. fig = manager.canvas.figure
  100. fig.number = manager.num
  101. label = fig.get_label()
  102. if label:
  103. manager.set_window_title(label)
  104. cls.set_active(manager)
  105. @classmethod
  106. def set_active(cls, manager):
  107. """Make *manager* the active manager."""
  108. cls.figs[manager.num] = manager
  109. cls.figs.move_to_end(manager.num)
  110. @classmethod
  111. def draw_all(cls, force=False):
  112. """
  113. Redraw all stale managed figures, or, if *force* is True, all managed
  114. figures.
  115. """
  116. for manager in cls.get_all_fig_managers():
  117. if force or manager.canvas.figure.stale:
  118. manager.canvas.draw_idle()
  119. atexit.register(Gcf.destroy_all)